C3 and diabetes mellitus: Typical PIGN is commonly characterized by glomerular granular deposition of C3 and IgG or C3 only by immunofluorescence and occasionally with IgM in PIGN.3 Conversely, immune-complex deposits in human glomerulonephritis related to staphylococcal infection are typically IgA-dominant or C3-dominant rather than IgG-dominant granular deposition in capillary walls detected using IF,2,4,9 especially in older patients with diabetes.