MICA*049, not MICA*009, is associated with Behçet’s disease in a Chinese population

Abstract

Abstract Behçet’s disease (BD) is a multi-systemic inflammatory disease. Previous reports indicated that MICA *009 confers susceptibility to BD. MICA *049 differs from MICA *009:01, a major MICA *009 subtype, only at codon 335 in exon 6. However, the potential association of MICA *049 with BD has not been addressed. In this study, we differentiated association among MICA *049, MICA *009 and HLA-B *51 with BD. A Han Chinese cohort consisting of 41 BD patients and 197 ethnically matched controls were examined with sequencing and T-ARMS-PCR for genotyping of MICA , and ARMS-PCR for HLA-B *51. The phenotype frequency of MICA *049 (41.5% versus 8.1%, OR = 8.01, P = 1.91 × 10 −8 ) and HLA-B *51 (46.3% versus 15.7%, OR = 4.62, P = 1.21 × 10 −5 ) were significantly higher in BD patients than those in controls, whereas MICA *009 showed no significant difference between the two groups (17.1% versus 13.2%, OR = 1.35, P = 0.51). After stratification for the effect of HLA-B *51, MICA *049 was still associated with BD in HLA-B *51 negative patients (OR = 40.61, P = 0.02). Our results indicate that MICA *049, not MICA *009, is a risk factor to BD, and that is independent from HLA-B *51 in the Han Chinese cohort.