Wegener's granulomatosis is a systemic vasculitis in which parenchymal and/or endobronchial inflammation frequently occur. The purpose of this investigation is to analyze bronchial and bronchoalveolar lavage fluid in patients with Wegener's granulomatosis for the presence of immunoregulatory mediators and pro-inflammatory cytokines. We will also be examining mucosal biopsies in these patients to define the histologic changes, the phenotype of infiltrating leukocytes, and the pattern of adhesion molecule expression that may be present. Such studies could lead to an improved understanding of the pathophysiology of this disease and of its pulmonary manifestations and provide potential directions for future therapy.