Fibrillary Glomerulonephritis: A Great Mimicker of Rapidly Progressive Glomerulonephritis

Abstract

Fibrillary glomerulonephritis (FGN) is a rare but severe kidney disease found to have non-amyloid fibrillary deposits in the mesangium and/or glomerular capillary wall. It was initially thought to be idiopathic, but recent studies show an association with autoimmune disease, malignancy, and hepatitis C infection. We report a case of a non-diabetic patient presenting with long-standing microscopic hematuria, progressive proteinuria, hypertension, and worsening kidney function. The kidney biopsy demonstrated subepithelial fibrillar deposits of size 17 mm randomly oriented with one partial cellular crescent on electron microscopy. Direct immunofluorescence showed no staining for IgG or light chains. It was weakly positive for Congo red staining with a slightly higher serum free kappa/lambda light chain ratio, but serum immunofixation showed no monoclonal protein detection. We empirically treated with rituximab but with no clear benefit or no renal recovery and eventually started on hemodialysis. FGN has an extremely poor prognosis with very few treatment options available. We report this case to emphasize the need for larger, multi-center studies for treatment approaches with collaborating and consolidating data from case reports and case series due to the rarity of the disease.

Antiglomerular basement membrane antibody type rapidly progressive glomerulonephritis with seizures: Two cases and literature review

“…RPGN is clinically manifestations as a rapidly progressive renal failure and pathologically as crescentic and necrotizing lesions with infiltration of inflammatory cells in the glomeruli 14 . The autoimmune development of antibodies towards type IV collagen in the glomerular and alveolar basement membranes leads to patients typically presenting with RPGN and pulmonary hemorrhage 15–17 . Evidence of anti‐GBM antibodies in serum or histologically is required for diagnosis 18 .…”

“…14 The autoimmune development of antibodies towards type IV collagen in the glomerular and alveolar basement membranes leads to patients typically presenting with RPGN and pulmonary hemorrhage. 15 , 16 , 17 Evidence of anti‐GBM antibodies in serum or histologically is required for diagnosis. 18 Treatment mainly involves the use of apheresis and intensive, strong immunosuppression such as cyclophosphamide.…”