Nephrotic syndrome with massive accumulation of type I and type III collagen in the glomeruli

A 54-year-old woman with nephrotic syndrome underwent renal biopsy. By light microscopy, the glomerular capillary lumen was remarkably narrowed because of diffuse accumulation of Periodic acid Shiff (PAS) positive material along the glomerular capillary wall. By electron microscopy, collagenous fibers were observed in the mesangium and subendothelial area. The fibrous material reacted with antibodies against type I and III collagen but not with those against laminin or type IV collagen by an indirect immunofluorescence technique. This case seemed to be a case of collagenofibrotic glomerulonephropathy.