Immune phenomena in localized and generalized Wegener's granulomatosis

Wegener's granulomatosis (WG) is characterized by granulomatous inflammation and systemic vasculitis with a predilection for the lungs and kidneys. In most patients WG begins with a localized organ involvement of the upper respiratory tract that progresses to systemic disease (generalized WG) (I). Because of the life-threatening nature of systemic vasculitis, much effort has concentrated on elucidating the pathogenesis of the vasculitis. However, based upon a renewed interest in (innate) immune defenses against microbes, a better understanding of the chronic granulomatous inflammation may contribute to a more precise insight into the early genesis of WG. Thus, this review focuses on summarizing and discussing data for a potential pattern of disease, i.e. from localized to generalized WG with a special emphasis on granulomatous lesions of the upper respiratory tract and their alterations during the disease course.