Genetic Association of HLA-A☆26, -A☆31, and -B☆51 with Behcet's Disease in Saudi Patients

BACKGROUND: HLA-B*51 has been universally associated with Behcet's disease ( BD) susceptibility, while different alleles of HLA-A have also been identified as independent BD susceptibility loci in various ethnic populations. The objective of this study was to investigate associations of HLA-A and -B alleles with BD in Saudi patients. MATERIALS AND METHODS: Genotyping for HLA-A and HLA-B was performed using HLA genotyping kit (Lab type(R) SSO) in 120 Saudi subjects, including 60 BD patients and 60 matched healthy controls. RESULTS: Our results revealed that frequencies of HLA-A*26, -A*31, and -B*51 were significantly higher in BD patients than in controls, suggesting that HLA-A*26, -A*31, and -B*51 are associated with BD. The frequency of HLA-B*15 was significantly lower in BD patients than in controls. Stratification of genotyping results into active and nonactive forms of BD revealed that the frequency of HLA-A*31 was significantly higher in the nonactive form than in the active form of BD, while there was no significant difference in the distribution of other alleles between the two forms of BD. CONCLUSION: This study suggests that HLA-A*26, -A*31, and -B*51 are associated with susceptibility risk to BD, while HLA-B*15 may be protective in Saudi patients. However, larger scale studies are needed to confirm these findings.