Wegener's granulomatosis: disease course, assessment of activity and extent and treatment.

Wegener's granulomatosis (WG) belongs to the group of necrotizing primary systemic vasculitides of unknown etiology, that are associated with anti-neutrophil cytoplasmic antibodies. The pathological hallmark of WG is the coexistence of vasculitis and granuloma. Due to more sensitive diagnostic instruments, especially ANCA testing, the incidence of diagnosis of WG has risen in the past ten years. Although the precise pathophysiology is not understood yet, there is ample evidence that ANCA, which can lead to cytotoxic reactions in the vascular texture, play a major role, possibly promoted by a dysbalance in the anti-idiotypic network. The clinical disease course is typically two-phasic, beginning with a granulomatous inflammation of the upper respiratory tract, that usually is followed by a generalized vasculitic phase, that can range from mild organ dysfuntion to life threatening multi-organ failure. Consequently, diagnostic procedures, patients' assessment and therapeutic regimens need to be individualized, adapted to stage and activity of the disease as well as standardized.