A 33-year-old woman with SLE has isolated heavy proteinuria without hematuria, hypertension, or depressed complement. Biopsy shows uniformly thickened capillary loops with strictly subepithelial deposits on electron microscopy and no endocapillary proliferation. According to the ISN/RPS classification, her lupus nephritis is:

• A Class III, focal lupus nephritis
• B Class IV, diffuse lupus nephritis
• C Class VI, advanced sclerosing lupus nephritis
• D Class V, membranous lupus nephritis ✓

Explanation

Class V lupus nephritis is defined by membranous pattern involvement: subepithelial immune deposits producing uniform capillary wall thickening, typically presenting as pure nephrotic syndrome. Class III involves less than half of glomeruli with focal endo- or extracapillary proliferation, class IV involves more than half diffusely with wire loops and hypocomplementemia, and class VI describes advanced global sclerosis involving at least 90 percent of glomeruli.

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.