Increased interleukin-11 associated with disease activity and development of interstitial lung disease in patients with rheumatoid arthritis

Objective To investigate the association of serum interleukin-11 (IL-11) with disease activity and occurrence of interstitial lung disease (ILD) in patients with rheumatoid arthritis (RA). Methods One hundred and six RA patients were included, including 31 with ILD. All patients were divided into two groups according to the 28-joint Disease Activity Score (DAS28), active-disease group (DAS28>3.2) and target-achieved group (DAS28 <= 3.2). Serum IL-11 was detected by ELISA. Serum autoantibodies [anticitrullinated protein antibody (ACPA) and rheumatoid factor (RF)], inflammatory markers [C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR)], and complete blood count were measured with routine methods. Results Serum IL-11 was upregulated in RA patients compared with healthy controls (HC), and increased more significantly in patients with ILD (RA-ILD) than patients without ILD (RA-nonILD). In both RA-ILD and RA-nonILD patients, serum level of IL-11 was higher in the active-disease group than that in the target-achieved group. Pearson correlation analysis confirmed that IL-11 was positively correlated with DAS28. No significant correlation was found between serum level of IL-11 and ACPA or RF. IL-11 was positively correlated with ESR and CRP levels and PLT count in RA patients. Conclusion IL-11 was found to be involved in the development of arthritis and ILD in RA patients, and might constitute a potential target for the treatment of RA-ILD.