Impact of interstitial lung disease on clinical remission and unfavourable events of rheumatoid arthritis: results from the IORRA cohort

Abstract Objectives We aimed to examine the impact of concomitant interstitial lung disease (ILD) on achieving clinical remission and the occurrence of unfavourable clinical events in patients with RA. Methods Among the participants in the Institute of Rheumatology, Rheumatoid Arthritis (IORRA) cohort from 2011 to 2012, patients not achieving remission of 28-joint disease activity score (DAS28) at baseline and those with chest CT images were enrolled. Based on the chest CT images, the patients were divided into two groups: the ILD group and non-ILD group. The associations among the presence of ILD with time to achieving DAS28 remission and development of death, hospitalized infection, major adverse cardiac events (MACE), or malignancy within 5 years were evaluated using time-dependent Cox regression models. Results We enrolled 287 patients in the ILD group and 1235 in the non-ILD group. DAS28 remission was achieved at least once in 55.7% and 75.0% of the ILD and non-ILD groups within 5 years, respectively. Presence of ILD was significantly associated with failure to achieve DAS28 remission (adjusted hazard ratio [aHR]: 0.71; 95% CI: 0.58, 0.89). ILD was also a significant factor associated with death (aHR: 3.24; 95% CI: 2.08, 5.03), hospitalized infection (aHR 2.60; 95% CI: 1.77, 3.83), MACE (aHR: 3.40; 95% CI: 1.76, 6.58), and lung cancer (aHR: 16.0; 95% CI: 3.22, 79.2), but not with malignant lymphoma (aHR: 2.27; 95% CI: 0.59, 8.81). Conclusion Concomitant ILD was a significant factor associated with failure to achieve clinical remission and the occurrence of the unfavourable clinical events in patients with RA.