A 35-year-old woman with SLE develops nephrotic-range proteinuria. Renal biopsy shows global diffuse proliferative glomerulonephritis with 'wire loop' lesions on light microscopy and subendothelial immune deposits on EM. This is classified as:

• A ISN/RPS Class IV lupus nephritis ✓
• B ISN/RPS Class III lupus nephritis
• C ISN/RPS Class V lupus nephritis
• D ISN/RPS Class II lupus nephritis

Explanation

ISN/RPS Class IV lupus nephritis is the diffuse proliferative form, affecting >50% of glomeruli globally or segmentally, characterised by endocapillary and mesangial proliferation, subendothelial immune deposits creating 'wire loop' thickening of capillary walls, and often crescents. It is the most severe and most common class in symptomatic SLE nephritis. Class III is focal (<50% glomeruli); Class V is the membranous pattern with subepithelial deposits; Class II shows only mesangial involvement.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.