A 22-year-old man presents with rapidly rising creatinine over two weeks. Biopsy shows crescents in 60 percent of glomeruli. Immunofluorescence demonstrates granular deposits of IgA and C3 in the mesangium. His RPGN should be classified as:

• A Type I, anti-GBM antibody mediated
• B Type IV, dual positive anti-GBM and ANCA
• C Type III, pauci-immune ANCA associated
• D Type II, immune complex mediated ✓

Explanation

Type II RPGN is defined by granular immune complex deposition on immunofluorescence and occurs as a severe form of any immune complex disease, including IgA nephropathy, lupus nephritis, and postinfectious GN. Linear IgG along the GBM identifies type I, and absent or scanty staining despite crescents defines type III pauci-immune disease. The granular mesangial IgA pattern here places this case squarely in type II.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.