HL-A antigens in insulin-dependent diabetes mellitus.

HLA antigen typing by lymphocytotoxicity was performed for 2 groups of unrelated caucasian subjects. The first group was composed of 100 subjects with insulin-dependent diabetes mellitus. The second group was composed of 270 healthy subjects without diabetes. Our study has shown that for the inhabitants of Languedoc the BW15 antigen is not the most frequently found (11% of the diabetics, 10% of the healthy subjects) contrary to findings reported by others. The B8 antigen was the most frequently found (20% of the diabetics, 16,3% of the healthy subjects), in agreement with the findings of the same authors. The frequency of BW15 and B8 found simultaneously was increased (observed 3%, expected 1.38%). The principal findings of our study were a significantly increased frequency of Da25 and B18 (23% and 25% for the diabetic subjects, 11.26% and 12.22% for the healthy subjects), and a significantly decreased frequency of A11 and B12 (6% and 18% for the healthy subjects). The association of Da25 and B18 was observed for HLA phenotypes, suggesting a higher incidence of the Da25-B18 haplotype. For the diabetics, the types BW15, BW40 and Da25-B18 have little hereditary character, and are rapidly insulin dependent individuals.