In membranous nephropathy, the antigen targeted by circulating autoantibodies in the primary (idiopathic) form is:

• A M-type phospholipase A2 receptor (PLA2R) on podocytes ✓
• B Alpha-3 chain of type IV collagen
• C Complement C3 nephritic factor
• D Heymann antigen (megalin)

Explanation

Anti-PLA2R antibodies are found in ~70% of primary membranous nephropathy cases and represent the human equivalent of Heymann nephritis antigen in rats. These IgG4 antibodies bind PLA2R on the podocyte surface, forming subepithelial immune complexes in situ. Anti-PLA2R titer correlates with disease activity and response to treatment. Alpha-3 type IV collagen is the target in anti-GBM disease.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.