[Role of the titration of anti-neutrophil cytoplasmic antibodies in therapeutic follow-up of patients with systemic vasculitis]. / Place du titrage des anticorps anticytoplasme des polynucléaires neutrophiles dans le suivi thérapeutique des patients atteints de vascularite systémique.

We studied clinical and biological data of 18 patients presenting ANCA associated diseases for 16 months at least. Five relapses were preceded by ANCA elevation, 1 relapse was not. Four transient elevations were noted without any clinical event. We think ANCA level elevation by itself is not enough for deciding therapy intensification, clinical data are necessary for doing so.