The etiology of pulmonary fibrosis in individuals with rheumatoid arthritis is unknown. Analysis of blood and specimens procured by bronchoscopy, lung biopsy, lung transplantation, or post-mortem examination from patients with this disorder will contribute to our understanding of the pathogenetic mechanisms of pulmonary fibrosis in rheumatoid arthritis. The purpose of this protocol is to obtain blood and specimens by bronchoscopy, lung biopsy, lung transplantation, or post-mortem examination from rheumatoid arthritis patients with and without pulmonary fibrosis, individuals with idiopathic pulmonary fibrosis, and healthy research volunteers.