Genetic association of HLA-A*2601 with ocular Behçet's disease in Japanese patients.

OBJECTIVES

Behçet's disease (BD) is known to be associated with HLA-B51, especially HLA-B5101, in many different ethnic groups. Recently, several HLA-A or -B alleles have been proposed as possible candidate genes for BD in addition to HLA-B*5101. To investigate those associations, we studied HLA-A and -B alleles in Japanese ocular BD patients and the association of possible susceptibility HLA genes with visual prognosis.

METHODS

Eighty-eight Japanese BD patients with uveitis and 104 healthy controls were enrolled for analyses of HLA-A and B alleles. Statistical analysis was performed with Fisher's exact test and odds ratio (OR). Association of the possible susceptible HLA gene and visual prognosis was also examined.

RESULTS

The phenotype frequency (PF) of HLA-A2601 was significantly higher in the patients (37.5%) than the controls (14.4%) (pc=0.00529, OR=3.56), especially in patients without HLA-B5101 (57.4% vs. 14.1%, pc=4.58x10-6, OR=8.21). In contrast, the PF of HLA-A2601 was not increased in patients with HLA-B5101 (14.6% vs. 15.8%). Also, the PF in patients possessing HLA-A2601 or HLAB 5101 was increased up to 77.3%. Interestingly, the PF of HLA-A*2601 was significantly associated with poor visual prognosis corresponding to visual acuity of 0.1 or less in the worse eye (p=0.0262).

CONCLUSIONS

Our results indicate that HLA-A2601 is possibly associated with ocular BD, independent of HLAB 5101, indicating that HLA-A2601 is an additional susceptibility allele candidate of ocular BD in Japan. HLAA 2601 would also be a possible marker for poor visual prognosis.