Rozprawy doktorskie na temat „Organ transplantation”

Cancer is an important cause of mortality among the recipients of organ transplantation. Cancer transmitted from the donors has poor outcome and the fear of such transmission results in non-acceptance of certain organs. Study of the recipients in the UK over 10 years identified 15 cases of transmitted cancers. The rate of cancer transmission was 0.05%.The risk of cancer transmission was 9 times higher from donors older than 45 years. A comparison of the organ donor data with the guidelines classifying the donor’s risk showed that a selected cohort of donors, who are classed as high risk of cancer transmission, could safely donate their organs resulting in valuable additional survival for the recipients, with low risk of cancer transmission. These results provide evidence, for modification of donor classification guidelines resulting in increased availability of safe organs for transplantation. The risk of recurrence after transplantation of cancers treated before transplantation was low in selected recipients undergoing transplantation after a 2 year-wait following the diagnosis of cancer. No association was found between the donor-recipient CMV status and the risk of post-transplant cancer. This research estimated the risk of cancer transmission to the organ transplant recipients enabling improved risk assessment in transplantation.

The twentieth century was a time of a lot of advances in medicine, none more so than in the field of transplantation. Thanks to the pioneering work of many different people in a variety of different fields it is now possible to transplant bone marrow and solid organs. Transplantation is a truly multidisciplinary specialty where patient care is shared between physicians and surgeons. As in all medical specialties good nursing care is essential and requires a high degree of specialisation. Pathologists are key in post operative management in order to promptly diagnose problems so that treatment can be commenced with the minimum of delays.

This is a compound work comprising two independent studies.

1. Characterization of gamma-delta-T cell subsets in organ transplantation

gamma-delta-T cells are innate-type lymphocytes that preferentially act as regulators of local effector immune responses. Recent reports found an altered distribution of the two main subpopulations of blood gamma-delta-T cells (V-delta-1 and V-delta-2) in operationally tolerant liver transplant recipients. Based on this, gamma-delta-T cells subset quantification was proposed as a biomarker of immunologic risk in liver transplantation. The specific characteristics of gamma-delta-T cell subsets in transplantation remain however unknown. We have investigated here the phenotype, repertoire and functional properties of gamma-delta-T cell subsets in a large population of allograft recipients. Our results indicate that alterations in the gamma-delta-T cell compartment are not restricted to tolerant liver recipients. In fact, most immunosuppressed liver and kidney recipients also display an enlarged peripheral blood gamma-delta-T cell pool mainly resulting from an expansion of V-delta-1 T cells exhibiting an oligoclonal repertoire and different phenotypic and cytokine production traits than V-delta-2 T cells. We propose that persistent viral infections are likely to contribute to these alterations. Our data provide novel insight in the biology of gamma-delta-T cells and a rationale for exploring these lymphocytes in more depth into the pathogenesis of viral infections in transplantation.

2. Comparative Transcriptional and Phenotypic Peripheral Blood Analysis of Kidney Recipients under Cyclosporin A or Sirolimus Monotherapy
Due to its low level of nephrotoxicity and capacity to harness tolerogenic pathways, sirolimus (SRL) has been proposed as an alternative to calcineurin inhibitors in organ transplantation. However, the exact mechanisms underlying its unique immunosuppressive profile in humans are still not well understood. In the current study, we aimed to depict the in vivo effects of SRL in comparison with cyclosporine A (CSA) by employing gene expression profiling and multiparameter flow cytometry on blood cells collected from stable kidney recipients under monotherapy with either SRL or CSA. In addition, the overall effect of these drugs on immunoregulatory pathways was assessed by measuring a transcriptional signature characteristic of operationally tolerant kidney recipients. Samples from SRL recipients displayed an increased frequency of effector memory T cells and were enriched in NFkB-related pro-inflammatory expression pathways and in monocyte and NK cell lineage-specific transcripts. Furthermore neither SRL nor CSA induced a gene expression profile comparable with that of tolerant kidney recipients. In conclusion, we show here that the overall pattern of SRL effect in vivo is dominated by innate immune cells and NFkB-related pro-inflammatory events. These data provide novel insights on the complex effects of SLR on the immune system in clinical transplantation.
"Biomarcadors fenotípics i transcripcionals
en el transplantament d'òrgans"

TEXT:


1. Estudi de les cèl·lules T gamma-delta A l'al·lotransplantament d'òrgans

1.1 Objectius
- Investigació detallada de la freqüència, fenotip, repertori del TCR i característiques funcionals de les poblacions Vdelta1 i Vdelta2 en sang perifèrica en trasplantats.
- Determinar si l'òrgan trasplantat, la teràpia immunosupressora i la presència d'infeccions víriques influeixen en la distribució i propietats de les subpoblacions gamma-delta.
- Avaluar el valor clínic de la quantificació de les cèl·lules T gamma-delta com a biomarcador diagnòstic de trasplantats tolerants operacionals de fetge.

1.2 Resultats
Es van quantificar les poblacions de gamma-delta totals, Vdelta1, Vdelta2 i ràtio Vdelta1/Vdelta2 en 201 trasplantats de fetge estables (STA-Liver), 29 tolerants operacionals trasplantats de fetge (TOL), 50 trasplantats estables de ronyó (STA-Kidney), 50 malalts amb insuficiència hepàtica terminal (ESLD) i 34 controls sans (CONT). Vem observar un increment de la població gamma-delta total en tots els grups de pacients trasplantats respecte CONT, que venia determinat per un increment de la població Vdelta1, més significatiu en el cas dels TOL, i una disminució de Vdelta2.
Vem demostrar que les freqüències del fenotip són estables en el temps determinant el percentatge d'expressió de Vdelta1 i Vdelta2 dues vegades amb 14 mesos de diferència.
El fenotipatge realitzat a les poblacions Vdelta1 i Vdelta2 en 19 pacients STA-Liver, va mostrar que aquestes subpoblacions expressen marcadors cel·lulars de superfície, intracel·lulars i funcionals diferents entre si. Aquests marcadors, però no serviren per diferenciar una cohort de 9 TOL i 10 STA-Liver. Vàrem assajar la utilitat diagnòstica dels percentatges de Vdelta1 i Vdelta2 per diferenciar TOL i STA-Liver utilitzant una corba ROC. Els resultats no varen ser positius.
Vam correlacionar la freqüència d'infeccions víriques persistents amb la distribució de les subpoblacions T gamma-delta. CMV i HCV, provocaven una alteració independent entre si i significativa en el ràtio Vdelta1/Vdelta2. Vam estudiar, finalment la diversitat clonal del TCR de la població Vdelta1. Es va clonar i seqüenciar la CDR3 del TCR Vdelta1. Els TOL mostren una tendència, estadísticament significativa, cap a un repertori restringit del TCR Vdelta1. Vam determinar si aquestes seqüències de nucleòtids es traduïen en grups d'aminoàcids compartits en la CDR3 de V1 però el resultat fou negatiu.

1.3. Conclusions
- La majoria dels receptors d'un transplantament mostren un increment en sang perifèrica de la població de cèl·lules T gamma-delta.
- La distribució alterada en sang perifèrica de les subpoblacions T gamma-delta és estable en un període de temps establert.
- Les infeccions per CMV i HCV afecten la freqüència relativa de les subpoblacions gamma-delta i el ràtio Vdelta1/Vdelta2 en sang perifèrica en pacients trasplantats de fetge.
- Les cèl·lules T Vdelta1 mostren ser fenotípica i funcionalment diferents de les Vdelta2.
- El repertori de CDR3 del receptor de les cèl·lules T Vdelta1 està restringit en receptors de fetge tolerants operacionals.
- Ni la quantificació de subpoblacions T gamma-delta ni la seva caracterització fenotípica permeten discriminar de forma acurada entre TOL i els STA-Liver.

2. Anàlisi fenotípic i transcripcional de receptors d'un transplantament de ronyó en monoteràpia amb CsA o sirolimus

2.1 Objectius
- Establir els efectes in vivo de sirolimus i CsA en sang perifèrica utilitzant tècniques de cribatge d'alt rendiment, per generar un perfil fenotípic i transcripcional de les dues cohorts de pacients.
- Determinar l'expressió d'una sèrie de biomarcadors associats a tolerància en aquests pacients, a partir d'un perfil generat anteriorment en tolerants operacionals renals.

2.2 Resultats
Es varen determinar les diferències fenotípiques de les dues cohorts i vàrem determinar que els pacients tractats amb sirolimus (SRL) mostraven un increment en la població CD4 de memòria efectora (CD45RA-CCR7-) respecte els pacients CSA. El grup SRL també presentava un increment en l'expressió de cèl·lules Tregs (CD4+CD25highFoxp3+) comparat amb CSA.
Vam fer estudis de microarray d'Affymetrix a partir de sang perifèrica. Vam fer un anàlisi comparatiu de dades utilitzant SAM (FDR<5%). El resultat d'aquest anàlisi ens va permetre identificar un total de 486 gens upregulated i 586 gens downregulated en el grup SRL respecte CSA.
Per interpretar el conjunt de gens diferentment expressats vam utilitzar el mètode GSEA, que ens va permetre identificar un enriquiment en el grup SRL de vies de senyalització relacionades amb mTOR i vies pro-inflamatòries comparat tant amb CSA com amb el grup d'individus sans.
Utilitzant Haematolgy Expression Atlas vam identificar una representació significativa de trànscrits específics per monòcits i cèl·lules NK en SRL, i per cèl·lules T CD4+ i limfòcits B en el grup CSA.
El software IPA-Tox va identificar NFκB com la via de senyalització més representativa respecte els gens estudiats.
Per últim vàrem determinar la prevalença de biomarcadors relacionats amb tolerància operacional en pacients trasplantats de ronyót. Dels 37 pacients estudiats només 1 SRL i 3 CSA varen ser predits com a potencialment tolerants.

2.3 Conclusions
- Els receptors estables d'un transplantament de fetge en monoteràpia amb sirolimus presenten un increment significatiu de la població TregFoxp3+ respecte tractament amb CsA.
¬- El perfil d'expressió en sang perifèrica del pacients tractats amb sirolimus mostra un enriquiment en vies metabòliques pro-inflamatòries i gens involucrats ambla senyalització mTOR.
-IPA-Tox identifica, entre les respostes farmacològiques prèviament definides, a NFκB com la via de senyalització més toxicològica a partir dels gens diferentment expressats.
- L'aplicació d'una signature de tolerància operacional prèviament definida no és capaç d'identificar diferències entre els pacients tractats amb CsA i els que reben sirolimus.

Background: Abdominal solid organ transplantation has evolved from an experimental procedure to a well-established therapy within a few decades. This success is largely due to the introduction of calcineurin inhibitor immunosuppression. Tacrolimus is the most widely used calcineurin inhibitor but has a narrow therapeutic range which requires close drug monitoring to prevent both toxicity and inadequate immunosuppression. Previous studies in renal transplantation have shown that genetic polymorphisms, CYP3A5, CYP3A4*22 and ABCB1 can influence the bioavailability and pharmacokinetics of tacrolimus. These polymorphisms are closely linked to ethnicity and have never been studied in a Scottish population before. Additionally, increasing evidence suggests that high variability of tacrolimus is linked to increased graft loss in kidney transplant patients. Methods: 5889 subjects were genotyped for the genetic polymorphisms CYP3A5 A > G allele transition, CYP3A4*22 C > T and ABCB1 C > T transition. This included 4899 healthy individuals from Generation Scotland bio-resource and 990 patients who underwent renal, liver, or simultaneous pancreas kidney transplants or were organ donors. Tacrolimus dose, trough level and renal function were measured at 11 time points from date of transplant up to and including 12 months post-transplant. Clinical data including episodes of acute rejection, graft and patient survival were compared between the different genotypes. Separate analyses were undertaken for kidney, SPK transplants, as well as liver transplants, the latter looking at recipient and liver donor genotype. A separate cohort of 103 renal transplant patients converted from twice-daily to once-daily tacrolimus had their tacrolimus variability calculated and compared with graft survival. Results: The distribution of the 3 different genotypes of CYP3A5, CYP3A4*22 and ABCB1 were comparable with other Caucasian populations studied previously. In renal transplant recipient expression of the A allele (GA/AA) led to significantly increased dose requirements of tacrolimus and initially lower tacrolimus trough levels. The different genotypes of ABCB1 had no effect. Expression of a CYP3A4*22 T allele trended towards a lower tacrolimus dose requirement but this was not significant. There was no difference in renal function, graft survival or patient survival with any of the polymorphisms. SPK patients had comparable results. In the liver transplant patients, the donor genotype had a greater influence than the recipient one. The donors with CYP3A5 A allele expression had significantly higher tacrolimus dose requirements and lower initial tacrolimus levels. This was apparent to a lesser extent with the recipient expression of CYP3A5 and did not reach statistical significance at all time points. There was no significant difference in tacrolimus dose requirements or level with either donor or recipient expression of ABCB1 or CYP3A4*22. There was a significantly higher incidence of acute rejection in donor CYP3A5 A allele expressers of liver transplant patients in univariate and multivariate analysis. There was no significant different in acute rejection with ABCB1 or CYP3A4*22 genotype. No differences in graft or patient survival with either donor or recipient genotype of any of the 3 polymorphisms were noted. Conversion from twice-daily to once-daily tacrolimus in the first 12 months post-transplant reduced tacrolimus variability. Patients with high tacrolimus variability pre and post conversion had significantly greater graft loss than patients with low tacrolimus variability. Conclusion: CYP3A5 expression results in increased tacrolimus requirements to achieve adequate immunosuppression in renal transplant and SPK patients. Donor rather than recipient CYP3A5 expression is relevant for liver transplantation and dose requirements. There may be an association with donor CYP3A5 expression in liver transplant patients and acute rejection which needs further evaluation. ABCB1 and CYP3A4*22 do not appear to have a significant impact in any of the organ transplants. High tacrolimus variability is associated increased graft loss in renal transplant patients.

Thesis advisor: Eric Strauss
A bioethics thesis focusing on the issues of organ transplantation and the organ trade in the nations of China and India. It explains how the organ transplantation procedure is done, the laws pertaining to organ transplantation, the ethics of organ transplantation, the organ trade in its various aspects in the nations of China and India, and finally shares the story of a living organ donor in the United States. It addresses questions such as: How do we classify brain death? Who should be allowed to donate their organs? Should organs be available for sale and purchase? Is the organ trade a violation human rights? It concludes with the author's opinions on the subject, which are decidedly against the organ trade
Thesis (BS) — Boston College, 2007
Submitted to: Boston College. College of Arts and Sciences
Discipline: Biology
Discipline: College Honors Program

Solid organ transplantation is a rare health intervention that saves lives, improves quality of life and, where there is an alternative such as dialysis, is cost-effective. However, organ transplantation is a complex intervention that is limited by the number of organ donors, and requires life-long immunosuppression of the recipient. Infections are a common complication of organ transplantation, and a major cause of death for transplant recipients. Donor-derived infections, while rare, are of particular concern for transplant clinicians, as a potentially avoidable consequence of transplantation. Donation practice must balance the risks of infection transmission with the risks of overly restrictive donation policies that could limit this life-saving intervention. Post-transplant, clinicians must remain vigilant for new recipient infections, whether donor-derived, reactivating or arising anew. In this thesis, I generate novel data regarding aspects of infections affecting solid organ donation and transplantation where current practice can be improved, focusing in particular on blood-borne viruses and preventable post-transplant infections. Theme 1: Assessment of potential organ donors for blood-borne virus transmission risk All potential solid organ donors are rigorously screened for their suitability to donate. One reason potential donors may be declined is where there is perceived to be an increased risk of transmission of infectious diseases, including blood-borne viruses (BBV) such as hepatitis B (HBV), hepatitis C (HCV) and human immunodeficiency virus (HIV). Unexpected BBV transmissions have indeed led to devastating recipient outcomes. However, testing and treatment for these conditions have evolved substantially in recent years and decades. Nucleic acid testing (NAT) is now both rapidly available and highly sensitive for infection. Implementation of NAT reduces serological window periods to smaller eclipse periods. Meanwhile, HCV has become curable in the vast majority of cases, HBV can be prevented with vaccination, or effectively suppressed, and even HIV now has effective suppressive treatments. Given these developments, a reassessment of suitability of potential organ donors with BBV, or risk factors for their acquisition, is warranted. The first aim of this thesis was to understand whether transplant clinicians can correctly interpret hepatitis serology and then consistently judge potential donor transmission risk and donation suitability. This is explored in Chapter 2 through an anonymous, self-completed, cross-sectional survey distributed electronically to Australian and New Zealand clinicians involved in kidney transplantation (2014-2015). We compared respondents’ interpretation of clinical scenarios with paired donor and recipient hepatitis B and C serology to recommendations in clinical practice guidelines. We then used logistic regression modelling to investigate characteristics associated with decisions on transplant suitability in scenarios with poor (<50%) guideline concordance. The 110 survey respondents in our sample had demographic characteristics representative of the target workforce. While donor and recipient hepatitis statuses were largely well understood, transplant suitability responses varied among respondents. For an HBV surface antigen (HBsAg) positive donor and vaccinated recipient, 44% of respondents suggested the donor was unsuitable for transplant (guideline concordant) but 35% suggested the donor was suitable with prophylaxis (guideline divergent). In four scenarios with transplant suitability guideline concordance of <50%, acute transplant care involvement predicted guideline concordant responses (OR [odds ratio] 1.69, p=0.04). Guideline concordant responses were chosen less by hepatologists, intensive care doctors (OR 0.23, 0.35 respectively, p=0.01), and New Zealanders (guideline concordant responses OR 0.17, p<0.01; alternative responses OR 4.31, p<0.01). Hence, we conclude that despite broadly consistent interpretations of hepatitis serology by respondents, resulting transplant suitability decisions vary, and often diverge from guidelines. Having established variability between clinicians, this thesis next aimed to describe current practice regarding potential donors with increased risk for BBV transmission in Chapter 3. Specifically, we aimed to describe the size and characteristics of this group, whether they proceeded to donate, and reasons not donating. To do this, we conducted a cohort study of all potential organ donors referred in New South Wales, Australia between 2010 and 2018. Baseline risk potential donors were compared to potential donors with increased BBV transmission risk, due to a personal history of HIV, HCV or HBV and/or behavioural risk factors. We found 624/5749 potential donors (10.9%) perceived to have increased BBV transmission risk. This included 298/5749 (5.2%) with HCV (including HBV co-infections) and 239/5749 (4.2%) with increased risk behaviours (no known BBV). Potential donors with HCV and those with increased risk behaviours were younger and had fewer comorbidities than baseline risk potential donors (p<0.001). Many potential donors (82 with HCV, 38 with risk behaviours) were declined for donation purely due to perceived BBV transmission risk. Most were excluded prior to BBV testing. When potential donors with HCV did donate, they donated fewer organs than baseline risk donors (median 1 versus 3, p<0.01), especially kidneys (OR 0.08, p<0.001) and lungs (OR 0.11, p=0.006). In summary, many potential donors were not accepted due to perceived increased BBV transmission risk, without viral testing, and despite otherwise favourable characteristics. This suggests the potential for transplantation rates to be substantially increased if more potential donors with HCV and/or increased risk behaviours were accepted. Taken together, the findings of variable donor suitability decision-making, and the rejection of otherwise high-quality potential donors without viral testing, suggest there may have been missed opportunities to donate from some potential donors with positive serology or increased risk behaviours. Supporting clinicians to identify such previously rejected potential donors with an acceptable risk profile, and using these organs for transplantation, may have the potential to significantly increase donation rates. Theme 2: Estimating the actual risks of BBV transmission To support change in clinical practice, estimates of the risks posed by increased risk donors are helpful. Blood-borne virus rates vary internationally, and no data from the Australian context was available. We synthesised existing literature to produce Australian estimates of the actual risk posed by potential donors with increased risk behaviours for BBV only (Chapter 4). We conducted a systematic review and meta-analysis of cohorts reporting incidence and prevalence of HIV, HCV and HBV among increased risk groups in Australia. The residual risks of window period infections were estimated in the setting of negative serology and NAT. Residual risk of HIV was found to be highest among men who have sex with men at 4.8 per 10,000 persons testing negative with serology (95% CI: 2.7-6.9), and 1.5 per 10,000 persons with additional negative NAT (95% CI: 0.9-2.2). Residual risk of HCV was highest among injecting drug users (IDU) with a residual risk of 289 per 10,000 persons (95% CI: 191-385) with negative serology, and 20.9 per 10,000 persons (95% CI: 13.8-28.0) with additional negative NAT. Residual risk for HBV was highest in IDU with 98.6 window period infections per 10,000 with negative serology (95% CI: 36.4-212.7) and 49.4/10,000 with additional negative NAT (95% CI: 18.2-106.9). We concluded that the absolute risks of window period infection are low among Australian groups with increased risk but negative viral testing. These findings inform shared decision-making by clinicians and recipients and have the potential to increase organ donation rates from increased risk donors where risks are considered tolerable. To understand the magnitude of transmission risks from donors with positive hepatitis serology, we next examined a cohort of linked donors and recipients (Chapter 5). The aims of this work included describing the rates of transmission and non-transmission of BBV from donors with BBV to recipients, and identifying any previously unrecognized transmissions from donors perceived to pose a baseline transmission risk. To do this, we linked transplant registries with administrative health data for all solid organ donor-recipient pairs in New South Wales, Australia, 2000-2015. All new recipient notifications of HBV, HCV or HIV after transplant were identified. Proven/probable donor-transmissions within 12 months of transplant were classified according to a published US algorithm. Of 2,120 organ donors, there were 72 with a viral infection (9/72 active, 63/72 past). These 72 donors donated to 173 recipients, of whom 24/173 already had the same infection as their donor, and 149/173 did not and so were at risk of donor-transmission. Among those at risk: 3/149 recipients had proven/probable viral transmissions (1 HCV, 2 HBV); none were unrecognised by donation services. There were no deaths from transmissions. There were no donor-transmissions from donors without known BBV. Our findings confirm the safety of organ donation in an Australian cohort, with no unrecognised viral transmissions and most donors with viral infections not transmitting the virus. The results support targeted increases in donation from donors with viral infections. Data-linkage can enhance current biovigilance systems. The local evidence of transmission risks generated in Chapters 4 and 5 provide much-needed data to tackle the evidence and practice gap established in Chapters 2 and 3. This allows the implementation of changes in clinical donation and transplantation practice which could safely increase donation rates. Theme 3: Recipient infections after transplantation Another finding from the research in Chapter 5 was the identification of a substantial number of new BBV infections that were unrelated to donor transmission risk. Beyond the 3 identified proven/probable transmissions reported above, an additional 68 recipients had new virus notifications, of whom 2/68 died due to HBV infection. The infections in these 68 recipients may have been undetected late transmission, reactivating HBV, or de novo infections. Substantial preventative measures are available for these conditions including vaccination and avoiding risk-exposures. Stimulated by this concern about preventable non-transmitted infection, Chapter 6 of this thesis aims to understand the burden of notifiable infections post-transplant, which often have known preventive strategies. To do this, we conducted a cohort study of all solid organ recipients transplanted in New South Wales, Australia, 2000-2015. We used data-linkage to connect transplant registers to hospital admissions, notifiable diseases database, and the death register. We then calculated standardised incidence ratios (SIR) relative to general population notification rates, accounting for age, sex, and calendar year, and identified infection-related hospitalisations and deaths. Among 4,858 solid organ recipients followed for 39,183 person-years, there were 792 notifications. Influenza was the most common infection (532 cases, incidence 1358/100,000 person-years, 95%CI:1247-1478), with the highest prevalence within 3 months post-transplant. The second most common was salmonellosis (46 cases, incidence 117/100,000 person-years, 95%CI:87-156), followed by pertussis (38 cases, incidence 97/100,000 person-years, 95%CI:71-133). Influenza and invasive pneumococcal disease (IPD) in transplant recipients showed significant excess cases compared with the general population (influenza SIR 8.5, 95%CI:7.8-9.2, IPD SIR 9.8, 95%CI:6.9-13.9), with high hospitalisation rates (47% influenza cases, 68% IPD cases) and some mortality (four influenza and one IPD deaths). By 10 years post-transplant, cumulative incidence of any vaccine-preventable disease was similar for most transplanted organs at 12%, except for lung recipients, where it was nearly 30%. Gastrointestinal diseases, tuberculosis and legionellosis had excess cases among transplant recipients, although there were few sexually transmitted infections and vector-borne diseases. Improved vaccination programs, health education, and pre-transplant donor and recipient screening have the potential to reduce preventable infections among transplant recipients. Conclusion: This thesis explores some ways in which infectious diseases impact organ donation and transplantation, and identifies areas where clinical practice could be improved. Transplant clinicians need more support to interpret hepatitis transmission risk as they have variable interpretations of suitability. Many potential donors have increased risks for BBV transmission, with otherwise favourable characteristics, and did not donate. Actual transmission risks from both Australian donors with BBV and potential donors with increased risk behaviours are, in absolute terms, low. A reconsideration of risk profiles for potential donors with increased BBV transmission risk could materially increase organ donation rates in Australia. In addition, organ transplant recipients have significant post-transplant infections, including both BBV and other notifiable infections such as vaccine-preventable and gastrointestinal infections. Important infections post-transplant could be prevented by improved vaccination uptake and optimised strategies, donor and recipient screening for latent infection, and donor recipient education.

A method for preserving transplant organs for extended periods of time has been developed in the transplant organ preservation cooler. The preservation cooler enhances organ viability by maintaining a temperature controlled organ bath and pumping perfusate through the transplant organ. The emphasis on the transplant organ preservation cooler is to provide a simple and portable system which will be powered by boiled off oxygen from a liquid oxygen source. The design of the preservation cooler pump and temperature control system are presented. Results of tests proving the successful operation of the preservation cooler prototype are also presented.
Master of Science

Most South Africans die without their organs being harvested for transplantation. In a country where motor vehicle accidents or violent crime are often the cause of death, presumably leaving most of the organs fit for transplantation, it is astounding that the offer of organs doesn’t meet the demand. The aim of this dissertation is to find a practical solution for the current shortage of transplantable human organs in South Africa. This is achieved by critically discussing current South African legislation regulating organ transplantation, considering alternative organ procurement methods, as well as the impact that bioethics and the Constitution might have on the success of an organ procurement system. This dissertation is concluded with the realisation that although the current organ procurement method needs to be changed to required request, relieving the organ shortage will only be achieved by combining several proposed legislative changes, including, but not limited to, creating a national donor as well as a national waiting list; launching an educational campaign; limiting the role of relatives; and expanding the definition of death for the purpose of organ harvesting. KEY TERMS: organ procurement methods; National Health Act; Constitution; organ shortage; bioethics; autonomy; dignity; required request.
Dissertation (LLM)--University of Pretoria, 2013.
gm2014
Public Law
unrestricted

Introduction: NKT cells are categorised as borderline between NK and T cells, sharing phenotypic and functional characteristics of both cells, demonstrating their capacity to contritube to both pro- or anti-inflammatory processes. However, the role of these cells among lung transplant recipients remains largely unknown. The aim of this study was to determine the role of NKT cells following lung transplantation. Methods: NKT cells were quantified and characterised according to markers of: activation (CD107a, CD161, NKG2D) and immunomodulation (CD200 and CD200R) in peripheral blood and BALs. NKT cell numbers and phenotypes were correlated to clinical variables: immunosuppression, acute rejection, acute infections (viral, bacterial and fungal), bronchiolitis obliterans syndrome (BOS grade), lung function, and demographic variables. Interactions between NKT cells and the transplanted lung were linked by determining the relative expression of immunomodulatory ligand CD200 in lung biopsies. In vitro models were employed to determine the role of NKT cells to acute lung injury, either alone or in combination with cells of the mononuclear phagocyte system (MPS). Results: Higher numbers of immunomodulatory NKT cells (CD200+ and CD200R+) were found as lung function decreased. Data from peripheral blood indicates that recipients whose donors or themselves had been exposed to CMV infection demonstrated increased numbers of NKT cells. Patients with active EBV infections demonstrated higher NKT cell numbers expressing CD200 and CD200R. Data from BALs, indicates that patients with active fungal infections present higher immunomodulatory (CD200R) NKT cells and lower cytotoxicity marker (CD107a). In peripheral blood, lung recipients demonstrated higher NKT cell numbers compared to healthy volunteers. However, the lower relative mean expression of functional markers in the lung transplant group suggests that cells are less active. In vitro cultures with immunosuppressants demonstrated that cell cycle inhibitors (MMF and AZA) and corticosteroids (Prednisolone) are likely to inhibit NKT cell proliferation, while calcineurin inhibitors (Cyclosporine A and Tacrolimus) decrease the relative mean expression of activation markers. Clinical observations indicate that higher doses of Azathioprine may correlate with increased NKT cell numbers and the relative expression of CD200 and CD200R. However, under these conditions the relative expression of activation marker NKG2D decreases. In vitro data from the acute injury model indicates that NKT cells are capable to migrate into the injured lung and become activated following transmigration which is facilitated by the presence of monocytes. We also observed the interaction of NKT cells with endothelial cells, monocytes and macrophages. Also, the relative mean expression of CD200 and CD200R increased at the capillary layer, regardless of injury while upregulation of activation markers (CD107a, CD161 and NKG2D) was found at the capillary layer, following injury. In contrast, the alveolar layer demonstrated a decrease in both activation and immunomodulatory markers, following acute injury. Conclusions: Despite immunosuppression, NKT cells remain present in peripheral blood and BAL following lung transplantation. NKT cell proliferation is likely to be reduced by effect of cell cycle inhibitors, while calcineurin inhibitors exert an immunomodulatory effect. Our data indicates that NKT cells can participate in inflammatory and immunomodulatory events at the alveolar bilayer. Their capacity to infiltrate the lungs was assisted by cells of the mononuclear phagocyte system (MPS), which play an important role in antigen presentation and modulation of acute injury. Further research is needed to elucidate the signals and mechanisms occurring between NKT and MPS interactions and the outcomes these populations drive in acute lung injury.

Transplantation has revolutionised the management of end stage organ disease, and is currently the treatment of choice in many developed western nations. The success of this treatment has led to an increasing demand for it, and concomitant increase in the demand for transplantable organs. Organ scarcity is widely acknowledged as the dominant, and most persistent, problem faced in contemporary transplantation. Scarcity of available organs undergirds the gift-of-life metaphor, upon which all transplantation discourses have been founded (Fox & Swazey, 2002). Gift-of-life discourse is routinely utilised in a bid to increase donation rates and enforce a ‘construction of care’ in recognition of, and reciprocity for, the scarce and precious gift received (Sothern & Dickinson, 2011). Shaw (2012) argued that gift-of-life rhetoric is prescriptive; directing, in large part, what can be felt and said in the context of transplantation. This can be problematic, as although transplantation undoubtedly extends life, it does not do so without incurring physiological and psychological cost. The immunosuppression regimens that recipients must adhere to and the psychosocial outcomes of transplantation mean that, in effect, transplantation may represent the exchange of one set of hardships for another (Sharp, 2006). Recipients often exist in a state of ‘persistent liminality’, caught between the worlds of the healthy and the sick (Crowley-Matoka, 2005). This research was undertaken to explore the lived experience of transplantation. I was particularly interested in exploring how gift-of-life understandings of transplantation might influence this experience. Given the normative expectation of gratitude in response to a gift/benefit received (McCullough & Tsang, 2004) and the centrality of gratitude to gift-of-life discourse (Shaw, 2012), I was also interested in exploring gratitude in the iii context of transplantation. Participants were 19 (i.e., 13 heart, 6 liver) recipients, and 11(i.e., 1 liver, 10 kidney) prospective recipients. I conducted semi-structured interviews, and adopted an interpretative phenomenological approach to analysis. Results indicated that a generic model cannot be applied across the range of transplantation experiences. The psychosocial experience of receiving a heart is not the same as the experience of receiving a liver, or that of receiving a kidney. Social constructions of the particular organ being received (e.g., the liver, a life-saving organ, is more ‘precious’ than the kidney, a quality-of-life organ), and of those most likely to need that organ (e.g., liver recipients are alcoholics who are responsible for their illness) shape the experience of receiving (or waiting to receive) a heart, liver, or kidney. While all participants acknowledged an awareness of gift-of-life discourse, and its potential to direct their experience (e.g., considerations of whether or not they were worthy or deserving of the gift-of-life), many reported they did not understand transplantation in this way. Recipients did not uniformly express gratitude and, here too, the particular organ being received appeared to exert an influence (e.g., heart recipients most often expressed gratitude, while many liver recipients did not report gratitude in relation to their transplant). These findings provide new insights with respect to the experience of transplantation, and also to the experience of gratitude.

This thesis sought to improve our understanding of how kidneys become injured as a consequence of organ donation, with the aim of improving the outcomes of transplantation. Every year, hundreds of patients on the waiting list die whilst awaiting a kidney transplant. With an ever-increasing demand for suitable organs, supply cannot keep up with the pressures on the transplant waiting list. As a consequence the transplant community are forced to use organs that previously would not have been considered suitable for transplant, including from older donors with additional comorbidities. This thesis aimed to develop an understanding as to how the kidney becomes injured during the donation process, identifying which key cellular homeostatic processes are disturbed as a consequence of donation. The thesis outlines the experimental development of rodent models of organ donation replicating the donation process for donation after brain death (DBD) and donation after circulatory death (DCD) donors and also the development of a kidney ischaemia reperfusion injury (IRI) model. Proteomics was subsequently used to identifying global protein alterations in the kidney as a consequence of brain death and ischemia reperfusion injury using bioinformatics tools to identify involvement of cellular pathways. The results indicated alterations in mitochondrial function and metabolic homeostasis occurring following brain death. Alterations in cellular metabolism and mitochondrial function were then confirmed using metabolomics and mitochondrial functional assays. I subsequently evaluated how alterations in cellular hypoxia and the hypoxia inducible factor system is altered in the brain dead organ donor kidney and aimed to target this system as a means of conditioning the brain dead organ donor to prevent mitochondrial and metabolic mediated injury to kidney cells following brain death. This involved exploring the role of prolyl hydroxylase inhibitors, including dimethyloxalylglycine, on mitochondrial function and whether this could be a therapeutic target in organ donation. This thesis provides important insights into the mechanism of injury of kidneys following brain death, providing evidence that even before procurement and preservation in the DBD donor alterations in mitochondrial function and metabolic homeostasis occur. I provide preliminary data on the use of prolyl hydroxylase inhibitors in altering mitochondrial function. I also outline my involvement in other ongoing projects in organ donation and machine perfusion that also aim to improve the outcomes of deceased donor kidney and liver transplantation.

Bakgrund: Antalet patienter som väntar på en organ transplantation har ökat stadigt under de senaste årtiondena. En förutsättning till att väntetiderna skall förkortas är att efterfrågan av organ blir mättat. Efterfrågan av organ är större än tillgången, detta medför förlängda väntetider inför en organ transplantation. Patienter som väntar på en organ transplantation blir lidande och detta bidrar till erfarenheter av fysiskt och psykiskt ohälsa. Syfte: Syftet var att beskriva erfarenheterna hos patienter som väntar på en organ transplantation samt att göra en metodologisk granskning av de valda artiklarnas datainsamlingsmetod. Metod: En beskrivande litteraturstudie som har undersökt 13 artiklar, majoriteten av artiklar var av kvalitativ design. Resultat: Patienters erfarenheter av att vänta på en organ transplantation förknippas ofta med känslor som ångest och depression. Patienter upplever att väntetiderna på att få en organ transplantation är långa och erfarenheter är att livet står på paus. Erfarenheter som patienterna upplever är att stöd från närstående och sjukvården har stor betydelse. Även att träffa andra patienter som väntar på en organ transplantation ansågs som ett stöd för patienterna. Patienterna beskrev att erfarenheterna av att få information från sjukvårdspersonalen om sin hälsosituation var av stor betydelse. De valda artiklarnas datainsamlingsmetod bestod av 11 kvalitativa intervjustudier. Två av artiklarna hade kvantitativ ansats där enkäter använts. Slutsats: Patienter som väntar på att genomgå en organ transplantation har ofta erfarenheter av att väntetiderna är långa och med tiden blir patienterna oroliga och rädda. Patienternas erfarenheter av stöd från sjukvårdpersonalen är viktiga för vårdprocessen och att sjuksköterskor därför har ett stort ansvar att anpassa vården efter patientens individuella behov.
Background: The number of patients waiting for an organ transplant has increased steadily for the past decades. A prerequisite for a successful transplantation program is of course that the demand for organs gets saturated by a steady supply of the same. This is unfortunately not the case as the gap between supply and demand is increasing, hence prolonging waiting times and negatively effecting the patients’ health and overall prognosis. Aim: Portrait the experiences of patients waiting for an organ transplant as well as conducting a methodological examination of the data collection method used in a selection of articles. Method: A descriptive literature that has examined 13 articles, the majority of articles were qualitative design. Results: Patients' experiences when waiting for an organ transplant is often associated with feelings such as anxiety and depression. Patients experiencing the waiting time to get an organ transplant as long and the experience is that the patient’s life is paused. Experiences which patients describes is that support from family and healthcare professionals are of great importance. Even to meet with other patients waiting for an organ transplant was considered as a support for patients. Patients described that experience of getting information from medical staff about his health situation was important for the patients. The articles selected data collection method consisted of 11 qualitative interview study. Two of the articles had quantitative design where surveys have been used. Conclusion: Patients waiting to undergo an organ transplant often have experience of waiting times are long and with time these patients are anxious and fearful. The patients experienced the support from medical staff is important to the care process and that nurses therefore have an important responsibility to adapt care to individual patient needs.

Foetal islets are functionally immature but retain their capacity for proliferation if harvested and cultured in an appropriate manner. Graft function was shown to depend largely on the gestational age and conditions of organ culture prior to transplantation. The required period of organ culture for optimal graft function was investigated for foetal mouse pancreas of different gestational ages. The growth of the graft in situ also depended on the diabetic state of the host, and chronic hyperglycaemia appeared to impair graft function. Subsequent studies using NOD recipient mice as a model for IDDM showed that recurrent autoimmune disease was seen in foetal islet isografts but rapid rejection of allografts and foetal pig xenografts also occurred. The striking differences seen between the allo-, and xenograft response was the presence of many eosinophils that dominated the infiltrate at the xenograft site. However, HAR was not a problem in this discordant xenograft and Gal(1-3)Gal expression, the major epitope for xenoreactive Ab, was not present on differentiated cells but was detectable on ductal cells. A brief treatment with a specific anti-CD4 MAb (GK1.5) had a profound effect in the survival of xenografts in NOD mice. There were consistent differences in xenograft survival and in the number of circulating T and B cells in other strains of mice, e.g. CBA, BALB/c, C57BL/6 compared to NOD mice. Prolongation of xenograft survival for up to 12 weeks was achieved with the use of peri-transplant and weekly treatment with anti-CD4 or anti-CD3 MAbs especially when the graft has been "immunomodulated" by using 90% O2 in organ culture. Using this protocol foetal pig xenografts maturing under the kidney capsule of spontaneously diabetic NOD mice reversed hyperglycaemia and appeared also to secrete growth factor(s) that induced regeneration of cells in the host pancreas.

Transplantation är idag etablerad behandling vid leversvikt och njursvikt med mycket goda resultat gällande överlevnad. För patienten är det dock en stor omställning att lida av en livshotande sjukdom och i nästa stund ha fått någon annan människas organ som gör det möjligt att leva. Den nya livssituationen ställer stora krav på patientens anpassningsförmåga då behandlingen med immundämpande mediciner orsakar en mängd konsekvenser i det dagliga livet och hälsotillståndet. För att kunna hjälpa patienten i deras återhämtningsprocess måste vi som sjuksköterskor ta del av människans livsvärld där patienters upplevelser och erfarenheter har en central roll. Syftet med denna uppsats är att beskriva människors upplevelser av att leva med en ny njure eller lever under de första åren efter transplantationen.Metoden är en litteraturstudie som utgår ifrån evidensbaserad omvårdnad med grund i analys av kvalitativ forskning eftersom patienters upplevelser av sin situation skall beskrivas. Resultatet sammanställs i teman: Att leva med otryggheten inför framtiden, betydelsen av en stödjande omgivning, tacksamhet för det nya livet, upplevelser av bristande autonomi, kampen om en nyorientering, medicineringens effekt på vardagen, behov av information.I resultatdiskussion diskuteras några av de teman som framkommit i resultatet. Otryggheten inför framtiden är centralt i resultatet. Rädslan för en avstötning präglar hela tillvaron och upplevs som ett osynligt hot. Stöd från familj och vänner upplevs som mycket viktigt för patienternas återhämtningsprocess. Efter transplantationen hamnar många i en ekonomisk svår situation som hämmar patienternas integritet och förmågan att återvända till ett normalt livsmönster. Det betonas även hur betydelsefullt det är att patienten är ordentligt informerad. I resultatdiskussionen belyses även praktiska implikationer för den kliniska omvårdnaden samt frågor av intresse för vidare forskning.

Program: Sjuksköterskeutbildning

Uppsatsnivå: C

Organ transplantation is one of the most important and effective solutions to save end-stage patients, who have one or more critical organ failures. However, the inadequate organs for transplantation to meet the demands has been the major issue. Even worse, the lack of accurate non-invasive assessment methods wastes 20% of donor organs every year. Currently, the most frequently used organ assessment methods are visual inspections and biopsy. Yet both methods are subjective: the assessment accuracy depends on the evaluator's experience. Moreover, repeating biopsies will potentially damage the organs. To reduce the waste of donor organs, online non-invasive and quantitative organ assessment methods are in great needs. Organ viability assessment is a challenging issue due to four reasons: 1) there are no universally accepted guidelines or procedures for surgeons to quantitatively assess the organ viability; 2) there is no easy-deployed and non-invasive biological in situ data to correlate with organ viability; 3) the organs viability is difficult to model because of heterogeneity among organs; 4) both visual inspection and biopsy can be applied only at present time, and how to forecast the viability of similar-but-non-identical organs at a future time is still in shadow. Motivated by the challenges, the overall objective of this dissertation is to develop online non-invasive and quantitative assessment methods to predict and forecast the organ viability. As a result, four data-driven modeling research tasks are investigated to achieve the overall objective: 1) Quantitative and qualitative models are used to jointly predict the number of dead cells and the liver viability based on features extracted from biopsy images. This method can quantitatively assess the organ viability, which could be used to validate the biopsy results from pathologists to increase the evaluation accuracy. 2) A multitask learning logistic regression model is applied to assess liver viability by using principal component analysis to extract infrared image features to quantify the correlation between liver viability and spatial infrared imaging data. This non-invasive online assessment method can evaluate the organ viability without physical contact to reduce the risk of damaging the organs. 3) A spatial-temporal smooth variable selection method is conducted to improve the liver viability prediction accuracy by considering both spatial and temporal effects from the infrared images without feature engineering. In addition, it provides medical interpretation based on variable selection to highlight the most significant regions on the liver resulting in viability loss. 4) A multitask general path model is implemented to forecast the heterogeneous kidney viability based on limited historical data by learning the viability loss paths of each kidney during preservation. The generality of this method is validated by tissue deformation forecasting in needle biopsy process to potentially improve the biopsy accuracy. In summary, the proposed data-driven methods can predict and forecast the organ viability without damaging the organ. As a result, the increased utilization rate of donor organs will benefit more end-stage patients by dramatically extending their life spans.
Doctor of Philosophy
Organ transplantation is the ultimate solution to save end-stage patients with one or more organ failures. However, the inadequate organs for transplantation to meet the demands has been the major issue. Even worse, the lack of accurate and non-invasive viability assessment methods wastes 20% of donor organs every year. Currently, the most frequently used organ assessment methods are visual inspections and biopsy. Yet both methods are subjective: the assessment accuracy depends on the personal experience of evaluator. Moreover, repeating biopsies will potentially damage the organs. As a result, online non-invasive and quantitative organ assessment methods are in great needs. It is extremely important because such methods will increase the organ utilization rate by saving more discarded organs with transplantation potential. The overall objective of this dissertation is to advance the knowledge on modeling organ viability by developing online non-invasive and quantitative methods to predict and forecast the viability of heterogeneous organs in transplantation. After an introduction in Chapter 1, four research tasks are investigated. In Chapter 2, quantitative and qualitative models jointly predicting porcine liver viability are proposed based on features from biopsy images to validate the biopsy results. In Chapter 3, a multi-task learning logistic regression model is proposed to assess the cross-liver viability by correlating liver viability with spatial infrared data validated by porcine livers. In Chapter 4, a spatial-temporal smooth variable selection is proposed to predict liver viability by considering both spatial and temporal correlations in modeling without feature engineering, which is also validated by porcine livers. In addition, the variable selection results provide medical interpretations by capturing the significant regions on the liver in predicting viability. In Chapter 5, a multitask general path model is proposed to forecast kidney viability validated by porcine kidney. This forecasting method is generalized to apply to needle biopsy tissue deformation case study with the objective to improve the needle insertion accuracy. Finally, I summarize the research contribution and discuss future research directions in Chapter 6. The proposed data-driven methods can predict and forecast organ viability without damaging the organ. As a result, the increased utilization rate of donor organs will benefit more patients by dramatically extending their life spans and bringing them back to normal daily activities.

On December 3rd, 1967, Dr Christian Barnard performed the world's first human heart transplant. This medical milestone propelled the technique of organ transplantation into the public arena, and simultaneously created a need for human organs that has never been met. The disparity between the numbers of organs needed for transplantation and the numbers of organ donated has generated substantial research. Most of this research has focused on individual characteristics and behaviours in an attempt to understand the individual's decision to donate. In contrast, the research in this thesis emanates from the position that we must first investigate how organ donation and transplantation is socially understood. The theory of social representations (Moscovici, 1984) proclaims an interdependence between the individual and the social, and their inseparability in the construction of social knowledge. Conceptualised thus, organ donation and transplantation moves from being understood in terms of an individual decision to a socially derived way of understanding a medical practice. Thus, the focus of the research presented in this thesis is a holistic conceptualisation of organ donation and transplantation as socially constructed knowledge. Three studies were conducted, each addressing this issue from a different methodological perspective. The first study, which was exploratory in nature, investigated whether there was a representation pertaining to organ donation and organ transplantation, and traced the development of the representation through the printed media. Drawing from research into the structural properties of a representation (Abric, 1993, 1996), and the notions of themata, anchoring and objectification (Moscovici, 1984, 1993), the findings from this study set the direction and design of the two studies that followed. The main finding from this study was the suggestion that what was initially considered to be two representations was better understood as one representational field organised around conflicting images of organ donation and transplantation as a Gift of Life and the Mechanistic removal and replacement of body parts. The findings, however, from the first study suggested a stasis to the representational field that did not accommodate the dynamism implied. Thus, the second study extended the findings of the first study and investigated the representational field through discourse from focus group discussions. The theoretical position here conceptualised consensus as consensual reality (Rose et al., 1995), and investigated the suggestion that the core of the representation is hierarchically arranged into normative and functional dimensions (Guimelli, 1998). The findings from this second study evidenced the contradictory nature of discourse around the issue of organ donation and transplantation. These were discussed in light of Billig' s (1988) rhetorical position of the role of argumentation in social thinking. The co-existence of contradiction was suggested through the differential elicitation of the normative and functional dimensions of the core (Guimelli, 1998). The final study extended the findings of both earlier studies through a delineation of the core and peripheral elements within the representational field so as to specifically investigate the dynamic co-existence of contradiction within the one representational field. The study employed a mail-out questionnaire embedded with 8 experimental conditions. This manipulated two tasks, scenario and rating scale and word association, in order to investigate the elicitation of the representation in accordance with context. This study developed the notion of themata (Markova, 2000), the role of contradiction in a representation (Wagner et al., 2000), reflexive and non-reflexive thought, and an understanding of consensus as consensual reality (Rose et al., 1995). The major conclusion of the thesis is that an investigation of the issue of organ donation and transplantation within the theoretical framework of social representations theory (Moscovici, 1984) reveals a contradictory representational field organised around the dialectical notions of Life and Death, emanating as two, seemingly contradictory, images of organ donation and transplantation as a Gift of Life and the Mechanistic removal and replacement of body parts. Moreover, the co-existence of this contradictory representational field is maintained through the differential elicitation of the normative and functional dimension of the representation in accordance with social context. An integration of the findings within the theoretical tenets of social representations theory is given, addressing the interdependence between the representational process and what is being represented. The practical implications of these findings as they relate to the societal issue of organ donation and transplantation are also discussed.

General Abstract Objective: In April 2006, the Scottish Liver Transplant Unit (SLTU) became the first NHS transplant unit in the UK to offer the option of Living Donor Liver Transplantation (LDLT). This represented a unique opportunity to evaluate the functional and psychosocial impact of LDLT upon healthy donors and their recipients. Subsequent aims were to investigate the challenge of introducing LDLT in Scotland and to establish the perceived deterrents and attractions of the procedure. An additional aim was to evaluate the impact of Living Donor Kidney Transplantation (LDKT) upon donors and recipients. Design: A series of cross sectional and longitudinal studies were designed for the purpose of this thesis (3 quantitative, 2 qualitative, and 1 mixed methods). Method: Self report questionnaires were used in each of the quantitative studies, with the addition of neuropsychological computerized tests in two studies. Semi-structured interviews were employed in the qualitative studies. Main Findings: •Prior to its introduction general support for the option of LDLT was found, although it was highlighted that the risk involved was not well understood by the general public. •Since becoming available LDLT has not been a readily acceptable treatment option from the perspective of patients due to the perceived risk for the donor, but it may be considered as a “last option”. Family members were motivated to save their loved one’s life but the personal implications of donating resulted in reconsideration of LDLT. • Staff at the SLTU perceived a lack of family commitment in relation to LDLT, which is explained as a cultural factor contributing to the slow uptake of LDLT. In Scotland, a donation from a younger to an older generation is not easily accepted. This, in addition to patients’ optimism that a deceased donation will arrive, and the poor health of potential donors, is thought to have affected the uptake of LDLT. As has the unit’s conservative approach to the promotion of LDLT. This approach is the result of a perceived reduction in the need for LDLT and a preference to avoid the risk to a healthy donor and conduct transplants with deceased donations. • In over 3 years, only one couple completed LDLT. The recipient showed functional and psychosocial improvement from pre to post procedure, whilst the donor showed slight deterioration in aspects of quality of life 6 weeks post donation, which did not always completely return to a baseline level by 6 months. The donor made sacrifices to provide her husband with a fresh start to life and unmet expectations were found to effect quality of life. •Willingness to become a liver donor is not thought to be influenced by the frame of the information provided. •Like the LDLT donor, LDKT donors experience some functional and psychosocial deterioration at 6 weeks post donation, but donors largely recover by 6 months post donation. However, the anticipated benefit to recipients was not evident and may not be quantifiable until after 6 months post operation. Conclusion: This thesis has added to current knowledge on living organ donation and specifically represents the first psychological evaluation of a UK LDLT programme. The slow uptake of LDLT was unexpected and has resulted in informative, novel research.

Since the 1950’s procuring organs for cadaveric transplantation has been based around a “gift of life” discourse, institutionalised through the carrying of donor cards/driving licence or registration on the NHS Organ Donor Register. Yet regardless of whether and how the deceased recorded their wishes to donate, their next-of-kin are always whether organs can be removed. Little is known about the reasons families give for refusing or agreeing to an organ donation request. In order to identify the circumstances in which an organ donation request is more likely to be accepted or refused by the family of a brain stem dead individual, semi-structured interviews were carried out in various areas of Scotland in order to ascertain donor and non-donor relatives’ beliefs, attitudes and experiences. The findings suggest that wider cultural beliefs embedded in society about the value of gifting, death and the body are brought to the specific context of an organ donation request. It is the interactions between these values and other factors, such as familial and hospital support and dynamics and the perceived value of the outcome from donation affects whether families will donate or not. The findings of such an investigation will have obvious policy implications for those interested in increasing the present UK organ procurement rate and can also inform debates about the merits of introducing alternative systems. However, a study of organ donation and transplantation can also provide the sociologist with a unique insight into several engaging areas of sociological interest: modern gift practices (including altruism and social exchange theory), the way meanings are constructed onto dead bodies by different groups, of how and when death is defined, and finally, can lead insight into an intricate relationship about how individuals’ view the relationship between personal, social and corporeal identity.

Brain death has adverse effects on the organ donor, increasing organ dysfunction and affecting transplantation outcomes. It can also render organs unsuitable for transplantation. Another determinant of organ quality is ischaemia-reperfusion injury, which limits ischaemic storage time for hearts to six hours. The aim of this thesis was to investigate the effectiveness of hormone resuscitation (HR) of the donor to ameliorate the effects of brain death. Another aim was to develop a donor management and organ preservation strategy to ameliorate the effects of ischaemia-reperfusion injury on the heart, thereby extending ischaemic preservation times. A porcine model of the brain-dead multi-organ donor with orthotopic cardiac transplantation was utilised. Donor HR was shown to improve cardiac contractility and haemodynamics, thereby reducing inotrope requirements. A follow-up study investigating the effects of three different donor management protocols demonstrated that donor haemodynamics, renal arterial flow and creatinine clearance were superior in HR animals compared with animals treated with noradrenaline or intravenous fluid alone. Noradrenaline was associated with a significant deterioration in pulmonary function (PaO2 and alveolar-arterial oxygen gradient) and a decline in donor pH. HR was not associated with any detrimental effects on the lungs, liver or pancreas compared with the other two groups. Preservation strategies incorporating glyceryl trinitrate (GTN) and cariporide, a Na+-H+ exchange inhibitor, were investigated to safely extend cardiac ischaemic preservation times. Pre-treatment with intravenous cariporide prior to heart explantation (donor) and reperfusion of the transplanted heart (recipient) was shown to effectively extend ischaemic time to 14 hours, evidenced by weaning off cardiopulmonary bypass. GTN and cariporide-supplemented Celsior, used as a cardioplegic/storage solution, was also effective in extending preservation time to 14 hours, with superior cardiac contractility compared with cariporide pre-treated hearts. Both treatments also ameliorated reperfusion injury, stabilising haemodynamics for up to three hours post-bypass. This thesis has demonstrated the effectiveness of HR to ameliorate the negative effects of donor brain death. It also provides evidence that combined GTN and cariporide-supplemented Celsior improves long-term preservation of the donor heart. These strategies offer the potential to increase the proportion of transplantable organs, to improve donor organ quality, and thereby improve transplantation outcomes.

Although the short-term outcomes of solid allograft survival have improved substantially over the last few decades, there has been no significant improvement in long-term survival of solid allografts. This thesis presents the initial characterisation of alloantibody mediated rejection in a murine heart transplant model, with particular focus on the impact of the different phases of the humoral alloimmune response (follicular or germinal centre) on graft rejection.