Efficacy of rituximab in maintenance therapy for antineutrophil cytoplasmic antibody-associated vas-culitis / 中华风湿病学杂志

ABSTRACT

Objective:To evaluate the efficacy and safety of rituximab(RTX) as remission-mainten-ance therapy in antineutrophil cytoplasmic antibody(ANCA) associated vasculitis(AAV).Methods:Patients with AAV, including granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA), treated with rituximab (RTX) in Peking Union Medical College Hospital during September 2005 to June 2021 were included into this study. Clinical data, relapse rate, time of first relapse and adverse events were collected and analyzed. The cumulative relapse rate was calculated by Kaplan-Meier, t test, and Man-Whithey U test and chi-square were used to compare differences between two groups. Results:① Thirty-nine AAV patients were enrolled, including 36 GPA and 3 MPA. During the 20(3, 104) months follow-up, 59.0%(23/39) patients had suffered relapses. The time for first relapse was 11(3, 42) months after remission. ② There were no difference in the relapse rate [60.0%(18/30) vs 55.6%(5/9), χ2=0.06, P=1.000), the time of first relapse [15(3, 42) vs 10(9, 30), Z=0.45, P=0.678], CD19 + B [23.5 (5, 148) cell/μl vs 3(2, 15) cell/μl, Z=0.57, P=0.605] and serum IgG [7.09(5.13, 13.90) g/L vs 9.72(5.32, 12.0) g/L, Z=0.36, P=0.770] between standard dose and low-dose groups. The rate of major relapse-free was significantly less in patients treated with standard dose than patients with reduced dose of RTX {87.1%[95% CI(73.4%, 100.8R%)] vs 64.3%[95% CI(23.1%, 105.4%)], χ2=7.59, P=0.006}. ③ There were no difference in relapse rate [50.0%(3/6) vs 60.6%(20/33), χ2=0.24, P=0.674], time of first relapse [23(6, 25) vs 11(3, 42), Z=0.05, P=0.982], CD19 + B[35(15, 50) cell/μl vs 10(0, 148) cell/μl, Z=0.95, P=0.382] and serum IgG[6.70(5.91, 7.49) g/L vs 7.69(3.78, 13.90) g/L, Z=0.48, P=0.700] between the fixed interval dosage and the on-demand dosage groups. There was no difference in the rate of major relapse-free between the two groups (100% vs 77.8%, χ2=1.79, P=0.181). ④ The incidence of infusion reaction was 5.1%(2/39) and infection was 20.5%(8/39). Serum IgG level was 4.37(3.78, 13.4) g/L at infection. There was no difference in safety between the standard and low-dose groups or between fixed interval and on-demand dosage groups ( P>0.05). Conclusion:There is no significant difference in relapse rate bet-ween the standard RTX dose and low-dose RTX induction therapy group, but the major relapse rate is sign-ificantly reduced in the standard dose RTX therapy. The relapse rate of fixed intervals dosage group is similar to that of on-demand dosage group. The safety profile of the standard dose and low-dose induction therapy groups or fixed intervals and on-demand dosage groups is similiar.