HLA-A, -B, and -DRB1 allele and haplotype diversity in a cohort of Brazilian renal transplant candidates

Abstract

The distribution of organs for renal transplant depends on HLA matching between donor and recipient. This study aimed to characterize the allele and haplotype frequencies of HLA-A, -B, and -DRB1 in a cohort of renal transplant candidates populations in the region of Sao José do Rio Preto (State of São Paulo), to compare the allele frequencies between Caucasian and Black in that region, as well as to compare these frequencies with different Brazilian populations reported. The HLA-A, -B, and -DRB1 allele and haplotypes frequencies were analyzed in a sample of 2.624 individuals and classified according to the ethnic group (2.347 Caucasians and 277 Blacks). The HLA class I (A, B) and class II (DRB1) specificities were determined by complement-dependent microlymphocytotoxic (CDC) and Polymerase Chain Reaction/Sequence Specific Priming (PCR-SSP) methods, respectively. Twenty-one HLA-A, 34 HLA-B and 13 HLA-DRB1 allelic groups were identified. The most frequent alleles for each locus were HLA-A(∗)02, HLA-B(∗)35, and HLA-DRB1(∗)11. The most frequent haplotypes found were A(∗)01 B(∗)08 DRB1(∗)03 among Caucasians and A(∗)29 B(∗)15 DRB1(∗)04 among Blacks. The most common alleles for each locus among RTx were HLA-A(∗)02, HLA-B(∗)35 and HLA-DRB1(∗)11. The haplotypes A(∗)01 B(∗)08 DRB1(∗)03 and A(∗)29 B(∗)44 DRB1(∗)07 prevailed among Caucasians and Blacks, respectively. This study provides the first data on the HLA-A, HLA-B and HLA-DRB1 allele and haplotype frequencies of renal transplant candidates populations in the region of Sao José do Rio Preto.

Keywords: Brazilian population; Gene frequency; Genetic polymorphism; HLA antigens; Transplantation.