Combination of Rituximab and Low-dose Tacrolimus in the Treatment of Refractory Membranous Nephropathy: A Retrospective Cohort Study

Conventional regimens for refractory idiopathic membranous nephropathy (IMN) still have limitations. Rituximab (RTX) has a good effect in the treatment of refractory IMN. However, whether RTX single or combined with immunosuppressive therapy is more effective and whether adverse events will increase are still inconclusive.To investigate the efficacy and safety of RTX combined with low-dose tacrolimus (TAC) versus RTX alone in the treatment of refractory IMN.A retrospective cohort study.We retrospectively studied 91 cases of refractory IMN diagnosed between January 2018 and June 2021, all of which immunosuppressive regimens had failed. Thirty-four patients received RTX combined with TAC (RTX + TAC group), and 57 patients were treated with RTX alone (RTX group). The RTX + TAC group was given RTX 1 g once every 2 weeks, two times, and TAC 0.03 mg/kg/day orally. In the RTX group, RTX was given at the same dosage as the RTX + TAC group. Clinical data were collected at 12 months of follow-up to compare the complete and partial remission rates and the incidence of adverse reactions between the two groups.The overall effectiveness rate of RTX + TAC in the treatment of refractory IMN was 87.14%, of which the partial and complete remission rates were 50.01% and 37.13%, respectively, and the median time to complete remission was 9 (interquartile range [IQR] 6.0, 12.0) months. The overall effectiveness rate of RTX was 65.87%, of which the partial and complete remission rates were 39.48% and 26.39%, respectively, and the median time to complete remission was 10.5 (IQR 6.0, 12.0) months. Adverse events occurred in 6 (17.65%) patients in the RTX + TAC group and in 11 (19.30%) in the RTX group (P = 0.473). Proteinuria and high titer of PLA2R are risk factors for non-remission.The complete and partial remission rates of RTX combined with low-dose TAC in the treatment of refractory IMN are higher than those of RTX alone, and no significant increase in adverse events was noted.