Four‐digit allele genotyping of the HLA‐A and HLA‐B genes in Japanese patients with Behcet's disease by a PCR‐SSOP‐Luminex method

Abstract

The present study represents the first four‐digit allele genotyping of HLA‐A and ‐B in Japanese Behcet's disease (BD) patients and controls using a new genotyping method (named the PCR‐SSOP‐Luminex method) to determine the association of certain HLA‐A or ‐B alleles with BD. Peripheral blood lymphocytes were collected from 180 Japanese BD patients and 170 healthy controls. The genotype frequency of HLA‐B*5101 was significantly increased in the patients (61.7%) as compared with the controls (15.9%) (Pc = 1 × 10⁻¹⁶, OR = 8.5). When we recalculated the phenotype frequencies after excluding the HLA‐B*51‐positive patients and controls to account for the effects of the linkage disequilibrium and the abundance of the HLA‐B*51 allele, the frequencies of HLA‐A*2602 and HLA‐B*3901 had a weak association in the patient group without HLA‐B*51 as compared with the control group without HLA‐B*51 (A*2602; Pc = 0.130, OR = 4.3, B*3901; Pc = 0.099, OR = 3.5). This study confirmed on the basis of using a new and more accurate genotyping method that Japanese BD patients have a strong primary association with HLA‐B*5101. The significant increase of HLA‐A*2602 and B*3901 in the patient group without HLA‐B*51 suggests that these two alleles might also have some secondary influence on the onset of BD.