A 52-year-old woman with nephrotic syndrome has a renal biopsy showing thickened GBMs with subepithelial deposits. Serological testing shows circulating antibodies against the M-type phospholipase A2 receptor expressed on podocytes. This finding indicates that her membranous nephropathy is:

• A Secondary to hepatitis B infection
• B Secondary to a solid organ malignancy
• C Drug induced by NSAIDs
• D Primary (idiopathic) ✓

Explanation

Antibodies against the M-type phospholipase A2 receptor (PLA2R), a transmembrane glycoprotein on podocyte foot processes, are found in roughly 70 to 80% of patients with primary membranous nephropathy and support an autoimmune pathogenesis with in situ immune complex formation. Secondary membranous nephropathy associated with hepatitis B, malignancy, or drugs such as NSAIDs is characteristically PLA2R antibody negative, so a positive titer argues against these etiologies.

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.