An immunofluorescence study of renal lesions in diabetes mellitus

Percutaneous renal biopsies were performed in 30 diabetic patients who presented with proteinuria. Tissues were studied for evidence of an immune lesion using immunofluorescence techniques. No consistent pattern of binding of FITC labelled polyvalent, monospecific IgG, IgA, IgM and labelled bovine insulin antisera in various diabetic renal lesions could be demonstrated. The binding of labelled insulin was observed even in biopsies of patients who had never received exogenous insulin therapy. It was therefore concluded that there is no evidence to support an immune pathogenesis in the morphogenesis of the diabetic renal lesions, nor do these lesions occur as a result of insulin therapy.