Diabetic retinopathy and HLA antigens in type 2 diabetes mellitus

PURPOSE. Diabetic retinopathy is the most common complication of diabetes mellitus. No single predisposing factor has been identified, and genetic factors may play a role in the development of severe retinopathy. In this study, we investigated the association between diabetic retinopathy and HLA antigens in type 2 diabetes mellitus. METHODS. This study was conducted at the retina unit of the Department of Ophthalmology of Ondokuz Mayis University between October 1999 and March 2000, and included 46 diabetics with non-proliferative retinopathy and 30 with proliferative retinopathy, with 30 nondiabetic controls. HLA class I (A, B, C) antigens were studied by Terasaki's microlymphocytotoxicity test and HLA class II (DR, DQ) typing was carried out using a polymerase chain reaction-sequence specific primer. RESULTS. HLA-DR4 and DQ8 frequencies were higher in patients with non-proliferative retinopathy than those with proliferative retinopathy, and HLA-DR7 frequency was higher in patients with proliferative retinopathy than non-proliferative cases (p<0.05). No significant differences in HLA antigens were found between patient groups and controls. CONCLUSIONS. The differences in HLA antigen frequencies between patients with and without proliferative retinopathy suggest a genetic contribution to diabetic retinopathy.