Diversity of HLA-B*40 Alleles and Haplotypes in Koreans

Whang, Dong Hee; Park, Myoung Hee

Abstract

BACKGROUND
HLA-B40 includes two serologic specificities, B60 and B61, and at least 45 alleles of the B*40 group have been identified. B40 shows a gene frequency of 13.4% (B60 4.5%, B61 8.9%) in Koreans. In this study, the distribution of HLA-B40 alleles and their association with HLA-A, -Cw and -DRB1 alleles were investigated in the Korean population. METHODS: A total of 453 healthy unrelated Koreans including 215 parents from 108 families were studied. For all samples, HLA-A, B, C serological typing, HLA-Cw low resolution typing using polymerase chain reaction (PCR)-sequence specific oligonucleotide (SSO) method, and HLA-DRB1 geno-typing using PCR-single strand conformation polymorphism (SSCP) method were performed. All of the 112 samples (24.7%) typed as B40 by serology were analyzed for B40 alleles using the PCR-SSCP method. RESULTS: Four B40 alleles were detected in the Korean population and their allele frequencies were: B*4001 4.4%, B*4002 5.0%, B*4003 0.4%, and B*4006 3.2%. A significant association (P<0.05) was observed for B*4001 with A24, A11, Cw*03, DRB1*0405, and DRB1*1405; B*4002 with A2, A26, Cw*03, DRB1*0405, DRB1*0802, DRB1*1401, and DRB1*1405; and B*4006 with A2, Cw*08, DRB1*0901, and DRB1*1201. Each B40 allele was very strongly associated with a particular Cw allele: B*4001 -Cw*03, B*4002-Cw*03 and B*4006-Cw*08. However, B40-DRB1 haplotypes showed weaker associations and diversity. CONCLUSIONS: The Korean population shows a heterogeneity in the distribution of B40 alleles and related haplotypes, and thus B40 subtype mismatch can occur between serologically matched donorrecipient pairs in unrelated marrow transplantation.