A 48-year-old man presents with oedema and proteinuria of 5.2 g/day. Serum albumin is 2.4 g/dL and cholesterol is elevated. Kidney biopsy shows diffuse thickening of the glomerular basement membrane without cellular proliferation, and silver stain reveals spike formation. Serum is positive for antibodies against phospholipase A2 receptor (PLA2R). Which is the MOST likely diagnosis?

• A Secondary membranous nephropathy due to hepatitis B
• B Membranoproliferative glomerulonephritis
• C Primary (idiopathic) membranous nephropathy ✓
• D Focal segmental glomerulosclerosis

Explanation

Anti-PLA2R antibodies are present in about 70 to 80 percent of cases of primary membranous nephropathy and are rarely found in secondary forms. Spike and dome appearance on silver stain reflects subepithelial immune deposits between GBM projections. A positive PLA2R titre makes secondary causes such as hepatitis C, solid tumours, or drugs like penicillamine unlikely, so searching for these is not the best answer here.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.