Assessment of renal response in Tunisian patients with proliferative lupus nephritis under three different induction immunosuppressive agents: A prognostic retrospective study.

Objective: The aim of our study was to evaluate the renal response (RR) of three immunosuppressive protocols in the induction treatment of proliferative lupus nephritis (PLN) in a Tunisian population.

Methods: We performed a retrospective prognostic cohort study in the Internal Medicine Department of the Habib Thameur University Hospital in Tunis from January 2000 to December 2023, and included kidney biopsy proven proliferative lupus nephritis patients. Three induction treatments were compared: High CYP regimen: glucocorticoids (GC) + IV cyclophosphamide (CYP) in monthly pulses of 0.7 g/m2 for 6 months; Low CYP regimen: GC + IV CYP in biweekly pulses of 500 mg for 3 months; and MMF regimen: GC + oral MMF 1.5 g twice daily for 6 months. The primary endpoint was the incidence of RR (complete and partial remission) at one year post-diagnosis. The additional outcomes were end-stage kidney disease (ESKD), severe adverse events (AEs) and death.

Results: Our study included 78 PLN patients (High CYP: 17, Low CYP: 40, MMF: 21). The study found that 94.1% of patients receiving High CYP achieved the primary endpoint, RR, compared to 67.5% of those receiving Low CYP and 61.9% in the MMF group. For the additional outcomes, there were 3 cases of ESKD, all in the Low CYP group, 5 cases of death (4 in the Low CYP group and 1 in the MMF group), and 20 cases of severe AEs, all of which were severe infections (5 in the High CYP group, 12 in the Low CYP group, and 3 in the MMF group). Multivariate analysis showed that the High CYP regimen was more associated with RR than the MMF regimen, with an adjusted OR of 9.846 (95% CI: 1.087-98.210); p = 0.042. Multivariate analysis did not show statistically significant differences between the High CYP regimen and the Low CYP regimen in terms of RR.

Conclusion: As an induction treatment for PLN, the High CYP regimen was strongly associated with a higher rate of RR than the MMF regimen. There were no statistically significant differences between the High CYP regimen and the Low CYP regimen in terms of RR.