HLA antigens and necrobiosis lipoidica diabeticorum--a comparison between insulin-dependent diabetics with and without necrobiosis.

To investigate whether HLA-A, -B, -C, and -DR alloantigen frequencies are different in diabetic patients with and without necrobiosis lipoidica diabeticorum we studied 37 insulin-dependent (Type I) diabetics, 15 with and 22 without necrobiosis, and 96 normal control subjects. Compared to controls Type I diabetics had increased frequencies of B8, CW3, and DR4 and decreased frequencies of DR5 and DR7. Diabetics with necrobiosis differed from diabetics without necrobiosis only in that HLA-A2 was significantly less frequent in patients with necrobiosis. It is suggested that the lack of major differences between patients with and without necrobiosis argues in favour of the role of metabolic and/or vascular rather than genetic factors in the aetiology of necrobiosis.