Wegener's granulomatosis: Evolving concepts in treatment

Wegener's granulomatosis (WG), the most common of the pulmonary granulomatous vasculitides, typically involves the upper respiratory tract, lower respiratory tract (bronchi and lung), and kidney, with varying degrees of disseminated vasculitis. Major histological features include a necrotizing vasculitis involving small vessels, extensive "geographic" necrosis, and granulomatous inflammation. Clinical manifestations of WG are protean; virtually any organ can be involved. Further, the spectrum and severity of the disease is heterogeneous, ranging from indolent disease involving only one site to fulminant, multiorgan vasculitis leading to death. The pathogenesis of WG has not been elucidated, but both cellular and humoral components are involved. Circulating antineutrophil cytoplasmic antibodies (cANCA) likely play a role in the pathogenesis and often correlate with activity of the disease. Treatment strategies are evolving. Cyclophosphamide (CYC) plus corticosteroids (CS) is the mainstay of therapy for generalized, multisystemic WG. Historically, the combination of CYC plus CS was used for a minimum of 12 months, but concern about late toxicities associated with CYC has led to novel treatment approaches. Currently, short-course (3-6 months) induction treatment with CYC plus CS, followed by maintenance therapy with less toxic agents (e.g., methotrexate, azathioprine) is recommended. Further, recent studies suggest that methotrexate combined with CS may be adequate for limited, non-life threatening WG. The role of other immunomodulatory agents (including trimethoprim-sulfamethoxazole) is also explored.