HLA-DR antigen frequencies in a North Indian type I diabetic population.

Eighty-eight North Indian patients with type I, insulin-dependent diabetes mellitus (IDDM) and 113 unaffected individuals were typed for HLA-DR antigens from DR1 to DR7. The frequency of HLA-DR3 was significantly increased in the patients as compared with the controls (78.4% versus 25.7%, corrected P = 1.68 X 10(-12], the relative risk (RR) of 10.52 being much higher than that reported in the Western IDDM population. HLA-DR2 showed a significant negative association (RR = 0.18, corrected P = 1.03 X 10(-5], but DR4 had no relationship with IDDM in the present study (RR = 1.12, P = 0.12). These results emphasize the differences in HLA-IDDM associations among different ethnic groups.