Comparison of mycophenolate mofetil and cyclophosphamide treatment in patients with ANCA associated vasculitis

Objective:To evaluate the clinical effects of mycophenolate mofetil (MMF) and cyclophosphamide(CTX) treatment for patients with antineutrophil cytoplasmic antibody (ANCA) associated vasculitis (AAV). Methodology:Thirty-five patients who had active AAV[15 male, 20 female: age(49.1±12.2)y], of whom 28 patients were MPO-ANCApositive and two were PR3-ANCA positive, were enrolled in this study. All patients had renal involvement with serum creatinine less than 500 μmol/L prior to the study and were received either MMF treatment (MMF group, n=18), or intermittent CTX pulse therapy (CTX group, n=17). The patients in both groups also received methylprednisolone (MP) pulse therapy followed by oral predenisone. The disease activity was monitored using the Birmingham Vasculitis Activity Score (BVAS). The chronic damage was measured by vasculitis damage index (VDI). The remission rate, drug-related adverse reactions and relapse were compared in the two groups. Results:The patients in the MMF group were treated with MMF for 6-24months and had a follow-up time ranged from 12 to 60 months (average 29.7±16.8) except 2 patients lost follow up after 6 months' treatment. The patients in the CTX group were followed up 12 to 63 months(average 28.5±14.6)except four patients dropped out. 17 of the 18 patients (94.4%) in the MMF group and 10 of the 13 patients (76.9%) in the CTX group had remission. At 3 months, 50% patients in MMF group, and 15.4% patients in CTX group had remission (P0.05), while the remission rate were 77.8% and 61.5%, 100% and 81.8% at 6 months and 12 months respectively ( P0.05). Two patients developed end stage renal failure in both groups during follow-up. At the last visit, 44.4% of MMF group and 15.4% of CTX group had their renal function recovered. The VDI scores after 12 months follow-up were significantly lower in the MMF group than that in the CTX group(P0.05). Furthermore, 5 of the 12 ANCA positive patients (41.7%) in the MMF group and 1 of the 5 patients (20%) in the CTX group were ANCA negative after 12 months treatment. The decrement of ANCA titer was found in 50% of patients in the MMF group and 40% in the CTX group. Two patients in the MMF group (11.8%) and 3 patients (30%)in the CTX group relapsed. One patient died in each group. The side effects included pneumonia (one), herpes zoster (one) and gastro-intestinal symptoms (2 patients) in the MMF group, and leukocytopenia (one), severe gastro-intestinal symptoms(4 patients) in the CTX group. Conclusion:MMF was more effective than intermittent CTX pulse therapy in inducing remission, improving renal function and reducing serum ANCA level in patients with ANCA associated vasculitis.