A 52-year-old man presents with nephrotic syndrome, proteinuria 6 g/day, and normal renal function. Serum albumin is 2.4 g/dL. Complement levels are normal, ANA and hepatitis serologies are negative, and serum anti-phospholipase A2 receptor (anti-PLA2R) antibody is strongly positive. Renal biopsy shows granular capillary wall staining for IgG on immunofluorescence. What is the most likely diagnosis?

• A Minimal change disease
• B Membranous lupus nephritis
• C Primary (idiopathic) membranous nephropathy ✓
• D Immune-complex membranoproliferative glomerulonephritis

Explanation

Anti-PLA2R antibodies against the podocyte phospholipase C2 receptor antigen are found in roughly 70 percent of patients with primary membranous nephropathy and are characteristically absent when the disease is secondary (SLE, hepatitis B, drugs, malignancy). The granular capillary loop IgG fits subepithelial immune deposits. Normal complement and negative serology exclude lupus and MPGN, while foot process effacement alone would be expected in minimal change disease.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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