Evaluation of HLA Matchmaker Compatibility as Predictor of Graft Survival and Presence of Anti-HLA Antibodies

Abstract

Background. HLA Matchmaker is a computer algorithm developed to evaluate donor/ receptor compatibility comparing sequences of polymorphic aminoacids (eplets) present in human leukocyte antigen (HLA) molecules. The aim of this study was to evaluate the predictive value of HLA Matchmaker for patient and graft survival, graft survival free of rejection, and the presence of anti HLA antibodies. Methods. Using this program, 62 of 173 kidney transplant patients, were retrospectively analyzed. HLA-I loci eplet mismatch value (EMM) was determined and correlated with graft survival, graft survival free of rejection, and the presence of anti HLA-I antibodies. EMM was compared with the traditional HLA antigen mismatch value (MM) in terms of the presence of anti HLA-I antibodies. Results. Graft survival and graft survival free of rejection showed no statistical differences (P-value .975 and .365, respectively) while comparing patients with less or more than 10 HLA-I EMM. Patients with 6 HLA-B EMM had an odds ratio (OR) of 5.6 (95% confidence interval [CI], 0.47– 66.45) of presenting anti HLA-I antibodies, with a sensitivity of 80% and specificity of 58.3%. For 2 HLA-B MM, the OR was 2.58 (95% CI, 0.46 –14.5), with a sensitivity of 40% and specificity of 75%. Conclusion. Even though in our study population compatibility by HLA Matchmaker did not correlate with graft survival or rejection-free graft survival, it showed a better sensitivity than traditional HLA antigen matching for the presence of anti HLA-I antibodies. HLA Matchmaker is a promising tool in predicting the appearance of anti-HLA antibodies.