HLA antigens and risk factors for nephropathy in Type 1 (insulin-dependent) diabetes mellitus

Summary This study of risk factors for diabetic nephropathy in juvenile Type 1 (insulin-dependent) diabetes mellitus compares two carefully characterised groups of patients, one with proteinuria (n = 23), the other a control group (n = 24) with no evidence of nephropathy despite more than 25 years of diabetic life. No significant difference was observed between the groups in any HLA-A, -B or -DR antigen or Bf allotype. DR3 was present in 87% of patients with proteinuria and 75% of the diabetic control group; DR4 was present in 48% of patients with proteinuria and 63% of diabetic controls; BfFl was present in 17% of patients with nephropathy and 9% of the diabetic control group. Compared with the control group, patients with proteinuria had significantly higher mean diabetic-clinic blood glucose concentrations before the diagnosis of microvascular disease, a significantly earlier age at diagnosis of diabetes, and had more often been treated with once-daily as opposed to twice-daily insulin regimens. Susceptibility to nephropathy in Type 1 diabetes appears to be determined by the quality of metabolic control and age of onset of diabetes; although the number of subjects studied was relatively small no evidence was found of any influence of HLA or Bf phenotype.