A 58-year-old man presents with nephrotic-range proteinuria (5.2 g/day), hypoalbuminaemia, and peripheral oedema. Serology for ANA, anti-dsDNA, HBsAg, HCV, and cryoglobulins is negative. Serum phospholipase A2 receptor (PLA2R) antibody is detected at high titre. This result most strongly supports which conclusion?

• A Secondary membranous nephropathy due to occult malignancy
• B Primary (idiopathic) membranous nephropathy ✓
• C Lupus nephritis class V
• D Focal segmental glomerulosclerosis with circulating permeability factor

Explanation

Anti-PLA2R antibodies are directed against the podocyte transmembrane phospholipase B2 receptor and are found in about 70 to 80 percent of patients with primary membranous nephropathy, and are typically absent in secondary forms such as lupus class V, hepatitis A related disease, and malignancy-associated membranous nephropathy. B high titre in an older man with negative secondary workup therefore strongly favours idiopathic membranous nephropathy. Titre levels also correlate with disease activity and predict relapse.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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