Double immunofluorescence studies of glomerular sialic acids in patients with diabetic nephropathy

A study of double immunofluorescence staining of sialic acids and IgG in the glomeruli from patients with diabetic nephropathy is described. Renal biopsy specimens from seven patients with diabetic nephropathy were stained with rhodamine-labeled tricum vulgaris (WGA), limulus polyphemus (LPA), and FITC-labeled anti-human IgG antiserum. Both binding of WGA and deposition of IgG in glomerular capillary walls were observed in all patients with diabetic nephropathy. However, the binding of LPA in tissue from the same patients was minimal, although deposition of IgG was marked. It is suggested that an accumulation of substances with an affinity for WGA (most probably N-acetyl glucosamine or N-acetyl neuraminic acid) occurs in the glomerular capillary walls of patients with diabetic nephropathy.