Relationship between disease activity and ANCA level by ELISA in the long-term management of vasculitis

Solid-phase immunoassays were used to examine the relationship between ANCA concentration and disease activity during follow-up of 63 patients with systemic vasculitis. ANCA levels fell with induction therapy. Relapses during long-term follow-up were generally associated with high or rising ANCA concentrations, although the temporal relationship between clinical relapse and changes in ANCA was variable.