ABSTRACT
Systemic vasculitides are diseases associated with high morbidity and mortality in which cyclophosphamide and corticosteroids are highly effective treatment. However, current treatment is toxic, and although successful in inducing remission is frequently complicated by infection1. Treatment-related toxicity, particularly infection, is a common cause of death or severe morbidity and is associated with leukopenia2, increasing age and concomitant steroid dose3. Most trials and meta-analyses4,5 monitor leukopenia and neutropenia, but not hypogammaglobulinemia, as an adverse effect of cyclophosphamide or azathioprine.
