A 32-year-old woman with SLE presents with pure nephrotic syndrome, 7 g/day proteinuria, normal serum complement levels, and a negative urine sediment. Renal biopsy shows diffuse thickening of capillary walls with subepithelial immune deposits on electron microscopy and granular full-house staining on immunofluorescence. The International Society of Nephrology/Renal Pathology Society class of lupus nephritis most consistent with these findings is:

• A Class II, mesangial proliferative
• B Class V, membranous ✓
• C Class IV, diffuse proliferative
• D Class III, focal proliferative

Explanation

Class V lupus nephritis mimics primary membranous nephropathy with subepithelial deposits, GBM spikes, and heavy proteinuria, typically producing nephrotic syndrome with a bland sediment and often preserved complement. Full-house granular staining distinguishes it from idiopathic membranous disease, which is PLA2R associated and lacks C1q. Classes II through IV are proliferative patterns dominated by hematuria, endocapillary hypercellularity, wire loops, and hypocomplementemia, features absent in this patient.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.