Fibrillary glomerulonephritis with splenic involvement: a detailed autopsy study.

Fibrillary glomerulonephritis (FGN) is characterized by the deposition of IgG-positive, randomly arranged, nonbranching, non-Congophilic fibrils in the glomeruli. The possibility of multiorgan involvement, as in amyloidosis, has been raised. The authors report the first detailed autopsy study on a patient with FGN, with thorough examination of the organs by electron microscopy, colloidal gold immunoelectron microscopy, and immunofluorescence staining. Thin, wavy fibrils (extracellular matrix filaments) ranging from 6 to 17 nm were seen in all other organs, but only kidney and spleen showed the typical rigid, nonbranching fibrils of FGN with specific gold label. This study suggests that FGN is mainly a renal-limited disease with possible involvement of the spleen.