TY - JOUR T1 - Two sides of the same coin? A review of the similarities and differences between idiopathic pulmonary fibrosis and rheumatoid arthritis associated interstitial lung disease JF - European Respiratory Journal JO - Eur Respir J DO - 10.1183/13993003.02533-2020 SP - 2002533 AU - Scott Matson AU - Joyce Lee AU - Oliver Eickelberg Y1 - 2020/01/01 UR - http://erj.ersjournals.com/content/early/2020/11/11/13993003.02533-2020.abstract N2 - Rheumatoid arthritis (RA) is a common disease, characterised by an erosive and inflammatory synovitis, which affects 1% of the general population [1]. Interstitial lung disease is a frequent extra-articular manifestation of RA and causes significant morbidity and mortality [2]. While ILD in RA is common, our understanding of the pathogenesis of RA-ILD is limited [3]. There have been observations that certain subtypes of RA-ILD may be clinically similar to idiopathic pulmonary fibrosis (IPF) [4], a form of progressive ILD, histologically characterised by a usual interstitial pneumonia (UIP) pattern [5]. Recent work in the genetics of RA-ILD has uncovered shared genetic risk factors between RA-ILD and IPF [6–8], further supporting a possible connection between these two conditions.FootnotesThis manuscript has recently been accepted for publication in the European Respiratory Journal. It is published here in its accepted form prior to copyediting and typesetting by our production team. After these production processes are complete and the authors have approved the resulting proofs, the article will move to the latest issue of the ERJ online. Please open or download the PDF to view this article.Conflict of interest: Dr. Matson has nothing to disclose.Conflict of interest: Dr. Lee reports grants from NIH, grants and personal fees from Boehringer Ingelheim, personal fees from Galapagos, personal fees from Eleven P15, personal fees from Celgene, outside the submitted work;.Conflict of interest: Dr. Eickelberg reports grants from NHLBI, during the conduct of the study; personal fees from Blade Therapeutics, personal fees from Pieris , personal fees from Boehringer Ingelheim, personal fees from Novartis, outside the submitted work;. ER -