A 50-year-old man with hepatitis C develops nephrotic syndrome and hypocomplementaemia. Renal biopsy shows a 'tram-track' pattern on PAS staining with mesangial interposition. Immunofluorescence shows IgG, IgM, and C3 in a granular mesangial and capillary wall distribution. The most likely diagnosis is:

• A Focal segmental glomerulosclerosis
• B Membranoproliferative glomerulonephritis (MPGN) ✓
• C Membranous nephropathy
• D IgA nephropathy

Explanation

MPGN (type I) is the characteristic glomerulonephritis associated with hepatitis C-induced cryoglobulinaemia. The 'tram-track' double contour on PAS staining is caused by mesangial cell interposition between the GBM and the endothelium, characteristic of MPGN. Immune complex deposits (IgG, IgM, C3) with hypocomplementaemia further support this diagnosis. Membranous nephropathy shows subepithelial 'spike and dome' deposits; FSGS shows segmental scarring; IgA nephropathy shows dominant mesangial IgA.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.