Evaluation of weekly-reduction regimen of glucocorticoids in combination with cyclophosphamide for anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis in Japanese patients

The current therapeutic regimen recommended by the European League against Rheumatism (EULAR) for anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) is continuation of initially administered doses of glucocorticoids (GCs) in combination with cyclophosphamide (CYC) for 1 month followed by gradual tapering. Considering the adverse effects of GCs, another tapering regimen of GCs with CYC, which was characterized by tapering GCs weekly, was reported by the British Society of Rheumatology (weekly-reduction regimen). The aim of the present study is to evaluate the safety and efficacy of this weekly-reduction regimen for Japanese AAV patients in comparison with the monthly-reduction regimen recommended by the EULAR. We retrospectively reviewed medical records of adult patients newly diagnosed with AAV during the period from April 2000 to December 2010. The outcome measures were rates of remission, relapse, infection, and GC-induced diabetes mellitus during the first 12 months. Clinical data in the two groups and categorial variables with a possible relation to the outcomes were compared by using the t test and chi-square test, respectively. Twenty-four patients were enrolled in our study. All of the patients achieved remission, and the rates of relapse during the first 12 months were not statistically different between the two groups (P = 0.16). Patients treated with the weekly-reduction regimen were less liable to have infection (P = 0.03) and impaired glucose tolerance (P = 0.017), compared with those treated with the monthly-reduction regimen. A therapeutic strategy using the weekly-reduction regimen of GCs would be effective and would have fewer side effects than the monthly-reduction regimen.