A patient with post-streptococcal glomerulonephritis (PSGN) has granular immune deposits on immunofluorescence. These deposits have a characteristic pattern described as:
- A Coarse granular IgG and C3 in the mesangium and along capillary walls ('starry sky') ✓
- B Linear IgG along GBM (anti-GBM pattern)
- C Mesangial IgA deposits only
- D Tram-track double contour of GBM with IgM deposits
Explanation
PSGN is caused by immune complex deposition (streptococcal antigens, principally nephritis-associated plasmin receptor and endostreptosin, trapped in glomeruli) rather than in situ formation. Immunofluorescence shows coarse ('lumpy-bumpy') granular deposits of IgG and C3 distributed throughout the mesangium and along capillary walls, classically described as a 'starry sky' pattern. Subepithelial humps (electron microscopy) are the ultrastructural hallmark. Linear IgG is seen in anti-GBM disease; mesangial IgA in IgA nephropathy; tram-track in membranoproliferative GN.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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