A Retrospective Study on Human Leukocyte Antigen Types and Haplotypes in a South African Population

Abstract

Context.— Human Leukocyte Antigen (HLA) is a polymorphic protein of the immune system with a central role in organ transplantation. Organ recipients can be sensitized against HLA from previous exposure, which increases the likelihood of antidonor immune responses and subsequently organ rejection. HLA matching represents an attractive option to improve graft function, reduce sensitization of recipients in first transplantations, and improve organ allocation. Objective.— To examine the feasibility of the reintroduction of HLA matching into the criteria in the Johannesburg program, we retrospectively assessed HLA types in our donor population. Design.— HLA types of 782 deceased and related living donors from 2015 until 2019 were recorded and analyzed to identify the most common HLA types and haplotypes. A virtual crossmatch was also done to examine the anti-HLA antibodies in the recipient population compared with the common HLA types identified in this study. Results.— Of the commonest HLA types identified, at least 1 was present in 732 (93.6%) of the renal donors assessed. The virtual crossmatch confirmed that most recipients are sensitized against most donors, and this greatly impacts the number of recipients who can receive organ transplants. Conclusions.— This study determined the most common HLA types and haplotypes in a South African organ donor population. This information, combined with the evidence suggesting the immunogenic potential of these common types, the high number of recipients with antibodies against common HLA types, and the ethnic distribution of the donor and recipient populations, informs the recommendation that the pretransplantation workup should not reinclude HLA matching.

A Retrospective Study on Human Leukocyte Antigen Types and Haplotypes in a South African Population

“…We have corrected the figure and resubmitted it in an erratum. 1 Of note, this did not materially affect the results because these inaccuracies comprised a small percentage of the population. Where discrepancies were identified, the sample was excluded from the final analysis.…”

“…To the Editor.-We read with interest the original article by Gandini et al 1 ''A retrospective study on human leukocyte antigen types and haplotypes in a South African population'' recently published in Archives of Pathology & Laboratory Medicine. The study reports the human leukocyte antigen (HLA) types of 782 donors and the HLA antibody profiles of 200 recipients in the Johannesburg transplant program with the goal of ''examining the feasibility of the reintroduction of HLA matching into the criteria of the Johannesburg program.''…”

“…The authors have no relevant financial interest in the products or companies described in this article. doi: 10.5858/arpa.2021-0228-LE In Reply.-We would like to thank you for the opportunity to respond to the notes raised in the letter to the editor regarding Gandini et al, 1 ''A Retrospective Study on Human Leukocyte Antigen Types and Haplotypes in a South African Population,'' and to clarify the methodology used. We would also like to thank the authors of the letter for their interest in our paper and for taking the time to express their concerns.…”