Background: How HLA-A26 modulates Behçet's disease (BD) ocular lesions such as iridocyclitis and retinochorioiditis has not been scrutinized.
Methods: Ministry of Health, Labour and Welfare of Japan provided us a database of BD patients who were registered from 2003 to 2014. We selected patients who satisfied International Criteria for BD and whose data for HLA-A26 was available.
Results: Eligible 557 patients consisting of 238 men (42.7%) and 319 women (57.3%), whose median age was 38 years old (interquartile range 29-47) were analyzed. Prevalence of general ocular lesions, iridocyclitis, retinochorioiditis, and chronic lesions were 43.1%, 30.7%, 34.1%, and 17.4%, respectively. The prevalence of ocular lesions was higher among HLA-A26 carriers compared to that among HLA-A26 non-carriers with odds ratio (OR) of 2.5 (95% confidence interval (95% CI) 1.8-3.5, p < .001) for general ocular lesions, OR of 2.5 (95% CI 1.7-3.6, p < .001) for iridocyclitis, OR of 2.8 (95% CI 1.9-4.0, p < .001) for retinochorioiditis, and OR of 2.7 (95% CI 1.7-4.3, p < .001) for 'chronic ocular lesion following iridocyclitis or retinochorioiditis'. The HLA-A26 had a similar impact on ocular lesions between HLA-B51 positive and negative cases (Breslow-Day test, p > .05). However, the HLA-A26 had a larger impact on iridocyclitis for men compared to women (Breslow-Day test, p = .040). The male HLA-A26 carriers had higher risk of iridocyclitis with OR of 3.4 (95% CI 2.0-5.9, p < .001), while the OR for women was 1.5 (95% CI 0.9-2.6, p = .146).
Conclusion: HLA-A26 carriers had higher risk for iridocyclitis and retinochorioiditis. However, the impact was more prominent for men.
Keywords: Histocompatibility antigens class I; eye disease; inflammation; posterior uveitis.