A 40-year-old woman presents with recurrent hemoptysis and rapidly progressive glomerulonephritis with crescent formation on renal biopsy. Immunofluorescence of the kidney shows linear IgG deposition along the glomerular basement membrane. Which antibody is most likely elevated?

• A Anti-neutrophil cytoplasmic antibody (c-ANCA/PR3)
• B Anti-dsDNA antibody
• C Anti-nuclear antibody (ANA)
• D Anti-glomerular basement membrane antibody (anti-GBM) ✓

Explanation

Goodpasture syndrome is caused by anti-GBM antibodies targeting type IV collagen in the basement membrane of alveoli and glomeruli, causing pulmonary hemorrhage and rapidly progressive glomerulonephritis. Linear IgG on immunofluorescence is pathognomonic. c-ANCA/PR3 is seen in granulomatosis with polyangiitis. Anti-dsDNA is seen in lupus nephritis, which shows granular (lumpy-bumpy) immunofluorescence.

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.