Is diabetic microangiopathy genetically heterogeneous? HLA and diabetic nephropathy.

We have studied the histocompatibility (HLA) antigens A and B in 99 insulin dependent diabetics (IDDN) with terminal uremia due to diabetic nephropathy and in 96 insulin dependent diabetic patients (IDD) without clinically detectable kidney disease. The two groups were matched for duration of disease and other clinical features. The frequencies of the HLA antigens B8, B15, B18 and B8/B15 were significantly increased in both groups and B7 and B12 were decreased. There were no significant differences between the two groups. These results contrast with previously described similar studies of HLA and diabetic proliferative retinopathy. In these studies B7 was significantly less common in patients with proliferative retinopathy as compared with patients without proliferative retinopathy and B15 was more common in a subset of patients with proliferative retinopathy. The differences between the two studies may reflect sample bias or a genetic difference between the two types of diabetic microangiopathy.