A 35-year-old woman with SLE has serum complement C3 22 mg/dL (low), anti-dsDNA titre rising from 1:80 to 1:640, and new-onset haematuria with RBC casts on urinalysis. Creatinine has risen from 0.9 to 1.8 mg/dL over 6 weeks. The MOST likely class of lupus nephritis and RECOMMENDED induction therapy is:

• A Class II (mesangial); hydroxychloroquine alone
• B Class V (membranous); ACE inhibitor alone
• C Class I; no immunosuppression needed
• D Class III or IV (proliferative); mycophenolate mofetil or cyclophosphamide plus glucocorticoids ✓

Explanation

Active urinary sediment (RBC casts), rising anti-dsDNA, low complement, and rising creatinine are hallmarks of proliferative lupus nephritis (Class III focal or Class IV diffuse), which carries the highest risk of ESRD. Renal biopsy is confirmatory. Induction therapy per EULAR/ACR 2019 guidelines is high-dose glucocorticoids PLUS either mycophenolate mofetil (2–3 g/day) or low-dose cyclophosphamide (Euro-Lupus regimen). Class V presents with nephrotic-range proteinuria without active sediment and is managed differently.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.