Wegener's granulomatosis: an update on diagnosis and therapy

Wegener's granulomatosis (WG) is a unique clinicopathological disease characterized by necrotizing granulomatous vasculitis of the respiratory tract, pauci-immune necrotizing glomerulonephritis and small-vessel vasculitis. Owing to its wide range of clinical manifestations, WG has a broad spectrum of severity that includes the potential for alveolar hemorrhage or rapidly progressive glomerulonephritis, which are immediately life threatening. WG is associated with the presence of circulating antineutrophil cytoplasm antibodies (c-ANCAs). The most widely accepted pathogenetic model suggests that c-ANCA-activated cytokine-primed neutrophils induce microvascular damage and a rapid escalation of inflammation with recruitment of mononuclear cells. The diagnosis of WG is made on the basis of typical clinical and radiologic findings, by biopsy of involved organ, the presence of c-ANCA and exclusion of all other small-vessel vasculitis. Currently, a regimen consisting of daily cyclophosphamide and corticosteroids is considered standard therapy. A number of trials have evaluated the efficacy of less-toxic immunosuppressants and antibacterials for treating patients with WG, resulting in the identification of effective alternative regimens to induce or maintain remission in certain subpopulations of patients. Recent investigation has focused on other immunomodulatory agents (e.g., TNF-alpha inhibitors and anti-CD20 antibodies), intravenous immunoglobulins and antithymocyte globulins for treating patients with resistant WG.