Goodpasture syndrome presents with pulmonary hemorrhage and rapidly progressive glomerulonephritis. The target antigen for the anti-GBM antibodies is specifically:

• A Heparan sulfate proteoglycan (perlecan) in the GBM
• B Laminin alpha-5 chain in the alveolar and glomerular basement membranes
• C Podocin in the slit diaphragm of podocytes
• D NC1 domain of the alpha-3 chain of type IV collagen [α3(IV)NC1] ✓

Explanation

Goodpasture syndrome is caused by IgG autoantibodies (type II hypersensitivity) targeting the NC1 (non-collagenous) domain of the alpha-3 chain of type IV collagen [α3(IV)NC1]. This alpha3(IV) chain is normally sequestered within the triple helix of the GBM and alveolar BM; environmental triggers (smoking, viral infections, oxidants) may expose the cryptic epitope. Linear IgG deposits on IF of kidney biopsy ('linear pattern') are diagnostic. Perlecan and laminin are GBM components but are not anti-GBM antibody targets.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.