Distribution of HLA-A, -B and -DRB1 antigenic groups and haplotypes from the Brazilian bone marrow donor registry (REDOME)

Abstract

To improve assistance for patients awaiting a bone marrow transplant from an unrelated donor, it is important to genetically characterize the Brazilian volunteer bone marrow donors registry (REDOME). Our objective was to describe the antigenic groups and haplotype frequencies of HLA-A, HLA-B and HLA-DRB1 in the five regions of Brazil and by self-reported ethnicity groups using the REDOME data. Our study included 3,038,286 individuals. HLA antigenic groups and haplotype frequencies were estimated using an Expectation-Maximization (EM) algorithm. All described HLA-A*, HLA-B* and HLA-DRB1* groups were identified in this study. A*02 (25.9%), B*35 (11.8%) and DRB1*13 (13.4%) are the most frequent antigenic groups in REDOME, and the A*01-B*08-DRB1*03 haplotype is the most frequent in the registry. The antigenic group and haplotype frequency data obtained in this study could be helpful for national donor recruitment strategies across the country.

Keywords: Bone marrow transplant; Donor registry; Expectation-maximization; HLA haplotypes; Haplotype frequency estimation; Human leukocyte antigen.