Different eplet software programs give discordant and incorrect results: An analysis of HLAMatchmaker vs Fusion Matchmaker Eplet calling software

HLA eplet matching is a novel approach to define acceptable HLA mismatches for transplant recipients. We performed an eplet analysis of three different transplant case-series to determine if the available software programs gave accurate results. Eplet analysis was performed for three different transplant case-series typed by NGS for all HLA class I and II loci. The three different HLA datasets were entered into both the HLAMatchmaker program (v2.1) and OLI Fusion MatchMaker (v4.2) software tools. Eplet results which were discordant were cross referenced against eplet registry and published HLA allele sequence data to determine the correct assignments. The comparison reveals that there was poor concordance between the two eplet programs. Analysis of the same donor/recipient pair often gave rise to different total eplet scores, incorrect eplet mismatches and antibody verification status, and both programs have eplets assigned to incorrect HLA alleles. Overall, the OLI Fusion MatchMaker eplet tool gave more accurate and useful eplet results. Eplet matching is still primarily a research tool. Before eplet matching can enter routine clinical practice further work is required to validate the accuracy of available eplet software programs. Incorrect eplet assignment could have serious adverse consequences in the clinical transplant setting.