Initial Preserved Renal Function as a Predictor of Favorable Renal Response to Rituximab in Refractory or Relapsing Lupus Nephritis: A Single-center Cohort Study in Korea

Objective: Previous studies investigating the beneficial effect of rituximab on lupus nephritis (LN) reported controversial results There have been few reports of renal response to rituximab according to renal function We investigated the efficacy of rituximab in refractory/relapsing LN and the role of renal function as a predictor of renal response.

Methods: From 2016 to 2019, we retrospectively reviewed 22 patients with refractory/relapsing LN receiving rituximab Renal responses (complete and partial) at 6 and 12 months were compared between normal (glomerular filtration rate [GFR]≥90 mL/min/173 m², n=11) and decreased (GFR<90 mL/min/173 m², n=11) GFR groups Multivariate Cox regression analysis was used to assess predictors of renal response.

Results: At baseline, the decreased GFR group had a higher urine proteinuria to creatinine ratio (p=0008) and proportion of refractory LN (p=0010) and previous cyclophosphamide therapy (p=0035) than the normal GFR group The overall renal response rate was 455% (10 patients) at 6 months and 545% (12 patients) at 12 months Renal response rates were higher in the normal GFR group (818% and 909% at 6 and 12 months, respectively) than in the decreased GFR group (91% and 182% at 6 and 12 months, respectively; p<0001) Normal GFR and anti-La were associated with renal response to rituximab, with hazard ratios of 9256 (p=0008) and 5478 (p=0041), respectively.

Conclusion: Rituximab is an effective therapy for refractory/relapsing LN, particularly in patients with preserved renal function.