J Andrew Bradley

University of Cambridge, Cambridge, England, United Kingdom

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Publications (136)942.38 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Adaptive CD8 T-cell immunity is the principal arm of the cellular alloimmune response, but its development requires help. This can be provided by CD4 T cells that recognize alloantigen "indirectly," as self-restricted allopeptide, but this process remains unexplained, because the target epitopes for CD4 and CD8 T-cell recognition are "unlinked" on different cells (recipient and donor antigen presenting cells (APCs), respectively). Here, we test the hypothesis that the presentation of intact and processed MHC class I alloantigen by recipient dendritic cells (DCs) (the "semidirect" pathway) allows linked help to be delivered by indirect-pathway CD4 T cells for generating destructive cytotoxic CD8 T-cell alloresponses. We show that CD8 T-cell-mediated rejection of murine heart allografts that lack hematopoietic APCs requires host secondary lymphoid tissue (SLT). SLT is necessary because within it, recipient dendritic cells can acquire MHC from graft parenchymal cells and simultaneously present it as intact protein to alloreactive CD8 T cells and as processed peptide alloantigen for recognition by indirect-pathway CD4 T cells. This enables delivery of essential help for generating cytotoxic CD8 T-cell responses that cause rapid allograft rejection. In demonstrating the functional relevance of the semidirect pathway to transplant rejection, our findings provide a solution to a long-standing conundrum as to why SLT is required for CD8 T-cell allorecognition of graft parenchymal cells and suggest a mechanism by which indirect-pathway CD4 T cells provide help for generating effector cytotoxic CD8 T-cell alloresponses at late time points after transplantation.
    Proceedings of the National Academy of Sciences 09/2015; DOI:10.1073/pnas.1513533112 · 9.67 Impact Factor
  • The Lancet 08/2015; 386(9995):719-21. DOI:10.1016/S0140-6736(15)61413-1 · 45.22 Impact Factor
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    ABSTRACT: The study of biliary disease has been constrained by a lack of primary human cholangiocytes. Here we present an efficient, serum-free protocol for directed differentiation of human induced pluripotent stem cells into cholangiocyte-like cells (CLCs). CLCs show functional characteristics of cholangiocytes, including bile acids transfer, alkaline phosphatase activity, γ-glutamyl-transpeptidase activity and physiological responses to secretin, somatostatin and vascular endothelial growth factor. We use CLCs to model in vitro key features of Alagille syndrome, polycystic liver disease and cystic fibrosis (CF)-associated cholangiopathy. Furthermore, we use CLCs generated from healthy individuals and patients with polycystic liver disease to reproduce the effects of the drugs verapamil and octreotide, and we show that the experimental CF drug VX809 rescues the disease phenotype of CF cholangiopathy in vitro. Our differentiation protocol will facilitate the study of biological mechanisms controlling biliary development, as well as disease modeling and drug screening.
    Nature Biotechnology 07/2015; 33:845–852. · 41.51 Impact Factor
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    ABSTRACT: In a number of countries, reimbursement to hospitals providing renal dialysis services is set according to a fixed tariff. While the cost of maintenance dialysis and transplant surgery are amenable to a system of fixed tariffs, patients with established renal failure commonly present with comorbid conditions that can lead to variations in the need for hospitalization beyond the provision of renal replacement therapy. Patient-level cost data for incident renal replacement therapy patients in England were obtained as a result of linkage of the Hospital Episodes Statistics dataset to UK Renal Registry data. Regression models were developed to explore variations in hospital costs in relation to treatment modality, number of years on treatment and factors such as age and comorbidities. The final models were then used to predict annual costs for patients with different sets of characteristics. Excluding the cost of renal replacement therapy itself, inpatient costs generally decreased with number of years on treatment for haemodialysis and transplant patients, whereas costs for patients receiving peritoneal dialysis remained constant. Diabetes was associated with higher mean annual costs for all patients irrespective of treatment modality and hospital setting. Age did not have a consistent effect on costs. Combining predicted hospital costs with the fixed costs of renal replacement therapy showed that the total cost differential for a patient continuing on dialysis rather than receiving a transplant is considerable following the first year of renal replacement therapy, thus reinforcing the longer-term economic advantage of transplantation over dialysis for the health service. © The Author 2015. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.
    Nephrology Dialysis Transplantation 06/2015; DOI:10.1093/ndt/gfv224 · 3.58 Impact Factor
  • International Journal of Surgery 06/2015; 18:243. DOI:10.1016/j.ijsu.2015.04.026 · 1.53 Impact Factor
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    ABSTRACT: Free radical production and mitochondrial dysfunction during cardiac graft reperfusion is a major factor in post-transplant ischemia-reperfusion (IR) injury, an important underlying cause of primary graft dysfunction. We therefore assessed the efficacy of the mitochondria-targeted anti-oxidant MitoQ in reducing IR injury in a murine heterotopic cardiac transplant model. Hearts from C57BL/6 donor mice were flushed with storage solution alone, solution containing the anti-oxidant MitoQ, or solution containing the non-anti-oxidant decyltriphenylphosphonium control and exposed to short (30 minutes) or prolonged (4 hour) cold preservation before transplantation. Grafts were transplanted into C57BL/6 recipients and analyzed for mitochondrial reactive oxygen species production, oxidative damage, serum troponin, beating score, and inflammatory markers 120 minutes or 24 hours post-transplant. MitoQ was taken up by the heart during cold storage. Prolonged cold preservation of donor hearts before IR increased IR injury (troponin I, beating score) and mitochondrial reactive oxygen species, mitochondrial DNA damage, protein carbonyls, and pro-inflammatory cytokine release 24 hours after transplant. Administration of MitoQ to the donor heart in the storage solution protected against this IR injury by blocking graft oxidative damage and dampening the early pro-inflammatory response in the recipient. IR after heart transplantation results in mitochondrial oxidative damage that is potentiated by cold ischemia. Supplementing donor graft perfusion with the anti-oxidant MitoQ before transplantation should be studied further to reduce IR-related free radical production, the innate immune response to IR injury, and subsequent donor cardiac injury. Copyright © 2015 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.
    The Journal of Heart and Lung Transplantation 06/2015; 29. DOI:10.1016/j.healun.2015.05.007 · 6.65 Impact Factor
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    ABSTRACT: Ischemia-reperfusion (IR) injury to the kidney occurs in a range of clinically important scenarios including hypotension, sepsis and in surgical procedures such as cardiac bypass surgery and kidney transplantation, leading to acute kidney injury (AKI). Mitochondrial oxidative damage is a significant contributor to the early phases of IR injury and may initiate a damaging inflammatory response. Here we assessed whether the mitochondria targeted antioxidant MitoQ could decrease oxidative damage during IR injury and thereby protect kidney function. To do this we exposed kidneys in mice to in vivo ischemia by bilaterally occluding the renal vessels followed by reperfusion for up to 24h. This caused renal dysfunction, measured by decreased creatinine clearance, and increased markers of oxidative damage. Administering MitoQ to the mice intravenously 15min prior to ischemia protected the kidney from damage and dysfunction. These data indicate that mitochondrial oxidative damage contributes to kidney IR injury and that mitochondria targeted antioxidants such as MitoQ are potential therapies for renal dysfunction due to IR injury. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.
    04/2015; 5:163-168. DOI:10.1016/j.redox.2015.04.008
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    ABSTRACT: The use of kidneys from controlled donation after circulatory death (DCD) donors has the potential to markedly increase kidney transplants performed. However, this potential is not being realized because of concerns that DCD kidneys are inferior to those from donation after brain-death (DBD) donors. The United Kingdom has developed a large and successful controlled DCD kidney transplant program that has allowed for a substantial increase in kidney transplant numbers. Here we describe recent trends in DCD kidney donor activity in the United Kingdom, outline aspects of the donation process, and describe donor selection and allocation of DCD kidneys. Previous UK Transplant Registry analyses have shown that while DCD kidneys are more susceptible to cold ischemic injury and have a higher incidence of delayed graft function, short- and medium-term transplant outcomes are similar in recipients of kidneys from DCD and DBD donors. We present an updated, extended UK registry analysis showing that longer-term transplant outcomes in DCD donor kidneys are also similar to those for DBD donor kidneys, and that transplant outcomes for kidneys from expanded-criteria DCD donors are no less favorable than for expanded-criteria DBD donors. Accordingly, the selection criteria for use of kidneys from DCD donors should be the same as those used for DBD donors. The UK experience suggests that wider international development of DCD kidney transplantation programs will help address the global shortage of deceased donor kidneys for transplantation.Kidney International advance online publication, 18 March 2015; doi:10.1038/ki.2015.88.
    Kidney International 03/2015; 88(2). DOI:10.1038/ki.2015.88 · 8.56 Impact Factor
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    ABSTRACT: Acute umbilical hernia rupture in patients with hepatic cirrhosis and ascites is an unusual, but potentially life-threatening complication, with postoperative morbidity about 70% and mortality between 60%-80% after supportive care and 6%-20% after urgent surgical repair. Management options include primary surgical repair with or without concomitant portal venous system decompression for the control of the ascites. We present a retrospective analysis of our centre's experience over the last 6 years. Our cohort consisted of 11 consecutive patients (median age: 53 years, range: 36-63 years) with advanced hepatic cirrhosis and refractory ascites. Appropriate patient resuscitation and optimisation with intravenous fluids, prophylactic antibiotics and local measures was instituted. One failed attempt for conservative management was followed by a successful primary repair. In all cases, with one exception, a primary repair with non-absorbable Nylon, interrupted sutures, without mesh, was performed. The perioperative complication rate was 25% and the recurrence rate 8.3%. No mortality was recorded. Median length of hospital stay was 14 d (range: 4-31 d). Based on our experience, the management of ruptured umbilical hernias in patients with advanced hepatic cirrhosis and refractory ascites is feasible without the use of transjugular intrahepatic portosystemic shunt routinely in the preoperative period, provided that meticulous patient optimisation is performed.
    03/2015; 21(10):3109-13. DOI:10.3748/wjg.v21.i10.3109
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    ABSTRACT: Uniquely, alloantigen is recognised by two pathways: as intact antigen on the surface of donor antigen-presenting cells (direct) and as self-restricted processed allopeptide (indirect). The indirect pathway is believed to be longlasting, and is generally considered to be a single entity. Here we address how indirect responses against different alloantigens differ in their strength and longevity, and how this knowledge could be used to direct immunoregulatory therapy with antigen-specific regulatory T cells (Tregs). A murine model of cardiac transplantation was used (bm12.Kd.IE to C57BL/6). Indirect CD4 T-cell allorecognition of mismatched donor MHC class I and II, and of H-Y minor histocompatibility antigen was assessed by quantifying proliferation of adoptively transferred monoclonal T-cell receptor transgenic T cells (TCR75, Tea, Mar). Antigen presentation by dendritic cells and B cells was assessed by selective depletion with diphtheria toxin or depleting anti-CD20 monoclonal antibody. Tregs were generated by in-vitro culture. Indirect pathway responses were heterogeneous. Whereas the indirect response against class I alloantigen was longlasting and persistently strong, the response against class II alloantigen decayed within 2 weeks. Leucocyte depletion studies confirmed that this difference was due to rapid destruction of MHC class II expressing donor B cells and dendritic cells in the recipient, whereas anti-class I responses were generated by continual processing of graft parenchymal cells; recognition of donor haemopoietic fraction was not required. Notably, transfer of MHC class I specific Tregs at transplant or 3 weeks later abrogated germinal centre alloantibody responses and blocked development of allograft vasculopathy, whereas class II specific Tregs were ineffective when transferred at the late timepoint. Although indirect allorecognition is considered to be a single entity, our results show that it consists of a number of responses that vary in duration and strength according to target alloantigen. The ability of class I allopeptide specific Tregs, but not class II specific Tregs, to prevent rejection when transferred at a late timepoint suggests that antigen-specific targeting of dominant and longlasting pathways might be particularly effective at preventing chronic rejection. Wellcome Trust Clinical Research Training Fellowship. Copyright © 2015 Elsevier Ltd. All rights reserved.
    The Lancet 02/2015; 385. DOI:10.1016/S0140-6736(15)60332-4 · 45.22 Impact Factor
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    ABSTRACT: Memory T cells are known to reside in peripheral non-lymphoid tissue, but how their presence within solid organ allografts affects transplant outcomes is not known. We have previously described how graft-versus-host (GVH) allorecognition by passenger CD4 T cells within MHC class II-mismatched bm12 heart grafts provokes antinuclear humoral autoimmunity in C57BL/6 recipient mice. Here we aimed to examine how such GVH recognition affects the alloresponse to allografts with greater mismatching. A MHC class I and II mismatched murine model of cardiac transplantation was developed (bm12.Kd.IE to C57BL/6). After transplantation, cellular and humoral responses against mismatched antigens were measured with ELISPOT and ELISA, and the effect of GVH recognition assessed by depletion of donor CD4 T cells before graft procurement. Antinuclear autoantibody development was assessedwith HeP-2 indirect immunofluorescence. The role of recipient natural killer (NK) cells was examined by depletion with anti-NK1.1 antibody. Bm12.Kd.IE heart grafts provoked strong germinal centre alloantibody and autoantibody responses in C57BL/6 recipients and developed allograft vasculopathy. By contrast, heart grafts from CD4 T-cell-depleted donors developed only minimal vasculopathy, and the alloantibody responses were weaker, without observable autoantibody. Bm12.Kd.IE CD4 T cells survived long term when transferred to RAG hosts suggesting that avoidance of killing by host NK cells might be essential for autoantibody development. In support, in a model of alloantibody-mediated vasculopathy, depletion of NK cells from a C57BL/6 recipient of a BALB/c heart graft resulted in the development of autoantibody, amplification of the alloantibody response, and rapid allograft rejection. This amplification was abrogated by depletion of donor CD4 T cells. Although host adaptive immunity is expected to bring about destruction of passenger lymphocytes within heart allografts, this process occurs too slowly to prevent GVH-mediated augmentation of the alloresponse to the graft. Rather, rapid killing of donor lymphocytes by host alloreactive NK cells is essential. Passenger CD4 lymphocytes might therefore contribute to chronic rejection in recipients receiving an allograft that does not prompt innate NK cell recognition. Wellcome Trust Clinical Research Training Fellowship. Copyright © 2015 Elsevier Ltd. All rights reserved.
    The Lancet 02/2015; 385. DOI:10.1016/S0140-6736(15)60333-6 · 45.22 Impact Factor
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    ABSTRACT: Background: We have previously shown that qualitative assessment of surface electrostatic potential of HLA class I molecules helps explain serological patterns of alloantibody binding. We have now used a novel computational approach to quantitate differences in surface electrostatic potential of HLA B-cell epitopes and applied this to explain HLA Bw4 and Bw6 antigenicity. Methods: Protein structure models of HLA class I alleles expressing either the Bw4 or Bw6 epitope (defined by sequence motifs at positions 77 to 83) were generated using comparative structure prediction. The electrostatic potential in 3-dimensional space encompassing the Bw4/Bw6 epitope was computed by solving the Poisson-Boltzmann equation and quantitatively compared in a pairwise, all-versus-all fashion to produce distance matrices that cluster epitopes with similar electrostatics properties. Results: Quantitative comparison of surface electrostatic potential at the carboxyl terminal of the α1-helix of HLA class I alleles, corresponding to amino acid sequence motif 77 to 83, produced clustering of HLA molecules in 3 principal groups according to Bw4 or Bw6 epitope expression. Remarkably, quantitative differences in electrostatic potential reflected known patterns of serological reactivity better than Bw4/Bw6 amino acid sequence motifs. Quantitative assessment of epitope electrostatic potential allowed the impact of known amino acid substitutions (HLA-B*07:02 R79G, R82L, G83R) that are critical for antibody binding to be predicted. Conclusions: We describe a novel approach for quantitating differences in HLA B-cell epitope electrostatic potential. Proof of principle is provided that this approach enables better assessment of HLA epitope antigenicity than amino acid sequence data alone, and it may allow prediction of HLA immunogenicity.
    Transplantation 02/2015; Online First(2). DOI:10.1097/TP.0000000000000546 · 3.83 Impact Factor
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    ABSTRACT: The monoclonal anti-CD20 antibody rituximab depletes B cells in the treatment of lymphoma and autoimmune disease, and contributes to alloantibody reduction in transplantation across immunological barriers. The effects of rituximab on T cells are less well described. T follicular helper cells (Tfh) provide growth and differentiation signals to germinal center (GC) B cells to support antibody production, and suppressive T follicular regulatory cells (Tfr) regulate this response. In mice, both Tfh and Tfr are absolutely dependent on B cells for their formation and on the GC for their maintenance. Here, we demonstrate that rituximab treatment results in a lack of GC B cells in human lymph nodes without affecting the Tfh or Tfr cell populations. These data demonstrate that human Tfh and Tfr do not require an on-going GC response for their maintenance. The persistence of Tfh and Tfr following rituximab treatment may permit rapid reconstitution of the pathological GC response once the B cell pool begins to recover. Strategies for maintaining remission after rituximab therapy will need to take this persistence of Tfh into account.
    Blood 09/2014; 124(17). DOI:10.1182/blood-2014-07-585976 · 10.45 Impact Factor
  • Elizabeth Day · Patrick K Kearns · Craig J Taylor · J Andrew Bradley
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    ABSTRACT: Advances in developmental biology have shown that monozygous twins may not be as phenotypically identical as once believed, and the mechanisms responsible for such differences are now becoming clearer. Whether such phenotypic differences are capable of triggering graft rejection of an organ transplanted between identical twins remains unknown but the risks seem low, and long-term transplant outcome is excellent. Available evidence to guide immunosuppressive therapy in this setting is limited but a prudent approach would include the use of steroids together with a calcineurin inhibitor after transplantation. However, once the inevitable inflammatory response associated with transplant surgery has resolved, cautious reduction and eventually withdrawal of immunosuppression should be possible.
    Transplantation 08/2014; 98(5). DOI:10.1097/TP.0000000000000274 · 3.83 Impact Factor
  • Chris J. Callaghan · J. Andrew Bradley
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    ABSTRACT: Transplantation is the preferred treatment for most patients with organ failure, and equitable access to organ transplantation is therefore essential. However, large inequalities in organ donation and transplantation rates are seen between countries. Specific patient cultural groups are also disadvantaged in their access to organ transplantation within countries. These inequities are at least partly due to variations in the legal, ethical, financial, organisational, and social frameworks that enable transplants to occur. Along with the global shortage in donor organs, these variations drive transplant commercialism, organ trafficking, and transplant tourism. This chapter examines selected ‘cultural’ variations that impact on access to transplantation, and explores the issues of transplant commercialism, organ trafficking, and transplant tourism. Finally, the arguments for and against the introduction of financial incentives for organ donation are discussed.
    Textbook of Organ Transplantation, 07/2014: pages 1662-1672; , ISBN: 9781118870143
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    ABSTRACT: Background: There is variation in time to listing and rates of listing for transplantation between renal units in the UK. While research has mainly focused on healthcare organization, little is known about patient perspectives of entry onto the transplant waiting list. This qualitative study aimed to explore patients' views and experiences of kidney transplant listing. Methods: Semi-structured interviews were conducted with patients aged under 75, who were on dialysis and on the transplant waiting list, not on the waiting list, undergoing assessment for listing or who had received a transplant. Patients were recruited from a purposive sample of nine UK renal units, which included transplanting and non-transplanting units and units with high and low wait-listing patterns. Interviews were transcribed verbatim and analysed using thematic analysis. Results: Fifty-three patients (5–7 per renal unit) were interviewed. Patients reported that they had received little information about the listing process. Some patients did not know if they were listed or had found they were not listed when they had thought they were on the list. Others expressed distress when they felt they had been excluded from potential listing based on age and/or comorbidity and felt the process was unfair. Many patients were not aware of pre-emptive transplantation and believed they had to be on dialysis before being able to be listed. There was some indication that pre-emptive transplantation was discussed more often in transplant than non-transplant units. Lastly, some patients were reluctant to consider family members as potential donors as they reported they would feel ‘guilty’ if the donor suffered subsequent negative effects. Conclusions: Findings suggest a need to review current practice to further understand individual and organizational reasons for the renal unit variation identified in patient understanding of transplant listing. The communication of information warrants attention to ensure patients are fully informed about the listing process and opportunity for pre-emptive transplantation in a way that is meaningful and understandable to them.
    Nephrology Dialysis Transplantation 07/2014; DOI:10.1093/ndt/gfu188 · 3.58 Impact Factor
  • Jing Zhao · Eleanor Bolton · Lucy Randle · J Andrew Bradley · Andrew Lever
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    ABSTRACT: : Renal transplantation is a successful treatment for patients with renal failure but its long-term efficacy is limited by untreatable transplant vasculopathy (TA). Endothelial damage contributes to TA and is potentially repairable by circulating endothelial progenitor cells (EPC). The frequency and function of EPC is variably influenced by end-stage renal failure (ESRF). This study aimed to characterise the late-outgrowth EPC (LO-EPC) from ESRF patients with a view to utilising autologous LO-EPC for endothelial repair following renal transplantation. LO-EPC isolated from ESRF patients and healthy volunteers were characterised phenotypically and functionally and their integrin expression profile was determined.ESRF patients generated more LO-EPC colonies than healthy controls, had higher plasma levels of IL-1rα, IL-16, IL-6, MIF, VEGF, Prolactin and PLGF. Patients' LO-EPC displayed normal endothelial cell morphology, increased secretion of PLGF, MCP-1 and IL-1β, decreased senescence and normal network formation in vitro and in vivo , but demonstrated decreased adhesion to extracellular matrix. Integrin gene profiles and protein expression were comparable in patients and healthy volunteers. In some patients, mesenchymal stem cells were co-isolated from peripheral blood and these could be differentiated into adipocytes and osteocytes in vitro . This is the first study to characterise LO-EPC from ESRF patients. Their behaviour in vitro reflects the presence of elevated trophic factors; their ability to proliferate in vitro and angiogenic function makes them candidates for prevention of transplant vasculopathy. Their impaired adhesion and the presence of MSC are areas for potential therapeutic intervention.
    Heart (British Cardiac Society) 06/2014; 100 Suppl 3:A113. DOI:10.1136/heartjnl-2014-306118.206 · 5.60 Impact Factor
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    ABSTRACT: We have analyzed the relationship between donor mismatches at each HLA locus and development of HLA locus-specific antibodies in patients listed for repeat transplantation. HLA antibody screening was undertaken using single-antigen beads in 131 kidney transplant recipients returning to the transplant waiting list following first graft failure. The number of HLA mismatches and the calculated reaction frequency of antibody reactivity against 10,000 consecutive deceased organ donors were determined for each HLA locus. Two-thirds of patients awaiting repeat transplantation were sensitized (calculated reaction frequency over 15%) and half were highly sensitized (calculated reaction frequency of 85% and greater). Antibody levels peaked after re-listing for repeat transplantation, were independent of graft nephrectomy and were associated with length of time on the waiting list (odds ratio 8.4) and with maintenance on dual immunosuppression (odds ratio 0.2). Sensitization was independently associated with increasing number of donor HLA mismatches (odds ratio 1.4). All mismatched HLA loci contributed to the development of HLA locus-specific antibodies (HLA-A: odds ratio 3.2, HLA-B: odds ratio 3.4, HLA-C: odds ratio 2.5, HLA-DRB1: odds ratio 3.5, HLA-DRB3/4/5: odds ratio 3.9, and HLA-DQ: odds ratio 3.0 (all significant)). Thus, the risk of allosensitization following failure of a first renal transplant increases incrementally with the number of mismatches at all HLA loci assessed. Maintenance of re-listed patients on dual immunosuppression was associated with a reduced risk of sensitization.Kidney International advance online publication, 9 April 2014; doi:10.1038/ki.2014.106.
    Kidney International 04/2014; 86(5). DOI:10.1038/ki.2014.106 · 8.56 Impact Factor
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    ABSTRACT: It is essential to minimize the unnecessary discard of procured deceased donor kidneys, but information on discard rates and the extent to which discard can be avoided are limited. Analysis of the UK Transplant Registry revealed that the discard rate of procured deceased donor kidneys has increased from 5% in 2002-3 to 12% in 2011-12. A national offering system for hard-to-place kidneys was introduced in the UK in 2006 (the Declined Kidney Scheme), but just 13% of kidneys that were subsequently discarded until 2012 were offered through the scheme. In order to examine the appropriateness of discard, 20 consecutive discarded kidneys from 13 deceased donors were assessed to determine if surgeons agreed with the decision that they were not implantable. Donors had a median (range) age of 67 (31-80) yr. Kidneys had been offered to a median of 3 (1-12) centers before discard. Four (20%) of the discarded kidneys were thought to be usable, and nine (45%) were possibly usable. As a result of these findings, major changes to the UK deceased donor kidney offering system have been implemented, including simultaneous offering and broader entry criteria for hard-to-place kidneys. Organizational changes are necessary to improve utilization of deceased donor kidneys.
    Clinical Transplantation 02/2014; 28(3). DOI:10.1111/ctr.12319 · 1.52 Impact Factor
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    ABSTRACT: Delayed graft function (DGF) after renal transplantation can be diagnosed according to several different definitions, complicating comparison between studies that use DGF as an endpoint. This is a particular problem after transplantation with kidneys from donation after circulatory death (DCD) kidneys, because DGF is common, and its relationship to early graft failure may differ depending on the definition of DGF. The presence of DGF in 213 donation after brain death (DBD) and 312 DCD kidney transplants from October 2005 to August 2011 was determined according to 10 different, but widely used, definitions (based on dialysis requirements, creatinine changes, or both). The relationship of DGF to graft function and graft survival was determined. The incidence of DGF varied widely depending on the definition used (DBD; 24%-70%: DCD; 41%-91%). For kidneys from DCD donors, development of DGF was only associated with poorer 1-year estimated glomerular filtration rate for 1 of 10 definitions of DGF, and no definition of DGF was associated with impaired graft survival. Conversely, for DBD kidneys, DGF, as defined in 9 of 10 different ways, was associated with poorer 1-year estimated glomerular filtration rate and inferior graft survival. Importantly, the predictive power for poorer transplant outcome was comparable for all definitions of DGF. No definition of DGF is superior. We suggest that the most widely used and most easily calculated definition-the use of dialysis in the first postoperative week-should be universally adopted as the definition of DGF clinically and as a study endpoint.
    Transplantation 09/2013; 96(10). DOI:10.1097/TP.0b013e3182a19348 · 3.83 Impact Factor

Publication Stats

3k Citations
942.38 Total Impact Points


  • 1999–2015
    • University of Cambridge
      • • Department of Surgery
      • • Department of Pathology
      Cambridge, England, United Kingdom
  • 2008
    • Cambridge University Hospitals NHS Foundation Trust
      Cambridge, England, United Kingdom
  • 2005
    • University of Leicester
      Leiscester, England, United Kingdom
  • 1991–2003
    • University of Glasgow
      • • Division of Biological Sciences
      • • Division of Immunology
      Glasgow, Scotland, United Kingdom