HLA-A Amino Acid Linked with Kidney Transplant Rejection
Study may aid in finding a compatible donor-recipient transplant
WEDNESDAY, Nov. 26 (HealthDay News) -- Researchers have identified specific amino acids in the antigen-binding site of the HLA-A protein associated with an increased risk of delayed kidney allograft function, according to a report published in the Dec. 2 issue of the Proceedings of the National Academy of Sciences.
In a prospective cohort study of 697 renal transplant recipients of deceased donors, Malek Kamoun, Ph.D., of the University of Pennsylvania School of Medicine in Philadelphia, and colleagues used a multivariate logistic regression model adjusted for non-immunologic risk factors, to investigate the association of amino acid mismatches at 66 variable sites of the HLA-A molecule with delayed allograft function.
The investigators found that delayed allograft function risk in white recipients increased significantly with amino acid mismatches at position 62, 95 and163 of the antigen recognition site of the HLA-A molecule, while the risk decreased with variation at HLA-A family-specific sites in the alpha-2 (position 149) and alpha-3 domains (positions 149, 193 and 246).
"Our findings support the hypothesis that HLA-A amino acid polymorphism can be used to assess the influence of the degree of HLA-A matching on delayed allograft function. Further studies with larger cohorts are needed to evaluate the effect of the interactions of HLA-A amino acid mismatches with covariates, such as cold ischemia time and pre-transplant anti-HLA antibodies, as well as the influence of HLA amino acid mismatches on other outcomes, such as acute rejection and allograft loss," the authors write.