A strong association between HLA-B*5101 and Behcet's disease in Greek patients

Behcet's disease is known to be associated with HLA-B51, one of the split antigens of HLA-BS, among many different ethnic groups. In a Greek population, an increased incidence of HLA-BS in the patient group has also been reported. Because the B51 antigen has been recently identified to comprise seven alleles, B*5101-B*5107, we performed HLA-B51 allele genotyping by the PCR-SSP method as well as serological HLA-A and -B typing among 31 Greek patients with Behcet's disease to investigate whether there is any correlation between one particular B51-associated allele and Behcet's disease. The frequency of B51 was remarkably high (80.6%) in the patient group as compared to the ethnically matched control group (26.7%). In addition, HLA-A26 was also increased in the patients (29.0%) as compared with the healthy controls (3.3%). B51 allele genotyping revealed that all these B51-positive patients carried B*5101. This study revealed a strong association of Behcet's disease in Greeks with one of the B51 subantigens, providing insight into the molecular mechanism underlying an HLA association with Behcet's disease.