Human leukocyte antigen associations with renal function among ethnic minorities in the United Kingdom

Donor-recipient race-ethnicity concordance and patient survival after liver transplantation

INTRODUCTION

We assessed the association between patient survival after liver transplantation (LT) and donor-recipient race-ethnicity (R/E) concordance.

METHODS

The Scientific Registry of Transplant Recipients (SRTR) was retrospectively analyzed using data collected between 2002 and 2019. Only adults without history of prior organ transplant and recipients of LT alone were included. The primary outcome was patient survival. Donors and recipients were categorized into five R/E groups: White/Caucasian, African American/Black, Hispanic/Latino, Asian, and Others. Statistical analyses were performed using Kaplan-Meier survival curves and Cox Proportional Hazards models, adjusting for donor and recipient covariates.

RESULTS

85,427 patients were included. Among all the R/E groups, Asian patients had the highest 5-year survival (81.3%; 95% CI = 79.9-82.7), while African American/Black patients had the lowest (71.4%; 95% CI = 70.3-72.6) (P < 0.001). Lower survival rates were observed in recipients who received discordant R/E grafts irrespective of their R/E group. The fully adjusted hazard ratio for death was statistically significant in African American/Black (aHR 1.07-1.18-1.31; P < 0.01) and in White∕Caucasian patients (aHR 1.00-1.04-1.07; P = 0.03) in the presence of donor-recipient R/E discordance.

CONCLUSION

Disparities in post-LT outcomes might be influenced by biological factors in addition to well-known social determinants of health.

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.

Taking a "Care Pathway/Whole Systems" Approach to Equality Diversity Inclusion (EDI) in Organ Donation and Transplantation in Relation to the Needs of "Ethnic/Racial/Migrant" Minority Communities: A Statement and a Call for Action

International evidence shows variation in organ donation and transplantation (ODT) based upon a range of patient characteristics. What is less well understood is the impact of patient "ethnicity/race/immigration background," as these terms are defined and intended differently across countries. We also know that these characteristics do not operate in isolation but intersect with a range of factors. In this paper, we propose a framework that seeks to clarify the definition of the key terms "ethnicity/race/migrant" and to review how these communities are operationalized across European studies about inequities in ODT. Further, patients and the public wish to see Equality Diversity Inclusion (EDI) approaches in their everyday lives, not just in relation to ODT. We propose a 'care pathway/whole-systems' approach to ODT encompassing culturally competent public health interventions for a) the prevention and management of chronic diseases, b) improvements in public engagement for the promotion of the culture of ODT and enhancements in end-of-life care, through to c) enhanced likelihood of successful transplant among migrant/ethnic minority communities. Our framework recognizes that if we truly wish to take an EDI approach to ODT, we need to adopt a more social, human and holistic approach to examining questions around patient ethnicity.

Systematic review of associations between HLA and renal function

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.

Associations between human leukocyte antigens and renal function

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.