Elevated VCAM-1, MCP-1 and ADMA serum levels related to pulmonary fibrosis of interstitial lung disease associated with rheumatoid arthritis.

Early diagnosis of interstitial lung disease (ILD) associated with rheumatoid arthritis (RA) constitutes a challenge for the clinicians. Pulmonary vasculopathy is relevant in the development of interstitial lung disease. Accordingly, we aimed to explore the role of vascular cell adhesion molecule-1 (VCAM-1), monocyte chemoattractant protein-1 (MCP-1) and asymmetric dimethylarginine (ADMA), key molecules in the vasculopathy, as potential biomarkers of pulmonary fibrosis in RA-ILD. We included 21 RA-ILD patients and two comparative groups: 25 RA-ILD patients and 21 idiopathic pulmonary fibrosis (IPF) patients. Serum levels of the molecules were determined by ELISA, and mRNA expression was quantified by qPCR. VCAM-1, MCP-1 and ADMA serum levels were increased in RA-ILD patients in relation to RA-ILD and IPF patients. Additionally, RA-ILD patients exhibited increased (gene encoding MCP-1) and decreased (gene related to ADMA synthesis) mRNA expression in relation to RA-ILD patients. A lower expression of , , and was observed in RA-ILD patients when compared with those with IPF. Furthermore, MCP-1 serum levels and mRNA expression were positively correlated with RA duration, and ADMA serum levels were positively associated with C-reactive protein in RA-ILD patients. Our study suggests that VCAM-1, MCP-1 and ADMA could be considered as useful biomarkers to identify ILD in RA patients, as well as to discriminate RA-ILD from IPF, contributing to the early diagnosis of RA-ILD.