Immunofluorescence of a renal biopsy shows linear IgG deposits along the glomerular basement membrane (GBM). This pattern is MOST consistent with:

• A IgA nephropathy
• B Membranous nephropathy
• C Anti-GBM disease (Goodpasture syndrome) ✓
• D Lupus nephritis class III

Explanation

Linear IgG deposition along the GBM is pathognomonic of anti-GBM disease, where autoantibodies target the alpha-3 chain of type IV collagen. This contrasts with granular (lumpy-bumpy) deposits seen in immune complex diseases like membranous nephropathy, IgA nephropathy, and lupus nephritis. Anti-GBM disease may cause pulmonary hemorrhage when the same antigen is targeted in alveolar basement membranes (Goodpasture syndrome).

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.