Efficacy of tacrolimus as maintenance therapy after cyclophosphamide for treating antineutrophil cytoplasmic antibody-associated vasculitis

Azathioprine (AZA), methotrexate, or rituximab is used for the maintenance therapy of antineutrophil cytoplasmic antibody-associated vasculitis (AAV). Although the efficacy of tacrolimus (TAC) in various autoimmune diseases has been demonstrated, there have been few reports on the efficacy of TAC in AAV. We investigated the efficacy of TAC as maintenance therapy for AAV and compared its efficacy with that of AZA.We retrospectively analyzed the medical records of 81 patients with AAV who received cyclophosphamide as induction therapy and AZA or TAC as maintenance therapy. All-cause death, relapse, and progression to end-stage renal disease (ESRD) were analyzed.Among 81 patients with AAV, 69 patients received AZA alone, 6 patients received TAC alone, and 6 patients received TAC after AZA for maintenance therapy. Overall, 11 patients (13.6%) died, 30 patients (37.0%) experienced relapse, and 16 patients (19.8%) progressed to ESRD during a median of 33.8 months. No significant differences were observed in cumulative patients', relapse-free, and ESRD-free survival rates between patients administered AZA alone and TAC alone. There were no significant differences in the cumulative patients' and relapse-free survival rate between patients who received AZA alone and TAC after AZA. However, the cumulative ESRD-free survival rate was lower in patients who received TAC after AZA than in those who received AZA alone (P = .027).Patients who received TAC as maintenance therapy showed a higher incidence of ESRD than those who received AZA; however, this might be attributed to the lack of efficacy of AZA rather than the low ESRD prevention effect of TAC.