Distribution of HLA epitope frequencies in Turkish population

Abstract

Objectives: The antibodies interact with the “Human Leukocyte Antigen (HLA) antigens” at specific epitopes. “Epitopes” are present on a single HLA or shared by multiple antigens. In this study, we aim to determine the frequency of prevalent epitopes common in the Turkish population. ethods: Non-related 644 healthy volunteers were recruited, and The “HLA-A, -B, -C, -DR -DQ’s” were typed using the “Next Generation Sequencing”. The provisional and confirmed epitopes were identified using the “HLA Epitope Registry databases, HLA Epitopia Maps and Immucor Epitope databases” dated 07.02.2018. Epitope frequencies were calculated by counting the shared epi- topes in the total number of shared HLA Class epitopes in our sample database. Results: Class I HLA’s had 298 epitopes that repeated a total of 158,117 times with frequencies ranging between 0.0006 and 2.03%, and the most frequent epitope was 170RY found on 119 different alleles. Class II HLA’s had 193 epitopes that repeated a total of 93,082 times with fre- quencies ranging between 0.002 and 1.36%, and the most frequent epitope was 108P found on 42 different alleles. Conclusions: Our findings summarize both the provi- sional, and confirmed epitope frequencies in the Turkish population and may help clinicians and immunogeneticists develop a better understanding of HLA epitope mismatches.