HLA-A, -B, and -DRB1 allelic and haplotypic diversity in a sample of bone marrow volunteer donors from Rio Grande do Sul State, Brazil.

The HLA A, B, and DRB1 allele, phenotype, and haplotype frequencies were studied in a sample of 5,000 volunteer bone marrow donors registered at the Brazilian Volunteer Bone Marrow Donor Registry. The participants live in the state of Rio Grande do Sul and were classified according to ethnic group (4,428 Caucasians, 324 mestizos [mixed race], and 248 blacks). Typing was performed using the polymerase chain reaction sequence-specific oligonucleotide method combined with Luminex technology. Twenty-one HLA-A, 33 HLA-B, and 13 HLA-DRB1 allele groups were identified. The most frequent allele groups for each locus were A*02, B*35, and DRB1*13. The most frequent haplotypes were A*01 B*08 DRB1*03 in Caucasians and mestizos and A*02 B*15 and DRB1*04 in blacks. The allele frequencies were compared with samples from different Brazilian regions. In most comparisons no significant differences were found. The most significant differences were observed in the comparison of the groups of our sample, indicating that human leukocyte antigen (HLA) is a good marker to distinguish among people from different ethnic groups. The data provide insight on the knowledge of HLA diversity in the population of Rio Grande do Sul and in the search for a better match for transplant.