Background Add-on intravenous pulse methylprednisolone (IVMP) is a strategy to reduce cumulative glucocorticoids (GCs) doses for treating proliferative lupus nephritis (LN). However, the benefit is still under debate. This study compares the efficacy and safety of add-on IVMP versus GCs alone in Thai patients with proliferative LN receiving monthly intravenous cyclophosphamide (IVCY).

Methods This study enrolled 63 biopsy-proven proliferative LN who underwent induction therapy in Songklanagarind hospital, from January 2009 to December 2019. 18 patients in add-on IVMP and 45 patients in medium to high dose GCs alone were reviewed and analysed. Both groups received monthly IVCY for the induction phase. The primary outcome was the remission rate, and the secondary outcomes were a 6-month proteinuria decline from baseline> 50%, renal survival, time to achieve remission, cumulative GCs dose, and proteinuria < 0.5 gm.

Results The remission rate in our study was 79.4%, which was no significant difference between add-on IVMP and GCs alone (66.7% vs. 84.5%, p= 0.214). The secondary outcomes were not different between groups demonstrated as renal survival (83.3% vs. 97.8%, p=0.067), median time (IQR) to achieve remission [180 (120,215) vs. 138 (103,237.2), p=0.962], proteinuria decline from baseline> 50% (66.7% vs. 86.7%, p=0.085), proteinuria < 0.5 gm (27.8% vs. 40.0%, p=0.535), and cumulative GCs dose. However, the 6-month renal function was significantly improved in add-on IVMP (72.2% vs.57.8%, p= 0.002). We compared the subgroups of 11 add-on IVMP with medium GCs and 45 GCs alone; the overall outcomes were similar, but the mean (SD) 6-month cumulative GCs dose tended to lower in add-on IVMP [3.7(1.2) vs. 4(1), gm, p= 0.052].

Conclusions The remission rate was not different between add-on IVMP and GCs alone but significant improvement of renal function in add-on IVMP in proliferative lupus nephritis who monthly IVCY.