Goodpasture syndrome shows Crescentic glomerulonephritis with linear deposition of IgG and C3 along the glomerular basement membrane. What is the characteristic glomerular lesion?

• A. Membranous nephropathy
• B. Focal segmental glomerulosclerosis
• C. IgA nephropathy
• D. Crescentic glomerulonephritis with linear IgG/C3

Answer: (A)

Goodpasture syndrome is an autoimmune attack on the glomerular basement membrane, leading to rapidly progressive glomerulonephritis. The key glomerular change is crescent formation in Bowman's space, produced by rupture of capillaries and proliferation of parietal epithelial cells with fibrin and inflammatory cells filling the space. Immunofluorescence shows a linear pattern of IgG and C3 along the glomerular basement membrane, reflecting the antibodies directly targeting GBM. This linear deposition distinguishes anti-GBM disease from other glomerulonephritides that have granular immune deposits or different localization. So the hallmark lesion here is crescentic glomerulonephritis with linear IgG and C3 along the GBM.