The Most Common HLA Alleles and Anti-HLA Antibodies to Know for Virtual Cross-Match.

OBJECTIVES: Human leukocyte antigens and HLAspecific antibodies are important before and after transplant treatment. The determination of the alloantibodies before transplant is useful for the estimation of risk for antibody-mediated rejection. Virtual crossmatch uses solid-phase assay to detect anti-HLA antibodies and allows exclusion of donors with unacceptable HLA antigens. The aim of our retrospective study was to investigate HLA class I and class II alleles and panel reactive antibody and Luminex Corporation (Austin, TX, USA) single-antigen bead assay positivity frequencies in the Southeastern region of Turkey.

MATERIAL AND METHODS: Tissue typing results for HLA class I (HLA-A, HLA-B, HLA-C) and class-II (DRB1and DQB1 haplotypes) in 1756 patients and 2951 donors who were at Baskent University Adana Research and Medical Center between 2010 and 2015 for transplant were studied using sequence-specific primers and/or sequence-specific oligonucleotides. Serum samples were analyzed by Luminex bead technology for antibody detection.

RESULTS: We found that, for class I, HLA-A*02,HLA-B*35, and HLA-A*24 and, for class II, DRB*11, DRB*01, and DRB*04 were the 4 most common antigens and HLAA02, B49, A68, B7 were the 3 most common anti-HLA antibodies, with mean fluorescence intensity values ≥ 2000 in our population group. Human leukocyte antigen alleles and anti-HLA antibodies were compared with each other except HLA-A*02, A2, with no correlations between allele and panel reactive antibody frequencies identified. However, there was a weak correlation between panel reactive antibodymean fluorescence intensity scores of 5000 and above with Luminex single-antigen bead assay.

CONCLUSIONS: This study is the first to conduct such a mass screening of a Turkish population. Our study results show that there is no correlation between HLA frequencies and anti-HLA antibody frequencies. However, there was a weak correlation between panel reactive antibody mean fluorescence intensity scores of 5000 and above with Luminex single-antigen bead assay. Of note, this pattern is important to know for virtual cross-match.