Influence of HLA-A, B, and -DRB1 genes and panel-reactive antibodies on the waitlist time for kidney transplantation in the state of Sao Paulo-Brazil.

BACKGROUND: Brazil ranks second in the absolute number of transplants. However, the supply remains insufficient to meet the demands, resulting in a lengthy waitlist. This study aimed to analyze whether the frequency of human leukocyte antigen (HLA) and the value of calculated panel reactive antibody (cPRA) would influence the waiting time for kidney transplantation. METHODS: The HLA-A, B, and -DRB1 frequencies and the cPRA value were analyzed in 11,186 kidney transplant candidates included in the waitlist from 2006 to 2016. RESULTS: The most frequent alleles were HLA-A*02, HLA-B*35, and HLA-DRB1*13. The overall mean length of stay on the list was 986 ± 1001 days. The mean waiting time for the three most frequent alleles of the HLA-A and B loci showed no significant difference when compared with the least frequent alleles; however, for the HLA-DRB1 locus, the most frequent alleles showed a shorter waiting time. In the association between HLA and PRA, the average length of stay on the list increased according to the candidate's degree of sensitization, regardless of the analyzed HLA frequency. CONCLUSION: The length of stay on the waitlist is influenced by the frequency of the HLA alleles of the DRB1 locus and the degree of sensitization.

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

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.