Prevalence of anti-HLA antibodies among live related renal transplant recipients: A retrospective observational study from a tertiary healthcare Center in India

Aim: Detection of anti-HLA antibodies is crucial for pre-transplant histocompatibility testing, donor selection, and graft survival. The aim of this study was to evaluate the spectrum of anti-HLA antibodies among live related renal transplant recipients from one of the largest transplant centers in north India.

Methods: In this study, retrospective data of transplant workup done in past four years were analyzed using GraphPad Prism 9 Version 9.2.0 (La Jolla, CA, USA). All samples received for pre-transplant work-up if showed positive screening results underwent Luminex single antigen bead (L-SAB) assay. Antibodies identified on L-SAB were evaluated for their specificity and the strength of their mean florescence intensity (MFI).

Results: A total of 1250 renal transplant samples were included for analysis. Out of these, 458 (36.64 %) samples were found positive in screening tests algorithm. All 458 samples were further analyzed for both class I and class II HLA antibodies by Luminex single antigen bead (L-SAB) assay. In this study, we observed that anti-A*24:01, anti-B*15:01 and anti-C*07*01 were the three most prevalent anti-HLA antibodies identified against HLA-class I antigens. However, anti-DRB1*11:01, anti-DQA1*05:01-DQB1*03:01 and anti-DPA1*02:01-DPB1*17:01 were the most common anti-HLA antibodies identified against HLA-class II antigen. Furthermore, our study found a significant association between anti-HLA class I antibody and the history of pregnancy. However, in re-transplant cases, we observed the presence of antibodies both against HLA class I and II antigens.

Conclusion: For a transplant center, it is of utmost importance to have comprehensive knowledge about the prevalence of HLA antibodies, their MFI, and their association with various sensitization events. This study may immensely help transplant communities in selecting appropriate prospective organ donors, planning desensitization regimes, managing recipients' care and predicting transplant outcomes in live related renal transplantation.