Search

Introduction: Kidney dysfunction is a highly significant disease, both in the United Kingdom and globally. Many previous studies have reported associations between human leukocyte antigens (HLA) and renal function; this systematic review attempts to identify, summarize and appraise all published studies of these associations. Methods: A literature search was performed using Medline, Embase and Cochrane Central Register of Controlled Trials to identify papers whose keywords included each of the following concepts: HLA, renal failure and genetic association. A total of 245 papers were identified and assessed for eligibility; 35 of these were included in the final study. Results: A total of 95 HLA types and 14 three-locus haplotypes were reported to be associated with either increased or decreased renal function. A number of these findings were replicated by independent studies that reported 16 types were protective against renal dysfunction and 15 types were associated with reduced renal function. A total of 20 HLA types were associated with both increased risk of renal disease and decreased risk by independent studies. Discussion: There is very little consensus on which HLA types have a protective or deleterious effect on renal function. Ethnicity may play a role, with HLA types possibly having different effects among different populations, and it is possible that the different primary diseases that lead to ESRD may have different HLA associations. Some of the studies may contain type I and type II errors caused by insufficient sample sizes, cohort selection and statistical methods. Although we have compiled a comprehensive list of published associations between renal function and HLA, in many cases, it is unclear which associations are reliable. Further studies are required to confirm or refute these findings.

All UK H&I laboratories and transplant units operate under a single national kidney offering policy, but there have been variations in approach regarding when to undertake the pre-transplant crossmatch test. In order to minimize cold ischaemia times for deceased donor kidney transplantation we sought to find ways to be able to report a crossmatch result as early as possible in the donation process. A panel of experts in transplant surgery, nephrology, specialist nursing in organ donation and H&I (all relevant UK laboratories represented) assessed evidence and opinion concerning five factors that relate to the effectiveness of the crossmatch process, as follows: when the result should be ready for reporting; what level of donor HLA typing is needed; crossmatch sample type and availability; fairness and equity; risks and patient safety. Guidelines aimed at improving practice based on these issues are presented, and we expect that following these will allow H&I laboratories to contribute to reducing CIT in deceased donor kidney transplantation.

Chronic rejection is the single biggest cause of premature kidney graft failure. HLA antibodies (Ab) are an established prognostic biomarker for premature graft failure so there is a need to test whether treatment decisions based on the presence of the biomarker can alter prognosis. The Optimised TacrolimuS and MMF for HLA Antibodies after Renal Transplantation (OuTSMART) trial combines two elements. Firstly, testing whether a routine screening programme for HLA Ab in all kidney transplant recipients is useful by comparing blinding versus unblinding of HLA Ab status. Secondly, for those found to be HLA Ab+, testing whether the introduction of a standard optimisation treatment protocol can reduce graft failure rates. OuTSMART is a prospective, open-labelled, randomised biomarker-based strategy (hybrid) trial, with two arms stratified by biomarker (HLA Ab) status. The primary outcome was amended from graft failure rates at 3 years to time to graft failure to increase power and require fewer participants to be recruited. Length of follow-up subsequently is variable, with all participants followed up for at least 43 months up to a maximum of 89 months. The primary outcome will be analysed using Cox regression adjusting for stratification factors. Analyses will be according to the intention-to-treat using all participants as randomised. Outcomes will be analysed comparing standard care versus biomarker-led care groups within the HLA Ab+ participants (including those who become HLA Ab+ through re-screening) as well as between HLA-Ab-unblinded and HLA-Ab-blinded groups using all participants. Changes to the primary outcome permit recruitment of fewer participants to achieve the same statistical power. Pre-stating the statistical analysis plan guards against changes to the analysis methods at the point of analysis that might otherwise introduce bias through knowledge of the data. Any deviations from the analysis plan will be justified in the final report. ISRCTN registry, ID: ISRCTN46157828 . Registered on 26 March 2013; EudraCT 2012–004308-36 . Registered on 10 December 2012.

Human leukocyte antigens (HLA) have been associated with renal function, but previous studies report contradictory findings with little consensus on the exact nature or impact of this observation. This study included 401,307 white British subjects aged 39–73 when they were recruited by UK Biobank. Subjects’ HLA types were imputed using HLA*IMP:02 software. Regression analysis was used to compare 362 imputed HLA types with estimated glomerular filtration rate (eGFR) as a primary outcome and clinical indications as secondary outcome measures. 22 imputed HLA types were associated with increased eGFR (and therefore increased renal function). Decreased eGFR (decreased renal function) was associated with 11 imputed HLA types, seven of which were also associated with increased risk of end-stage renal disease and/or chronic kidney disease. Many of these HLA types are commonly inherited together in established haplotypes, for example: HLA-A*01:01, B*08:01, C*07:01, DRB1*03:01, DQB1*02:01. This haplotype has a population frequency of 9.5% in England and each allele was associated with decreased renal function. 33 imputed HLA types were associated with kidney function in white British subjects. Linkage disequilibrium in HLA heritance suggests that this is not random and particularly affects carriers of established haplotypes. This could have important applications for the diagnosis and treatment of renal disease and global population health.

Human leukocyte antigens (HLA) have been associated with renal function, but previous studies report contradictory findings. There has been a lack of research into how HLA affects renal function in Black, Asian and Minority Ethnic (BAME) people in the UK, despite BAME people being disproportionately affected by renal dysfunction. This study included >27 000 UK Biobank subjects of six ethnicities (>12 100 Irish, >5400 Indian, >4000 Black Caribbean, >3000 Black African, >1600 Pakistani, and > 1400 Chinese) aged 39-73. Subjects' high-resolution HLA genotypes were imputed using HLA*IMP:02 software. Regression analysis was used to compare 108 imputed HLA alleles with two measures of estimated glomerular filtration rate (eGFR): one based on serum creatinine; one based on serum cystatin. Secondary analysis compared CKD stage 2 subjects to healthy controls. Nine imputed HLA alleles were associated with eGFR (adjusted P < 0.05). Six associations were based on creatinine in Black African subjects: HLA-B*53:01 (beta = -2.628, adjusted P = 4.69x10-4 ); C*04:01 (beta = -1.667, adjusted P = 0.0269); DPA1*02:01 (beta = -1.569, adjusted P = 0.0182); and DPA1*02:02 (beta = -1.716, adjusted P = 0.0251) were linked to decreased renal function, while DRB1*03:01 (beta = 3.200, adjusted P = 3.99x10-3 ) and DPA1*01:03 (beta = 2.276, adjusted P = 2.31x10-5 ) were linked to increased renal function. Two of these (HLA-B*53:01 and C*04:01) are commonly inherited together. In Irish subjects, HLA-DRB1*04:01 (beta = 1.075, adjusted P = 0.0138) was linked to increased eGFR (based on cystatin); in Indian subjects, HLA-DRB1*03:01 (beta = -1.72, adjusted P = 4.78x10-3 ) and DQB1*02:01 (beta = -1.755, adjusted P = 2.26x10-3 )were associated with decreased eGFR (based on cystatin). No associations were found in the other three ethnic groups. Nine HLA alleles appear to be associated with kidney function in BAME people in the UK. This could have applications for the diagnosis and treatment of renal disease and could help reduce health inequalities in the UK. This article is protected by copyright. All rights reserved.

ObjectiveTo identify whether renal transplant activity varies in a reproducible manner across the year.DesignRetrospective cohort study using NHS Blood and Transplant data.SettingAll renal transplant centres in the UK.ParticipantsA total of 24 270 patients who underwent renal transplantation between 2005 and 2014.Primary outcomeMonthly transplant activity was analysed to see if transplant activity showed variation during the year.Secondary outcomeThe number of organs rejected due to healthcare capacity was analysed to see if this affected transplantation rates.ResultsAnalysis of national transplant data revealed a reproducible yearly variance in transplant activity. This activity increased in late autumn and early winter (p=0.05) and could be attributed to increased rates of living (October and November) and deceased organ donation (November and December). An increase in deceased donation was attributed to a rise in donors following cerebrovascular accidents and hypoxic brain injury. Other causes of death (infections and road traffic accidents) were more seasonal in nature peaking in the winter or summer, respectively. Only 1.4% of transplants to intended recipients were redirected due to a lack of healthcare capacity, suggesting that capacity pressures in the National Health Service did not significantly affect transplant activity.ConclusionUK renal transplant activity peaks in late autumn/winter in contrast to other countries. Currently, healthcare capacity, though under strain, does not affect transplant activity; however, this may change if transplantation activity increases in line with national strategies as the spike in transplant activity coincides with peak activity in the national healthcare system.

There are limited data regarding the presence of DSAs and their effect on graft function in pediatric renal transplantation. The role for serial DSA monitoring in routine clinical practice is unclear. All patients attending a regional transplant clinic were tested for DSAs, measured using Luminex single/mixed antigen beads. Any patient having a positive result subsequently underwent historic testing on samples previously obtained. DSA-positive patients underwent prospective monitoring of DSAs, and correlation with clinical events was studied. Nine of a total of 50 patients (18%) were DSA-positive, of whom six had graft dysfunction. The DSA-positive cohort had significantly increased episodes of AR (p = 0.01). There were two graft losses in the DSA-positive group and none in the DSA-negative group. Eight of the DSA-positive group had potentially reduced exposure to IS because of either adherence issues or clinical indications. DSAs were associated with increased risk of rejection. There appears to be a role for serial monitoring of DSAs in patients where there has been a reduced exposure to IS so that early intervention with optimized IS can be considered.

Background. Kidneys from older donors are likely to have a lower nephron mass. Nevertheless they constitute a valuable source of kidney allografts. Long cold ischemic time (CIT), with or without delayed graft function (DGF), has been associated with reduced graft survival. The aim of this study was to review the experience of a single UK center to assess the interaction of cold storage time, donor age, organ exchange, and HLA-DR mismatching on short- and long-term survival. Methods. We analyzed 788 first cadaver kidney transplants that were performed in our center from 1990 to 1997 and had complete data available. A donor age of 55 years was the cutoff age for “old” and “young” donor kidneys. The primary outcome measured was graft failure from any cause. Results. There were 132 grafts from donors 55 years or older (16.7%), with 76.8% of the kidneys implanted after >20 hr of CIT. Kidney grafts from donors older than 55 years had worse graft survival than grafts from donors younger than 55 (87% vs. 78% at 1 year and 80% vs. 58% at 5 years after transplant, P =0.0001). A CIT of >20 hr significantly reduced graft survival (91% vs.74.3% at 5 years after transplant, P =0.0002) in the young donor group and was associated with an overall graft survival in the old donor group of 57.5% at 5 years. In the same group, ignoring the HLA-DR mismatching to achieve shorter CIT, the predicted initial cost on graft survival at 1 year would have been 3.7% but would have increased to 9% 5 years after transplant. For young donors a CIT of >20 hr had a cost of approximately 18% at 5-year graft survival, far higher than a single DR mismatch. Occurrence of DGF decreased survival in both short (P =0.001) and long (P =0.00001) CIT groups. Conclusion. Forming local alliances (common recipient lists) and minimizing delays within the hospital might reduce CIT and DGF while achieving excellent HLA matching. This should improve significantly the outcome of both old and young donor kidney grafts.

Pancreas transplantation in complicated type 1 (insulin dependent) diabetes mellitus improves the quality of life, increases longevity and stabilizes diabetic complications. There may be clinician reticence due to perceived poor outcomes with published associated mortality rates of 5-8% due to significant co-morbidities, particularly cardiovascular impairment.Retrospective analysis was performed on patients undergoing pancreas transplantation in a single centre since the programme's initiation [simultaneous pancreas kidney (SPK) = 148, pancreas after kidney (PAK) = 33 and pancreas transplant alone (PTA) = 11] compared with a control group accepted contemporaneously onto the waiting list. The primary endpoint was patient mortality. The risk factors including medical and diabetic history, demographics, transplant type and waiting time were analysed.The waiting list mortality was 30% (35 of 120) compared with a mortality of 9% (20 of 193) post-transplantation (P0.001). Deaths on the waiting list compared with transplantation up to 1 year had a relative risk of 2.67 (95% CI: 0.81-3.51; P = 0.19), whilst those surviving1 year had a relative risk of 5.89 of dying on the waiting list (95% CI: 1.70-3.20; P0.0005). There were no differences in terms of cardiovascular or renal-associated risk factors, nor in other potential confounding factors other than duration of diabetes (P = 0.02). Median survival from listing was shorter in younger patients (50; P0.0001).Type 1 diabetics with renal failure listed for pancreas transplantation are at a significant risk of mortality even without surgery. Transplantation offers considerable survival benefits, despite associated surgical and immunosuppressive risks. In selected patients, pancreas transplantation remains the benchmark treatment for type 1 diabetes mellitus.

Classical immunological dogma stipulates that reexposure to antigen results in an immediate and forceful response by the adaptive immune system. In the context of organ retransplantation this response is influenced by several factors, including antibody specificity of the primary response [1], affinity and isotype of preformed antibody, dose and immunogenicity of the antigen, immune responsiveness and health of the recipient. The pioneering work of Kissmeyer-Nielsen in Europe and Terasaki in the USA in the mid 1960s established that kidney transplants could be rejected hyperacutely by thrombosis of the transplant due to binding of preformed recipient antibody to donor antigen. It is now accepted that the most frequent target antigens in such instances are HLA antigens, coded for by the class I (HLA-A, -B, -Cw) or class II (HLA-DR,-DQ) genes of the major histocompatibility complex. Primary sensitization in transplant recipients usually occurs by one of three routes: blood transfusions, pregnancy and organ transplantation [2].

Background. We carried out a retrospective study of C4d staining in paraffin sections from renal transplant biopsies to determine the association between C4d staining, donor-specific antibodies (DSA), histological features, and graft outcome. Methods. We studied 92 patients who had been biopsied for graft dysfunction. Biopsies were classified using Banff 97 criteria and features suggestive of antibody-mediated rejection were noted. Paraffin sections were stained with a polyclonal antibody using an immunoperoxidase technique. The presence of DSA in concurrent sera was determined by enzyme-linked immunosorbent assay and clinical data were reviewed. Results. Of the 92 cases, 15% showed diffuse and 24% showed focal C4d positivity. The grafts failed in 36% of the diffuse (P

We have developed a flow cytometry-based screening method using FlowPRA (One Lambda) human leukocyte antigen (HLA) class I panel beads and FlowPRA (One Lambda) HLA class I specificity beads for the detection and definition of immunoglobulin (Ig)M HLA-specific antibodies in the presence of IgM autoantibodies. Forty-six autoantibody-positive patients who were on the waiting list for a renal transplant (56 sera) were tested in parallel with FlowPRA (One Lambda) HLA class I beads and FlowPRA (One Lambda) control beads. Sera that were positive for IgM HLA class I antibodies were subsequently tested with FlowPRA HLA class I specificity beads to determine the HLA specificities. Thirteen of the 46 patients were positive for IgM HLA class I-specific antibodies. Eleven of the 13 had previous failed transplants and 2 were awaiting a primary transplant. For 9 of the 13 positive patients, IgM HLA class I specificities were defined. We have demonstrated the presence of IgM HLA-specific antibodies in patients with IgM autoantibodies. This study demonstrates the value of FlowPRA HLA class I panel and specificity beads for the detection and definition of IgM HLA class I-specific antibodies.

LATM, Quikscreen (QS), and B-Screen (QSB) are ELISA-based tests for the detection of HLA specific antibodies. FlowPRA beads are microparticles coated with HLA antigens for the detection of HLA specific antibodies by flow cytometry. The aim of this study was to evaluate the sensitivity and specificity of the LATM, QS, QSB, and FlowPRA screening tests. One hundred sixty-three sera from renal transplant patients were tested using LATM, FlowPRA, QS, and QSB. Discrepant results were further investigated using complement dependent cytotoxicity, QuikID, and PRA-STAT. When QS was compared with LATMI and FlowPRAI for the detection of HLA class I specific antibodies the overall concordance was 82.8% with no particular specificity missed by any one test. Comparing QSB with LATMII and FlowPRAII, for the detection of HLA class II specific antibodies, there was 90.7% concordance. Although the overall concordance was better for class II specific antibodies, QSB failed to detect antibodies to HLA-DQ in a number of samples from different patients. Of the methods tested, flow cytometry using FlowPRA beads appeared to be the most sensitive and specific, missing the least number of specificities. However, the ELISA methods offer the advantage of being more suitable for testing large numbers of samples in a more time- and cost-effective manner.