A New UK 2006 National Kidney Allocation Scheme for Deceased Heart-Beating Donor Kidneys

Impact of Asian and Black Donor and Recipient Ethnicity on the Outcomes After Deceased Donor Kidney Transplantation in the United Kingdom

Patients of Asian and black ethnicity face disadvantage on the renal transplant waiting list in the UK, because of lack of human leucocyte antigen and blood group matched donors from an overwhelmingly white deceased donor pool. This study evaluates outcomes of renal allografts from Asian and black donors. The UK Transplant Registry was analysed for adult deceased donor kidney only transplants performed between 2001 and 2015. Asian and black ethnicity patients constituted 12.4% and 6.7% of all deceased donor recipients but only 1.6% and 1.2% of all deceased donors, respectively. Unadjusted survival analysis demonstrated significantly inferior long-term allograft outcomes associated with Asian and black donors, compared to white donors. On Cox-regression analysis, Asian donor and black recipient ethnicities were associated with poorer outcomes than white counterparts, and on ethnicity matching, compared with the white donor-white recipient baseline group and adjusting for other donor and recipient factors, 5-year graft outcomes were significantly poorer for black donor-black recipient, Asian donor-white recipient, and white donor-black recipient combinations in decreasing order of worse unadjusted 5-year graft survival. Increased deceased donation among ethnic minorities could benefit the recipient pool by increasing available organs. However, it may require a refined approach to enhance outcomes.

Early experience of a new national lung allocation scheme in the UK based on clinical urgency

INTRODUCTION

A new UK Lung Allocation Scheme (UKLAS) was introduced in 2017, replacing the previous geographic allocation system. Patients are prioritised according to predefined clinical criteria into a three-tier system: the super-urgent lung allocation scheme (SULAS), the urgent lung allocation scheme (ULAS) and the non-urgent lung allocation scheme (NULAS). This study assessed the early impact of this scheme on waiting-list and post-transplant outcomes.

METHODS

A cohort study of adult lung transplant registrations between March 2015 and November 2016 (era-1) and between May 2017 and January 2019 (era-2). Outcomes from registration were compared between eras and stratified by urgency tier and diagnostic group.

RESULTS

During era-1, 461 patients were registered. In era-2, 471 patients were registered (19 (4.0%) SULAS, 82 (17.4%) ULAS and 370 (78.6%) NULAS). SULAS patients were younger (median age 35 vs 50 and 55 for urgent and non-urgent, respectively, p=0.0015) and predominantly suffered from cystic fibrosis (53%) or pulmonary fibrosis (37%). Between eras 1 and 2, the odds of transplantation within 6 months of registration were increased (OR=1.41, 95% CI 1.07 to 1.85, p=0.0142) despite only a 5% increase in transplant activity. Median time-to-transplantation during era-1 was 427 days compared with waiting times in era-2 of 8 days for SULAS, 15 days for ULAS and 585 days for NULAS patients. Waiting-list mortality (15% era-1 vs 13% era-2; p=0.5441) and post-transplant survival at 1 year (81.3% era-1 vs 83.3% era-2; p=0.6065) were similar between eras.

CONCLUSION

The UKLAS scheme prioritises the critically ill and improves transplantation odds. The true impact on waiting-list mortality and post-transplant survival requires further follow-up.

Beyond donation to organ utilization in the UK

PURPOSE OF REVIEW

Optimizing deceased donor organ utilization is gaining recognition as a topical and important issue, both in the United Kingdom (UK) and globally. This review discusses pertinent issues in the field of organ utilization, with specific reference to UK data and recent developments within the UK.

RECENT FINDINGS

A multifaceted approach is likely required in order to improve organ utilization. Having a solid evidence-base upon which transplant clinicians and patients on national waiting lists can base decisions regarding organ utilization is imperative in order to bridge gaps in knowledge regarding the optimal use of each donated organ. A better understanding of the risks and benefits of the uses of higher risk organs, along with innovations such as novel machine perfusion technologies, can help clinician decision-making and may ultimately reduce the unnecessary discard of precious deceased donor organs.

SUMMARY

The issues facing the UK with regards to organ utilization are likely to be similar to those in many other developed countries. Discussions around these issues within organ donation and transplantation communities may help facilitate shared learning, lead to improvements in the usage of scarce deceased donor organs, and enable better outcomes for patients waiting for transplants.

Pediatric renal transplantation-A UNOS database analysis of donor-recipient size mismatch

BACKGROUND

We used the BSAi (Donor BSA/Recipient BSA) to assess whether transplanting a small or large kidney into a pediatric recipient relative to his/her size influences renal transplant outcomes.

METHODS

We included 14 322 single-kidney transplants in pediatric recipients (0-17 years old) (01/2000-02/2020) from the United Network for Organ Sharing database. We divided cases into four BSAi groups (BSAi ≤ 1, 1 < BSAi ≤ 2, 2 < BSAi ≤ 3, BSAi > 3).

RESULTS

There were no differences concerning delayed graft function (DGF) or primary non-function (PNF) rates, whether the grafts were from living or brain-dead donors. In both transplants coming from living donors and brain-dead donors, cases with BSAi > 3 and cases with 2 < BSAi ≤ 3 had similar graft survival (p = .13 for transplants from living donors, p = .413 for transplants from brain-dead donors), and both groups had longer graft survival than cases with 1 < BSAi ≤ 2 and cases with BSAi ≤ 1 (p < .001). The difference in 10-year graft survival rates between cases with BSAi > 3 and cases with BSAi ≤ 1 reached around 25% in both donor types. The better graft survival in transplants with BSAi > 2 was confirmed in multivariable analysis.

CONCLUSIONS

There is no significant impact of donor-recipient size mismatch on DGF and PNF rates in pediatric renal transplants. However, graft survival is significantly improved when the donor's size is more than twice the pediatric recipient's size.

Utilisation and clinical outcomes of kidney transplants from deceased donors with albuminuria in the UK: a national cohort study

BACKGROUND

Urinalysis is a standard component of potential deceased kidney donor assessment in the UK. The value of albuminuria as a biomarker for organ quality is uncertain. We examined the relationship between deceased donor albuminuria and kidney utilisation, survival, and function.

METHODS

We performed a national cohort study on adult deceased donors and kidney transplant recipients between 2016 and 2020, using data from the UK Transplant Registry. We examined the influence of donor albuminuria, defined as ≥ 2 + on dipstick testing, on kidney utilisation, early graft function, graft failure, and estimated glomerular filtration rate (eGFR).

RESULTS

Eighteen % (1681/9309) of consented donors had albuminuria. After adjustment for confounders, kidneys from donors with albuminuria were less likely to be accepted for transplantation (74% vs 82%; OR 0.70, 95% CI 0.61 to 0.81). Of 9834 kidney transplants included in our study, 1550 (16%) came from donors with albuminuria. After a median follow-up of 2 years, 8% (118/1550) and 9% (706/8284) of transplants from donors with and without albuminuria failed, respectively. There was no association between donor albuminuria and graft failure (HR 0.91, 95% CI 0.74 to 1.11). There was also no association with delayed graft function, patient survival, or eGFR at 1 or 3 years.

CONCLUSIONS

Our study suggests reluctance in the UK to utilise kidneys from deceased donors with dipstick albuminuria but no evidence of an association with graft survival or function. This may represent a potential to expand organ utilisation without negatively impacting transplant outcomes.

Kidney Transplantation From Deceased Donors With Vaccine-induced Immune Thrombocytopenia and Thrombosis: An Updated Analysis of the UK Experience

BACKGROUND

The emergence and attendant mortality of vaccine-induced immune thrombocytopenia and thrombosis (VITT) as a consequence of vaccination against severe acute respiratory syndrome coronavirus 2 have resulted in some patients with VITT being considered as deceased organ donors. Outcomes after kidney transplantation in this context are poorly described. Because the disease seems to be mediated by antiplatelet factor 4 antibodies, there is a theoretical risk of transmission via passenger leukocytes within the allograft.

METHODS

We analyzed the experience of kidney transplantation from donors with VITT in the United Kingdom between January and June 2021. We followed-up all recipients of kidney-only transplants from donors with VITT to detect major postoperative complications or features of disease transmission and assess graft survival and function.

RESULTS

There were 16 kidney donors and 30 single kidney transplant recipients in our study period. Of 11 preimplantation biopsies, 4 showed widespread glomerular microthrombi. After a median of 5 mo, patient and graft survival were 97% and 90%, respectively. The median 3-mo estimated glomerular filtration rate was 51 mL/min/1.73 m 2 . Two recipients had detectable antiplatelet factor 4 antibodies but no evidence of clinical disease after transplantation. Major hemorrhagic complications occurred in 3 recipients, all of whom had independent risk factors for bleeding, resulting in the loss of 2 grafts. The involvement of VITT could not be completely excluded in one of these cases.

CONCLUSIONS

The UK experience to date shows that favorable outcomes are possible after kidney transplantation from donors with VITT but highlights the need for ongoing vigilance for donor-related complications in these patients.

The MHC class I MICA gene is a histocompatibility antigen in kidney transplantation

The identity of histocompatibility loci, besides human leukocyte antigen (HLA), remains elusive. The major histocompatibility complex (MHC) class I MICA gene is a candidate histocompatibility locus. Here, we investigate its role in a French multicenter cohort of 1,356 kidney transplants. MICA mismatches were associated with decreased graft survival (hazard ratio (HR), 2.12; 95% confidence interval (CI): 1.45–3.11; P < 0.001). Both before and after transplantation anti-MICA donor-specific antibodies (DSA) were strongly associated with increased antibody-mediated rejection (ABMR) (HR, 3.79; 95% CI: 1.94–7.39; P < 0.001; HR, 9.92; 95% CI: 7.43–13.20; P < 0.001, respectively). This effect was synergetic with that of anti-HLA DSA before and after transplantation (HR, 25.68; 95% CI: 3.31–199.41; P = 0.002; HR, 82.67; 95% CI: 33.67–202.97; P < 0.001, respectively). De novo-developed anti-MICA DSA were the most harmful because they were also associated with reduced graft survival (HR, 1.29; 95% CI: 1.05–1.58; P = 0.014). Finally, the damaging effect of anti-MICA DSA on graft survival was confirmed in an independent cohort of 168 patients with ABMR (HR, 1.71; 95% CI: 1.02–2.86; P = 0.041). In conclusion, assessment of MICA matching and immunization for the identification of patients at high risk for transplant rejection and loss is warranted.

Analysis of a multicenter cohort of kidney transplants shows that mismatches in the MICA locus and the presence of anti-MICA donor-specific antibodies are associated with reduced graft survival and increased rejection.

Waiting, strange: transplant recipient experience, medical time and queer/crip temporalities

People who receive a 'solid' organ transplant from a deceased person may experience imaginative challenges in making sense of how the transfer impacts their own past and future, as shown in existing scholarship. Building on such work, this article considers how the temporalities of medical encounter itself may also become temporally ambiguous, posing representational challenges both pre-transplantation and post-transplantation. The dominant narrative of transplant in transplantation journals and hospital communications, both clinical and patient-facing, presents surgery as a healing moment, yet the recipient's experience of hospital, pharmacology and daily self-monitoring may be disorienting in multiple ways which resist conventional conceptions of medical temporalities of cure. Examining memoirs by Robert Pensack and Richard McCann, this article suggests the transplant temporalities may be fruitfully approached through scholarship of 'queering' time and 'crip' time. While the medical narrative of transplant focuses on the event of transplantation, these texts construct post-transplant time as still profoundly structured by waiting, expectation and suspense, the transformed body less healed than permanently contingent and fragile in different ways. I do not purport to uncover the 'truth' of bleak survival hidden within a story of the miraculous. Rather, I am reaching for a critical practice to recognise subtle entanglements of medicalised time, and identify a tension and synthesis between miracle and the chronic, an insight which may also be of service for other critical approaches to memoir of heroic medicine.

Outcomes after simultaneous pancreas-kidney transplantation from donation after circulatory death donors: A UK registry analysis

There are concerns that simultaneous pancreas-kidney (SPK) transplants from donation after circulatory death (DCD) donors have a higher risk of graft failure than those from donation after brain death (DBD) donors. A UK registry analysis of SPK transplants between 2005 and 2018 was performed. Pancreas survivals of those receiving organs from DCD or DBD donors were compared. Multivariable analyses were used to adjust for baseline differences between the two groups and to identify factors associated with pancreas graft loss. A total of 2228 SPK transplants were implanted; 403 (18.1%) were from DCD donors. DCD donors were generally younger, slimmer, less likely to have stroke as a cause of death, with lower terminal creatinines and shorter pancreas cold ischemic times than DBD donors. Median (IQR) follow-up was 4.2 (1.6-8.1) years. On univariable analysis, there were no statistically significant differences in 5-year death-censored pancreas graft survival between the two donor types (79.5% versus 80.4%; p = .86). Multivariable analysis showed no statistically significant differences in 5-year pancreas graft loss between transplants from DCD (n = 343) and DBD (n = 1492) donors (hazard ratio 1.26, 95% CI 0.76-1.23; p = .12). The findings from this study support the increased use of SPK transplants from DCD donors.

Effect of delayed graft function on longer-term outcomes after kidney transplantation from donation after circulatory death donors in the United Kingdom: A national cohort study

Kidneys from donation after circulatory death (DCD) donors are utilized variably worldwide, in part due to high rates of delayed graft function (DGF) and putative associations with adverse longer-term outcomes. We aimed to determine whether the presence of DGF and its duration were associated with poor longer-term outcomes after kidney transplantation from DCD donors. Using the UK transplant registry, we identified 4714 kidney-only transplants from controlled DCD donors to adult recipients between 2006 and 2016; 2832 recipients (60·1%) had immediate graft function and 1882 (39·9%) had DGF. Of the 1847 recipients with DGF duration recorded, 926 (50·1%) had DGF < 7 days, 576 (31·2%) had DGF 7-14 days, and 345 (18·7%) had DGF >14 days. After risk adjustment, the presence of DGF was not associated with inferior long-term graft or patient survivals. However, DGF duration of >14 days was associated with an increased risk of death-censored graft failure (hazard ratio 1·7, p = ·001) and recipient death (hazard ratio 1·8, p < ·001) compared to grafts with immediate function. This study suggests that shorter periods of DGF have no adverse influence on graft or patient survival after DCD donor kidney transplantation and that DGF >14 days is a novel early biomarker for significantly worse longer-term outcomes.

The implications of donor-recipient size mismatch in renal transplantation

INTRODUCTION

Transplanting kidneys small for recipient's size results in inferior graft function. Body surface area (BSA) is related to kidney size. We used the BSA index (BSAi) (Donor BSA/Recipient BSA) to assess whether the renal graft size is sufficient for the recipient.

METHODS

We included 26,223 adult single kidney transplants (01/01/2007-31/12/2019) from the UK Transplant Registry. We divided renal transplants into groups: BSAi ≤ 0.75, 0.75 < BSA ≤ 1, 1 < BSAi ≤ 1.25, BSAi > 1.25. We compared delayed graft function rates, primary non-function rates and graft survival among them. (Reference category: BSAi ≤ 0.75).

RESULTS

Cases with BSAi ≤ 0.75 had the highest delayed graft function rates in living-donor renal transplants (11.1%) (0.75 < BSAi ≤ 1: OR = 0.59, 95% CI = 0.32-1.1, p = 0.095, 1 < BSAi ≤ 1.25: OR = 0.46, 95% CI = 0.23-0.89, p = 0.022, BSAi > 1.25: OR = 0.32, 95% CI = 0.13-0.77, p = 0.011) and in renal transplants from donors after brain death (26.2%) (0.75 < BSAi ≤ 1: OR = 0.72, 95% CI = 0.55-0.96, p = 0.024, 1 < BSAi ≤ 1.25: OR = 0.62, 95% CI = 0.47-0.83, p = 0.001, BSAi > 1.25: OR = 0.65, 95% CI = 0.47-0.9, p = 0.01). There were no significant differences in renal transplants from donors after circulatory death regarding delayed graft function rates (~ 40% in all groups). Graft survival was similar among BSAi groups in renal transplants from living donors and donors after brain death. Renal transplants from donors after circulatory death with BSAi ≤ 0.75 had the shortest graft survival (0.75 < BSAi ≤ 1: HR = 0.55, 95% CI = 0.41-0.74, p < 0.001, 1 < BSAi ≤ 1.25: HR = 0.48, 95% CI = 0.35-0.66, p < 0.001, BSAi > 1.25: HR = 0.45, 95% CI = 0.31-0.66, p < 0.001). Ten-year graft survival rate was 58.4% for renal transplants from donors after circulatory death with BSAi ≤ 0.75.

CONCLUSIONS

Delayed graft function risk is higher in renal transplants with BSAi ≤ 0.75 coming from living donors and donors after brain death. Graft survival is greatly reduced in renal transplants from donors after circulatory death with BSAi ≤ 0.75.

HLA-DPB1 allele frequencies in the West Midlands region of the United Kingdom: A critical evaluation against the common, intermediate and well-documented allele catalogues CWD 2.0.0, EFI CWD and CIWD 3.0.0

The Birmingham H&I laboratory performed HLA typing on 456 potential deceased solid organ donors in the UK between 2014 and 2016. Accurate DPB1 typing is essential for determining HLA compatibility in transplantation, thus we report HLA-DPB1 for potential deceased solid organ donors. To correctly interpret HLA typing data, laboratories must understand both international and local HLA allele frequencies. In this analysis, we determined HLA-DPB1 allele and genotype frequencies for these 456 donors. HLA-DPB1 diversity was evaluated against the common and well-documented (CWD) alleles 2.0.0 catalogue, the European Federation for Immunogenetics (EFI) CWD catalogue and the common, intermediate and well-documented (CIWD) 3.0.0 catalogue. Additionally, we determined which alleles are common in our local deceased donor population. We observed 27 HLA-DPB1 alleles with DPB1*04:01 being the most frequently observed (allele frequency = 0.4342). All alleles detected locally were present in CIWD 3.0.0, however, DPB1*124:01 and *135:01 were not present in CWD 2.0.0 and DPB1*104:01 and *135:01 were not present in EFI CWD. Twenty of 27 DPB1 alleles identified were defined as locally common and also listed as common in CIWD 3.0.0 representing 62.5% of common alleles in the subset of CIWD 3.0.0 from individuals of a European geographic, ancestral or ethnic background. The alleles HLA-DPB1*16:01 and *20:01 are locally common but not listed as common in EFI CWD and DPB1*104:01 is not listed as common in CWD 2.0.0 catalogue. Our analysis showed that the detected alleles and locally common alleles within our population were aligned with the CIWD 3.0.0 catalogue.

Renal transplantation during the SARS-CoV-2 pandemic in the UK: Experience from a large-volume center

There is uncertainty about the safety of kidney transplantation during the SARS-CoV-2 pandemic due to the risk of donor transmission, nosocomial infection and immunosuppression use. We describe organ donation and transplant practice in the UK and assess whether kidney transplantation conferred a substantial risk of harm. Data from the UK transplant registry were used to describe kidney donation and transplant activity in the UK, and a detailed analysis of short-term, single-center, patient results in two periods: during the pre-pandemic era from 30th December 2019 to 8th March 2020 ("Pre-COVID era") and the 9th March 2020 to 19th May 2020 ("COVID era"). Donor and recipient numbers fell by more than half in the COVID compared to the pre-COVID era in the UK, but there were more kidney transplants performed in our center (42 vs. 29 COVID vs. pre-COVID respectively). Overall outcomes, including re-operation, delayed graft function, primary non-function, acute rejection, length of stay and graft survival were similar between COVID and pre-COVID era. 6/71 patients became infected with SARS-CoV-2 but all were discharged without critical care requirement. Transplant outcomes have remained similar within the COVID period and no serious sequelae of SARS-CoV-2 infection were observed in the peri-transplant period.

Associations with kidney transplant survival and eGFR decline in children and young adults in the United Kingdom: a retrospective cohort study

Background

Although young adulthood is associated with transplant loss, many studies do not examine eGFR decline. We aimed to establish clinical risk factors to identify where early intervention might prevent subsequent adverse transplant outcomes.

Methods

Retrospective cohort study using UK Renal Registry and UK Transplant Registry data, including patients aged < 30 years transplanted 1998–2014. Associations with death-censored graft failure were investigated with multivariable Cox proportional hazards. Multivariable linear regression was used to establish associations with eGFR slope gradients calculated over the last 5 years of observation per individual.

Results

The cohort (n = 5121, of whom n = 371 received another transplant) was 61% male, 80% White and 36% had structural disease. Live donation occurred in 48%. There were 1371 graft failures and 145 deaths with a functioning graft over a 39,541-year risk period. Median follow-up was 7 years. Fifteen-year graft survival was 60.2% (95% CI 58.1, 62.3).

Risk associations observed in both graft loss and eGFR decline analyses included female sex, glomerular diseases, Black ethnicity and young adulthood (15–19-year and 20–24-year age groups, compared to 25–29 years). A higher initial eGFR was associated with less risk of graft loss but faster eGFR decline. For each additional 10 mL/min/1.73m² initial eGFR, the hazard ratio for graft loss was 0.82 (95% CI 0.79, 0.86), p < 0.0001. However, compared to < 60 mL/min/1.73m², higher initial eGFR was associated with faster eGFR decline (> 90 mL/min/1.73m²; − 3.55 mL/min/1.73m²/year (95% CI -4.37, − 2.72), p < 0.0001).

Conclusions

In conclusion, young adulthood is a key risk factor for transplant loss and eGFR decline for UK children and young adults. This study has an extended follow-up period and confirms common risk associations for graft loss and eGFR decline, including female sex, Black ethnicity and glomerular diseases. A higher initial eGFR was associated with less risk of graft loss but faster rate of eGFR decline. Identification of children at risk of faster rate of eGFR decline may enable early intervention to prolong graft survival.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-020-02156-2.

The Toxic Impact of Honey Adulteration: A Review

Honey is characterized as a natural and raw foodstuff that can be consumed not only as a sweetener but also as medicine due to its therapeutic impact on human health. It is prone to adulterants caused by humans that manipulate the quality of honey. Although honey consumption has remarkably increased in the last few years all around the world, the safety of honey is not assessed and monitored regularly. Since the number of consumers of honey adulteration have increased in recent years, their trust and interest in this valuable product has decreased. Honey adulterants are any substances that are added to the pure honey. In this regard, this paper provides a comprehensive and critical review of the different types of adulteration, common sugar adulterants and detection methods, and draws a clear perspective toward the impact of honey adulteration on human health. Adulteration increases the consumer's blood sugar, which can cause diabetes, abdominal weight gain, and obesity, raise the level of blood lipids and can cause high blood pressure. The most common organ affected by honey adulterants is the liver followed by the kidney, heart, and brain, as shown in several in vivo research designs.

Equity-Efficiency Trade-offs Associated With Alternative Approaches to Deceased Donor Kidney Allocation: A Patient-level Simulation

Supplemental Digital Content is available in the text.

Background.

The number of patients waiting to receive a kidney transplant outstrips the supply of donor organs. We sought to quantify trade-offs associated with different approaches to deceased donor kidney allocation in terms of quality-adjusted life years (QALYs), costs, and access to transplantation.

Methods.

An individual patient simulation model was developed to compare 5 different approaches to kidney allocation, including the 2006 UK National Kidney Allocation Scheme (NKAS) and a QALY maximization approach designed to maximize health gains from a limited supply of donor organs. We used various sources of patient-level data to develop multivariable regression models to predict survival, health state utilities, and costs. We simulated the allocation of kidneys from 2200 deceased donors to a waiting list of 5500 patients and produced estimates of total lifetime costs and QALYs for each allocation scheme.

Results.

Among patients who received a transplant, the QALY maximization approach generated 48 045 QALYs and cost £681 million, while the 2006 NKAS generated 44 040 QALYs and cost £625 million. When also taking into consideration outcomes for patients who were not prioritized to receive a transplant, the 2006 NKAS produced higher total QALYs and costs and an incremental cost-effectiveness ratio of £110 741/QALY compared with the QALY maximization approach.

Conclusions.

Compared with the 2006 NKAS, a QALY maximization approach makes more efficient use of deceased donor kidneys but reduces access to transplantation for older patients and results in greater inequity in the distribution of health gains between patients who receive a transplant and patients who remain on the waiting list.

Cold Pulsatile Machine Perfusion Versus Static Cold Storage for Kidneys Donated After Circulatory Death: A Multicenter Randomized Controlled Trial

BACKGROUND

The benefits of cold pulsatile machine perfusion (MP) for the storage and transportation of kidneys donated after circulatory death are disputed. We conducted a UK-based multicenter, randomized controlled trial to compare outcomes of kidneys stored with MP versus static cold storage (CS).

METHODS

Fifty-one pairs of kidneys donated after circulatory death were randomly allocated to receive static CS or cold pulsatile MP. The primary endpoint, delayed graft function, was analyzed by "intention-to-treat" evaluation.

RESULTS

There was no difference in the incidence of delayed graft function between CS and MP (32/51 (62.8%) and 30/51 (58.8%) P = 0.69, respectively), although the trial stopped early due to difficulty with recruitment. There was no difference in the incidence of acute rejection, or in graft or patient survival between the CS and MP groups. Median estimated glomerular filtration rate at 3 months following transplantation was significantly lower in the CS group compared with MP (CS 34 mL/min IQR 26-44 vs MP 45 mL/min IQR 36-60, P = 0.006), although there was no significant difference in estimated glomerular filtration rate between CS and MP at 12 months posttransplant.

CONCLUSIONS

This study is underpowered, which limits definitive conclusions about the use of MP, as an alternative to static CS. It did not demonstrate that the use of MP reduces the incidence of delayed graft function in donation after circulatory death kidney transplantation.

Hypoperfusion warm ischaemia time in renal transplants from donors after circulatory death

Background

The donor hypoperfusion phase before asystole in renal transplants from donors after circulatory death (DCD) has been considered responsible for worse outcomes than those from donors after brain death (DBD).

Methods

We included 10 309 adult renal transplants (7128 DBD and 3181 DCD; 1 January 2010–31 December 2016) from the UK Transplant Registry. We divided DCD renal transplants into groups according to hypoperfusion warm ischaemia time (HWIT). We compared delayed graft function (DGF) rates, primary non-function (PNF) rates and graft survival among them using DBD renal transplants as a reference.

Results

The DGF rate was 21.7% for DBD cases, but ∼40% for DCD cases with HWIT ≤30 min (0–10 min: 42.1%, 11–20 min: 43%, 21–30 min: 38.4%) and 60% for DCD cases with HWIT &gt;30 min (P &lt; 0.001). All DCD groups showed higher DGF risk than DBD renal transplants in multivariable analysis {0–10 min: odds ratio [OR] 2.686 [95% confidence interval (CI) 2.352–3.068]; 11–20 min: OR 2.531 [95% CI 2.003–3.198]; 21–30 min: OR 1.764 [95% CI 1.017–3.059]; &gt;30 min: OR 5.814 [95% CI 2.798–12.081]}. The highest risk for DGF in DCD renal transplants with HWIT &gt;30 min was confirmed by multivariable analysis [versus DBD: OR 5.814 (95% CI 2.798–12.081) versus DCD: 0–10 min: OR 2.165 (95% CI 1.038–4.505); 11–20 min: OR 2.299 (95% CI 1.075–4.902); 21–30 min: OR 3.3 (95% CI 1.33–8.197)]. No significant differences were detected regarding PNF rates (P = 0.713) or graft survival (P = 0.757), which was confirmed by multivariable analysis.

Conclusions

HWIT &gt;30 min increases the risk for DGF greatly, but without affecting PNF or graft survival.

Outcomes of Patients Suspended From the National Kidney Transplant Waiting List in the United Kingdom Between 2000 and 2010

BACKGROUND

In the United Kingdom, 1 in 3 patients on the National Kidney Transplant Waiting List (NKTWL) is suspended from the list at least once during their wait. The mortality of this large cohort of patients remains underreported and poorly described.

METHODS

We linked patient records from the UK transplant registry to mortality data from the Office of National Statistics and evaluated the impact of a clinically induced suspension event by estimating hazard ratios (HRs) that compared mortality and graft survival between those who had experienced a suspension event and those who had not.

RESULTS

Between January 1, 2000, and December 31, 2010, 16.7% (2221/13 322) of all patients registered on the NKTWL were suspended. Forty-eight percent (588/1225) of those who were suspended and who were never transplanted died, most often from cardiothoracic causes. A suspension event was associated with increased mortality from the time of listing (adjusted HR [aHR], 1.79; 1.64-1.95) and from the time of transplantation (aHR, 1.20; 1.06-1.37; P = 0.005). Graft survival was also poorer in those who had been suspended (aHR, 1.13; 1.01-1.28; P = 0.04).

CONCLUSIONS

Patients suspended on the NKTWL have a significantly higher rate of mortality both on the waiting list and following transplantation. Earlier prioritization of patients at risk of experiencing a suspension event may improve their outcomes.

Utilization and Outcomes of Single and Dual Kidney Transplants from Older Deceased Donors in the United Kingdom

BACKGROUND AND OBJECTIVES

Kidneys from elderly deceased donors are often discarded after procurement if the expected outcomes from single kidney transplantation are considered unacceptable. An alternative is to consider them for dual kidney transplantation. We aimed to examine the utilization of kidneys from donors aged ≥60 years in the United Kingdom and compare clinical outcomes of dual versus single kidney transplant recipients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Data from the United Kingdom Transplant Registry from 2005 to 2017 were analyzed. We examined utilization rates of kidneys retrieved from deceased donors aged ≥60 years, and 5-year patient and death-censored graft survival of recipients of dual and single kidney transplants. Secondary outcomes included eGFR. Multivariable analyses and propensity score analysis were used to correct for differences between the groups.

RESULTS

During the study period, 7841 kidneys were procured from deceased donors aged ≥60 years, of which 1338 (17%) were discarded; 356 dual and 5032 single kidneys were transplanted. Donors of dual transplants were older (median, 73 versus 66 years; P<0.001) and had higher United States Kidney Donor Risk Indices (2.48 versus 1.98; P<0.001). Recipients of dual transplants were also older (64 versus 61 years; P<0.001) and had less favorable human leukocyte antigen matching (P<0.001). After adjusting for confounders, dual and single transplants had similar 5-year graft survival (hazard ratio, 0.81; 95% CI, 0.59 to 1.12). No difference in patient survival was demonstrated. Similar findings were observed in a matched cohort with a propensity score analysis method. Median 12-month eGFR was significantly higher in the dual kidney transplant group (40 versus 36 ml/min per 1.73 m²; P<0.001).

CONCLUSIONS

Recipients of kidneys from donors aged ≥60 years have similar 5-year graft survival and better graft function at 12 months with dual compared with single deceased donor kidney transplants.

Overview of the Evolution of the UK Kidney Allocation Schemes

Purpose of Review

Allocation of deceased donor kidneys for transplantation has evolved since the first utilitarian approach in 1989. This review looks at how the schemes have evolved over the ensuing three decades.

Recent Findings

Four kidney offering schemes have been used in the last 30 years. Successive schemes have evolved from offering only one donor kidney for a nationally prioritised patient to offering both kidneys, from addressing only kidneys from donors after brain death (DBD) to offering kidneys from both DBD and circulatory death donors (DCD) and from prioritising purely on the basis of zero class 2 and minimising class 1 mismatches to a more relaxed approach for older donors and more difficult to match patients while introducing the concept of longevity matching.

Summary

UK kidney offering schemes have evolved through a series of evidence-based analyses to try to optimally address the principles of utility and fairness in kidney offering.

UK renal transplant outcomes in low and high BMI recipients: the need for a national policy

INTRODUCTION

We assessed the effect of recipient body mass index (BMI) on the outcomes of renal transplantation and the management of obese patients with end-stage renal disease across the UK.

METHODS

We analyzed data of 25539 adult renal transplants (2007-2016) from the UK Transplant Registry. Patients were divided in BMI groups [underweight: < 18.5, normal: 18.5-24.9 (reference group), overweight: 25-29.9, class I obese: 30-34.9, class II/III obese: ≥ 35]. We also conducted a national survey of all UK renal transplant centers on the influence of BMI on decisions regarding management of renal transplant candidates.

RESULTS

BMI ≥ 25 was an independent risk factor for delayed graft function and primary non-function (p ≤ 0.001). Underweight (p = 0.001), class I obese (p = 0.017) and class II/III obese recipients (p < 0.001) had poorer graft survival, however, 5- and 10-year graft survival rates were good. Patient survival was shorter for underweight recipients (p < 0.001) and longer for overweight (p = 0.028) and class I obese recipients (p = 0.013). The national survey revealed significant variability among transplant centers in BMI threshold for listing patients on transplant waiting list and limited support with conservative or surgical procedures for weight control.

CONCLUSIONS

Obesity alone should not be a barrier for renal transplantation. A national strategy is required to give all patients equal chances in transplantation.

The omission of the "wet" pre-transplant crossmatch in renal transplant centres in Scotland

The methods used for assessment of immunological risk for a patient receiving a kidney from a deceased donor have undergone significant change in the last few years. Many centres now proceed to transplant without any additional laboratory-based HLA testing for patients who are well defined as HLA antibody negative. Using rapid HLA antibody tests at the time of donor offer, such as Luminex, it is also possible to omit wet crossmatches in many sensitised patients. This virtual crossmatch (vXM) approach provides benefits in reducing cold ischaemia time (CIT), but also carries risks such as missing clinically relevant non-HLA reactivity or allelic HLA antibody reactivity. A number of factors need to be in place in a laboratory to enable a vXM policy to be extended to both sensitised and non-sensitised patients including access to complete donor HLA typing, ability to undertake Luminex-based HLA antibody testing out of working hours, and access to senior H&I Scientist expertise to assess and interpret results. Other approaches, such as using peripheral blood lymphocytes for crossmatching, may also enable a reduction in CIT and transplant units need to assess the risks of extending vXM processes for their patients against potential benefits.

Barriers to living donor kidney transplantation in the United Kingdom: a national observational study

Background. Living donor kidney transplantation (LDKT) provides more timely access to transplantation and better clinical outcomes than deceased donor kidney transplantation (DDKT). This study investigated disparities in the utilization of LDKT in the UK.

Methods. A total of 2055 adults undergoing kidney transplantation between November 2011 and March 2013 were prospectively recruited from all 23 UK transplant centres as part of the Access to Transplantation and Transplant Outcome Measures (ATTOM) study. Recipient variables independently associated with receipt of LDKT versus DDKT were identified.

Results. Of the 2055 patients, 807 (39.3%) received LDKT and 1248 (60.7%) received DDKT. Multivariable modelling demonstrated a significant reduction in the likelihood of LDKT for older age {odds ratio [OR] 0.11 [95% confidence interval (CI) 0.08–0.17], P < 0.0001 for 65–75 years versus 18–34 years}; Asian ethnicity [OR 0.55 (95% CI 0.39–0.77), P = 0.0006 versus White]; Black ethnicity [OR 0.64 (95% CI 0.42–0.99), P = 0.047 versus White]; divorced, separated or widowed [OR 0.63 (95% CI 0.46–0.88), P = 0.030 versus married]; no qualifications [OR 0.55 (95% CI 0.42–0.74), P < 0.0001 versus higher education qualifications]; no car ownership [OR 0.51 (95% CI 0.37–0.72), P = 0.0001] and no home ownership [OR 0.65 (95% CI 0.85–0.79), P = 0.002]. The odds of LDKT varied significantly between countries in the UK.

Conclusions. Among patients undergoing kidney transplantation in the UK, there are significant age, ethnic, socio-economic and geographic disparities in the utilization of LDKT. Further work is needed to explore the potential for targeted interventions to improve equity in living donor transplantation.

HLA Matching in Pediatric Kidney Transplantation: HLA Poorly Matched Living Donor Transplants Versus HLA Well-Matched Deceased Donor Transplants

BACKGROUND

Based on an analysis of 542 pediatric kidney transplants recorded by the UK Transplant Registry from 2000 to 2012, it was concluded that the survival rate of HLA poorly matched living donor transplants is not inferior to that of HLA well-matched deceased donor transplants.

METHODS

We analyzed the impact of HLA matching on kidney graft survival in 3627 pediatric living donor transplants performed during 2000 to 2015 using the data of the Collaborative Transplant Study. The impact of HLA mismatches on graft survival was analyzed and survival rates of transplants from poorly matched living donors were compared with those from well-matched deceased donors. Multivariate Cox regression analysis was used to account for the influence of confounders.

RESULTS

HLA matching had a statistically significant impact on graft survival of pediatric kidney transplants (P < 0.001). Ten-year graft survival of pediatric transplants from living donors with 4 to 6 HLA-A+B+DR mismatches was significantly worse than that of transplants from well-matched deceased donors with 0 to 1 HLA mismatch (log rank, P = 0.006).

CONCLUSIONS

In pediatric kidney transplantation, graft survival of kidneys from deceased donors with 0 to 1 HLA mismatches compares favorably with that of grafts from living donors with 4 to 6 HLA mismatches. If possible, living donor pediatric kidney transplants should be performed from donors with fewer than 4 HLA-A+B+DR mismatches.

Local Expansion of Donation After Circulatory Death Kidney Transplant Activity Improves Waitlisted Outcomes and Addresses Inequities of Access to Transplantation

In the United Kingdom, donation after circulatory death (DCD) kidney transplant activity has increased rapidly, but marked regional variation persists. We report how increased DCD kidney transplant activity influenced waitlisted outcomes for a single center. Between 2002-2003 and 2011-2012, 430 (54%) DCD and 361 (46%) donation after brain death (DBD) kidney-only transplants were performed at the Cambridge Transplant Centre, with a higher proportion of DCD donors fulfilling expanded criteria status (41% DCD vs. 32% DBD; p = 0.01). Compared with U.K. outcomes, for which the proportion of DCD:DBD kidney transplants performed is lower (25%; p < 0.0001), listed patients at our center waited less time for transplantation (645 vs. 1045 days; p < 0.0001), and our center had higher transplantation rates and lower numbers of waiting list deaths. This was most apparent for older patients (aged >65 years; waiting time 730 vs. 1357 days nationally; p < 0.001), who received predominantly DCD kidneys from older donors (mean donor age 64 years), whereas younger recipients received equal proportions of living donor, DBD and DCD kidney transplants. Death-censored kidney graft survival was nevertheless comparable for younger and older recipients, although transplantation conferred a survival benefit from listing for only younger recipients. Local expansion in DCD kidney transplant activity improves survival outcomes for younger patients and addresses inequity of access to transplantation for older recipients.

Patient preferences, knowledge and beliefs about kidney allocation: qualitative findings from the UK-wide ATTOM programme

OBJECTIVE

To explore how patients who are wait-listed for or who have received a kidney transplant understand the current UK kidney allocation system, and their views on ways to allocate kidneys in the future.

DESIGN

Qualitative study using semistructured interviews and thematic analysis based on a pragmatic approach.

PARTICIPANTS

10 deceased-donor kidney transplant recipients, 10 live-donor kidney transplant recipients, 12 participants currently wait-listed for a kidney transplant and 4 participants whose kidney transplant failed.

SETTING

Semistructured telephone interviews conducted with participants in their own homes across the UK.

RESULTS

Three main themes were identified: uncertainty of knowledge of the allocation scheme; evaluation of the system and participant suggestions for future allocation schemes. Most participants identified human leucocyte anitgen matching as a factor in determining kidney allocation, but were often uncertain of the accuracy of their knowledge. In the absence of information that would allow a full assessment, the majority of participants consider that the current system is effective. A minority of participants were concerned about the perceived lack of transparency of the general decision-making processes within the scheme. Most participants felt that people who are younger and those better matched to the donor kidney should be prioritised for kidney allocation, but in contrast to the current scheme, less priority was considered appropriate for longer waiting patients. Some non-medical themes were also discussed, such as whether parents of dependent children should be prioritised for allocation, and whether patients with substance abuse problems be deprioritised.

CONCLUSIONS

Our participants held differing views about the most important factors for kidney allocation, some of which were in contrast to the current scheme. Patient participation in reviewing future allocation policies will provide insight as to what is considered acceptable to patients and inform healthcare staff of the kinds of information patients would find most useful.

Living Donation Has a Greater Impact on Renal Allograft Survival Than HLA Matching in Pediatric Renal Transplant Recipients

BACKGROUND

Living donor (LD) kidney transplantation accounts for around half of all pediatric renal transplant recipients and results in improved renal allograft survival. The aim of this study was to determine the effect of HLA matching on deceased and LD renal allograft outcomes in pediatric recipients.

METHODS

Data were obtained from the UK Transplant Registry held by NHS Blood and Transplant on all children who received a donation after brain death (DBD) or LD kidney-only transplant between 2000 and 2011. HLA-A, HLA-B and HLA-DR mismatches were categorized into 4 levels and 2 groups. Data were fully anonymized.

RESULTS

One thousand three hundred seventy-eight pediatric renal transplant recipients were analyzed; 804 (58%) received a DBD donor kidney, 574 (42%) received an LD kidney. Five-year renal allograft survival was superior for children receiving a poorly HLA-matched LD kidney transplant (88%, 95% confidence interval [95% CI], 84-91%) compared with children receiving a well HLA-matched DBD kidney transplant (83%, 95% CI, 80-86%, log rank test P = 0.03). Five-year renal allograft survival was superior for children receiving an LD kidney with 1 or 2 HLA-DR mismatches (88%, 95% CI, 84-91%) compared with children receiving a DBD kidney with 0 HLA-DR mismatches (83%, 95% CI, 80-86%, log rank test P = 0.03).

CONCLUSIONS

In children, poorly HLA-matched LD renal transplant outcomes are not inferior when compared with well HLA-matched DBD renal transplants. It is difficult to justify preferentially waiting for an improved HLA-matched DBD kidney when a poorer HLA-matched LD kidney transplant is available.

Should Children Be Given Priority in Kidney Allocation?

Kidneys for transplantation are scarce, and many countries give priority to children in allocating them. This paper explains and criticizes the paediatric priority. We set out the relevant ethical principles of allocation, such as utility and severity, and the relevant facts to do with such matters as sensitization and child development. We argue that the facts and principles do not support and sometimes conflict with the priority given to children. We next consider various views on how age or the status of children should affect allocation. Again, these views do not support priority to children in its current form. Since distinctions based on age ought to be positively justified, the failure of all these attempts at justification implies that the priority to children is ethically mistaken. Finally, the paper points to evidence that the paediatric priority reduces the overall supply of kidneys, at least in the United States. Paediatric priority is a real-world policy that seems discriminatory, in some places probably reduces the supply of organs, has no robust official defence, and is unsupported by mainstream ethical principles. Consequently, it should be ended.

Balancing competing needs in kidney transplantation: does an allocation system prioritizing children affect the renal transplant function?

Children often merit priority in access to deceased donor kidneys by organ-sharing organizations. We report the impact of the new Swiss Organ Allocation System (SOAS) introduced in 2007, offering all kidney allografts from deceased donors <60 years preferentially to children. The retrospective cohort study included all paediatric transplant patients (<20 years of age) before (n = 19) and after (n = 32) the new SOAS (from 2001 to 2014). Estimated glomerular filtration rate (eGFR), urine protein-to-creatinine ratio (UPC), need for antihypertensive medication, waiting times to kidney transplantation (KTX), number of pre-emptive transplantations and rejections, and the proportion of living donor transplants were considered as outcome parameters. Patients after the new SOAS had significantly better eGFRs 2 years after KTX (Mean Difference, MD = 25.7 ml/min/1.73 m² , P = 0.025), lower UPC ratios (Median Difference, MeD = -14.5 g/mol, P = 0.004), decreased waiting times to KTX (MeD = -97 days, P = 0.021) and a higher proportion of pre-emptive transplantations (Odds Ratio = 9.4, 95% CI = 1.1-80.3, P = 0.018), while the need for antihypertensive medication, number of rejections and living donor transplantations remained stable. The new SOAS is associated with improved short-term clinical outcomes and more rapid access to KTX. Despite lacking long-term research, the study results should encourage other policy makers to adopt the SOAS approach.

Predicting patient survival after deceased donor kidney transplantation using flexible parametric modelling

BACKGROUND

The influence of donor and recipient factors on outcomes following kidney transplantation is commonly analysed using Cox regression models, but this approach is not useful for predicting long-term survival beyond observed data. We demonstrate the application of a flexible parametric approach to fit a model that can be extrapolated for the purpose of predicting mean patient survival. The primary motivation for this analysis is to develop a predictive model to estimate post-transplant survival based on individual patient characteristics to inform the design of alternative approaches to allocating deceased donor kidneys to those on the transplant waiting list in the United Kingdom.

METHODS

We analysed data from over 12,000 recipients of deceased donor kidney or combined kidney and pancreas transplants between 2003 and 2012. We fitted a flexible parametric model incorporating restricted cubic splines to characterise the baseline hazard function and explored a range of covariates including recipient, donor and transplant-related factors.

RESULTS

Multivariable analysis showed the risk of death increased with recipient and donor age, diabetic nephropathy as the recipient's primary renal diagnosis and donor hypertension. The risk of death was lower in female recipients, patients with polycystic kidney disease and recipients of pre-emptive transplants. The final model was used to extrapolate survival curves in order to calculate mean survival times for patients with specific characteristics.

CONCLUSION

The use of flexible parametric modelling techniques allowed us to address some of the limitations of both the Cox regression approach and of standard parametric models when the goal is to predict long-term survival.

Increasing the acceptability and rates of organ donation among minority ethnic groups: a programme of observational and evaluative research on Donation, Transplantation and Ethnicity (DonaTE)

Background

Black, Asian and minority ethnic (BAME) groups have a high need for organ transplantation but deceased donation is low. This restricts the availability of well-matched organs and results in relatively long waiting times for transplantation, with increased mortality risks.

Objective

To identify barriers to organ donor registration and family consent among the BAME population, and to develop and evaluate a training intervention to enhance communication with ethnic minority families and identify impacts on family consent.

Methods

Three-phase programme comprising (1) community-based research involving two systematic reviews examining attitudes and barriers to organ donation and effective interventions followed by 22 focus groups with minority ethnic groups; (2) hospital-based research examining staff practices and influences on family consent through ethics discussion groups (EDGs) with staff, a study on intensive care units (ICUs) and interviews with bereaved ethnic minority families; and (3) development and evaluation of a training package to enhance cultural competence among ICU staff.

Setting

Community focus group study in eight London boroughs with high prevalence of ethnic minority populations. Hospital studies at five NHS hospital trusts (three in London and two in Midlands).

Participants

(1) Community studies: 228 focus group participants; (2) hospital studies: 35 nurses, 28 clinicians, 19 hospital chaplains, 25 members of local Organ Donation Committees, 17 bereaved family members; and (3) evaluation: 66 health professionals.

Data sources

Focus groups with community residents, systematic reviews, qualitative interviews and observation in ICUs, EDGs with ICU staff, bereaved family interviews and questionnaires for trial evaluation.

Review methods

Systematic review and narrative synthesis.

Results

(1) Community studies: Organ Donor Register – different ethnic/faith and age groups were at varying points on the ‘pathway’ to organ donor registration, with large numbers lacking knowledge and remaining at a pre-contemplation stage. Key attitudinal barriers were uncertainties regarding religious permissibility, bodily concerns, lack of trust in health professionals and little priority given to registration, with the varying significance of these factors varying by ethnicity/faith and age. National campaigns focusing on ethnic minorities have had limited impact, whereas characteristics of effective educational interventions are being conducted in a familiar environment; addressing the groups’ particular concerns; delivery by trained members of the lay community; and providing immediate access to registration. Interventions are also required to target those at specific stages of the donation pathway. (2) Hospital studies: family consent to donation – many ICU staff, especially junior nurses, described a lack of confidence in communication and supporting ethnic minority families, often reflecting differences in emotional expression, faith and cultural beliefs, and language difficulties. The continuing high proportion of family donation discussions that take place without the collaboration of a specialist nurse for organ donation (SNOD) reflected consultants’ views of their own role in family consent to donation, a lack of trust in SNODs and uncertainties surrounding controlled donations after circulatory (or cardiac) death. Hospital chaplains differed in their involvement in ICUs, reflecting their availability/employment status, personal interests and the practices of ICU staff. (3) Evaluation: professional development package – a digital versatile disc-based training package was developed to promote confidence and skills in cross-cultural communication (available at:www.youtube.com/watch?v=ueaR6XYkeVM&feature=youtu.be). Initial evaluation produced positive feedback and significant affirmative attitudinal change but no significant difference in consent rate over the short follow-up period with requirements for longer-term evaluation.

Limitations

Participants in the focus group study were mainly first-generation migrants of manual socioeconomic groups. It was not permitted to identify non-consenting families for interview with data regarding the consent process were therefore limited to consenting families.

Conclusions

The research presents guidance for the effective targeting of donation campaigns focusing on minority ethnic groups and provides the first training package in cultural competence in the NHS.

Future work

Greater evaluation is required of community interventions in the UK to enhance knowledge of effective practice and analysis of the experiences of non-consenting ethnic minority families.

Funding

The National Institute for Health Research Programme Grants for Applied Research programme.

Kidney donation after circulatory death (DCD): state of the art

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 donation after circulatory death (DCD): state of the art

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 24 h. This caused renal dysfunction, measured by decreased creatinine clearance, and increased markers of oxidative damage. Administering MitoQ to the mice intravenously 15 min 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.

Impact of expanded criteria variables on outcomes of kidney transplantation from donors after cardiac death

INTRODUCTION

To expand the donor pool, kidney transplants are being performed using donors who were previously considered unacceptable. We applied the United Network for Organ Sharing criteria to define expanded criteria donors (ECD) within the donation after cardiac death (DCD) and donation after brain stem death (DBD) cohorts. We compared outcomes of DCD and DBD transplants with and without (standard criteria donor [SCD]) the ECD criteria.

METHODS

This was a single-center retrospective study of all deceased donor transplants from 2004 to 2010 (n=359). Four groups were identified--DBD-SCD (n=154), DBD-ECD (n=93), DCD-SCD (n=78), and DCD-ECD (n=34). Kaplan-Meier analysis of graft and patient survival and multiple regression analysis of 1-year graft function were performed.

RESULTS

One-year and two-year uncensored graft survivals were similar between DCD-ECD and DCD-SCD cohorts (1 year, 90% and 93%; 2 years, 81% and 93% respectively; log-rank test P=0.2). Median estimated glomerular filtration rate (eGFR) was lower in DCD-ECD recipients at 12 months (41 vs. 53 mL/min, P=0.003) and 24 months (33 vs. 54 mL/min, P<0.001) compared with DCD-SCD recipients. Compared with DBD-ECD recipients also at 24 months, DCD-ECD recipients showed a lower graft function (median, eGFR 33 vs. 47 mL/min; P=0.007) but similar graft survival. Expanded criteria donor status (B=-9.7, P=0.01) was associated with a lower 1-year eGFR within the DCD cohort, with donor age (B=-0.42, P=0.002) being the only significant ECD variable.

CONCLUSION

Short-term graft survival in DCD-ECD transplants was comparable to DCD-SCD and DBD-ECD transplants albeit with poorer allograft function at 2 years. Quality-of-life studies are needed to determine the true value of these transplants, particularly when performed to older recipients.

Matching for Human Leukocyte Antigens (HLA) in corneal transplantation - to do or not to do

As many patients with severe corneal disease are not even considered as candidates for a human graft due to their high risk of rejection, it is essential to find ways to reduce the chance of rejection. One of the options is proper matching of the cornea donor and recipient for the Human Leukocyte Antigens (HLA), a subject of much debate. Currently, patients receiving their first corneal allograft are hardly ever matched for HLA and even patients undergoing a regraft usually do not receive an HLA-matched graft. While anterior and posterior lamellar grafts are not immune to rejection, they are usually performed in low risk, non-vascularized cases. These are the cases in which the immune privilege due to the avascular status and active immune inhibition is still intact. Once broken due to infection, sensitization or trauma, rejection will occur. There is enough data to show that when proper DNA-based typing techniques are being used, even low risk perforating corneal transplantations benefit from matching for HLA Class I, and high risk cases from HLA Class I and probably Class II matching. Combining HLA class I and class II matching, or using the HLAMatchmaker could further improve the effect of HLA matching. However, new techniques could be applied to reduce the chance of rejection. Options are the local or systemic use of biologics, or gene therapy, aiming at preventing or suppressing immune responses. The goal of all these approaches should be to prevent a first rejection, as secondary grafts are usually at higher risk of complications including rejections than first grafts.

Alemtuzumab-based induction treatment versus basiliximab-based induction treatment in kidney transplantation (the 3C Study): a randomised trial

BACKGROUND

Calcineurin inhibitors (CNIs) reduce short-term kidney transplant failure, but might contribute to transplant failure in the long-term. The role of alemtuzumab (a potent lymphocyte-depleting antibody) as an induction treatment followed by an early reduction in CNI and mycophenolate exposure and steroid avoidance, after kidney transplantation is uncertain. We aimed to assess the efficacy and safety of alemtuzumab-based induction treatment compared with basiliximab-based induction treatment in patients receiving kidney transplants.

METHODS

For this randomised trial, we enrolled patients aged 18 years and older who were scheduled to receive a kidney transplant in the next 24 h from 18 transplant centres in the UK. Using minimised randomisation, we randomly assigned patients (1:1; minimised for age, sex, and immunological risk) to either alemtuzumab-based induction treatment (ie, alemtuzumab followed by low-dose tacrolimus and mycophenolate without steroids) or basiliximab-based induction treatment (basiliximab followed by standard-dose tacrolimus, mycophenolate, and prednisolone). Participants were reviewed at discharge from hospital and at 1, 3, 6, 9, and 12 months after transplantation. The primary outcome was biopsy-proven acute rejection at 6 months, analysed by intention to treat. The study is registered at ClinicalTrials.gov, number NCT01120028, and isrctn.org, number ISRCTN88894088.

FINDINGS

Between Oct 4, 2010, and Jan 21, 2013, we randomly assigned 852 participants to treatment: 426 to alemtuzumab-based treatment and 426 to basiliximab-based treatment. Overall, individuals allocated to alemtuzumab-based treatment had a 58% proportional reduction in biopsy-proven acute rejection compared with those allocated to basiliximab-based treatment (31 [7%] patients in the alemtuzumab group vs 68 [16%] patients in the basiliximab group; hazard ratio (HR) 0·42, 95% CI 0·28-0·64; log-rank p<0·0001). We detected no between-group difference in treatment effect on transplant failure during the first 6 months (16 [4%] patients vs 13 [3%] patients; HR 1·23, 0·59-2·55; p=0·58) or serious infection (135 [32%] patients vs 136 [32%] patients; HR 1·02, 0·80-1·29; p=0·88). During the first 6 months after transplantation, 11 (3%) patients given alemtuzumab-based treatment and six (1%) patients given basiliximab-based treatment died (HR 1·79, 95% CI 0·66-4·83; p=0·25).

INTERPRETATION

Compared with standard basiliximab-based treatment, alemtuzumab-based induction therapy followed by reduced CNI and mycophenolate exposure and steroid avoidance reduced the risk of biopsy-proven acute rejection in a broad range of patients receiving a kidney transplant. Long-term follow-up of this trial will assess whether these effects translate into differences in long-term transplant function and survival.

FUNDING

UK National Health Service Blood and Transplant Research and Development Programme, Pfizer, and Novartis UK.

Association of human leukocyte antigen donor-recipient matching and pediatric heart transplant graft survival

BACKGROUND

The effect of donor-recipient human leukocyte antigen (HLA) matching on outcomes remains relatively unexplored in pediatric patients. The objective of this study was to investigate the effects of donor-recipient HLA matching on graft survival in pediatric heart transplantation.

METHODS AND RESULTS

The UNOS (United Network for Organ Sharing) database was queried for heart transplants occurring between October 31, 1987, and December 31, 2012, in a recipient aged ≤17 years with ≥1 postoperative follow-up visit. Retransplants were excluded. Transplants were divided into 3 donor-recipient matching groups: no HLA matches (HLA-no), 1 or 2 HLA matches (HLA-low), and 3 to 6 HLA matches (HLA-high). Primary outcome was graft loss. Four thousand four hundred seventy-one heart transplants met the study inclusion criteria. High degree of donor-recipient HLA matching occurred infrequently: HLA-high (n=269; 6%) versus HLA-low (n=2683; 60%) versus HLA-no (n=1495; 34%). There were no differences between HLA matching groups in the frequency of coronary vasculopathy (P=0.19) or rejection in the first post-transplant year (P=0.76). Improved graft survival was associated with a greater degree of HLA donor-recipient matching: HLA-high median survival, 17.1 (95% confidence interval, 14.0-20.2) years; HLA-low median survival, 14.2 (13.1-15.4) years; and HLA-no median survival, 12.1 (10.9-13.3 years) years; P<0.01, log-rank test. In Cox-regression analysis, HLA matching was independently associated with decreased graft loss: HLA-low versus HLA-no hazard ratio, 0.86 (95% confidence interval, 0.74-0.99), P=0.04; HLA-high versus HLA-no, 0.62 (95% confidence interval, 0.43-0.90), P<0.01.

CONCLUSIONS

Decreased graft loss in pediatric heart transplantation was associated with a higher degree of donor-recipient HLA matching, although a difference in the frequency of early rejection or development of coronary artery vasculopathy was not seen.