Tailoring Maintenance Therapy to Cluster of Differentiation 5 Positive (CD5+) Regulatory B Cell Recovery in ANCA Vasculitis

The goal of this study is to test the hypothesis that, in ANCA vasculitis, use of CD5+ B cells at the time of B cell reconstitution in the peripheral blood can be used to stratify patients between those with low % CD5+ B cells at greater risk of relapse who would need maintenance immunosuppression and those with normalized CD5+ B cells who would be at lower risk of relapse, and therefore may not need maintenance immunosuppression. The latter group will be randomized to either maintenance immunosuppression vs close clinical observation without maintenance immunosuppression. This study is not designed to evaluate the efficacy of new therapies in ANCA vasculitis. The treatment regimen used in the proposed study are routinely used in the treatment of patients with ANCA vasculitis and considered standard-of-care.