Long-Term Outcome of Lupus Nephritis in Patients Treated with Cellcept (MMF)- vs. Cyclophosphamide (CYP)-Based Regimens

Background: Lupus nephritis (LN) remains a significant cause of morbidity and progression to end-stage renal disease. While CYP and MMF are established induction therapies, their long-term comparative outcomes, especially in the Saudi population are limited. Methods: This retrospective cohort study analyzed 121 biopsy-proven proliferative LN patients at King Faisal Specialist Hospital & Research Centre between 2011–2023. Patients were grouped based on induction therapy: CYP vs MMF. Primary outcome was response rates (complete, partial, no response) at 6 months, 1, 3, and 5 years. This response was defined according to KDIGO guidelines. Results: The cohort was predominantly female (87.6%), with Class IV LN being most common (41.3%). 55.9% received CYP and 44.1% received MMF. Complete remission at 6 months was 56%, and 80% at 5 years. Complete remission rates was better for CYP at 1 year (P= 0.04), but this effect disappeared at 5 years (P=0.6). Relapse rates were 3% at 6 months, 8.7% at 1 year, 8.6% at 3 years, and 8.8% at 5 years. Both therapies demonstrated sustained remission and low relapse over five years Conclusion: Both CYP and MMF are effective induction therapies for LN, with sustained remission and low relapse rates over five years. Long-term renal survival appears comparable, supporting MMF as a safe, long-term maintenance option.Remission rates CYP VS MMF - Duration Induction agents Complete Remission Partial Remission No response 6 months CYP MMF 24 (48.9%) 24 (64.8%) 20 (40.8%) 7 (18.9%) P = 0.03 5 (10.2%) 6 (16.2%) 1 year CYP MMF 28 (56%) 29 (76.3%) P =0.04 16 (32%) 6 (15.7%) 6 (12%) 3 (7.8%) 5 years CYP MMF 32 (78%) 20 (83.3%) P=0.6 6 (14.6%) 3 (12.5%) 3 (7.3%) 1 (4.1%) P: P Value