A 42-year-old man presents with nephrotic-range proteinuria (4.2 g/day), oedema, and normal serum complement. Kidney biopsy shows diffuse thickening of glomerular capillary walls with subepithelial immune deposits. Which serological marker is used both diagnostically and to monitor disease activity in primary membranous nephropathy?
- A Antibody against phospholipase A2 receptor (anti-PLA2R) ✓
- B Anti-glomerular basement membrane antibody
- C Anti-proteinase 3 (anti-PR3) ANCA
- D Anti-dsDNA antibody
Correct answer: A. Antibody against phospholipase A2 receptor (anti-PLA2R)
Explanation
About 70 to 80 percent of patients with primary membranous nephropathy have circulating anti-PLA2R antibodies directed against the podocyte transmembrane phospholipase B2 receptor. Titres correlate with disease activity and fall before remission, making the assay useful for monitoring. Anti-GBM and anti-dsDNA define anti-GBM disease and lupus respectively, while PR3-ANCA defines granulomatosis with polyangiitis; none are markers of primary membranous nephropathy.
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.