A 45-year-old with SLE has class IV lupus nephritis on biopsy. The WHO/ISN class IV is characterized by:
- A Diffuse endocapillary or mesangiocapillary proliferation involving ≥50% of glomeruli ✓
- B Mesangial immune deposits only
- C Focal segmental endocapillary proliferation involving <50% of glomeruli
- D Diffuse membranous glomerulopathy with subepithelial deposits
Correct answer: A. Diffuse endocapillary or mesangiocapillary proliferation involving ≥50% of glomeruli
Explanation
ISN/RPS class IV lupus nephritis (diffuse proliferative) is defined by involvement of ≥50% of glomeruli with endocapillary or mesangiocapillary proliferation and subendothelial immune deposits. It is the most severe class and requires aggressive immunosuppression. Class II is mesangial; class III is focal (<50%); class V is membranous lupus nephritis with subepithelial deposits.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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