MEDICAL PHYSIOLOGY AND RHEUMATIC DISEASES: Edited by Jose ScherThe lung in rheumatoid arthritis, cause or consequence?Chatzidionisyou, Aikaterini; Catrina, Anca I.Author Information Department of Medicine, Solna, Rheumatology Unit, Karolinska University Hospital and Institutet, Stockholm, Sweden Correspondence to Anca I. Catrina, Department of Medicine, Rheumatology Unit, Karolinska Institutet/Karolinska University Hospital, 171 76, Stockholm, Sweden. Tel: +46 (8) 51772475; fax: +46 (8) 51773080; e-mail: [email protected] Current Opinion in Rheumatology: January 2016 - Volume 28 - Issue 1 - p 76-82 doi: 10.1097/BOR.0000000000000238 Buy Metrics Abstract Purpose of review Recent discoveries implicate the lungs as a possible extra-articular mucosal site for initiating rheumatoid arthritis-associated immunity. Recent findings Individuals at risk for developing arthritis and patients with early untreated rheumatoid arthritis show signs of lung involvement on high-resolution computer tomography. Rheumatoid arthritis-associated antibodies are present in patients with respiratory complains such as bronchiectasis and unexplained dyspnea even in the absence of joint disease and might predict future development of rheumatoid arthritis in these patients. Rheumatoid arthritis-associated antibodies are detected in the sputum of individuals at risk for developing rheumatoid arthritis but not yet having disease. Signs of bronchial mucosal inflammation with germinal center formation and local production of antibodies have been described in patients with early untreated rheumatoid arthritis. Shared antigenic targets have been identified and characterized in the lungs and joints of rheumatoid arthritis patients. Summary Recent findings support an important role for the lung as a mucosal extra-articular place were inflammation induced by external triggers (such as smoking) leads to tolerance break and generation of rheumatoid arthritis-specific immunity already before disease onset with only secondary targeting of the joints. Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.