INCIDENCE OF DENOVO HLA ANTIBODIES - CORRELATION WITH EPLET MISMATCH LOAD AND GRAFT OUTCOME; A SINGLE CENTRE STUDY

Introduction:

Immunologic rejection plays an important role in kidney transplant failure, both antibody-mediated rejection (ABMR) caused by denovo donor-specific HLA antibodies (DSA) and T cell–mediated rejection. Recent studies show eplet mismatches are associated with risks of denovo DSA formation, ABMR and graft failure. Aims of this study were to investigate the incidence of de-novo HLA antibodies in kidney transplant recipients in the first year post transplant, and to evaluate the correlation between their development and eplet mismatch load. The objectives also included assessing the impact of de-novo HLA antibodies on eGFR trends, new onset proteinuria, acute rejection, graft loss, and patient mortality.

Methods:

This was a single center retrospective-prospective (amphidirectional) study. All patients who underwent renal transplantation from 1st Jan 2022 for one year were included. They were followed up from January 1st 2023 for a further one year.  HLA antibodies of recipients on day 0 and 1 year post-transplant samples were checked. Eplet mismatch score was determined with the HLA Matchmaker program. Clinical outcomes such as eGFR trends, new onset proteinuria, acute rejection episodes, graft loss, and patient mortality were also assessed.

Results:

A total of 83 kidney transplant recipients were included in this study, with a median age of 33 years, and 66.3% were males. Of the participants 16.9% developed de-novo anti-HLA antibodies within the first year post-transplant.

 A significant association was found between prolonged dialysis vintage and denovo HLA antibody formation (p = 0.023). 

The total antibody-verified eplet mismatch load was significantly higher in the denovo HLA antibody-positive group (p = 0.01). 

There was no significant association between de-novo HLA antibodies with eGFR trends, proteinuria, or acute rejection episodes. No graft loss or patient mortality was observed during the study period. This study is limited by its single-center design, homogeneous population, and lack of renal biopsies to detect subclinical rejections.

Conclusions:

Total antibody verified eplet mismatch load can help in predicting the risk of formation of de novo HLA antibodies in kidney transplant recipients which may lead to poor graft outcomes. Larger, multi-center studies with more diverse populations are needed to validate these findings and assess the long-term impact of eplet mismatch algorithms on graft outcomes.

I have no potential conflict of interest to disclose.

I did not use generative AI and AI-assisted technologies in the writing process.