Specificity of the Chemical Alteration in the Diabetic Glomerular Basement Membrane

A distinct chemical change has previously been described in the glomerular basement membrane (GBM) of patients with long standing diabetes mellitus. To assess the specificity of this lesion the chemical composition of the GBM was determined in a group of patients with nondiabetic renal disease associated with significant proteinuria and agematched normal controls. The chemical composition of the GBM in these diverse cases closely resembled that seen in controls. The increase in glucosyl-galactosyl hydroxylysine and the decrease in lysine previously described in the diabetic GBM were not observed in the nondiabetic cases. The absence of significant change in chemical composition of the GBM in nondiabetic renal disease would tend to support the hypothesis that the chemical change in the diabetic GBM is specific for the renal disease associated with long standing diabetes mellitus.