HLA class I and II typing of the patients with Behçet's disease in Saudi Arabia.

Thirteen Saudi Arabian patients with Behçet's disease (BD) were typed for HLA-A and -B alleles by the conventional serologic typing and for HLA-DRB1, -DQB1 and -DPB1 alleles by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. As a result, the phenotype frequency of the B51 antigen was significantly increased in the patient group as compared to the ethnically matched control group (76.9% in patients vs. 22.20% in controls), but no significant difference was observed in HLA-A, -DRB1, -DQB1 or -DPB1 alleles between the patients and controls, as previously observed in Japanese BD. Further, by HLA-B51 allelic genotyping performed by the polymerase chain reaction-sequence specific primers (PCR-SSP) method, all of the B51-positive patients and controls were found to carry one particular allele, B*5101, except one patient with B*5108.