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<title>The Science of Transplantation</title></titleStmt>

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<idno>lslct011</idno>

<availability><p>The British Academic Spoken English (BASE) corpus was developed at the

Universities of Warwick and Reading, under the directorship of Hilary Nesi

(Centre for English Language Teacher Education, Warwick) and Paul Thompson

(Department of Applied Linguistics, Reading), with funding from BALEAP,

EURALEX, the British Academy and the Arts and Humanities Research Board. The

original recordings are held at the Universities of Warwick and Reading, and

at the Oxford Text Archive and may be consulted by bona fide researchers

upon written application to any of the holding bodies.

The BASE corpus is freely available to researchers who agree to the

following conditions:</p>

<p>1. The recordings and transcriptions should not be modified in any

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<p>2. The recordings and transcriptions should be used for research purposes

only; they should not be reproduced in teaching materials</p>

<p>3. The recordings and transcriptions should not be reproduced in full for

a wider audience/readership, although researchers are free to quote short

passages of text (up to 200 running words from any given speech event)</p>

<p>4. The corpus developers should be informed of all presentations or

publications arising from analysis of the corpus</p><p>

Researchers should acknowledge their use of the corpus using the following

form of words:

The recordings and transcriptions used in this study come from the British

Academic Spoken English (BASE) corpus, which was developed at the

Universities of Warwick and Reading under the directorship of Hilary Nesi

(Warwick) and Paul Thompson (Reading). Corpus development was assisted by

funding from the Universities of Warwick and Reading, BALEAP, EURALEX, the

British Academy and the Arts and Humanities Research Board. </p></availability>

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<recording dur="01:39:12" n="14936">

<date>02/12/2002</date><equipment><p>video</p></equipment>

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<item n="speechevent">Lecture</item>

<item n="acaddept">Biological Sciences</item>

<item n="acaddiv">ls</item>

<item n="partlevel">UG3</item>

<item n="module">Biological Perspectives on Human Disease</item>

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<u who="nm0260"><kinesic desc="projector is on showing slide" iterated="n"/> can i just say a few words <pause dur="0.7"/> before i actually formally start lecturing <pause dur="0.4"/> # <pause dur="0.2"/> i want to explain just a little bit <pause dur="0.3"/> about what we're trying to do <pause dur="0.3"/> # in these half-dozen or so lectures <pause dur="0.5"/> # <pause dur="0.7"/> my <pause dur="1.5"/> aim in a way with these lectures has been to try <pause dur="0.3"/> and illustrate a <trunc>s</trunc> <pause dur="0.2"/> # a chunk of medical practice <pause dur="0.4"/> # today now <pause dur="0.3"/> # rather than <pause dur="0.3"/> have sort of all a lot of theoretical stuff about the epidemiology of disease <pause dur="0.3"/> and genetics of disease and so on <pause dur="0.2"/> just trying to show you how actually <pause dur="0.3"/> # clinicians cope with disease <pause dur="0.3"/> and try and relate that to the science to the biology underlying the pathology of the disease <pause dur="0.3"/> and the nature of the treatments they're using <pause dur="0.6"/> so sometimes people find this these few lectures a little bit <pause dur="0.2"/> bitty <pause dur="0.3"/> which i'm afraid they are <pause dur="0.4"/> # now you had Dr <gap reason="name" extent="1 word"/> <pause dur="0.5"/> # was it this morning <pause dur="0.3"/> # talking to you about the physiology of kidney <pause dur="0.4"/> # kidneys <pause dur="0.4"/> # and of kidney disease the way kidney diseases develop <pause dur="0.6"/> and talking you to you i think in general terms about the nature of treatment of kidney

disease <pause dur="0.3"/> now Dr <gap reason="name" extent="1 word"/> is not # the usual lecturer i have to say that the usual lecturer that gives those lectures is Dr # Dr <gap reason="name" extent="1 word"/> <pause dur="0.3"/> whom i know very well and i don't know Dr <gap reason="name" extent="1 word"/> <pause dur="0.4"/> and i i'm # <pause dur="0.2"/> told that he did a good job and i sincerely hope he did <pause dur="0.4"/> # but the point about that <pause dur="0.3"/> is to give you background <trunc>in</trunc> into the understanding of renal disease <pause dur="0.5"/> now <pause dur="1.4"/> my colleague <pause dur="0.2"/> Dr <pause dur="0.3"/> # <pause dur="0.5"/> <unclear>golly</unclear> my colleague <shift feature="voice" new="laugh"/>Dr his name drops out of my <trunc>mi</trunc> <shift feature="voice" new="normal"/><gap reason="name" extent="2 words"/> <pause dur="0.3"/> # on Thursday will be talking to you about <pause dur="0.2"/> care and maintenance <pause dur="0.2"/> looking after of <pause dur="0.4"/> # patients who've been transplanted for kidney disease <pause dur="0.3"/> and he'll be talking to you a little bit about the ethics of transplantation <pause dur="0.3"/> and inevitably he will go over some of the ground <pause dur="0.3"/> that i'm going to present now <pause dur="0.3"/> what i want to talk about as you can see <pause dur="0.5"/> is the science of transplantation in other words i'm going to present to you the biology <pause dur="0.4"/> underlying <pause dur="0.3"/> transplantation of organs and of bone marrow <pause dur="0.4"/> # and how <pause dur="0.4"/> the

physicians <pause dur="0.4"/> # can cope with that and make it work <pause dur="0.3"/> okay <pause dur="0.7"/> so i'm providing the scientific backup <pause dur="0.3"/> # as it were <pause dur="0.4"/> to the clinical side <pause dur="0.4"/> and a and as i say the aim is overall to get you some give you some feel <pause dur="0.4"/> for how modern clinical medicine works <pause dur="0.3"/> in a rather <pause dur="0.3"/> highly technical biological area <pause dur="0.4"/> now we can't hope to cover the whole of medicine so we've honed in homed in i'm sorry <pause dur="0.3"/> on this little area <vocal desc="clears throat" iterated="n"/><pause dur="0.3"/> of <pause dur="0.2"/> renal disease <pause dur="0.3"/> and renal transplantation <pause dur="0.6"/> okay <pause dur="0.4"/> now <pause dur="0.7"/> those of you and i know some of you have already looked at the web <pause dur="0.3"/> may have looked at my lecture notes # and i'm sorry <pause dur="0.4"/> i but i've actually revised the lectures and what i'm presenting this afternoon <pause dur="0.5"/> is related to what's on the web already <pause dur="0.3"/> but is in fact <pause dur="0.2"/> presented in quite a different way <pause dur="0.3"/> what i've deliberately done is actually cut down on the detail and try i'm trying to bring out <pause dur="0.3"/> a bit more clearly the principles <pause dur="0.4"/> because in my experience if i try and teach too

much <pause dur="0.3"/> about histocompatibility <pause dur="0.3"/> and about how <pause dur="0.4"/> # T-cells respond <pause dur="0.3"/> to histocompatibility antigens in detail <pause dur="0.3"/> # # people don't really cope with that <pause dur="0.4"/> # in the short period that i have to present it <pause dur="0.3"/> so i'm giving it to you in rather more general terms today <pause dur="0.5"/> # and i know some people may not like that some people i know <pause dur="0.3"/> prefer to have much more detail well you can find detail in your textbooks i always say <pause dur="1.3"/> these <pause dur="0.4"/> lecture notes will go up onto the web <pause dur="0.2"/> # within the very next few days <pause dur="0.3"/> what i haven't done yet either <pause dur="0.3"/> is revised # the reading <pause dur="0.4"/> that i have on the web <pause dur="0.3"/> site <pause dur="0.2"/> i will do that before the end of term which i'm very much aware is Friday <pause dur="0.7"/> okay <pause dur="0.3"/> so i hope by Friday i won't absolutely guarantee but i hope by Friday to have <pause dur="0.3"/> some reading some more up to date reading <pause dur="0.2"/> some of the reading material as i say is still perfectly valid <pause dur="0.5"/> so it will remain there <pause dur="0.3"/> but i will try to put some new stuff on as well <pause dur="0.6"/> okay </u><gap reason="break in recording" extent="uncertain"/> <u who="nm0260" trans="pause"> we've got a

two hour slot <pause dur="0.5"/> now the material i'm going to present i suspect will take more than an hour but i'm hoping <pause dur="0.2"/> very much that it won't take two hours but in the past i've tried to present it in one hour <pause dur="0.3"/> and i've had to rush it so i've extended it to two hours but i don't think i need two hours <pause dur="1.5"/> right so let's actually get on with things <pause dur="0.3"/> the title <pause dur="0.2"/> of these lectures is The Science of Transplantation <pause dur="0.3"/> and that's very much what i'm going to be talking about # rather than the medical clinical aspect of transplantation which as i've said <pause dur="0.4"/> i'm leaving to <gap reason="name" extent="1 word"/> # <gap reason="name" extent="2 words"/> <pause dur="0.9"/> so <pause dur="0.8"/> the first point the first thing i want to do is just <kinesic desc="changes slide" iterated="n"/> show you the aims a little bit about the aims of these lectures <pause dur="0.4"/> what i want to cover <pause dur="0.4"/> # is the range of transplant medicine the sorts of areas where transplantation is done and why it's done <pause dur="0.7"/> okay <pause dur="0.7"/> secondly <pause dur="0.4"/> i want to give you <pause dur="0.4"/> # an understanding <pause dur="0.2"/> of the immunological basis of graft rejection <pause dur="0.5"/> i'll define these terms presently <pause dur="0.4"/> # then i shall go on

to talk to you about immunosuppressive therapy and how that works to present prevent <pause dur="0.2"/> <sic corr="graft">grant</sic> rejection <pause dur="0.5"/> and finally a few words on what might be the future <pause dur="0.5"/> # the way forward for transplantation science <pause dur="0.4"/> and its application to medicine <pause dur="1.7"/> so i shall start off <pause dur="0.4"/> with a few <pause dur="0.2"/> simple definitions <pause dur="0.5"/> # <pause dur="1.0"/> couple of them are pretty obvious <pause dur="0.8"/><kinesic desc="changes slide" iterated="n"/> we talk about the host <pause dur="0.9"/> that is the person who receives the transplantation whatever it is <pause dur="0.4"/> although in fact more commonly the term we use is recipient somebody who receives <pause dur="0.3"/> the graft <pause dur="0.7"/> and then secondly <pause dur="0.4"/> the partner in this business of course <pause dur="0.3"/> is the donor <pause dur="0.6"/> and that is the one who provides the graft <pause dur="0.5"/> now donors <pause dur="0.5"/> are going to fall into two main categories those that are alive <pause dur="0.6"/> and those that are dead <pause dur="0.3"/> now living donors <pause dur="0.3"/> # would may be either unrelated to the recipient <pause dur="0.3"/> or related a sibling or or parent or whatever <pause dur="1.5"/> obviously living donors can donate things like blood <pause dur="0.4"/> bone marrow <pause dur="0.4"/> and one of your two kidneys but they're going to

be hard-pressed <pause dur="0.3"/> indeed <pause dur="0.2"/> to donate <pause dur="0.3"/> lungs or something like that <pause dur="0.4"/> so <pause dur="0.9"/> more often in fact much more often <pause dur="0.4"/> # in transplantation medicine <pause dur="0.5"/> the <trunc>s</trunc> donor <pause dur="0.3"/> is dead <pause dur="0.4"/> and is a cadaver <pause dur="0.4"/> cadaveric donor <pause dur="0.3"/> and obviously under those circumstances <pause dur="0.3"/> the whole range of organs potentially is available for transplantation <pause dur="0.4"/> now just <pause dur="0.3"/> in passing <pause dur="0.3"/> when i say <trunc>d</trunc> dead cadaveric <pause dur="0.3"/> # <trunc>r</trunc> rather ghoulishly <trunc>w</trunc> # it <trunc>ha</trunc> the the the the person has to be <pause dur="0.3"/> somewhat freshly dead because of course <pause dur="0.4"/> # very shortly after death <pause dur="0.5"/> the tissues and the organs <pause dur="0.3"/> of the cadaver start to decay <pause dur="0.3"/> and and disintegrate <pause dur="0.3"/> and so <pause dur="0.3"/> if somebody dies in a traffic accident <pause dur="0.3"/> or is in the intensive therapy unit or something like that and is on a heart lung machine which they're about to turn off <pause dur="1.2"/> okay <pause dur="0.3"/> then the surgeons come in <pause dur="0.5"/> and whip out <pause dur="0.4"/> the bits the kidney the liver the lungs and so on <pause dur="0.3"/> now i'm not going to go into the ethical aspects of that <pause dur="0.3"/> but obviously there's a lot of ethics <pause dur="0.4"/> # which well <gap reason="name" extent="1 word"/> will deal with tomorrow <pause dur="0.3"/>

Thursday rather <pause dur="0.3"/> a lot of ethical issues are around about organ donation <pause dur="0.5"/> in both living <pause dur="0.5"/> and <pause dur="0.3"/> cadaveric donors <pause dur="0.9"/> okay <pause dur="2.9"/><kinesic desc="changes slide" iterated="n"/> more simple definitions <pause dur="0.3"/> the word transplant is # synonymous we use <trunc>th</trunc> them synonymously <pause dur="0.3"/> use it synonymously with graft <pause dur="0.4"/> the transplanted graft may be actually <pause dur="0.2"/> tissue of some sort such as blood or marrow or indeed skin <pause dur="0.9"/> or may be # an intact whole organ such as kidney <pause dur="0.6"/> all right <pause dur="0.7"/> now there are three other <pause dur="0.7"/> simple terms that i need to define <pause dur="0.3"/> one is autograft <pause dur="0.5"/> that means that you're grafting from one part of the body <pause dur="0.3"/> to another part of the body <pause dur="0.3"/> and that's very commonly done for skin in the case of burns <pause dur="0.4"/> obviously autografting we # the <pause dur="0.4"/> equivalent term is autologous graft <pause dur="0.3"/> autografting <pause dur="0.3"/> presents <pause dur="0.2"/> no immunological differences because you're just moving a bit of tissue <pause dur="0.4"/> from one part of the body to another part of a body <pause dur="1.3"/> autografting is actually very important and i was talking to a surgical friend of mine

and she was describing to me the sort of facial reconstructions that happen in severe burn patients <pause dur="0.4"/> # <pause dur="0.4"/> <trunc>i</trunc> or severe or in situations where there's been a severe <trunc>d</trunc> <trunc>dec</trunc> severe accident and there's been extensive damage say to the face <pause dur="0.4"/> they transplant bits of bone <pause dur="0.3"/> # from the femur or a humerus or something like that to reconstruct the bone <pause dur="0.4"/> and muscle they get from somewhere else and skin from somewhere else and they reconstruct <pause dur="0.5"/> # the person's face <pause dur="0.3"/> and that is of course <pause dur="0.2"/> autografting <pause dur="1.4"/><vocal desc="clears throat" iterated="n"/><pause dur="1.6"/> in the case <pause dur="1.5"/> of things like kidneys <pause dur="0.4"/> what's much more often <pause dur="0.3"/> done is an allograft now people <pause dur="0.4"/> you will recollect the use of the world word allele <pause dur="0.3"/> which means different <pause dur="0.2"/> an allograft comes from a different individual of the same species <pause dur="0.7"/> okay <pause dur="0.8"/> # allogeneic graft is a term which is often used simultaneously <trunc>s</trunc> synonymously i'm sorry <pause dur="0.8"/> and finally <pause dur="0.7"/> in this sort of # hierarchy of grafting <pause dur="0.3"/> we

have a xenograft now xeno <pause dur="0.2"/> means foreign <pause dur="0.6"/> and xenografts come from <pause dur="0.4"/> or or xenogeneic graft <pause dur="0.3"/> comes from a member of a different species <pause dur="0.5"/> for example pig to man <pause dur="0.6"/> yeah <pause dur="4.5"/> so let's <pause dur="0.2"/><vocal desc="clears throat" iterated="n"/><pause dur="0.2"/> briefly look at the range of transplant medicine what is done and why <pause dur="1.0"/><vocal desc="clears throat" iterated="n"/><pause dur="4.6"/><kinesic desc="changes slide" iterated="n"/> i'm going to talk <pause dur="0.2"/> briefly about currently successful grafts that is grafting transplanting which <pause dur="0.2"/> in which is <pause dur="0.2"/> <trunc>w</trunc> which is in use in medical practice today <pause dur="0.3"/> right at the end i shall refer to perhaps <pause dur="0.2"/> some possible future types of graft <pause dur="0.5"/> now blood transfusion <pause dur="0.3"/> is obviously a kind of graft which has been in use for a very long time <pause dur="0.8"/> # <pause dur="0.3"/> bone marrow <pause dur="0.5"/> or stem cell transplantation <pause dur="0.4"/> is much more recently used <pause dur="0.4"/> # and i'll describe that in a moment <pause dur="0.4"/> and then finally <pause dur="0.4"/> # we have solid organ transplantation things like kidneys and livers <pause dur="0.3"/> so there are these three <pause dur="0.3"/> broad areas of transplantation bone <pause dur="0.2"/> sorry <pause dur="0.2"/> blood <pause dur="0.3"/>

bone marrow <pause dur="0.3"/> and solid organs <pause dur="0.3"/> and they are actually <pause dur="0.3"/> all of them really <pause dur="0.3"/> somewhat different in their characteristics <pause dur="5.0"/><kinesic desc="changes slide" iterated="n"/><vocal desc="clears throat" iterated="n"/> now blood transfusions <pause dur="0.6"/> # <pause dur="0.4"/> have been attempted <pause dur="0.3"/> were attempted in <trunc>th</trunc> in in the nineteenth century <pause dur="3.4"/> and <trunc>th</trunc> there were a number of problems immediately discovered the major problem <pause dur="0.5"/> comes from the A-B-O blood group system <pause dur="0.4"/> # which i guess many of you will be familiar with <pause dur="0.3"/> there are on the surface <pause dur="0.2"/> there is on the surface of <pause dur="0.3"/> red cells <pause dur="0.2"/> an antigen <pause dur="0.3"/> which occurs in three # <pause dur="0.2"/> allelic forms there's the A form <pause dur="0.3"/> the B form <pause dur="0.3"/> and the null or zero form <pause dur="0.4"/> okay <pause dur="0.6"/> # obviously you can get heterozygotes so you get A-A A-B B-B <pause dur="0.3"/> <sic corr="A-O">A-BO</sic> and B-O and whatever <pause dur="0.5"/> now obviously if you transfuse blood <pause dur="0.3"/> of one <pause dur="0.5"/> # blood group type <pause dur="0.2"/> into an individual of another blood group type <pause dur="0.6"/> the immune system of the recipient will recognize the blood as foreign <pause dur="0.4"/>

and you will get <pause dur="0.3"/> an immune response typically <pause dur="0.4"/> you will get an antibody response to the <pause dur="0.3"/> A-B-O antigen <pause dur="0.3"/> and that will lyse the red cells with the aid of complement <pause dur="0.3"/> and do all sorts of serious damage to the individual <pause dur="0.4"/> # the consequence <pause dur="0.3"/> <trunc>o</trunc> of the damage that's done is often very severe illness <pause dur="0.4"/> # indeed death in some cases if you transfuse the wrong blood <pause dur="1.1"/> once the A-B-O group <pause dur="0.5"/> system <pause dur="0.5"/> blood system is properly was properly worked out <pause dur="0.4"/> <trunc>m</trunc> early in the last century <pause dur="0.5"/> # <pause dur="0.4"/> # <trunc>s</trunc> <trunc>b</trunc> blood transfusion is obviously a simple straightforward and life saving <pause dur="0.2"/> treatment <pause dur="0.4"/> okay <pause dur="0.3"/> so having overcome the A-B-O problem <pause dur="0.3"/> that's fine <pause dur="0.3"/> but <pause dur="0.3"/> still <pause dur="0.3"/> you will <pause dur="0.2"/> recollect you will understand <pause dur="0.4"/> # that there are residual problems <pause dur="0.3"/> in blood transfusion <pause dur="0.4"/> particularly <pause dur="0.2"/> this issue of the transmission of blood borne pathogens <pause dur="0.5"/> # and virologists will recognize <pause dur="0.3"/> all those acronyms <pause dur="0.3"/> H-I-V <pause dur="0.3"/> # # human immunodeficiency virus and H-B-V and H-C-V too <pause dur="0.3"/> hepatitis viruses <pause dur="0.3"/> and of course C-J-D <pause dur="0.3"/> now these are

blood borne <pause dur="0.3"/> pathogens <pause dur="0.2"/> which of course if you transfuse blood contaminated with those pathogens <pause dur="0.3"/> you pass <pause dur="0.2"/> the # transmit <pause dur="0.3"/> # the disease <pause dur="1.2"/> obviously <pause dur="0.3"/> # the viral problems can be resolved by screening you check <pause dur="0.4"/> the blood for the presence of the # viruses either antigenically by serotype <pause dur="0.5"/> <trunc>se</trunc> serological assays <pause dur="0.3"/> or by some sort of molecular assay <pause dur="0.3"/> and if the blood is clear <pause dur="0.3"/> then you're happy to use it <pause dur="0.5"/><vocal desc="clears throat" iterated="n"/> C-J-D <pause dur="0.6"/> Creutzfeldt-Jakob Disease is much more problematic <pause dur="0.4"/> # because there's no simple test to detect C-J-D so you can't screen <pause dur="2.0"/> this <pause dur="0.2"/> # problem if it is a problem <pause dur="0.4"/> # has been solved <pause dur="0.3"/> largely by separating the leukocytes from the red blood cells <pause dur="0.4"/> when you're doing a regular blood transfusion what's needed is not the leukocytes but of course the red cells for carrying oxygen around the body <pause dur="0.9"/> you can eliminate the leukocytes fairly straightforwardly by a a kind of # gradient <pause dur="0.5"/> centrifugation <pause dur="0.5"/> so that

you can prepare blood which is essentially completely free of leukocytes now prions <pause dur="0.4"/> which are the C-J-D organism <pause dur="0.5"/> # are in leukocytes if they're in blood at all <pause dur="0.4"/> not in the red cells so if you get rid of the leukocytes then you can transfuse the blood <pause dur="0.3"/> safely <pause dur="0.7"/> okay <pause dur="0.2"/> so blood transfusion is a form of transplantation which is very <pause dur="0.3"/> straightforward <pause dur="0.5"/><kinesic desc="changes slide" iterated="n"/> # and sorted out <pause dur="2.0"/> go on to bone marrow transplantation now everybody is familiar with what bone marrow is bone marrow <pause dur="0.4"/> is the <pause dur="0.4"/> # or is the tissue which generates all the <trunc>haema</trunc> haematopoietic tissues the blood and the white blood cells <pause dur="0.4"/> # and <trunc>o</trunc> other parts of the haematopoietic system <pause dur="0.7"/> # individuals <pause dur="0.3"/> who have failed bone marrow <pause dur="0.6"/> # are going to be very sick <pause dur="0.7"/> # and a life saving treatment is <pause dur="0.3"/> the trans<pause dur="0.2"/>plantation of bone marrow into those individuals <pause dur="0.3"/> now when i say <pause dur="0.4"/> bone marrow transplantation <pause dur="0.5"/> actually i mean it <pause dur="0.2"/> in a slightly wider sense <pause dur="0.3"/> it can be the actual bone marrow which is taken from

the donor's <pause dur="0.3"/> bone <pause dur="0.6"/> and i have had it <pause dur="0.2"/> i have done it and i tell you it is very painful <pause dur="0.4"/> don't recommend it except for very close friends <pause dur="0.5"/> # <pause dur="0.2"/> so you can take the actual bone marrow <pause dur="0.5"/> or you can take <pause dur="0.6"/> what are called C-D-thirty-four cells now <pause dur="1.2"/> those of you who are familiar with immunology will recollect <pause dur="0.4"/> that <pause dur="0.2"/> C-D-thirty-four <pause dur="0.4"/> is the antigen <pause dur="0.2"/> which <pause dur="0.2"/> defines <pause dur="0.3"/> the <pause dur="0.4"/> # pluripotent stem cell which generates all cells <pause dur="0.3"/> of the haematopoietic <trunc>ser</trunc> system <pause dur="0.4"/> now the C-D-thirty-four cells are normally within the bone marrow that's why you go for the bone marrow <pause dur="0.5"/> but you can get C-D-thirty-four cells <pause dur="0.2"/> out of the bone marrow <pause dur="0.6"/> into the peripheral circulation <pause dur="0.3"/> by treating people with certain cytokines <pause dur="0.3"/> which cause the <trunc>C-D-thoity-fo</trunc> thirty-four cell <pause dur="0.3"/> to proliferate <pause dur="0.3"/> and move <pause dur="0.2"/> from the bone marrow into the periphery <pause dur="0.2"/> into the circulation <pause dur="0.4"/> so that's why we speak about <pause dur="0.4"/> mobilization <pause dur="0.6"/> of C-D-thirty-four cells into the periphery <pause dur="0.5"/> and then of course you can get these cells by simply taking blood <pause dur="0.7"/> and

that's much less painful than bone marrow donation <pause dur="0.9"/> okay <pause dur="0.3"/> so you can get <pause dur="0.3"/> the stem cells <pause dur="0.2"/> of the haematopoietic system either from the bone marrow <pause dur="0.4"/> or <pause dur="0.3"/> from the blood if you treated patients people <pause dur="0.3"/> with a <trunc>cert</trunc> with the cytokines <pause dur="1.8"/> now bone marrow transplantation <pause dur="0.5"/> is used broadly in these two situations <pause dur="1.0"/><vocal desc="clears throat" iterated="n"/><pause dur="1.0"/> the one <pause dur="0.8"/> major condition <pause dur="0.3"/> # where <pause dur="0.2"/> the bone marrow <pause dur="0.3"/> completely is non-functional is a condition called SCID severe combined <pause dur="0.6"/> immunodeficiency <pause dur="0.4"/> okay <pause dur="0.9"/> and the other situation <pause dur="0.4"/> # <pause dur="0.4"/> where bone marrow fails completely <pause dur="0.4"/> is in certain therapeutic <pause dur="0.9"/> manoeuvres carried out in the treatment of some cancers and i'll talk about both these in a moment <pause dur="0.9"/> so let's <pause dur="0.2"/> go on briefly and talk about <kinesic desc="changes slide" iterated="n"/> SCID just for a moment <pause dur="0.8"/> some of you writing the essay on on gene therapy will have heard about <pause dur="0.4"/> SCID in the context of <pause dur="0.3"/> gene therapy <pause dur="0.5"/> so you will recollect that SCID is an inherited failure <pause dur="0.3"/> of the ontogeny of T-cells individuals who've inherited this condition <pause dur="0.3"/>

fail <pause dur="0.2"/> to produce functional T-cells <pause dur="0.7"/> what that means <pause dur="0.3"/> is not having T-cells is that essentially you have no immune responsiveness at all you have <pause dur="0.3"/> you have the non-adaptive immune system things like natural killer cells <pause dur="0.5"/> but your T-cell system has failed <pause dur="0.2"/> and so the adaptive immune system is essentially absent <pause dur="0.3"/> you can neither generate <pause dur="0.3"/> cell-mediated immunity <pause dur="0.3"/> nor can you make antibodies so you are <pause dur="0.2"/> very sick extremely susceptible <pause dur="0.4"/> to infection <pause dur="0.8"/> okay <pause dur="1.4"/> quite simply in this situation <pause dur="0.4"/> bone marrow transplantation provides the patient with normal T-cells <pause dur="0.3"/> which are of course derived from the donor <pause dur="0.9"/> okay <pause dur="0.3"/> so the transplanted <trunc>r</trunc> the <trunc>r</trunc> <trunc>r</trunc> recipient's T-cells <pause dur="0.4"/> after the transplant are of course <pause dur="0.3"/> of donor origin not his own <pause dur="0.2"/> that goes without <pause dur="0.4"/> saying <pause dur="4.7"/><kinesic desc="changes slide" iterated="n"/> now in certain cancers # <pause dur="1.0"/><vocal desc="clears throat" iterated="n"/><pause dur="1.7"/> the therapy of cancer <pause dur="0.5"/> often depends on the use of so-called cytotoxic drugs now these cytotoxic drugs <pause dur="0.4"/> are

designed <pause dur="0.3"/> to kill the cancer cells <pause dur="0.6"/> but they are never completely specific well rarely are they even slightly <trunc>sic</trunc> specific in fact <pause dur="0.4"/> # to the cancer cells <pause dur="0.3"/> and so if you treat patients with cancer <pause dur="0.3"/> with these drugs a consequence is damage <pause dur="0.4"/> to all those organs and tissues which are rapidly proliferating <pause dur="1.0"/> all right <pause dur="0.6"/> so if you give a large dose of this sort of therapy <pause dur="0.5"/> you will damage <pause dur="0.4"/> # the bone marrow <pause dur="0.3"/> of the patient <pause dur="0.3"/> to such an extent that the bone marrow <pause dur="0.3"/> will no longer function is no longer able to produce <pause dur="0.3"/> haematopoietic cells <pause dur="0.4"/> under those circumstances the patient <pause dur="0.3"/> will die <pause dur="0.9"/> okay <pause dur="0.4"/> so what we do what is done rather <pause dur="0.5"/> is that <pause dur="0.4"/> the patients who are treated with very large doses of therapy to destroy the cancer <pause dur="0.7"/> are what <pause dur="0.2"/> what is called <pause dur="0.2"/> rescued <pause dur="0.5"/> by bone marrow transplantation now what that simply obviously means <pause dur="0.3"/> is that the bone the patient <pause dur="0.3"/> is <pause dur="0.2"/> <shift feature="voice" new="laugh"/>in <shift feature="voice" new="normal"/>a <trunc>se</trunc> <trunc>es</trunc> essentially brought back to life by the transplantation of bone marrow <pause dur="1.7"/> now equally <pause dur="1.4"/> transplanted marrow <pause dur="0.5"/> in this

in some situations <pause dur="0.3"/> also seems to have an anti-cancer effect which is a by-product a bonus if you like <pause dur="0.4"/> in other words <pause dur="0.2"/> the transplanted marrow <pause dur="0.3"/> seems to develop <pause dur="0.6"/> some sort of immune response to the cancer and that actually helps survival in some circumstances but i'm not going to talk about that in detail <pause dur="2.2"/> now <pause dur="0.9"/><vocal desc="clears throat" iterated="n"/><pause dur="1.4"/> talking about SCID <pause dur="2.0"/> the graft <pause dur="0.3"/> obviously <pause dur="0.2"/> has to be an allograft <pause dur="0.7"/> because the patient has no bone marrow of his own no no no <pause dur="0.2"/> adequate bone marrow at least so the <pause dur="0.3"/> situation there it has to be an allograft <pause dur="0.6"/> in the case of the cancer therapy <pause dur="0.4"/> you can actually autograft in other words you can take the patient's own bone marrow <pause dur="1.0"/> treat the guy with cytotoxic therapy <pause dur="0.3"/> and then replace his own bone marrow <pause dur="2.0"/> okay <pause dur="1.0"/><vocal desc="clears throat" iterated="n"/><pause dur="1.2"/> you can also do an allograft in that situation <pause dur="0.4"/> and both <pause dur="0.2"/> these techniques have their <trunc>ad</trunc> <pause dur="0.2"/> advantages and disadvantages <pause dur="0.6"/> the advantage of the autograft is you have # you no

immunological problems again <pause dur="0.7"/> the disadvantage of the autograft <pause dur="0.5"/> is that potentially <pause dur="0.7"/> the engrafted marrow carries with it cancer cells <pause dur="0.9"/> okay <pause dur="0.6"/> which <pause dur="0.2"/> of course is self-defeating <pause dur="0.3"/> because the cancer cells will then start growing again 'cause they haven't been subjected to the therapy <pause dur="0.6"/> so the autograft has the disadvantage that in fact you may be grafting cancer cells at the same time <pause dur="0.4"/> as you're grafting back <pause dur="0.2"/> the patient's marrow <pause dur="2.3"/> in the case of the allograft you have immunological problems which i'll describe presently <pause dur="1.3"/> but the allograft seems <pause dur="0.2"/> surprisingly <pause dur="0.3"/> to have a better <pause dur="0.5"/> # anti-cancer effect <pause dur="1.3"/> than the autograft <pause dur="0.3"/> so there are advantages both ways <pause dur="1.4"/> from a clinical point of view <pause dur="0.2"/> # i think <pause dur="0.8"/> the autograft generally is preferred because it's easier to manage because the immunological consequences of the allograft can be very severe which we'll get on to in a moment <pause dur="1.7"/> okay <pause dur="3.1"/> pause a moment to let you catch up <pause dur="5.3"/><kinesic desc="changes slide" iterated="n"/><vocal desc="clears throat" iterated="n"/> so this <pause dur="0.7"/>

is showing it <pause dur="0.2"/> diagrammatically this is the sick patient <pause dur="0.4"/> who has a cancer say originating in the stomach <pause dur="0.5"/> which has spread about the body now this patient is going to die unless you can treat the cancer that's spread about the body <pause dur="0.5"/> so you give him very large dose of anti-cancer drugs <pause dur="1.0"/> sufficient to kill all the cancer cells but at the cost of destroying the bone marrow <pause dur="0.2"/> so that's what that bomb is <pause dur="0.5"/> so this guy is flat out <pause dur="1.0"/> and you put back in stem cells by stem cells i mean either bone marrow <pause dur="0.3"/> or the C-D-thirty-four <pause dur="0.2"/> cells <pause dur="0.6"/> # and who from either i autograft or allograft <pause dur="0.4"/> to replace the haematopoietic system <pause dur="0.4"/> and then <pause dur="0.4"/> with luck <pause dur="0.3"/> the patient's cured and there is actually good evidence that cures do occur under these circumstances <pause dur="0.8"/> so this is a sort of therapy <pause dur="0.9"/> important therapy <pause dur="3.2"/><kinesic desc="changes slide" iterated="n"/> so let's go on to solid organ grafts <vocal desc="clears throat" iterated="n"/><pause dur="1.6"/> and the idea here is very straightforward and simple <pause dur="0.6"/> # if an

organ fails <pause dur="0.3"/> replace it <pause dur="1.0"/> all right <pause dur="1.3"/> straightforward <pause dur="0.7"/> but we do there are a number of problems as you imagine <pause dur="0.3"/> the first <pause dur="1.1"/> problem # # and this was <pause dur="0.2"/> and continues to be a very serious problem <pause dur="0.4"/> is that the success of the graft <pause dur="0.4"/> depends on the feasibility of the surgery <pause dur="0.4"/> required to transfer <pause dur="0.3"/> the solid organ from the donor to the recipient <pause dur="0.5"/> now in the case of things like kidney and liver <pause dur="0.3"/> # to <pause dur="0.2"/> a large extent lung and heart <pause dur="0.5"/> the plumbing if you like the blood vessels and the various <pause dur="0.3"/> # # nervous connections <pause dur="0.3"/> are relatively straightforward <pause dur="0.5"/> and so the surgeon can transfer an organ from one individual to another <pause dur="0.3"/> without too much difficulty <pause dur="0.9"/> with other organs and the arch-example is the pancreas it would be marvellous to transplant the pancreas to treat diabetes remember <pause dur="0.8"/> the pancreas <pause dur="0.3"/> the plumbing <pause dur="0.4"/> is so complex <pause dur="0.3"/> that <pause dur="0.4"/> surgically <pause dur="0.2"/> it's not feasible it's simply too complex <pause dur="0.3"/> for the surgeon <pause dur="0.3"/> to be able successfully to transfer the organ <pause dur="0.3"/> it's just not possible <pause dur="0.2"/> take too long <pause dur="0.3"/>

too detailed too many tubes too many <pause dur="0.3"/> arteries too many veins too many <pause dur="0.4"/> this and that and the other <pause dur="0.4"/> so it's not practical to transplant things like pancreas <pause dur="0.4"/> so this is the first consideration <pause dur="0.3"/> is the surgery practical <pause dur="3.9"/><kinesic desc="changes slide" iterated="n"/> so <pause dur="0.7"/> assuming <pause dur="0.3"/> that we have got through to the situation where we have <pause dur="0.4"/> # <pause dur="0.9"/> practical surgery <pause dur="0.4"/> for the transplantation of a tissue <pause dur="2.4"/><vocal desc="clears throat" iterated="n"/><pause dur="0.4"/> now i want to move along to <pause dur="0.2"/> talking about the immunological basis of graft rejection <pause dur="0.6"/> now obviously this is the scientific aspect <pause dur="0.3"/> that i really need to <pause dur="0.5"/> talk about to dwell on <pause dur="0.4"/> in some detail <pause dur="1.6"/> right <pause dur="0.7"/> do recommend <pause dur="0.5"/> # that you review your second year immunology notes and think about <pause dur="0.5"/> # immunology <pause dur="0.3"/> i should have should have said at the beginning <pause dur="0.3"/> that some of the material that i'm presenting now obviously is related <pause dur="0.3"/> to what <pause dur="0.4"/> i presented to you in the second year so some of it will be familiar i hope it'll be familiar <pause dur="0.4"/> and you should also look

at your second year notes <pause dur="5.3"/><kinesic desc="changes slide" iterated="n"/> so what's the problem <pause dur="1.5"/> manifestly the problem is graft rejection <pause dur="1.4"/> graft rejection <pause dur="0.4"/> is the <pause dur="0.3"/> # phenomenon <pause dur="0.2"/> in which the transplanted organ <pause dur="0.4"/> # is damaged <pause dur="0.5"/> fails through large-scale inflammation <pause dur="0.4"/> # and then literally starts to fall apart under immunological attack <pause dur="0.9"/> okay <pause dur="0.6"/> now the reason for this is that <pause dur="0.3"/> in an allograft not an autograft i should have included with autografts <pause dur="0.5"/> grafting from identical twins of course that's equivalent to an autograft <pause dur="1.0"/> but in the case of allografts <pause dur="1.4"/> the immune system of the recipient <pause dur="0.8"/> sees the graft <pause dur="0.6"/> as non-self <pause dur="0.8"/> somebody else manifestly <pause dur="0.9"/> and this is because there are alloantigens on the in the and on <pause dur="0.2"/> the graft <pause dur="0.3"/> which are different from the self-antigens <pause dur="2.0"/> these alloantigens <pause dur="0.2"/> you see the word allo it's related to allele again <pause dur="0.4"/> different alleles of the same gene <pause dur="0.5"/> okay related to allogeneic and allograft <pause dur="0.3"/> the alloantigens <pause dur="0.8"/> are recognized by the host immune system <pause dur="1.4"/> and adaptive

immune <pause dur="0.2"/> mechanisms <pause dur="0.4"/> develop in the host <pause dur="0.3"/> which will eliminate the transplanted the non-self organ <pause dur="0.3"/> non-self tissue <pause dur="3.2"/> now <pause dur="0.3"/><vocal desc="clears throat" iterated="n"/><pause dur="1.2"/> what we have to <pause dur="0.4"/> recognize what you have to understand <pause dur="0.4"/> is that the situations with bone marrow transplantation <pause dur="0.9"/> and solid organ <pause dur="0.3"/> transplantation <pause dur="2.1"/> is that in the bone marrow transplantation <pause dur="0.3"/> the recipient <pause dur="0.3"/> the host <pause dur="0.3"/> doesn't have an immune system <pause dur="0.9"/> so obviously <pause dur="0.3"/> the host is not going to recognize the engrafted marrow <pause dur="0.4"/> as foreign <pause dur="0.3"/> got no <trunc>ho</trunc> <trunc>go</trunc> the host has got no immune system <pause dur="0.4"/> but of course <pause dur="0.4"/> the engrafted <pause dur="0.3"/> marrow <pause dur="0.3"/> is a source of immune cells <pause dur="0.8"/> and those immune cells <pause dur="0.4"/> as they encounter the host's tissues <pause dur="0.3"/> will recognize the host <pause dur="0.3"/> the recipient as foreign <pause dur="1.2"/> so in bone marrow transplantation and this is what makes <pause dur="0.4"/> this such a hazardous situation <pause dur="0.8"/> # <pause dur="0.8"/> the the bone marrow transplant <pause dur="0.4"/> actually <pause dur="0.5"/> rejects the host <pause dur="1.4"/> a rather unpleasant <pause dur="1.0"/> thought <pause dur="2.7"/> obviously in the situation of the solid organ allograft <pause dur="0.3"/> or indeed xenograft <pause dur="0.5"/> # <pause dur="0.5"/> the

host <pause dur="0.7"/> # which has an intact immune system is rejecting <pause dur="0.2"/> the graft <pause dur="1.4"/> okay so we have these two different situations <pause dur="0.4"/> in the bone marrow <pause dur="0.4"/> and the solid <pause dur="0.7"/> organ <trunc>gr</trunc> # graft <pause dur="1.8"/><kinesic desc="changes slide" iterated="n"/><vocal desc="clears throat" iterated="n"/><pause dur="1.8"/> so <pause dur="0.9"/> in sort of <pause dur="0.4"/> clinical terms <pause dur="0.9"/> what's happening in graft rejection <pause dur="1.4"/> basically you're getting an immune response to the host tissue in G-V-H-D i should have defined graft versus host disease is abbreviated as G-V-H <pause dur="0.7"/> or G-V-D or G-V-H-D <pause dur="0.4"/> okay <pause dur="0.4"/> in this situation you get <pause dur="0.3"/> severe damage to the host epithelial <pause dur="0.5"/> # tissues <pause dur="0.5"/> the skin <pause dur="0.5"/> # and the lining of the gut <pause dur="2.3"/> but perhaps more seriously you get <pause dur="0.4"/> damage to the endothelium now you remember <pause dur="0.6"/> that the endothelium <pause dur="0.4"/> # is the lining of blood vessels and in the case of capillaries <pause dur="0.7"/> the very fine blood vessels <pause dur="0.3"/> the endothelial cells <pause dur="0.3"/> are the entire wall of the blood vessel <pause dur="0.7"/> so if you're getting an immunological reaction <pause dur="0.6"/> # <pause dur="0.3"/> to <pause dur="0.7"/> the endothelium <pause dur="0.3"/> you're going to get extensive bleeding into the tissues <pause dur="0.3"/> and remember

that particularly in the kidney say <pause dur="0.3"/> the endothelium provides a very has a very important <pause dur="0.4"/> functional role 'cause this the endothelium which performs <pause dur="0.3"/> the filtration <pause dur="0.6"/> in the glomerulus <pause dur="0.5"/> and the various other bits and pieces of the kidney <pause dur="0.7"/> so if you're damaging the glomerulus with immune response <pause dur="0.3"/> then the kidney function's going to fail <pause dur="0.4"/> so in the case of graft versus host disease the patient <pause dur="0.5"/> has severe <pause dur="0.2"/> # generalized organ failure <pause dur="0.8"/> and if it's not treated that will inevitably result # in death of the patient <pause dur="1.1"/> now in the case of solid organ rejection <pause dur="0.6"/><vocal desc="clears throat" iterated="n"/> of course essentially the same thing is happening <pause dur="0.4"/> and you're getting damage <pause dur="0.4"/> again particularly to the endothelium but also again <pause dur="0.4"/> to the actual cells within the organ <pause dur="0.8"/> okay leading to failure of the organ <pause dur="0.6"/> so that <pause dur="0.4"/> simply is the nature of rejection it's the destruction <pause dur="0.4"/> of the cells of the organ <pause dur="6.3"/><kinesic desc="changes slide" iterated="n"/> right <pause dur="0.3"/> now <pause dur="0.2"/><vocal desc="clears throat" iterated="n"/>

i'm going to <pause dur="0.4"/> specialize now and talk particularly about kidney transplantation because that's the subject of these lectures <pause dur="0.4"/> and it happens to be what i know about most <pause dur="0.7"/><vocal desc="clears throat" iterated="n"/><pause dur="1.4"/> so <pause dur="0.2"/> we'll get on now and talk specifically about kidneys <pause dur="0.7"/> now <pause dur="0.2"/> as you will have heard from Dr <gap reason="name" extent="1 word"/> <pause dur="0.4"/> # earlier <pause dur="0.5"/> # <pause dur="0.4"/> kidney transplantation without any question <pause dur="0.7"/> is the best <pause dur="0.5"/> # treatment for what is called end-stage renal failure <pause dur="0.6"/> end-stage renal failure is when you have <trunc>irrespo</trunc> irreversible <pause dur="0.3"/> and total failure of the kidney <pause dur="0.9"/> okay <pause dur="1.2"/> # <pause dur="1.7"/> because <pause dur="0.5"/> transplantation allows the patient <pause dur="0.3"/> to have essentially <pause dur="0.2"/> normal function <pause dur="0.2"/> normal functioning <pause dur="0.4"/> they can walk around as usual go swimming doesn't have to have the dialysis bag <pause dur="0.5"/> # doesn't have to worry about things like <pause dur="0.3"/> haematopoietin injections <pause dur="0.3"/> his diet can be fairly free <pause dur="0.4"/> he can drink reasonably <pause dur="0.3"/> modest amounts of alcohol and so on <pause dur="0.3"/> so a kidney transplant patient <pause dur="0.3"/> really has a <pause dur="0.2"/> more or less normal function <pause dur="0.3"/>

whereas somebody on dialysis is severely limited <pause dur="0.3"/> in lifestyle <pause dur="0.3"/> and in health <pause dur="0.8"/> and i think the point has been made quite clearly <pause dur="0.6"/> that transplantation despite the initial costs of the actual operation <pause dur="0.4"/> is in the longer run <pause dur="0.4"/> much cheaper <pause dur="0.2"/> than dialysis dialysis i forget what it costs <pause dur="0.4"/> five-thousand a year something like that <pause dur="0.3"/> whereas <pause dur="0.2"/> once you've done the transplant which maybe costs ten-thousand the cost of maintaining the patient <pause dur="0.4"/> is much less so over a period of ten years <pause dur="0.4"/> the transplant is <sic corr="cheaper">teacher</sic> <pause dur="0.3"/> and in our modern new up to date N-H-S it cost that matters <pause dur="0.3"/> very much indeed <pause dur="1.9"/> the main limitation <pause dur="0.3"/> as i suspect <pause dur="0.2"/> you are all familiar <pause dur="0.6"/> is # the availability of donors <pause dur="0.3"/> now <pause dur="0.3"/> again <gap reason="name" extent="1 word"/> will talk about this more tomorrow <pause dur="0.3"/> so i won't go into that in detail <pause dur="0.4"/> but the lack <pause dur="0.4"/> of donors the <pause dur="0.2"/> few number of small number of donors means that there are <pause dur="0.4"/> serious scientific consideration <pause dur="0.4"/> to other <pause dur="0.3"/> ways and means <pause dur="0.3"/> of

restoring organ function replacing organ function i should say <pause dur="2.7"/><kinesic desc="changes slide" iterated="n"/> so <pause dur="0.4"/><vocal desc="clears throat" iterated="n"/><pause dur="1.0"/> as i was saying just now <pause dur="0.9"/> kidney transplantation is <pause dur="0.9"/> surgically straightforward surgically quite feasible <pause dur="0.4"/> there's the ureter to reconnect <pause dur="0.3"/> there's a couple of arteries a couple of veins to reconnect <pause dur="0.3"/> but basically surgeons find this fairly straightfoward <pause dur="0.6"/> # <pause dur="2.1"/> so the main problem <pause dur="0.3"/> is as i've been saying <pause dur="0.3"/> rejection of the graft <pause dur="0.2"/> and you've got to control that rejection <pause dur="0.8"/> now <pause dur="1.4"/> experience with <pause dur="0.2"/> patients who've been transplanted implies has told us taught us that there are actually three <pause dur="0.6"/> forms <pause dur="0.6"/> of <pause dur="0.2"/> rejection <pause dur="1.0"/> three different kinds of rejection <pause dur="0.5"/> # which are described as hyperacute <pause dur="0.6"/> and acute <pause dur="0.5"/> and chronic <pause dur="2.7"/><vocal desc="clears throat" iterated="n"/><pause dur="0.7"/> now the hyperacute rejection <pause dur="0.4"/> happens more or less immediately as soon as the kidney <pause dur="0.4"/> is <pause dur="0.2"/> plumbed into the recipient <pause dur="0.3"/> and the veins and arteries are reconnected <pause dur="0.3"/> and blood <pause dur="0.4"/> starts to flow

through the kidney the host's blood starts <pause dur="0.3"/> the flow through the kidney <pause dur="0.4"/> what happens is that if there is hyperacute rejection going on <pause dur="0.3"/> immediately or very very quickly before the <pause dur="0.3"/> cessation of the operation <pause dur="0.4"/> # it will be seen that the kidney starts to swell <pause dur="0.2"/> become oedematous <pause dur="0.6"/> okay starts to swell <pause dur="0.5"/> and <pause dur="0.4"/> goes much darker in colour <pause dur="0.7"/> # and the consequence <pause dur="0.4"/> of the rejection is that the organ very quickly will fail <pause dur="0.4"/> and immediately has to be replaced <pause dur="0.3"/> and they have to rejoin the various bits and pieces <pause dur="0.3"/> close up the patient <pause dur="0.3"/> and put him back onto dialysis until a more suitable kidney comes along <pause dur="2.3"/> okay <pause dur="0.2"/> so that happens immediately during the operation we'll talk about the causes in a moment <pause dur="0.9"/> acute <pause dur="0.3"/> rejection <pause dur="0.3"/> despite the term acute meaning again more or less immediate acute rejection <pause dur="0.4"/> tends to occur <pause dur="0.3"/> some weeks after the actual transplantation six to twelve weeks typically <pause dur="1.2"/> what happens in this situation of course you can't see <pause dur="0.2"/> what's

happening <pause dur="0.5"/> # <vocal desc="laugh" iterated="n"/><pause dur="0.7"/> obviously <pause dur="0.3"/> # but <pause dur="0.6"/> clinically what's happening is that kidney function starts rapidly to decline <pause dur="0.4"/> so it's all the symptoms of end-stage renal failure that you will have heard from Dr <gap reason="name" extent="1 word"/> this morning <pause dur="0.4"/> # where <pause dur="0.3"/> you start to get <pause dur="0.3"/> protein in the urea <pause dur="0.3"/> # urine <pause dur="0.4"/> # and you start to get <pause dur="0.6"/> large amounts of creatinine <pause dur="0.4"/> in the circulation because of damage to tissues and things like that <pause dur="0.7"/> okay <pause dur="0.4"/> now <pause dur="1.0"/> i should have said that hyperacute <pause dur="0.3"/> rejection is actually irreversible once it's set in there's nothing can be done <pause dur="0.5"/> okay and that's why you have to remove it and start again <pause dur="1.4"/> in the case of acute <pause dur="0.2"/> rejection <pause dur="0.6"/> usually <pause dur="0.4"/> # it can be reversed we'll go on to why and how if there's time presently <pause dur="1.1"/> okay </u><pause dur="0.9"/> <u who="sf0261" trans="pause"> does that if the <pause dur="0.2"/> if the hyperacute one <pause dur="0.4"/> does that kill the kidney </u><pause dur="0.2"/> <u who="nm0260" trans="pause"> yes </u><u who="sf0261" trans="latching"> so you can't use it </u><u who="nm0260" trans="latching"> can't use it it's dead finished <pause dur="0.3"/> and i'll tell you why in a moment <pause dur="0.8"/> okay <pause dur="1.6"/> now the acute rejection as

i say usually can be reversed by <trunc>w</trunc> adjusting the therapy that's being carried out <pause dur="1.1"/><vocal desc="clears throat" iterated="n"/><pause dur="0.3"/> chronic rejection <pause dur="1.0"/> happens years <pause dur="0.2"/> after the transplantation five years ten years <pause dur="0.2"/> longer <pause dur="1.8"/> what it is it's a gradual slow <pause dur="0.4"/> but <pause dur="0.2"/> sadly irreversible decline in kidney function over a period of years <pause dur="0.3"/> and <trunc>u</trunc> ultimately the kidney fails completely <pause dur="0.4"/> and the patient is back <pause dur="0.6"/> # in square one <pause dur="0.8"/> okay <pause dur="0.5"/> so let's go on <pause dur="0.5"/><kinesic desc="changes slide" iterated="n"/> # and actually talk about <pause dur="0.4"/> the causes <pause dur="0.3"/> the immunological <pause dur="0.4"/> causes <pause dur="0.3"/> of these different kinds of <pause dur="0.4"/> rejection <pause dur="0.5"/> now <pause dur="0.3"/> hyperacute rejection is actually pretty straightforward <pause dur="2.4"/> it's due to the presence in the patient <pause dur="0.3"/> of antibodies <pause dur="0.4"/> circulating antibodies <pause dur="0.2"/> which are specific for the transplanted tissue which recognize antigens <pause dur="0.3"/> on a transplanted tissue <pause dur="0.3"/> especially <pause dur="0.4"/> by recognizing alloantigens <pause dur="0.3"/> on the endothelium <pause dur="1.1"/> of the transplanted tissue <pause dur="1.0"/> okay <pause dur="0.5"/> having recognized antigens on the endothelium <pause dur="0.5"/> # you remember complement <pause dur="0.4"/> okay <pause dur="0.3"/> and how antigen-antibody

complexes <pause dur="0.4"/> activate complement <pause dur="0.5"/> and the <trunc>co</trunc> activated complement destroys <pause dur="0.3"/> cell membranes locally <pause dur="0.9"/> so you've got <pause dur="0.2"/> a complement-mediated <pause dur="1.0"/> lysis <pause dur="0.4"/> of the endothelium <pause dur="0.4"/> of the organ <pause dur="0.5"/> now i've mentioned endothelium as a target for attack <pause dur="0.4"/> # in rejection phenomena <pause dur="0.3"/> the result is <pause dur="0.4"/> loss massive loss <pause dur="0.4"/> of fluid into the organ <pause dur="0.3"/> and that causes the swelling <pause dur="0.3"/> okay the organ becomes oedematous <pause dur="0.4"/> and of course the damage to the glomerulus in this situaton completely <pause dur="0.4"/> # destroys the function of the kidney <pause dur="0.3"/> so that kidney <pause dur="0.4"/> is dead <pause dur="0.7"/> now <pause dur="0.2"/> you might ask where did these antibodies arise <pause dur="0.4"/> how do they arise rather <pause dur="0.6"/> # and the answer is <pause dur="0.2"/> # <pause dur="0.9"/> often through pregnancy <pause dur="0.9"/> the fetus <pause dur="0.8"/> is in effect in effect an allograft <pause dur="0.4"/> because immunologically the fetus <pause dur="0.3"/> is a hybrid between the father and the mother <pause dur="1.0"/> so the mother <pause dur="0.3"/> will potentially become sensitized <pause dur="0.4"/> to the paternal antigens of the fetus now there is <pause dur="0.3"/> a little bit of exchange <pause dur="0.3"/> of <pause dur="0.2"/> blood <pause dur="0.3"/> across the placenta <pause dur="0.3"/> there's no <trunc>qu</trunc> it it's quite clear

that there will be fetal cells in the maternal circulation <pause dur="0.4"/> so <pause dur="0.2"/> the mother will develop antibodies to the fetus <pause dur="0.4"/> okay <pause dur="0.3"/> now suppose <pause dur="0.9"/> that the transplant <pause dur="0.5"/> for whatever reason maybe it comes from the husband or father perhaps i should say partner <pause dur="0.5"/> maybe that transplant comes from the husband you wouldn't do this in fact for these reasons <pause dur="0.5"/> # but obviously # under those circumstances the transplant will share <pause dur="0.7"/> antigens with the fetus <pause dur="0.3"/> and the mother's <pause dur="0.3"/> antibodies will destroy it <pause dur="0.9"/> # the other situation where <pause dur="0.2"/> you are likely to get these <pause dur="0.2"/> antigens antibodies sorry arising <pause dur="0.3"/> is where there's been blood tranfusions now if you've had blood transfusion <pause dur="0.5"/> in the past that meant <pause dur="0.3"/> you will have had the leukocytes as well from the donor <pause dur="0.8"/> # <pause dur="0.9"/> and you obviously you had the blood the red blood cells but the leukocytes will bear <pause dur="0.4"/> antigens that are shared by the endothelium <pause dur="0.9"/> okay <pause dur="0.3"/> so if by chance you've been transplanted with blood <pause dur="0.3"/> that shares antigens <pause dur="0.3"/> with <pause dur="0.3"/> your <trunc>tran</trunc> sorry <pause dur="0.3"/> so if by

chance you've been transfused <pause dur="0.3"/> with blood that shares <pause dur="0.3"/> antigens with <pause dur="0.4"/> the donor <pause dur="0.6"/> tissue <pause dur="0.2"/> then you will have antibodies to it <pause dur="0.3"/> okay <pause dur="6.0"/><kinesic desc="changes slide" iterated="n"/> so how to avoid <pause dur="0.2"/> hyperacute <pause dur="0.5"/><vocal desc="clears throat" iterated="n"/><pause dur="0.3"/> rejection <pause dur="0.3"/> it is actually very straightforward as i've said <pause dur="0.3"/> there's obviously no point <pause dur="0.5"/> in transplanting an organ if it's going to be immediately rejected <pause dur="0.3"/> so <pause dur="0.3"/> quite simply you check in advance that the recipient does not have any anti-donor antibodies <pause dur="0.6"/> and that's actually very simply done by the so-called crossmatch test <pause dur="0.9"/><vocal desc="clears throat" iterated="n"/><pause dur="1.0"/> so you take donor leukocytes <pause dur="0.7"/> all right <pause dur="0.8"/> and you incubate those leukocytes with serum <pause dur="0.2"/> from the recipient <pause dur="1.0"/> if the <trunc>ser</trunc> <trunc>s</trunc> recipient <pause dur="0.8"/> <trunc>a</trunc> <trunc>a</trunc> <trunc>a</trunc> and sorry and a source of complement <pause dur="0.7"/> so if the donor cells lyse under those circumstances you know <pause dur="0.3"/> there are antibodies <pause dur="0.3"/> in the recipient serum <pause dur="0.5"/> which with complement will lyse the target leukocytes <pause dur="0.6"/> okay <pause dur="0.2"/> so under those

circumstances if the crossmatch test fails <pause dur="0.3"/> you would not transplant that particular <pause dur="0.3"/> organ into that particular recipient <pause dur="0.5"/> okay <pause dur="0.4"/> you may ask where the leukocytes come from to do this test <pause dur="0.4"/> in the case of a live related live donor <pause dur="0.3"/> it's <pause dur="0.3"/> perfectly obvious you take a little bit of blood <pause dur="0.7"/> in the case of the cadaveric donor you use usually the spleen <pause dur="0.4"/> as a sort of <trunc>l</trunc> source of leukocytes for this test <pause dur="0.5"/> okay <pause dur="0.3"/> very straightforward simple test <pause dur="0.3"/> and if <trunc>a</trunc> and if if it if you fail then you don't do the transplant <pause dur="2.4"/><kinesic desc="changes slide" iterated="n"/> but <pause dur="0.3"/><vocal desc="clears throat" iterated="n"/> acute rejection <pause dur="0.5"/> is a very different situation <pause dur="0.8"/> # and this is due to the development over a period of weeks <pause dur="1.1"/> cell-mediated responses to donor alloantigens <pause dur="0.4"/> okay <pause dur="0.4"/> # <pause dur="0.2"/> these <pause dur="0.3"/> responses <pause dur="0.3"/> particularly <pause dur="0.4"/> are C-D-eight-positive cytotoxic T-cells now you've all <pause dur="0.4"/> come across <pause dur="0.3"/> cytotoxic cells in immunology before now <pause dur="0.5"/> # <pause dur="0.2"/> if you generate anti-<pause dur="0.7"/>donor <pause dur="0.6"/> C-D-eight cells <pause dur="0.3"/> those will <pause dur="0.8"/> obviously damage

the donor tissues <pause dur="0.4"/> and in particular again <pause dur="0.3"/> it's the endothelium which is damaged <pause dur="0.7"/> and a little bit of <trunc>techno</trunc> technical terminology here if the endothelium is being damaged <pause dur="0.6"/> this is <trunc>r</trunc> <pause dur="0.2"/> # described as vascular rejection for obvious reasons 'cause the endothelium is the vasculature <pause dur="1.9"/> and <pause dur="0.3"/> may also <pause dur="1.3"/> as well <pause dur="0.4"/> or alternatively <pause dur="0.3"/> # damage the actual cells of the organ and that is described as cellular rejection <pause dur="0.6"/> after infiltrating into the organ <pause dur="1.7"/> now i make this distinction <pause dur="0.3"/> # because <pause dur="0.4"/> vascular rejection <pause dur="0.4"/> is much more severe <pause dur="0.3"/> than straightforward cellular rejection <pause dur="0.3"/> # celluclar rejection is much more easily coped with <pause dur="0.3"/> than is vascular rejection for the obvious reason <pause dur="0.3"/> that if you're getting vascular damage damage to the endothelium <pause dur="0.3"/> that is going to do much more severe damage to the organ <pause dur="0.3"/> than a <trunc>l</trunc> than damage to the # parenchymal cells of the organ <pause dur="5.2"/><kinesic desc="changes slide" iterated="n"/> okay <pause dur="0.5"/> few more words about <pause dur="0.3"/> the acute rejection <pause dur="3.8"/> as a part of the diagnostic process for

acute rejection <pause dur="0.5"/> # perhaps i should say if a if a patient is <pause dur="0.7"/> # well i've already said that you get <pause dur="0.4"/> # <pause dur="0.3"/> protein in the urea and you get an increase of creatinine <pause dur="0.2"/> during acute rejection <pause dur="0.3"/> but the patient also becomes feverish <pause dur="0.3"/> now you remember fever is a symptom <pause dur="0.3"/> of immunological activations and the patient is feverish has these other problems <pause dur="0.4"/> # now there are various reasons <pause dur="0.3"/> why the patient may become feverish and have these sorts of problems <pause dur="0.3"/> not all of them are <trunc>rec</trunc> are rejection <pause dur="0.4"/> so as a part of the diagnosis <pause dur="0.3"/> of rejection <pause dur="0.5"/> what is done is that a biopsy is taken to do that <pause dur="0.3"/> # the physician inserts <pause dur="0.4"/> a needle <pause dur="0.5"/> # into the kidney under ultrasonic <pause dur="0.3"/> # direction <pause dur="0.3"/> and takes <pause dur="0.3"/> in the needle hollow needle obviously a hypodermic needle <pause dur="0.3"/> takes <pause dur="0.3"/> a piece of core <pause dur="0.4"/> a core of tissue <pause dur="0.4"/> and removes that <pause dur="0.5"/> and you can stain this and examine it histologically <pause dur="1.1"/> and if you do that <pause dur="0.2"/> and there's rejection occurring <pause dur="0.3"/> then you see all the classical hallmarks of inflammation <pause dur="0.8"/> which i hope you recollect <pause dur="0.3"/> are

things like leukocytic infiltration <pause dur="0.5"/> into the organ <pause dur="0.4"/> things like activation of adhesion molecules remember <pause dur="0.8"/> release of cytokines remember <pause dur="0.6"/> and chemokines <pause dur="0.3"/> so if the biopsy <pause dur="0.4"/> the histological <pause dur="0.2"/> appearance of the biopsy is that <pause dur="0.3"/> then you've got a clear <pause dur="0.4"/> # <pause dur="0.6"/> diagnosis <pause dur="0.5"/> of rejection <pause dur="0.3"/> and if it's vascular involvement it's vascular rejection if it's just cellular involvement it's cellular rejection <pause dur="0.4"/> i've already said about damage to the endothelium <pause dur="0.5"/> that will lead to kidney failure <pause dur="3.2"/><kinesic desc="changes slide" iterated="n"/> so <pause dur="1.7"/> the question that arises is how to avoid <pause dur="0.5"/> graft loss due to acute rejection <pause dur="2.3"/> now since the point that i have been making <pause dur="0.6"/><vocal desc="clears throat" iterated="n"/> is that <pause dur="0.5"/> the immunological <pause dur="0.8"/> response is due to <trunc>allo</trunc> alloantigenic differences between the donor <pause dur="0.4"/> and the recipient <pause dur="1.2"/> manifestly one of the things that is going to be done is to try and minimize <pause dur="0.3"/> the differences the antigenic differences <pause dur="0.4"/> between the donor <pause dur="0.3"/> and the host <pause dur="0.7"/> okay <pause dur="1.3"/> and this <pause dur="0.7"/> you may understand is called tissue type matching <pause dur="0.9"/> tissue typing

for short <pause dur="1.3"/> so you match as closely as possible <pause dur="0.4"/> the antigenic properties <pause dur="0.3"/> of the donor tissue <pause dur="0.4"/> to the antigenic properties of the <pause dur="0.6"/> recipient i'll go into this in more detail presently <pause dur="2.2"/> and quite obviously the other thing <pause dur="0.5"/> that's done <pause dur="1.8"/> is that in the case of these patients <pause dur="0.3"/> the immune response <pause dur="0.3"/> will be suppressed <pause dur="0.6"/> by drug treatment <pause dur="0.7"/> okay so you do have two <pause dur="0.6"/> # two <pause dur="0.2"/> strategies one is <pause dur="0.2"/> reduce the antigenic differences by tissue typing <pause dur="0.9"/> tissue matching <pause dur="1.2"/> and suppress <pause dur="0.3"/> the immune response so that the immune response when it occurs and it will occur <pause dur="0.7"/> # is minimized <pause dur="0.8"/> doesn't do too much damage <pause dur="0.2"/> is the hope <pause dur="1.9"/><kinesic desc="changes slide" iterated="n"/> so we go on to chronic rejection <pause dur="0.7"/> now this <pause dur="0.8"/> is actually a somewhat different situation <pause dur="1.2"/> # <pause dur="0.8"/> histologically <pause dur="0.5"/> # that is microscopically <pause dur="0.4"/> # the <trunc>a</trunc> <pause dur="0.2"/> appearance of the tissue undergoing chronic rejection <pause dur="0.4"/> is quite different from the <pause dur="0.2"/> <trunc>t</trunc> appearance of tissue undergoing acute rejection <pause dur="0.4"/> there is no clear-cut evidence of inflammatory responses <pause dur="0.3"/> there may be some

evidence of minor inflammation but not much <pause dur="1.0"/> okay <pause dur="0.4"/> so it's not really <pause dur="0.5"/> an immunologically-mediated rejection <pause dur="1.0"/> but what is found is that in these situations <pause dur="1.5"/> that you get deposition <pause dur="0.2"/> of <pause dur="0.5"/> quantities of fibrous scar tissue # collagen and <pause dur="0.5"/> and fibres # fibroblastic <pause dur="0.3"/> cells in large numbers <pause dur="0.4"/> and suchlike <pause dur="1.8"/> obviously <pause dur="0.4"/> if you have a lot of fibrous scar tissue deposited in in in the organ # in the kidney <pause dur="0.4"/> whose <pause dur="0.6"/> function is crucially dependent on the delicate structure of the glomerulus <pause dur="0.6"/> and the other bits and pieces <pause dur="0.6"/> then <pause dur="0.3"/> # you'll get <pause dur="0.3"/> literally quite literally clogging up of these parts of the organ <pause dur="0.4"/> and gradual <pause dur="0.5"/> loss of function <pause dur="1.0"/> okay <pause dur="0.8"/> as i've already said <pause dur="0.3"/> this <pause dur="0.3"/> is irreversible cannot be reversed <pause dur="0.3"/> and once the organ has failed it <pause dur="0.2"/> has to be removed and you start again <pause dur="1.0"/><vocal desc="clears throat" iterated="n"/><pause dur="1.0"/> though i've said <pause dur="0.4"/> that it is probably not an immunological response immunological <pause dur="0.2"/> # effect <pause dur="0.3"/> because you see no real signs of inflammation <pause dur="0.4"/> and inflammation is

the hallmark <pause dur="0.4"/> of an immune response <pause dur="1.8"/> almost certainly this chronic rejection is due to <pause dur="0.2"/> a long period of chronic but low-level inflammation there are there is a little bit of inflammation going on <pause dur="0.4"/> so there is continuous <pause dur="0.3"/> minor damage to the tissues <pause dur="0.3"/> okay <pause dur="1.4"/> in order to repair this minor damage <pause dur="0.3"/> you have <pause dur="0.3"/> what amounts to wound healing responses occurring now wound healing <pause dur="0.4"/> is a very interesting biological phenomenon <pause dur="0.3"/> you've all of you experienced wound healing <pause dur="0.3"/> you cut yourself <pause dur="0.3"/> and a scar <pause dur="0.3"/> develops <pause dur="0.5"/> to <pause dur="0.2"/> close up the tissue <pause dur="0.4"/> the scar <pause dur="0.3"/> is the deposition of fibrous tissue particularly collagen collagen fibrals <pause dur="0.6"/> and obviously <pause dur="0.4"/> that happens in the kidney <pause dur="0.2"/> or the liver of whatever <pause dur="0.3"/> you have the consequence of the failure of the organ <pause dur="0.6"/> so almost certainly <pause dur="0.5"/> # <pause dur="0.2"/> we've got <pause dur="0.2"/> a wound healing response generating <pause dur="0.6"/> fibrous tissue in response <pause dur="0.3"/> in as a consequence of the chronic inflammation <pause dur="1.3"/><kinesic desc="changes slide" iterated="n"/> so what can we do <pause dur="0.8"/> about that <pause dur="0.4"/> now as i've said <pause dur="0.4"/> there is <pause dur="0.3"/> no

effective therapy <pause dur="1.1"/> and <pause dur="0.9"/> it is supposed that in fact <pause dur="0.4"/> probably all grafts eventually <pause dur="0.5"/> are lost <pause dur="0.2"/> through chronic rejection <pause dur="0.3"/> but <pause dur="0.3"/> # it might be such a slow process that the patient <pause dur="0.4"/> may actually in fact outlive the graft and there is quite <pause dur="0.3"/> good evidence that this does happen people die from other causes <pause dur="0.3"/> before <pause dur="0.5"/> the organ fails <pause dur="0.8"/> now <pause dur="2.0"/> if as i say the chronic rejection is due to <pause dur="0.2"/> chronic <pause dur="0.3"/> inflammation <pause dur="0.4"/> or is due to the inflammation which was generated perhaps in the acute rejection <pause dur="1.2"/><vocal desc="clears throat" iterated="n"/> then <pause dur="0.2"/> one supposes that chronic rejection is less likely to develop if you can minimize <pause dur="0.6"/> the acute rejection in other words if you manage the patient carefully <pause dur="0.3"/> so that the acute response <pause dur="0.3"/> to the tissues <pause dur="0.4"/> is minimized <pause dur="0.3"/> so if you want to reduce <pause dur="0.6"/> chronic infection and this very much appears to be the situation <pause dur="0.4"/> the way to do that <pause dur="0.4"/> is to <pause dur="0.3"/> reduce the probability <pause dur="0.3"/> of <pause dur="0.3"/> acute <trunc>infec</trunc> acute rejection <pause dur="0.3"/> at the early stage <pause dur="0.5"/> of the transplantation <pause dur="0.7"/> okay <pause dur="5.9"/><kinesic desc="changes slide" iterated="n"/> i will have a break

in a few minutes because Natalie has to change her <pause dur="0.3"/> # tape in any case <pause dur="0.9"/> so i'll stop in a few minutes and we'll have a short break <pause dur="0.7"/><vocal desc="clears throat" iterated="n"/> but i want to talk first before i stop <pause dur="0.4"/> a little bit about this issue of tissue matching <pause dur="1.7"/> and this is <pause dur="0.3"/> where we <pause dur="0.4"/> could <pause dur="0.4"/> get into some pretty heavy immunology i'm not going to <pause dur="3.9"/> animal in animal models when you graft from one mouse to another <pause dur="0.7"/> it's long been established <pause dur="0.3"/> that there are two <pause dur="2.3"/> antigenic differences which matter <pause dur="0.6"/> and we talk about major histocompatibility antigens <pause dur="0.2"/> okay major histocompatibility <pause dur="0.4"/> alloantigens strictly speaking <pause dur="0.8"/> you've heard of these <pause dur="0.8"/> they are H-L-A in the human <pause dur="0.3"/> and H-two in the mouse <pause dur="1.0"/> if <pause dur="0.4"/> two individuals differ in their H-L-A in their major histocompatibility antigens <pause dur="0.7"/> what happens is severe <pause dur="0.3"/> and rapid rejection occurs that's why these things are called major histocompatibility antigens <pause dur="2.9"/> but they aren't the only histocompatibility antigens they aren't the

only alloantigens which mediate <pause dur="0.4"/> # tissue rejection <pause dur="0.4"/> and there's actually a whole bundle <pause dur="1.4"/> of minor histocompatibility antigens <pause dur="0.9"/> two examples in the human are H-Y <pause dur="0.3"/> and H-A-one <pause dur="0.6"/> and in the mouse <pause dur="0.3"/> it's everything that's not H-two H-one H-three H-four H-five and so on <pause dur="0.7"/> okay if anybody had ever wondered <pause dur="0.3"/> why the M-H-C of the mouse was H-two <pause dur="0.5"/> it's because there are multiple loci controlling tissue rejection <pause dur="0.3"/> which were numbered one to N <pause dur="0.4"/> and two happened to be the major <pause dur="0.9"/> complex <pause dur="0.4"/> okay <pause dur="0.5"/> now if you have <pause dur="0.3"/> if you have <pause dur="0.4"/> identity <pause dur="0.2"/> for the major histocompatibility antigens <pause dur="0.4"/> for differences <pause dur="0.3"/> in the minor histocompatibility antigens <pause dur="0.3"/> you still get rejection it still occurs <pause dur="0.5"/> but <pause dur="0.2"/> as <pause dur="0.8"/> the minor implies <pause dur="0.6"/> # the rejection is less severe <pause dur="0.7"/> and rather slower <pause dur="0.2"/> but <pause dur="0.3"/> nonetheless quite short <pause dur="5.5"/><kinesic desc="changes slide" iterated="n"/> now <pause dur="0.8"/> just very briefly <pause dur="0.8"/><vocal desc="clears throat" iterated="n"/> when we take <pause dur="0.2"/> two individuals from a population if we ask the question can we match <pause dur="0.5"/>

absolutely <pause dur="0.5"/> # tissues from those two individuals taken at random they're not <pause dur="0.4"/> twins <pause dur="0.4"/> two individuals taken at random <pause dur="0.4"/> and the answer is that total matching of tissues <pause dur="0.4"/> is in fact completely impossible <pause dur="1.8"/> for two reasons one is <pause dur="0.2"/> i hope you recollect that the H-L-A system is extremely polymorphic <pause dur="0.4"/> what that means <pause dur="0.3"/> is that there are many alleles dozens of alleles <pause dur="0.3"/> at any one locus and they are <pause dur="0.5"/> not randomly distributed amongst the population <pause dur="0.4"/> but <trunc>m</trunc> <pause dur="0.2"/> # <pause dur="0.2"/> fairly randomly distributed amongst the population <pause dur="0.6"/> okay <pause dur="0.6"/> and there are <pause dur="0.2"/> six <trunc>ma</trunc> six major loci <pause dur="0.3"/> on each chromosome <pause dur="0.9"/> and there are two <pause dur="0.3"/> chromosomes <pause dur="0.3"/> so an in any in any individual <pause dur="0.4"/> there's going to be twelve loci <pause dur="0.3"/> with dozens of alleles at each <trunc>loc</trunc> locus <pause dur="0.3"/> so you can quickly imagine <pause dur="0.3"/> that the probability of finding

two identical individuals is going to be very small indeed <pause dur="1.2"/> # i won't <pause dur="0.4"/> well i will remind you class one and class two A B C D-R D-P D-Q <pause dur="1.8"/> all right <pause dur="0.3"/> now even supposing by chance you're lucky enough to match all the majors <pause dur="0.5"/> the probability of matching all the minors <pause dur="1.1"/> is nil <pause dur="0.4"/> because a minor antigen essentially <pause dur="0.6"/> is <pause dur="0.3"/> the product <pause dur="0.3"/> of any gene <pause dur="0.5"/> for which you have <pause dur="0.6"/> different alleles <pause dur="0.4"/> okay now when you think about the <trunc>n</trunc> <pause dur="0.3"/> the way <pause dur="0.3"/> genetics works <pause dur="0.3"/> it's going to be impossible to find two individuals that have no allelic differences at all <pause dur="0.2"/> except twins <pause dur="0.9"/> okay <pause dur="0.2"/> so total matching is impossible <pause dur="1.0"/> so that is why in transplantation <pause dur="0.5"/> you have to have <pause dur="0.5"/> immunosuppression <pause dur="0.8"/> okay <pause dur="0.4"/> we'll make a short break there # if you want to nip out and get a cup of coffee <pause dur="0.4"/> i will restart in ten minutes <pause dur="1.2"/> okay </u><gap reason="break in recording" extent="uncertain"/> <u who="nm0260" trans="pause">

can we settle down <pause dur="7.6"/> as i was saying at the end of the <pause dur="0.5"/> previous <pause dur="0.4"/> hour <pause dur="0.4"/> tissue matching total tissue matching is obviously impossible <pause dur="0.6"/> # for the reasons i've given you <pause dur="1.5"/><kinesic desc="changes slide" iterated="n"/> that doesn't mean to say that <pause dur="0.5"/> partial matching is not <trunc>impo</trunc> not <pause dur="0.3"/> is not possible <pause dur="0.4"/> # <pause dur="0.2"/> there's a couple of phenomena <pause dur="0.3"/> which make partial matching <pause dur="0.2"/> quite possible <pause dur="0.5"/> one is the the phenomenon of linkage disequilibrium <pause dur="0.5"/> what that means is that <trunc>s</trunc> # within a population <pause dur="0.3"/> some sets of alleles tend to stick together <pause dur="0.4"/> okay <pause dur="0.3"/> and occur <pause dur="0.2"/> at a higher frequency than others <pause dur="0.4"/> what i mean by the term of haplotype i think you'll probably <pause dur="0.5"/> intuitively understand <pause dur="0.3"/> is you have a series of loci <pause dur="0.4"/> along a chromosome <pause dur="0.4"/> linked along a chromosome <pause dur="0.3"/> then a haplotype <pause dur="0.6"/> is a set of alleles <pause dur="0.5"/> on along those particular <pause dur="0.5"/> along that <pause dur="0.3"/> along those <trunc>p</trunc> of those particular loci and we'll talk about haplotypes <pause dur="0.3"/> # with <gap reason="name" extent="1 word"/> next <trunc>t</trunc> on on Thursday <pause dur="1.8"/> so <pause dur="0.2"/> linkage <trunc>diseq</trunc> equilibrium

ensures that some <pause dur="0.6"/> haplotypes are more common than others <pause dur="0.7"/> okay so the chance of getting a set <pause dur="0.9"/> of <pause dur="0.3"/> histocompatibility antigens together in two individuals is rather better <pause dur="0.3"/> than <trunc>y</trunc> than you'd expect if there really was <pause dur="0.3"/> random segregation now you remember that Mendel said that traits <pause dur="0.3"/> are randomly segregated that's not true as you know they are linked <pause dur="0.4"/> and so what we're talking about is linkage keeping together <pause dur="0.3"/> a chunk of the chromosome <pause dur="0.3"/> so that the chances of having a set of <pause dur="0.6"/> alleles together is <pause dur="0.3"/> actually much higher than you'd expect by chance <pause dur="3.5"/><kinesic desc="changes slide" iterated="n"/> the second point that matters <pause dur="0.2"/> that's important is although i said there are six loci <pause dur="0.4"/> # <pause dur="0.5"/> some H-L-A antigens <pause dur="0.3"/> i'm talking exclusively about humans of course that's why i use the terminology H-L-A and not M-H-C <pause dur="0.8"/> okay <pause dur="0.2"/> some H-L-A antigens seem to matter much more <pause dur="0.4"/> in transplantation <pause dur="0.3"/> in particular it seems that the D-R <pause dur="0.4"/> of class two is very important <pause dur="0.6"/> and A and B of

class one <pause dur="0.3"/> is also very important <pause dur="0.3"/> implying that D-P and D-Q <pause dur="0.4"/> and C don't matter so much which it seems to be the case <pause dur="2.2"/> now another point <pause dur="0.5"/> # which <pause dur="0.2"/> course you'll immediately understand <pause dur="0.4"/> is that if you're working with live related donors <pause dur="0.6"/> # <pause dur="1.2"/> those individuals will have at least one haplotype in common <pause dur="1.9"/> # # # perhaps i should be a little bit careful what i say here but there's been one or two unfortunate <pause dur="0.2"/> situations <pause dur="0.5"/> where fathers and children are found not to be related <pause dur="0.3"/> and that's always very embarrassing <pause dur="0.4"/> for the transplant physician to explain <pause dur="3.1"/> the important <pause dur="0.3"/> essential thing is that <pause dur="0.5"/> if we can partially match <pause dur="1.5"/> and that does actually improve graft survival <pause dur="0.2"/> again <gap reason="name" extent="1 word"/> will talk about this on Thursday <pause dur="1.0"/> many other factors matter <pause dur="0.4"/> <trunc>a</trunc> as well <pause dur="0.4"/> <trunc>m</trunc> some factors perhaps matter more <pause dur="0.5"/> # than matching but matching is not unimportant so that <pause dur="0.3"/> is <pause dur="0.3"/> an end an aim <pause dur="1.0"/><kinesic desc="changes slide" iterated="n"/> now how is it done <pause dur="1.2"/> how do you tissue match <pause dur="0.4"/> the old-fashioned way <pause dur="0.3"/> is to use

antibodies specific for particular <pause dur="0.3"/> H-L-A types <pause dur="0.7"/> in much the same sort of way as in the crossmatch test <pause dur="0.4"/> if you have an antibody say to <pause dur="0.5"/> H-L-A <pause dur="0.3"/> B-twenty-seven <pause dur="0.8"/> and that will lyse the target cells from the donor <pause dur="0.3"/> then those target cells must be H-L-A B-twenty-seven <pause dur="0.6"/> so there's a simple <pause dur="0.6"/> serological test <pause dur="0.3"/> the disadvantage of serological tests <pause dur="0.4"/> comes from the very polymorphism <pause dur="0.3"/> that they use to detect <pause dur="0.3"/> there are so many <pause dur="0.4"/> different possible <trunc>t</trunc> antigenic types <pause dur="0.3"/> that you have to have very large batteries <pause dur="0.5"/> of <pause dur="0.4"/> # <pause dur="0.4"/> antibodies <pause dur="1.2"/> and a worse problem <pause dur="0.4"/> is that antibodies <pause dur="0.4"/> do not cannot distinguish between some closely related <pause dur="0.4"/> allelic types <pause dur="0.2"/> okay <pause dur="0.3"/> so you have an antibody that says two types are the same <pause dur="0.3"/> whereas in fact they're different <pause dur="1.0"/> <trunc>w</trunc> don't want to go into that in any detail but <pause dur="0.5"/> because <pause dur="0.3"/> # <pause dur="1.6"/> what happens what happens now <pause dur="0.4"/> is that P-C-R techniques are used for typing <pause dur="1.2"/> # <pause dur="0.3"/> using allele specific primers okay <pause dur="0.3"/> so that primer <pause dur="0.3"/> will only prime that particular allele <pause dur="0.5"/> so you can only detect that

particular <trunc>a</trunc> allele <pause dur="0.5"/> and you set up the reactions <pause dur="0.4"/> in a multiplex fashion <pause dur="0.3"/> so you can use use multiple primers in the same reaction <pause dur="0.4"/> and run just one track <pause dur="0.2"/> on a gel and you see <pause dur="0.3"/> various bands depending on which one <pause dur="0.4"/> is is there which <pause dur="0.4"/> haplotype which which antigenic type is there <pause dur="0.6"/> and of course if you run multiplex reactions <pause dur="0.3"/> # and multiple gel tracks <pause dur="0.4"/> you can very easily and quickly <pause dur="0.3"/> analyse dozens <pause dur="0.4"/> of different H-L-A types <pause dur="0.2"/> in the same <pause dur="0.6"/> in in the same # <pause dur="0.2"/> test <pause dur="0.8"/> so it's done by multiplex <pause dur="0.3"/> P-C-R <pause dur="0.3"/> which with <pause dur="0.2"/> which now makes <pause dur="0.4"/> # antibody typing <pause dur="0.2"/> quite obsolete <pause dur="2.1"/><kinesic desc="changes slide" iterated="n"/> okay <pause dur="0.8"/> so there we are <pause dur="0.3"/> we match as closely as possible <pause dur="3.0"/> # but we can never completely match so let's go on now and talk about how the immune system actually does recognize the foreign tissue <pause dur="0.7"/> # this is where we perhaps get into slightly heavy immunology <pause dur="2.7"/> i hope that you <trunc>recogni</trunc> <trunc>r</trunc> remember recollect the classical paradigm of T-cell recognition of antigen <pause dur="0.6"/> okay <pause dur="0.4"/> cast

your mind back to the second year immunology lectures <pause dur="0.4"/> where you were taught <pause dur="0.3"/> that the T-cell receptor for antigen <pause dur="1.2"/> recognizes on the surface of the target cell <pause dur="0.3"/> or the antigen presenting cell call it what you will <pause dur="0.6"/> not <pause dur="0.2"/> the antigen <pause dur="0.5"/> not the foreign antigen i should say <pause dur="0.4"/> but a fragment <pause dur="0.4"/> of the <trunc>pep</trunc> of the foreign antigen a peptide fragment of the foreign antigen <pause dur="0.4"/> in association with <pause dur="0.2"/> the H-L-A antigen <pause dur="1.1"/> and the essential point with that <pause dur="0.4"/> is that the T-cell will only recognize <pause dur="0.5"/> the foreign peptide in association <pause dur="0.3"/> with self <pause dur="0.2"/> H-L-A <pause dur="0.5"/> this is the phenomenon <pause dur="0.3"/> of H-L-A restriction <pause dur="0.4"/> that the T-cell will only recognize <pause dur="0.2"/> foreign antigenic peptides <pause dur="0.4"/> in the context of its own <pause dur="0.4"/> H-L-A <pause dur="0.8"/> own H-L-A <pause dur="2.0"/> self H-L-A <pause dur="2.1"/> that's what happens for example in virus infections <pause dur="0.8"/> now <pause dur="0.7"/> in transplantation <pause dur="2.1"/> there's a rather different situation <pause dur="0.3"/> and on the face of it <pause dur="0.3"/> it <pause dur="0.2"/> contradicts this paradigm <pause dur="0.5"/> because what is being recognized and this is very well established <pause dur="0.5"/> is not <pause dur="0.3"/> self <pause dur="0.5"/> plus <pause dur="0.3"/> foreign peptide but instead <pause dur="0.4"/> is <pause dur="0.5"/> the

foreign <pause dur="0.8"/> M-H-C antigen itself the foreign H-L-A itself which is recognized by the T-cell <pause dur="1.4"/> so this is different from the classical paradigm of <pause dur="0.2"/> antigenic recognition by T-cells <pause dur="2.1"/> okay <pause dur="0.8"/> now <pause dur="0.7"/><kinesic desc="changes slide" iterated="n"/> i know i talked about this a little bit <pause dur="2.2"/> in the second year <pause dur="2.8"/> we distinguished <pause dur="0.4"/> <trunc>t</trunc> actually <pause dur="0.2"/> two forms <pause dur="0.5"/> of <pause dur="0.2"/> antigenic recognition and transplantation <pause dur="0.3"/> one is so-called <pause dur="0.2"/> direct recognition <pause dur="1.3"/> where what is happening is what i've just said <pause dur="0.5"/> is if the host and the donor differ in H-L-A <pause dur="0.5"/> and that the T-C-R <pause dur="0.3"/> of the T-cell T-cell receptor recollect <pause dur="0.4"/> of the T-cell <pause dur="0.4"/> is binding to the foreign H-L-A <pause dur="0.3"/><kinesic desc="changes slide" iterated="n"/> now i showed you this diagram and i probably didn't explain it very well <pause dur="2.3"/> but this is the classical situation <pause dur="1.3"/> with viral antigens <pause dur="0.4"/> this is the T-cell receptor of the T-cell <pause dur="0.7"/> this <pause dur="0.6"/> is the <pause dur="0.2"/> is the self <pause dur="0.7"/> H-L-A antigen <pause dur="0.3"/> with which is associated <pause dur="0.2"/> a peptide a foreign peptide <pause dur="0.4"/> and these <pause dur="0.4"/> double <pause dur="0.3"/> lines <pause dur="0.4"/> are supposed to imply <pause dur="0.6"/> recognition <pause dur="0.8"/> by the T-cell receptor <pause dur="0.2"/> of <pause dur="0.3"/>

this target structure <pause dur="0.6"/> okay <pause dur="0.3"/> so that's what normally happens that's what the T-cell receptor's for <pause dur="0.8"/> now what we are saying <pause dur="1.1"/> is <pause dur="0.2"/> where we have <pause dur="0.5"/> # <pause dur="0.2"/> foreign H-L-A being recognized <pause dur="0.9"/> essentially this same T-cell receptor <pause dur="1.1"/> is cross-reacting <pause dur="1.1"/> remember <pause dur="0.4"/> antigenic cross-reaction <pause dur="0.6"/> this is an equivalent situation <pause dur="0.5"/> it's cross-reacting <pause dur="0.5"/> with the foreign H-L-A which as you can see has a different shape <pause dur="0.5"/> from the safe <trunc>s</trunc> self H-L-A <pause dur="1.2"/> in conjunction with <pause dur="0.2"/> a different peptide <pause dur="0.6"/> but the point is by chance <pause dur="0.5"/> these two structures are similar <pause dur="0.5"/> by chance <pause dur="0.3"/> so that the same T-cell receptor recognizes both <pause dur="2.9"/> and that is the basis <pause dur="0.4"/> of so-called <pause dur="0.4"/> allorecognition <pause dur="0.4"/> of foreign H-L-A <pause dur="2.2"/> so that's direct recognition direct <pause dur="0.4"/> because it's the H-L-A <pause dur="0.8"/> which is being recognized <pause dur="3.0"/> should say in passing <pause dur="0.3"/> that H-L-A antigens <pause dur="0.4"/> on the cell surface are never empty <pause dur="0.5"/> they always have a peptide associated with them <pause dur="0.8"/> okay <pause dur="0.2"/> so again the structure is <pause dur="0.2"/> always peptide plus <pause dur="0.3"/> H-L-A <pause dur="0.7"/> 'cause you never get empty H-L-A on cell surface <pause dur="0.5"/> so it's a

rather complicated situation <pause dur="0.3"/> but there is good experimental evidence plenty of good experimental evidence <pause dur="0.4"/> that this actually is what's going on and i don't want to go into the experimental evidence because it really is too complicated <pause dur="0.9"/> don't have time <pause dur="3.2"/><kinesic desc="changes slide" iterated="n"/> now <pause dur="2.2"/> having said that there's direct recognition <pause dur="1.7"/> that implies also that there is indirect recognition <pause dur="1.7"/> now this indirect recognition <pause dur="0.4"/> is much more like <pause dur="0.3"/><vocal desc="clears throat" iterated="n"/> the classical paradigm <pause dur="0.3"/> of self H-L-A plus foreign peptide <pause dur="0.8"/> 'cause the situation here <pause dur="0.6"/> is where the host <pause dur="0.3"/> and the donor <pause dur="0.5"/> have at least one matched H-L-A antigen <pause dur="0.7"/> okay now i've been saying <pause dur="0.3"/> that you make an effort to match H-L-A antigens for a transplant <pause dur="0.6"/> so normally <pause dur="0.5"/> you transplant there will be matched <pause dur="0.4"/> H-L-A antigens between donor <pause dur="0.5"/> and recipient <pause dur="0.6"/> now the matched H-L-A antigen <pause dur="0.9"/> will be seen as self <pause dur="1.0"/> by the host T-cell receptors <pause dur="0.9"/> okay <pause dur="1.7"/> and <pause dur="0.4"/> if <pause dur="0.4"/> you have <pause dur="0.4"/> shall we say a foreign peptide <pause dur="0.9"/> in

the H-L-A groove in the peptide groove <pause dur="0.3"/> that complex <pause dur="0.2"/> of foreign peptide <pause dur="0.5"/> plus matched H-L-A <pause dur="0.5"/> in effect <pause dur="0.7"/> is equivalent to a say a virus peptide <pause dur="0.3"/> and self H-L-A <pause dur="0.3"/> and potentially will activate the T-cell <pause dur="0.7"/> now this <pause dur="0.3"/> is exactly the same situation as with virus recognition <pause dur="0.2"/> exactly the same <pause dur="2.0"/> the question that arises <pause dur="0.3"/> is <pause dur="0.2"/> where then does the foreign <pause dur="0.2"/> peptide come from <pause dur="1.5"/> okay <pause dur="1.7"/> to sit in the peptide groove <pause dur="0.3"/> of the matched H-L-A <pause dur="1.0"/> where does that foreign peptide come from <pause dur="2.0"/> and the answer is <pause dur="0.3"/> that it is <pause dur="0.5"/> potentially derived from any <pause dur="0.6"/> alloantigen <pause dur="1.4"/> in the donor cell <pause dur="1.2"/> now i've talked about minor antigens remember <pause dur="1.5"/> so if the minor antigen <pause dur="0.3"/> provides a peptide which can associate <pause dur="0.3"/> with the matched H-L-A <pause dur="0.4"/> that <pause dur="0.3"/> can drive the T-cell response in exactly the same way <pause dur="0.3"/> as a viral antigen will there's no difference <pause dur="0.6"/> so the indirect recognition pathway <pause dur="0.3"/> is actually equivalent <pause dur="0.3"/> to the classical <pause dur="0.8"/> virus <pause dur="0.2"/> peptide <pause dur="0.4"/> activation pathway <pause dur="0.3"/> so it's <pause dur="0.3"/> that's the simple one <pause dur="0.4"/> the complex one is the direct because you

have to think about <pause dur="0.4"/> # cross-reaction <pause dur="0.8"/> okay so i say the foreign peptide can be derived from any alloantigen <pause dur="0.3"/> i've said minor <pause dur="0.2"/> antigens or i'll <pause dur="0.2"/> mention a a minor antigen in a moment <pause dur="0.8"/> but obviously <pause dur="0.9"/> peptides derive from mismatched <pause dur="0.6"/> H-L-A antigens in the donor tissue <pause dur="0.3"/> could also provide <pause dur="0.6"/> # peptides <pause dur="0.4"/> which would function in this way <pause dur="0.9"/> okay <pause dur="1.0"/> so we have direct recognition <pause dur="0.3"/> and indirect recognition two different pathways <pause dur="0.4"/> of T-cell activation <pause dur="0.3"/> which <pause dur="0.5"/> essentially amount to the same end result which is activation of the T-cell and damage to the tissues <pause dur="1.9"/> i won't show you that again <pause dur="2.2"/><kinesic desc="changes slide" iterated="n"/> but i will give you an example of a minor antigen <pause dur="0.7"/> now <pause dur="1.5"/> again <pause dur="0.4"/> from your genetics you know that a major genetic difference between males and females <pause dur="0.4"/> is that males in addition to the X chromosome possess a Y chromosome <pause dur="0.6"/> now Y <trunc>chro</trunc> chromosomes don't <pause dur="0.7"/> don't encode very much <pause dur="0.5"/> they encode maleness <pause dur="0.7"/> they do encode <pause dur="0.4"/> what's called the male specific antigen <pause dur="0.9"/>

okay which is not surprising isn't it <pause dur="0.3"/> the <trunc>H</trunc> the Y chromosome is going to have <pause dur="0.5"/> <trunc>pro</trunc> <pause dur="0.2"/> going to encode proteins <pause dur="0.2"/> which are not present in the female <pause dur="0.4"/> so you've got <trunc>w</trunc> male specific antigen which <pause dur="0.4"/> # is called the H-<pause dur="0.2"/>Y <pause dur="0.3"/> antigen <pause dur="0.4"/> H for histocompatibility <pause dur="0.3"/> Y for the Y chromosome <pause dur="0.5"/> encoded by the Y chromosome <pause dur="0.4"/> it's expressed in all male tissues <pause dur="1.7"/> so you your kidney your liver <pause dur="0.2"/> or my kidney my liver <pause dur="0.3"/> # bear Y <pause dur="0.7"/> antigen <pause dur="1.9"/> and fragments <pause dur="0.2"/> of that Y antigen <pause dur="0.4"/> can be presented by H-L-A A-one <pause dur="0.5"/> or B-seven <pause dur="0.4"/> or B-eight <pause dur="1.3"/> what does that point-two mean i can't remember <pause dur="0.9"/> what i mean by that is obviously different # <pause dur="0.2"/> one fragment is presented by H-L-A A-one <pause dur="0.3"/> which is a particular <pause dur="0.3"/> H-L-A A type <pause dur="0.4"/> another fragment of the H-Y antigen <pause dur="0.3"/> is presented by B-seven <pause dur="0.3"/> another <trunc>fractio</trunc> fragment of the Y antigen is presented by B-eight <pause dur="0.9"/> so <pause dur="0.7"/> what happens <pause dur="0.3"/> when you transplant male tissues into a female <pause dur="0.7"/> these H-Y antigens <pause dur="0.3"/> will activate <pause dur="0.4"/> T-cell responses in the female <pause dur="2.2"/> okay <pause dur="1.3"/> and you can demonstrate these T-cell responses <pause dur="3.3"/> get a

C-D-eight T-cell responses to the female <pause dur="0.7"/> to the male tissue <pause dur="0.2"/> to the male tissue <pause dur="0.4"/> in the female <pause dur="2.3"/> again for reasons that i'm not going to go into at the present but <trunc>b</trunc> that <gap reason="name" extent="1 word"/> will go into <pause dur="0.4"/> # that actually doesn't <shift feature="voice" new="laugh"/>matter <shift feature="voice" new="normal"/>terribly much <pause dur="0.4"/> so when you have the choice of a if you're a a woman <pause dur="0.3"/> and you have the choice of a male <pause dur="0.3"/> or a female kidney it actually doesn't matter <pause dur="1.1"/> but in bone marrow transplantation it does <pause dur="0.6"/> 'cause bone marrow transplantation <pause dur="0.4"/> the matching actually is much more critical <pause dur="0.7"/> and it is clear <pause dur="0.4"/> that if you have <pause dur="0.3"/> Y or other minor antigen mismatches <pause dur="0.4"/> in bone marrow transplantations <pause dur="0.3"/> that can cause <pause dur="0.2"/> distinct problems immunological problems <pause dur="0.3"/> but in solid organ transplantation it doesn't really matter <pause dur="2.3"/> as things are clinically i should say <pause dur="1.5"/><kinesic desc="changes slide" iterated="n"/> but the point that i want to make there <pause dur="1.2"/> that i'm leading up to <pause dur="0.6"/> is that you have a <pause dur="0.5"/> in <trunc>tran</trunc> tissue matching <pause dur="0.3"/> there is <pause dur="0.3"/> not not so much <pause dur="0.3"/> a double whammy as the catch-twenty-two situation <pause dur="0.6"/> if you match <pause dur="0.4"/>

H-L-A <pause dur="0.8"/> completely which is not impossible but unlikely <pause dur="0.7"/> # there'll be no direct recognition <pause dur="1.0"/> 'cause the H-L-As are all the same <pause dur="1.8"/> but there will still be indirect recognition <pause dur="0.6"/> of minor antigens <pause dur="2.5"/> on the other hand <pause dur="0.5"/> if you <pause dur="0.3"/> completely mismatch so there are no shared H-L-A antigens <pause dur="0.6"/> there'll be no <sic corr="indirect recognition">indirecognition</sic> because there'll be no <pause dur="0.4"/> inverted commas self H-L-A to present <pause dur="0.3"/> the peptides <pause dur="0.3"/> but there will be massive direct <trunc>rejec</trunc> # recognition <pause dur="0.9"/> okay <pause dur="0.3"/> so <pause dur="0.2"/> this just is to reinforce give you a bit of background <pause dur="0.3"/> to the science of immunology of transplantation <pause dur="0.4"/> a bit of background to why <pause dur="0.4"/> how it <pause dur="0.3"/> what are the causes for rejection <pause dur="0.6"/> and lead me <pause dur="0.3"/> to this point <pause dur="0.6"/> that under any circumstances <pause dur="0.4"/> immunosuppression <pause dur="0.5"/> is going to be always necessary to suppress <pause dur="0.5"/> the immune responses <pause dur="0.3"/> which are inevitably going to arise to the transplanted tissue <pause dur="3.9"/><kinesic desc="changes slide" iterated="n"/> so that logically brings me on to the next section <pause dur="0.3"/> which is <pause dur="0.7"/> how does

immunosuppressive therapy work <pause dur="3.0"/><kinesic desc="changes slide" iterated="n"/> quite simply immunosuppression is the use of drugs <pause dur="0.5"/> to prevent the development of the immune response <pause dur="0.4"/> obviously these drugs <pause dur="0.4"/> had to be chosen so that they're not too toxic so they don't damage the individual too much which they do they have side effects <pause dur="0.4"/> but they suppress immune responses <pause dur="0.3"/> so that you do not <pause dur="0.2"/> reject the tissue <pause dur="0.7"/> okay <pause dur="3.2"/><kinesic desc="changes slide" iterated="n"/> there's actually lots and lots and lots of immunosuppressive drugs available now many many many <pause dur="0.2"/> # dozens <pause dur="0.4"/> some are fantastically expensive <pause dur="0.5"/> # <pause dur="0.5"/> none is completely effective <pause dur="1.9"/> all have more or less severe side effects some less severe some very <pause dur="1.3"/> some essentially trivial some really unpleasant <pause dur="0.9"/> and <pause dur="1.5"/> the worst thing about them <pause dur="1.0"/> is that all of them are non-specific by non-specific i mean they suppress all immune responses <pause dur="0.3"/> not just the immune response of the grafted tissue which is what you want <pause dur="0.4"/> you don't want to suppress immune response to other things <pause dur="0.4"/> obviously <pause dur="0.6"/> so none of

these drugs is ideal <pause dur="1.9"/><kinesic desc="changes slide" iterated="n"/> and just very quickly <pause dur="0.4"/> # we talk about first line drugs now first line drugs <pause dur="0.4"/> are those that are <pause dur="0.3"/> the first choice of drugs in clinical treatment <pause dur="0.6"/> and there are three types of drugs which are in in <pause dur="0.2"/> common use <pause dur="0.7"/> # you'll get a bit more <trunc>fr</trunc> about this from <gap reason="name" extent="1 word"/> and there's plenty to read about about these drugs <pause dur="0.4"/> there are the so-called calcineurin inhibitors <pause dur="0.4"/> what these do is intervere <pause dur="0.3"/> interfere <pause dur="0.5"/> with the activation of the I-L-two gene <pause dur="0.6"/> okay <pause dur="0.4"/> so I-L-two gene I-L-two production <pause dur="0.4"/> is blocked <pause dur="1.3"/> okay <pause dur="0.8"/> remember I-L-two <pause dur="0.3"/> is an essential T-cell <pause dur="0.4"/> factor T-cell growth factor <pause dur="0.3"/> so in the absence of I-L-two T-cells will not proliferate <pause dur="0.3"/> so that's why the calcineurin inhibitors <pause dur="0.4"/> are good <pause dur="0.2"/> immunosuppressive drugs they prevent T-cell proliferation <pause dur="1.1"/> the second class <pause dur="1.4"/> are the steroids things like prednisolone <pause dur="0.4"/> # which <pause dur="0.9"/> fairly broadly suppress production of a range of cytokines now you remember the importance of cytokines in immune responses <pause dur="0.6"/> so if you've suppressed cytokine production

you're going to generally <pause dur="0.4"/> depress <pause dur="0.3"/> # inflammatory responses across the board immune responses across the board <pause dur="0.4"/> so steroids are often used or are used they're a front line drug <pause dur="0.4"/> first line drug <pause dur="0.9"/> and then the third class <pause dur="0.4"/> are inhibitors of D-N-A synthesis <pause dur="0.4"/> which <pause dur="0.6"/> block cell proliferation in a non-specific way <pause dur="0.5"/> now remember <pause dur="0.3"/> in an immune response <pause dur="0.3"/> a major part of the immune response the development of the immune response is clonal <pause dur="0.5"/> proliferation <pause dur="0.3"/> clonal expansion <pause dur="0.3"/> so if you have drugs which prevent cell proliferation you'll block clonal <pause dur="0.5"/> expansion <pause dur="0.5"/> so <pause dur="0.3"/> these three classes of drugs <pause dur="1.1"/><kinesic desc="changes slide" iterated="n"/> ah <pause dur="0.4"/> other drugs <pause dur="1.1"/> that are also used <pause dur="0.5"/> tend to be <pause dur="0.8"/> the expensive drugs which are good drugs very effective drugs <pause dur="0.3"/> but they're so expensive <pause dur="0.5"/> # that they're only used <pause dur="0.2"/> if the other drugs aren't working <pause dur="0.8"/> okay <pause dur="0.3"/> and they tend to be used transiently <pause dur="0.4"/> examples of those are antibodies to T-cells <pause dur="0.4"/> you imagine perfectly well <pause dur="0.3"/> if you treat an individual with antibody to C-D-three antigen <pause dur="0.4"/> that will lyse with complement <pause dur="0.2"/> all the T-cells <pause dur="0.5"/>

so this <pause dur="0.2"/> anti-C-D-three <pause dur="0.3"/> or for that matter I-L-two-R <pause dur="0.6"/> is going to be a very potent immunosuppressive drug <pause dur="0.5"/> but it's so expensive <pause dur="0.6"/> # monoclonal antibodies <pause dur="0.6"/> # cost <pause dur="0.2"/> if we have to use them in gram quantities and in gram quantities they are very expensive <pause dur="0.6"/> and there's more drugs <pause dur="0.4"/> which are coming into clinical practice now <pause dur="0.4"/> rapamycin looks like a favourite <pause dur="0.6"/> which seems to be another inhibitor of self-proliferation <pause dur="0.4"/> and this one works by blocking growth factor <pause dur="0.5"/> # signalling within the cell <pause dur="0.8"/> okay <pause dur="0.3"/> so these are second line drugs <pause dur="2.4"/><kinesic desc="changes slide" iterated="n"/> how are they used <pause dur="1.0"/> now the general principi for many kinds of chemotherapy for all sorts of disease now <pause dur="0.4"/> is to use combinations of drugs not one drug alone <pause dur="0.4"/> but two or three or four or five drugs together <pause dur="1.3"/> it's found that these tend to be more effective the combinations are more effective than single drugs <pause dur="0.2"/> now let's for example suppose that drug A <pause dur="0.4"/> inhibits ninety per cent of the immune response drug B

ditto drug C ditto <pause dur="0.6"/> supposing that these three drugs work in different ways <pause dur="0.4"/> you might expect that the combination <pause dur="0.3"/> will inhibit ninety-nine-point-nine per cent of the immune reponse <pause dur="0.5"/> okay <pause dur="0.5"/> which is much better <pause dur="0.4"/> so they're used in combination <pause dur="0.7"/> and it's also found <pause dur="0.4"/> # that using them in combination <pause dur="0.3"/> you can actually <pause dur="0.3"/> reduce the doses that are used <pause dur="0.4"/> and that reduces the <trunc>s</trunc> undesirable side effects of the drugs which i'll come on to <pause dur="0.5"/> so actually <pause dur="0.3"/> this <trunc>a</trunc> <pause dur="0.2"/> tells us # <pause dur="1.5"/> some important things about drug therapy generally in medicine <pause dur="0.3"/> and i can mention drug therapy for cancer for example <pause dur="0.4"/> drug therapy for H-I-V infections <pause dur="0.6"/> the tendency is to use multiple drugs because in combination <pause dur="0.3"/> they're more effective than the single drugs alone <pause dur="0.4"/> perhaps it's not so surprising <pause dur="1.9"/> now initially <pause dur="0.7"/> the drugs are used in high concentrations high doses <pause dur="0.5"/> # # # and this is because <pause dur="0.3"/> when the patient has just been transplanted <pause dur="0.4"/> obviously that's a situation <pause dur="0.3"/> where the immune system of the patient <pause dur="0.3"/> is getting

this tremendous jolt half a kilo or so <pause dur="0.3"/> of foreign tissue being put in <pause dur="0.5"/> and so you get tremendous activation potentially <pause dur="0.5"/> of the immune response so that's the point <pause dur="0.4"/> where you the <trunc>s</trunc> physicians come in with very large amounts of these drugs <pause dur="0.3"/> in order to suppress <pause dur="0.5"/> the very strong immune response <pause dur="0.5"/> which will occur <pause dur="0.6"/> initially <pause dur="1.5"/> the happy thing is that in fact <pause dur="0.5"/> the drug doses can be tapered down and this tells us actually something quite important <pause dur="0.6"/> you can reduce over a period of months the amount of drugs that are used <pause dur="0.5"/> and this is telling us that in fact <pause dur="0.4"/> that the patient is becoming acclimatized if you like become adapted to the graft <pause dur="1.2"/> okay getting used to the graft immunologically speaking that's an important observation <pause dur="2.1"/> it's never reduce to zero because generally if the drugs are abandoned then the tissue the the organ is rejected so you # is what it means is that <pause dur="0.5"/> the patients who have transplants <pause dur="1.5"/> are going to be treated by <trunc>im</trunc> with

immunosuppression forever <pause dur="0.8"/> or <unclear>well the</unclear> <pause dur="0.2"/> continue the rest the rest of the their life or at least the rest of the <pause dur="0.7"/> graft's life <pause dur="3.7"/> now i've mentioned <pause dur="0.9"/> this issue of acute rejection one wants to minimize acute rejection <pause dur="0.4"/> so as soon as patients start to show symptoms of acute rejection <pause dur="0.4"/> the dosage <pause dur="0.5"/> of the drugs is increased <pause dur="0.6"/> and if that doesn't work to prevent the rejection <pause dur="0.3"/> then the second line drugs like anti-C-D-three <pause dur="0.3"/> are used as well <pause dur="1.0"/> so the acute rejection is a sort of emergency situation <pause dur="0.6"/> where the drug dosages are put up <pause dur="0.6"/> in an attempt to prevent rejection <pause dur="2.1"/> and the fact is that the physicians have got so used to using these drugs and so accustomed to their patients <pause dur="0.5"/> that in fact <pause dur="0.2"/> # <pause dur="0.6"/> acute rejection is now quite rare # i can't remember the figures but <pause dur="0.3"/> the actual so-called episodes <pause dur="0.3"/> where acute rejection occurs <pause dur="0.3"/> when i say acute rejection i don't mean that the tissue is lost i mean that symptoms of <trunc>r</trunc> rejection <pause dur="0.2"/> develop <pause dur="0.4"/> which have to be treated <pause dur="0.3"/> successful treatment of course prevents

the acute rejection so you don't lose the tissue <pause dur="0.6"/> must make that clear <pause dur="1.1"/> # and the physicians <pause dur="0.4"/> have got this so well under control that graft loss <pause dur="0.5"/> to acute rejection almost never happens now it's very rare <pause dur="0.5"/> well not very rare but it's it's rare <pause dur="6.3"/><kinesic desc="changes slide" iterated="n"/> okay <pause dur="0.4"/> so that summarizes these points really <pause dur="1.7"/> in the absence of immunosuppression grafts are <pause dur="0.3"/> inevitably rejected <pause dur="1.3"/> acute rejection occurs <pause dur="0.9"/> after a delay i suppose because in the presence of immunosuppression it takes a long time <pause dur="0.4"/> for the immune responses to develop <pause dur="0.4"/> something that <trunc>w</trunc> should normally take a few days <pause dur="0.3"/> takes a few weeks because you're reducing the proliferation of the cells <pause dur="2.7"/> and that's what i'm saying in this last point that anti-graft T-cells grow more slowly under <trunc>immuno</trunc> immunosuppression <pause dur="3.8"/><kinesic desc="changes slide" iterated="n"/> now <pause dur="0.7"/> this brings us to another point i mentioned <pause dur="0.3"/> that there looks as if there's some sort of adaptive phenomenon <pause dur="0.4"/> which occurs <pause dur="0.2"/> in the patient because you can taper off the drug dosage without losing <pause dur="0.4"/> the graft <pause dur="2.2"/> studies <pause dur="0.2"/>

with mice and other rodents <pause dur="0.2"/> have shown have suggested <pause dur="0.4"/> that if you graft foreign tissues into the animal <pause dur="0.3"/> whilst that animal is strongly immunosuppressed <pause dur="0.7"/> okay <pause dur="0.4"/> you <trunc>indru</trunc> induce <pause dur="0.5"/> a condition called tolerance which <pause dur="0.5"/> i hope you're familiar with <pause dur="0.4"/> in which <pause dur="0.4"/> you do not get an immune response with the foreign <pause dur="0.3"/> antigen <pause dur="3.1"/> in that situation <pause dur="0.3"/> you can stop all <pause dur="0.2"/> the immune suppression and the graft does not reject it because the animal is tolerant <pause dur="1.6"/> okay and this has been demonstrated repeatedly in mice <pause dur="1.9"/> i will say <pause dur="0.3"/> that mouse mice are really very different from humans <pause dur="0.3"/> and you cannot transfer <pause dur="0.5"/> # experimental data from murine models <pause dur="0.3"/> directly to human <pause dur="0.4"/> so it is not the case <pause dur="0.4"/> # that <pause dur="0.3"/> tolerance <pause dur="0.2"/> is sure to arise <pause dur="0.4"/> and there are many differences again i'm not got time to go into the differences between the mouse models and the human situation but the differences <pause dur="0.4"/> are significant enough <pause dur="0.4"/> to persuade one that the two situations are not the same <pause dur="0.9"/> but still the question

arises <pause dur="0.4"/> does some sort of <pause dur="0.5"/> tolerance phenomenon <pause dur="0.3"/> arise in humans <pause dur="1.8"/> now i'm going to <pause dur="0.5"/><vocal desc="clears throat" iterated="n"/> dip into <pause dur="1.2"/><kinesic desc="changes slide" iterated="n"/> a little bit of <pause dur="0.9"/> my own research <pause dur="2.5"/><vocal desc="clears throat" iterated="n"/><pause dur="0.4"/> # which we've done <pause dur="0.3"/> here # in collaboration with the local hospitals the local transplant unit <pause dur="1.0"/> # <pause dur="1.4"/> in principle <pause dur="0.4"/> you can <pause dur="0.2"/> <trunc>d</trunc> <pause dur="0.2"/> detect <pause dur="0.3"/> the development of tolerance in <pause dur="0.2"/> transplanted humans <pause dur="0.5"/> because what you can do <pause dur="0.5"/> is measure <pause dur="0.4"/> the numbers of T-cells in the recipient <pause dur="0.6"/> who are able which are able <pause dur="0.4"/> to respond <pause dur="0.2"/> to the donor's antigens <pause dur="0.6"/> okay <pause dur="0.3"/> so if you can count the numbers of <pause dur="0.4"/> # T-cells that respond to the patient to to the donor <pause dur="0.4"/> tissues <pause dur="0.5"/> enumerate them <pause dur="0.4"/> # then <pause dur="0.3"/> if you can show <pause dur="0.4"/> that these numbers are declining with time <pause dur="0.9"/> okay <pause dur="0.3"/> you can then argue that tolerance is developing <pause dur="0.9"/> but unfortunately in experimental terms this is not an easy thing to do <pause dur="0.6"/> and i just want to give you a little bit of the technology <pause dur="0.5"/> # <trunc>c</trunc> we are talking about science after all <pause dur="0.8"/> okay <pause dur="1.2"/><kinesic desc="changes slide" iterated="n"/> the way this <pause dur="0.4"/> has

been done is by the so-called lymphocyte dilution <pause dur="0.2"/> assay <pause dur="0.7"/> lymphocyte dilution i've forgotten to write that down oh there it is lymphocyte dilution assay i'm sorry <pause dur="1.7"/> what we do here those of you that have done <pause dur="1.0"/> some tissue culture may be <pause dur="0.3"/> familiar with ninety-six well plates you will have done <pause dur="0.4"/> those that are done by others you will have used them for the <pause dur="0.3"/> for the # <pause dur="0.8"/> what's that red blood cell assay i've forgotten haemagglutination assay <pause dur="0.6"/> # so you can you take these ninety-six well plates <pause dur="0.7"/> # and you put <pause dur="0.4"/> in each well <pause dur="0.6"/> a fixed number of <pause dur="0.3"/> the cell of cells from the donor these we call the stimulator cells fixed numbers same across the plate every well gets the same number <pause dur="0.9"/> okay <pause dur="1.7"/> what you do then <pause dur="0.2"/> is titrate <pause dur="0.2"/> across the plate <pause dur="0.5"/> # successively reducing numbers <pause dur="1.1"/> of the recipient cells which we describe as the responder <pause dur="0.7"/> cells okay 'cause they're going to respond to the antigens on the donor cell <pause dur="0.5"/> and you will have noticed i've made a <pause dur="0.4"/> bog-up here of these numbers <pause dur="0.8"/> but what i'm trying to

show is <pause dur="0.2"/> doubling dilutions as you go across the plate <pause dur="1.2"/> okay <pause dur="0.6"/> now <pause dur="0.6"/> if you score <pause dur="0.4"/> some <pause dur="0.3"/> measure <pause dur="0.3"/> of T-cell activation <pause dur="0.6"/> in these wells <pause dur="0.3"/> and i should say <pause dur="0.2"/> all this particular column has got the same number of responder cells <pause dur="0.4"/> all this column have got the same number so you've got <pause dur="0.2"/> twelve sorry eight <pause dur="0.4"/> replicates <pause dur="0.8"/> for each column <pause dur="0.4"/> okay so you do this <pause dur="0.4"/> in eight replicates across the plate <pause dur="1.2"/> if <pause dur="0.5"/> the responder T-cell <pause dur="0.3"/> does in fact respond if there is a responder T-cell and it does respond <pause dur="0.4"/> then if you have some sort of readout for the response you can score <pause dur="0.4"/> the well as positive <pause dur="1.2"/> or negative <pause dur="0.7"/> okay <pause dur="0.6"/> so if you go across the plate <pause dur="0.4"/> at this very high number of responder cells <pause dur="0.5"/> all the wells <pause dur="0.2"/> show response <pause dur="0.5"/> the next <pause dur="0.2"/> all the wells show response again <pause dur="0.2"/> the next <pause dur="0.4"/> all the wells show response <pause dur="0.4"/> then <pause dur="0.5"/> you find <pause dur="0.5"/> a column on your plate <pause dur="0.3"/> where not all the wells show response okay so X is response <pause dur="0.2"/> blank is no response <pause dur="0.8"/> so along here you've got one two three four five six out of eight <pause dur="1.0"/> has my arithmetic

gone wrong again <pause dur="0.7"/> however many <pause dur="2.8"/> a number <pause dur="0.4"/> of responding wells <pause dur="0.3"/> and in this column <pause dur="0.3"/> you've got a smaller number of responding wells and in this column you've got no responding wells <pause dur="0.3"/> now what you can argue <pause dur="0.5"/> is where there's a response there's at least one <pause dur="0.8"/> responding T-cell at least one <pause dur="0.6"/> okay <pause dur="1.4"/> so <pause dur="0.4"/> by the application of simple statistical methods <pause dur="0.3"/> you can then calculate back <pause dur="1.1"/> what is the proportion <pause dur="0.3"/> of responding T-cells <pause dur="0.4"/> in the original starting population <pause dur="0.4"/> now this <pause dur="0.4"/> is <pause dur="0.5"/> a classical dilution analysis assay <pause dur="0.3"/> now you've done dilution analysis <pause dur="0.3"/> you did dilution analysis or the virologists did anyway <pause dur="0.6"/> # in your haemagglutination titrations <pause dur="0.3"/> which is exactly the same principle you dilute <pause dur="0.6"/> across a plate <pause dur="0.3"/> an indicator <pause dur="0.4"/> and you score positive or negative <pause dur="0.4"/> and then you <pause dur="0.9"/> have an end point <pause dur="0.5"/> it's exactly what we're doing here <pause dur="0.3"/> but what we're doing in essence is counting <pause dur="0.3"/> the number of responding T-cells in the patient <pause dur="0.5"/> okay <pause dur="0.6"/> and i'll <kinesic desc="changes slide" iterated="n"/> show you <pause dur="0.3"/> some

typical # <pause dur="0.3"/> data slightly difficult <pause dur="0.3"/> data to understand <pause dur="2.0"/> the <trunc>c</trunc> the rows <pause dur="0.9"/> indicate <pause dur="0.8"/> individual patients patients one to five for ethical reasons i can't tell you who they were <pause dur="2.5"/> this is the response <pause dur="0.3"/> to the donor <pause dur="0.5"/> cells as i've just described <pause dur="0.4"/> and as a control <pause dur="1.0"/> we have what we call the anti-third party response let's not worry too much about that <pause dur="0.9"/> # let's in fact leave the third party response out <pause dur="0.4"/> because what i want to concentrate on <pause dur="0.4"/> is the anti-donor response <pause dur="0.4"/> prior to transplantation <pause dur="0.3"/> and sometime post-transplantation <pause dur="0.6"/> in some patients you find that the number <pause dur="0.3"/> of responding cells <pause dur="0.4"/> declines these are cells per million <pause dur="0.4"/> C-D-three cells <pause dur="0.4"/> going down roughly tenfold there <pause dur="0.3"/> and roughly tenfold there <pause dur="1.0"/> in these other individuals they've stayed pretty much the same <pause dur="0.5"/> or gone down a little bit <pause dur="0.6"/> okay <pause dur="0.3"/> so there clearly are differences between the individual patients <pause dur="0.3"/> and in some patients the numbers of responding cells <pause dur="0.4"/> go down quite

dramatically <pause dur="0.3"/> implying some sort of tolerance <pause dur="0.5"/> and if we <pause dur="0.4"/> put together <pause dur="0.3"/><kinesic desc="changes slide" iterated="n"/> the data <pause dur="0.5"/> generally <pause dur="0.4"/> # <pause dur="1.1"/> again i don't want # haven't got the time to go into detail here <pause dur="0.4"/> but these <pause dur="0.3"/> are the responses that i've just been describing <pause dur="1.2"/> in terms of <pause dur="0.3"/> cells per million <pause dur="0.7"/> prior to the transplantation <pause dur="0.6"/> and in the same patients that's why they're joined up <pause dur="1.3"/> okay <pause dur="1.0"/> sometime after the transplantation <pause dur="0.3"/> now in <kinesic desc="indicates point on slide" iterated="n"/> these patients the numbers clearly have gone down <pause dur="0.3"/><kinesic desc="indicates point on slide" iterated="n"/> in these patients they've stayed static or clearly gone up <pause dur="0.9"/> now again i'm not going to go into the clinical details of this <pause dur="0.4"/> but <pause dur="0.4"/> these patients actually <pause dur="0.5"/> are doing less well <pause dur="0.4"/> than those patients <pause dur="0.9"/> okay <pause dur="1.1"/> so in experimental terms <pause dur="0.3"/> one can demonstrate <pause dur="0.3"/> that some sort of tolerance does indeed develop <pause dur="0.4"/> in some patients who have transplanted <pause dur="0.4"/> so in theory <pause dur="0.5"/><kinesic desc="indicates point on slide" iterated="n"/> these guys <pause dur="1.9"/> do not need <pause dur="0.4"/> full <pause dur="0.4"/> immune <trunc>respon</trunc> # # immune suppression <pause dur="0.6"/> and indeed <kinesic desc="indicates point on slide" iterated="n"/> these patients <pause dur="0.5"/> # <pause dur="1.1"/> there

were <pause dur="0.4"/> steroids <pause dur="0.4"/> were no longer used in their treatment <pause dur="0.5"/> and they got no worse so they were able to do without steroids so <trunc>y</trunc> they only needed <pause dur="0.3"/> two <pause dur="0.3"/> of the three <pause dur="0.2"/> drugs that are normally used <pause dur="0.4"/> so <kinesic desc="indicates point on slide" iterated="n"/> these patients who <pause dur="0.2"/> appear tolerant <pause dur="0.4"/> clearly are better <pause dur="0.4"/> than those patients that <pause dur="0.2"/> that don't <pause dur="0.4"/> okay <pause dur="0.3"/> so you can do it <pause dur="0.4"/> you can demonstrate tolerance <pause dur="4.2"/><kinesic desc="changes slide" iterated="n"/> so the implications of the development of tolerance <pause dur="0.2"/> in in patients then <pause dur="0.6"/> # is that <pause dur="0.5"/> at least in principle <pause dur="0.4"/> you can discontinue <pause dur="0.6"/> the drug use <pause dur="0.7"/> or perhaps <pause dur="0.2"/> drastically reduce the drug use you want to perhaps have a little bit of immunosuppression but very much less than you would <pause dur="1.1"/> normally <pause dur="0.6"/> # <pause dur="0.5"/> and in fact <pause dur="0.4"/> very occasionally patients have abandoned the use of their drugs they get fed up taking all these drugs all their life and say bugger it i'm not going to take them any more <pause dur="0.7"/> usually what happens then is that the graft is rejected but in a few <pause dur="0.6"/> lucky people <pause dur="0.4"/> # the <pause dur="0.4"/> graft is not rejected and they are genuinely

obviously tolerant <pause dur="0.5"/> okay <pause dur="0.5"/> but <pause dur="0.2"/> # if you talk to <gap reason="name" extent="1 word"/> on Thursday he will say this will be a very brave physician <pause dur="0.4"/> that will say okay we've got laboratory information that tells us the patients are tolerant <pause dur="0.2"/> therefore we shall stop the drugs <pause dur="1.9"/> so there are ethical issues here again <pause dur="1.4"/> all right so that's a little bit of # <pause dur="0.5"/> a sideway <pause dur="2.3"/><kinesic desc="changes slide" iterated="n"/> sideline <pause dur="2.5"/> why would we want to discontinue drugs <pause dur="0.6"/> it's because of the side effects of drugs you don't want to use these nasty things you can avoid <trunc>th</trunc> avoid it <pause dur="0.7"/> side effects <pause dur="1.5"/> in increasing severity in fact are hairiness <pause dur="0.4"/> # <pause dur="0.6"/> it wouldn't bother me so much but i daresay there are some ladies that would <pause dur="0.2"/> object to growing beards well they do don't they <pause dur="0.6"/> # <pause dur="0.3"/> also <pause dur="0.3"/> some of the drugs <pause dur="0.2"/> are actually toxic <pause dur="0.2"/> to the kidney they damage the kidney that's not an ideal situation no <pause dur="0.8"/> there's even some argument that the development of chronic rejection is due to the nephrotoxicity of the drugs that are used to prevent rejection <pause dur="0.4"/>

i think that's not the case <pause dur="1.1"/> obviously <pause dur="0.6"/> a considerable <pause dur="0.2"/> problem is infection <pause dur="1.3"/> okay <pause dur="0.5"/> # patients on immunosuppression <pause dur="0.4"/> by definition <pause dur="0.5"/> are susceptible to infection <pause dur="0.3"/> in fact that's not too bad <pause dur="0.3"/> because by <pause dur="0.2"/> and large <pause dur="0.3"/> # the guys who are transplanted <pause dur="1.5"/> people that are transplanted are a little bit older <pause dur="0.2"/> in their fifties sixties usually <pause dur="1.3"/> these guys have experienced most common infections <pause dur="0.3"/> and so they have lots of antibodies circulating <pause dur="0.3"/> so they are essentially <pause dur="0.3"/> immune <pause dur="0.3"/> to common infections like common colds or perhaps more severe things like streptococcus sore throats and so on <pause dur="0.7"/> one of the few compensations for growing old <pause dur="0.3"/> is that you tend not to get colds because you're immune to all the cold viruses that circulate <pause dur="0.5"/> so by and large infection normally is not too much of a problem <pause dur="1.1"/> but what is a very severe problem is cancer <pause dur="0.4"/> # and it turns out that in in <pause dur="0.4"/> transplanted <pause dur="0.2"/> immunosuppressed individuals <pause dur="0.4"/> can't forget can't remember the exact numbers <pause dur="0.4"/> the exact risk of

cancer but it's a significantly elevated risk <pause dur="0.4"/> of cancer in patients who are immunosuppressed <pause dur="1.2"/> okay <pause dur="0.4"/> # and the cancers that arise the most common ones are skin cancers <pause dur="0.7"/> those don't matter too much <pause dur="0.6"/> because they're <pause dur="0.6"/> easily visible i'm not talking about melanoma if anybody has heard of melanoma there are other skin cancers i'm talking about non-melanoma skin cancers <pause dur="1.5"/> these <pause dur="0.7"/> are alarming <pause dur="0.2"/> but not dangerous because they're quite well treated and obviously they're easily recognized quickly and easiy recognized <pause dur="0.4"/> so skin cancers are not too much of a problem <pause dur="1.6"/> but what is a problem are B-cell lymphomas <pause dur="0.5"/> # <pause dur="0.4"/> and now those of you that are virologists will recollect Epstein-Barr virus <pause dur="0.7"/> and that this can transform B-cells and make them into malignant cells <pause dur="0.5"/> normally <pause dur="0.3"/> the immune system prevents <pause dur="0.3"/> the transform the Epstein-Barr virus transform cells from <pause dur="0.6"/> <trunc>cour</trunc> <pause dur="0.2"/> developing into a cancer <pause dur="0.3"/> but if you immunosuppress <pause dur="0.6"/> then there is probability <pause dur="0.7"/> # that the transformed

B-cells will develop into a lymphoma and that is a very serious situation <pause dur="0.5"/> very serious indeed for all sorts of reasons <pause dur="0.4"/> so <pause dur="0.4"/> these <pause dur="0.3"/> side effects <pause dur="0.5"/> are all very undesirable so that is why <pause dur="0.4"/> drug treatment is tapered off <pause dur="1.3"/> luckily that can be done <pause dur="0.4"/> and ideally drug treatment would be reduced to nothing <pause dur="1.5"/><kinesic desc="changes slide" iterated="n"/> okay <pause dur="0.4"/> so i'm close to winding up now we will <trunc>l</trunc> <pause dur="0.2"/> end a little before five o'clock <pause dur="0.9"/> what may be the future <pause dur="1.8"/><kinesic desc="changes slide" iterated="n"/> better drugs <pause dur="0.3"/> okay <pause dur="0.2"/> more effective <pause dur="0.5"/> less toxic <pause dur="0.3"/> ideally graft specific <pause dur="0.3"/> that's the ideal <pause dur="3.6"/><kinesic desc="changes slide" iterated="n"/> there are <pause dur="0.2"/> problems in the development of new drugs and again from a pharmaceutical those of you who are interested in the pharmaceutical industry this strikes me <pause dur="0.5"/> as actually <pause dur="0.3"/> really quite a problem for the pharmaceutical industry <pause dur="1.0"/> present <pause dur="0.6"/> immunosuppressive regimes are very good they work very well as i've said you almost never lose <pause dur="0.2"/> transplants through acute rejection <pause dur="3.9"/> so <pause dur="1.2"/> to demonstrate better drugs is going to take <pause dur="0.2"/> years of

clinical study years <trunc>v</trunc> very long clinical trials <pause dur="0.4"/> because i forget what is the average survival of a graft nowadays but it's many years several years five eight years something like that <pause dur="0.4"/> so if you set up <pause dur="0.4"/> a clinical trial to compare two different <pause dur="0.5"/> # drug regimes immunosuppressive regimes <pause dur="0.3"/> it's going to be years <pause dur="0.4"/> before you're going to get a result and drug companies are not happy with that <pause dur="2.6"/> and the second thing <pause dur="0.3"/> which actually <pause dur="0.6"/> in some ways <pause dur="0.7"/> is more difficult <pause dur="2.2"/> is that testing new drugs <pause dur="0.2"/> may well be unethical <pause dur="0.4"/> now you will not have been exposed to much ethics <pause dur="0.4"/> sadly i think you ought to be <pause dur="0.5"/> but the point is <pause dur="0.3"/> that if you have <pause dur="0.4"/> a drug <pause dur="0.5"/> regime <pause dur="0.3"/> which is an effective therapy <pause dur="0.8"/> there is no way <pause dur="0.3"/> that you can <pause dur="0.2"/> say to a patient <pause dur="0.3"/> we are not going to treat you because we want to <pause dur="0.2"/> test a new drug <pause dur="0.9"/> so inevitably <pause dur="0.4"/> in <pause dur="0.5"/> immunotherapy and other kinds <trunc>o</trunc> <pause dur="0.2"/> sorry immunosuppression <pause dur="0.3"/> and in other kinds of therapy <pause dur="0.4"/> if you want to test a new drug that is usually

going to be <pause dur="0.4"/> by adding it in <pause dur="0.6"/> to the previous set of drugs <pause dur="0.5"/> or at best exchanging it <pause dur="0.3"/> for one of the currently used drugs <pause dur="1.0"/> for ethical reasons <pause dur="0.6"/> now <pause dur="0.2"/> unless the new drug is significantly better <pause dur="0.3"/> clearly better than the old drug <pause dur="0.9"/> and remember the old drugs are very good <pause dur="0.5"/> then it's going to be extremely difficult <pause dur="0.5"/> to demonstrate a real difference because you can't leave the patient untreated except for your new drug <pause dur="0.7"/> in other words you can't and you cannot possibly <pause dur="0.4"/> do placebo trials people will have <trunc>h</trunc> have <pause dur="0.4"/> heard of what a <trunc>place</trunc> or heard of the term placebo <pause dur="0.3"/> that's when you use a dummy drug <pause dur="0.7"/> when you want to test a new drug you couldn't possibly use dummy drugs in this situation <pause dur="0.7"/> so there are ethical problems in testing new drugs <pause dur="0.8"/> as well as <pause dur="0.5"/><vocal desc="clears throat" iterated="n"/> straightforward practical problems <pause dur="1.7"/><kinesic desc="changes slide" iterated="n"/> now <pause dur="0.8"/> another severe problem which i pointed out right at the beginning <pause dur="0.4"/> is that actually transplantation <pause dur="0.6"/> # is presently limited <pause dur="0.4"/> not by the clinical <pause dur="0.3"/>

skills <pause dur="1.2"/> but by the numbers of donors i forget <pause dur="0.2"/> what the numbers of <pause dur="0.4"/> people on the waiting lists are locally it's large numbers <pause dur="0.4"/> and after the Alder Hey <pause dur="0.4"/> thing that you <pause dur="0.2"/> may have heard of <pause dur="0.3"/> # numbers of donors declined dramatically <pause dur="0.2"/> in this country people decided they weren't going to give up their <pause dur="0.2"/> <trunc>or</trunc> organs even after death <pause dur="1.3"/> and <vocal desc="laugh" iterated="n"/><pause dur="0.2"/> another <pause dur="0.2"/> # significant thing is that with the reduction <pause dur="0.3"/> of the violence <pause dur="0.2"/> in Northern Ireland which is an excellent thing <pause dur="0.4"/> there are fewer <pause dur="0.2"/> freshly dead cadavers to provide <pause dur="0.4"/> transplants so the numbers of <pause dur="0.4"/> organs from Northern Ireland has dried up <pause dur="0.4"/> in fact i think <gap reason="name" extent="1 word"/> will be telling you <pause dur="0.2"/> on Thursday <pause dur="0.3"/> that one of the main sources of organs is actually Spain <pause dur="0.5"/> # where they drive so badly <pause dur="0.5"/> that there are <pause dur="0.5"/> large numbers of traffic accidents which are a source of <pause dur="0.9"/> transplant tissues <pause dur="0.5"/> okay <pause dur="0.3"/> so there are things like that <pause dur="0.2"/> anyway <pause dur="1.3"/> <trunc>w</trunc> we talk about xenografting <pause dur="0.2"/> to overcome shortage of donors <pause dur="0.2"/> pig <pause dur="1.1"/> kidneys <pause dur="0.7"/> primates <pause dur="0.6"/> are obviously <pause dur="0.3"/> a potential source

of grafts because they're so closely related to us but they're ruled out for all sorts of reasons <pause dur="1.3"/> pig kidneys are about the same size as ours and their biochemistry is similar <pause dur="0.3"/> but <pause dur="0.4"/> there is <pause dur="0.2"/> a severe problem of hyperacute <pause dur="0.2"/> # rejection <pause dur="0.5"/> for reasons which aren't very clear to # to me <pause dur="0.6"/> all of us or very nearly all of us have <pause dur="0.2"/> large amounts of circulating antibodies <pause dur="0.3"/> which will react with pig tissues <pause dur="0.3"/> and cause hyperacute rejection <pause dur="0.5"/> so this problem actually as you know has been <kinesic desc="changes slide" iterated="n"/> solved and i don't know if i <pause dur="0.7"/> showed you this by humanizing kidneys <pause dur="1.1"/> basically what is done is that the kidney tissues are <pause dur="0.3"/> <trunc>genet</trunc> kidney the sorry the pig <pause dur="0.5"/> is genetically engineered <pause dur="0.3"/> so that the <pause dur="0.2"/> the tissues are not susceptible to complement lysis <pause dur="0.5"/> and again the details don't matter <pause dur="0.3"/> but the <trunc>t</trunc> <pause dur="0.2"/> tissues are not lysed by complement <pause dur="0.5"/> so humanization <pause dur="0.3"/> of pigs <pause dur="0.3"/> prevents <pause dur="0.3"/> hyperacute rejection <pause dur="0.4"/>

now <pause dur="0.4"/><kinesic desc="changes slide" iterated="n"/> this has never been tested <pause dur="0.6"/> in human <pause dur="0.6"/> # <pause dur="0.4"/> transplantation <pause dur="0.3"/> it has been tested in primate transplantation so you take <pause dur="0.3"/> humanized <pause dur="0.6"/> pig kidney <pause dur="0.3"/> and transplant it into a chimpanzee this has been done on a smaller scale <pause dur="0.3"/> half a dozen or so chimpanzees or whatever <pause dur="1.7"/> and you find that the hyperacute rejection problem is overcome <pause dur="0.4"/> but <pause dur="0.3"/> # <pause dur="0.6"/> the <pause dur="0.4"/> the acute rejection which occurs <pause dur="0.3"/> is violent and cannot be controlled <pause dur="0.4"/> with the immunosuppressive drugs <pause dur="0.8"/> so <pause dur="0.2"/> any human trial <pause dur="0.5"/> of xenografting <pause dur="0.4"/> irrespective of any other problems ethical or otherwise <pause dur="0.4"/> any sort of xenograft trial in humans is a long way off if ever <pause dur="3.9"/><kinesic desc="changes slide" iterated="n"/> we have talked about therapeutic stem cell cloning and i for one <pause dur="0.4"/> have got <pause dur="0.7"/> serious ethical reservations about stem cell cloning <pause dur="0.8"/> # sorry embryonic stem cells it depends how you go about it perhaps but i have reservations <pause dur="1.7"/> give it a little bit of thought <pause dur="0.4"/><vocal desc="clears throat" iterated="n"/><pause dur="1.8"/> you might be able to generate

stem cells we could regenerate say T-cells <pause dur="0.5"/> which <pause dur="0.3"/> as you appreciate <pause dur="0.3"/> will function in suspension you do not need to have an organized tissue <pause dur="0.5"/> for stem cells T-cells to work <pause dur="0.4"/> well that's not quite true because you know <pause dur="0.4"/> know i i hope <pause dur="0.4"/> that the main immunological interactions <pause dur="0.3"/> occur in lymphoid tissues <pause dur="0.8"/> so the T-cells do function <pause dur="0.5"/> in an organized tissue environment <pause dur="0.4"/> but <pause dur="0.2"/> T-cells are as you know able to circulate <pause dur="0.4"/> and put themselves into the tissues where they want to be <pause dur="0.4"/> so <pause dur="0.2"/> you can well imagine <pause dur="0.5"/> # that <pause dur="0.5"/> T-cells which function in this way <pause dur="0.4"/> could be used <pause dur="0.4"/> could be derived from embryonic stem cells and effectively used <pause dur="0.5"/> but i for one <pause dur="0.3"/> i cannot see that you would be able to generate in vitro <pause dur="0.7"/> notice in vitro <pause dur="0.4"/> an organ such as a kidney which is a complex assembly of many different cell types <pause dur="0.3"/> put together in a very elaborate manner <pause dur="0.9"/> okay <pause dur="0.6"/> so i do not see that an organ can be made in vitro even if <pause dur="0.5"/> # we could genuinely <trunc>m</trunc> generate <pause dur="0.4"/> stem cells which could potentially <pause dur="0.5"/> generate a kidney it's

just too complicated <pause dur="0.8"/> so if you want a kidney that means you and you want it by embryonic technology <pause dur="0.4"/> that means you've got to grow the fetus <pause dur="0.7"/> to a point at which it has intact kidneys and that is to my mind <pause dur="0.3"/> ethically <pause dur="0.3"/> obviously <pause dur="0.2"/> completely <pause dur="0.4"/> impossible <pause dur="1.6"/> so <pause dur="0.3"/> therapeutic stem cell cloning there's a big question mark over that except in perhaps in simple situations <pause dur="4.2"/><kinesic desc="changes slide" iterated="n"/> now <pause dur="0.2"/> if you think <pause dur="0.3"/> i've talked about <pause dur="0.3"/> basically bone marrow blood bone marrow kidneys liver <pause dur="0.6"/> # <pause dur="0.4"/> heart and lung <pause dur="2.9"/> and i've said that some kinds of <pause dur="0.6"/> transplants are impractical because the surgery is just too difficult <pause dur="1.1"/> now <pause dur="0.2"/> people have talked about limb transplantation and and rather horrifying <pause dur="0.2"/> to me <pause dur="0.4"/> thought is face <pause dur="0.2"/> transplantation has been talked about <pause dur="1.2"/> the surgeons say that this is technically possible and indeed a hand has been transplanted <pause dur="0.7"/> but i don't know if anybody recollects the patient got very unhappy <pause dur="0.5"/> and had it amputated <pause dur="0.8"/> he was very unhappy with having somebody else's hand <pause dur="0.3"/> could see it all

the time <pause dur="0.4"/> 'cause a kidney <pause dur="0.3"/> okay <pause dur="0.4"/> you can forget about it but not a hand <pause dur="1.1"/> so the guy had the hand <pause dur="0.4"/> amputated <pause dur="2.1"/> face transplants <pause dur="0.5"/> it has been said they are technically possible the technology the surgical technology there is very complicated because your face <pause dur="0.4"/> has lots of different muscles which work in a very complex way so we are <pause dur="0.3"/> have very expressive faces # most other animals <pause dur="0.3"/> do not have expressive faces we do <pause dur="0.4"/> and that's because of the complicated nervous <pause dur="0.5"/> # # # and and vasculature <pause dur="0.6"/> <trunc>n</trunc> nerves and vasculature in the face <pause dur="0.4"/> okay <pause dur="1.5"/> but the surgeons say that it's technically possible <pause dur="0.4"/> but again there's a massive ethical problem here which doesn't seem to have been recognized <pause dur="0.5"/> is that what if <pause dur="0.5"/> subsequently that patient <pause dur="0.5"/> # <pause dur="0.5"/> acute rejection or chronic rejection occurred <pause dur="0.5"/> and the face <pause dur="0.2"/><vocal desc="clicks with tongue" iterated="n"/><kinesic desc="demonstrates rejection of face" iterated="n"/> <pause dur="0.6"/> was rejected what do you do you nip out and find another corpse <pause dur="1.2"/> or what <pause dur="1.0"/> so for ethical reason although it's been discussed in the press <pause dur="1.0"/> in the media a face transplant is <pause dur="0.2"/> not really on <pause dur="1.3"/> pancreas <pause dur="0.2"/>

that was the example that i used at the beginning <trunc>o</trunc> of something which is surgically impractical <pause dur="0.2"/> but highly desirable because of diabetes <pause dur="0.7"/> if you could transplant the pancreas into a into a diabetic <pause dur="0.7"/> perhaps that might # give you <pause dur="0.4"/> # a cure for diabetes remember <pause dur="0.3"/> diabetes is treatable <pause dur="0.3"/> by insulin but is not curable but if you can transplant a pancreas <pause dur="0.3"/> that would cure it <pause dur="0.5"/> now what is being attempted <pause dur="1.8"/> is to <pause dur="0.5"/> generate beta cells the islet cells which make insulin remember from the pancreas <pause dur="0.8"/> prepare those in vitro from a pancreas <pause dur="0.3"/> and invue infuse them <pause dur="0.3"/> through the portal vein which takes them into the <pause dur="0.2"/> liver <pause dur="0.5"/> # and with luck <pause dur="0.5"/> the beta cells will <pause dur="0.3"/> lodge in the liver tissue and there be functional <pause dur="0.9"/> # and secrete insulin <pause dur="0.7"/> perhaps <pause dur="0.3"/> in brackets <pause dur="0.3"/> this is <pause dur="0.4"/> this sort of technology is just coming into clinical testing <pause dur="0.8"/> so that's a possibility <pause dur="1.8"/><kinesic desc="changes slide" iterated="n"/> but <pause dur="0.2"/> to bring my <pause dur="0.3"/> me to the <trunc>s</trunc> final conclusion <pause dur="0.8"/> # <pause dur="2.4"/> plainly <pause dur="0.3"/> spare part surgery <pause dur="0.3"/> and bone

marrow transplantation and things like that <pause dur="0.3"/> does work <pause dur="0.2"/> whereas <pause dur="0.6"/> technically <trunc>a</trunc> <pause dur="0.2"/> and ethically possible it does work <pause dur="1.1"/> # and it works so well that in fact in many cases the graft as it were outlives the patient patient dies from other some other cause <pause dur="0.6"/> # and the kidney liver whatever <pause dur="0.3"/> is still functioning at the time of death <pause dur="0.4"/> the other cause may be <pause dur="0.4"/> due to the underlying disease perhaps <pause dur="0.6"/> give you an example # <trunc>d</trunc> <pause dur="0.5"/> <trunc>diabete</trunc> diabetics sadly <pause dur="0.4"/> # often have <pause dur="0.7"/> kidney failure <pause dur="0.6"/> # and they can be treated obviously with kidney transplantation <pause dur="0.5"/> but sadly they tend to die <pause dur="0.5"/> # from other complications of diabetes such as heart disease <pause dur="0.5"/> and if they die of heart disease their kidney may be still perfectly all right <pause dur="0.4"/> so spare part surgery <pause dur="0.4"/> as we have it now is actually pretty good <pause dur="2.1"/> but <pause dur="0.5"/> you might

might think me that i'm a <pause dur="0.2"/> think of me as a bit of a sceptic # # # <pause dur="0.2"/> and perhaps i am <pause dur="0.4"/> but in fact <pause dur="0.2"/> for <pause dur="0.7"/> very good reasons <pause dur="0.3"/> i don't myself see any radical improvements likely in the near future <pause dur="0.3"/> and i think pretty well all <pause dur="0.3"/> the clinicians i talk to and indeed the scientists the rational scientists <pause dur="0.4"/> that i talk to about this <pause dur="0.3"/> tend to agree that in in in in in <pause dur="0.2"/> transplantation <pause dur="0.3"/> and indeed in a number of areas of modern medicine <pause dur="0.4"/> we have reached <pause dur="0.4"/> some sort of <pause dur="0.4"/> # <pause dur="1.0"/> limit <pause dur="0.5"/> which we seem <pause dur="0.3"/> to be unable to get across all the simple sort of problems have been solved <pause dur="0.5"/> the hard problems <pause dur="0.3"/> are too hard <pause dur="1.4"/> okay well i'll leave it there <pause dur="0.4"/> # and as i say <gap reason="name" extent="2 words"/> will be talking to you about <pause dur="0.4"/> more clinical aspects of how to care for transplant patients on Thursday

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