The Complex Role of the Lung in the Pathogenesis and Clinical Outcomes of Rheumatoid Arthritis.

While the primary manifestation of rheumatoid arthritis (RA) is articular disease, extra-articular disease may also occur. In particular, pulmonary disease is a frequent extra-articular manifestation of seropositive RA and a leading cause of morbidity and mortality in this population. This review will highlight studies published in the last several years and will, in particular, discuss the relationship of antibodies to citrullinated protein/peptide antigens (ACPA) and lung disease in patients with RA. We will also review the data regarding the potential role of the lung and generation of RA-related autoantibodies in a period of disease development termed "preclinical RA." Finally, we will discuss the role of ACPA and other Abs in non-RA pulmonary diseases and discuss a research agenda for next steps in the understanding and management of the lung in RA.