B-cell depletion in Wegener's granulomatosis.

Wegener's granulomatosis (WG) is a chronic, relapsing, systemic necrotizing vasculitis with typical pathologic findings of granulomatous inflammation and pauci-immune vasculitis. Untreated, the condition has a very high mortality, and contemporary treatment strategies carry a high risk of treatment-related morbidity. Antineutrophil cytoplasmic antibodies (ANCA) play a central role in the pathogenesis of the disease. It is unclear how ANCA develop, but B cells are of major importance in the disease pathogenesis as precursors of ANCA-producing plasma cells and, possibly, also as antigen-presenting and cytokine-producing cells. Therefore, the use of B-cell depletion therapy, e.g., with rituximab appears to be an attractive treatment option in WG. Several small clinical trials and case reports show promising results with a high rate of clinical remissions achieved in patients that were refractory to or intolerant of conventional treatment regimens. However, granulomatous manifestations seemed to be less responsive to B-cell depletion therapy. B-cell depletion therapy was generally well tolerated. A large prospective, randomized, double-blind clinical trial evaluating the efficacy of B-cell depletion therapy in WG is pending.