ESTABLISHMENT OF A PROSPECTIVE COHORT FOR RHEUMATOID ARTHRITIS PATIENTS WITH INTERSTITIAL LUNG DISEASE: COMPARISON OF BASELINE CHARACTERISTICS BETWEEN RHEUMATOID ARTHRITIS PATIENT WITH OR WITHOUT INTERSTITIAL LUNG DISEASE

Abstract

Background: Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) has a clinical significance of high mortality rate in patients with RA. Hence, we established a multidisciplinary prospective single center cohort for RA-ILD patients with multidisciplinary collaboration called the HUMANISM. Patients with RA who have checked a chest computed tomography (CT) scan within previous 2 years were eligible for the enrollment, and they were classified according to the presence of ILD by expert radiologists. All RA patients were assessed with various outcomes of RA, and reviewed for treatment pattern of medications annually.

Objectives: To introduce a prospective, non-interventional cohort of RA-ILD patients, HUMANISM cohort and to compare baseline characteristics and treatment patterns between RA patients according to the presence of ILD using the enrollment data of this prospective cohort.

Methods: We compared the baseline characteristics between RA patients with and without ILD using the Chi-square test and Student’s t-test. For RA-ILD patients, we described the ILD patterns that could be identified in high-resolution CT (HRCT) to determine their dominant radiological characteristics.

Results: A total of 74 RA-ILD patients and 239 RA patients without ILD were consecutively enrolled between May 2017 and October 2018. At the baseline, RA-ILD patients showed higher proportion of male patients and older age compared to RA patients without ILD. They also showed higher RF positivity than those without ILD. RA-ILD patients also have higher disease activity measured with DAS28. In the treatment, oral glucocorticoids (OC) are used in higher rate and higher doses in RA-ILD patients than those without ILD. Methotrexate (MTX) use rate was higher in RA without ILD patients compared to RA-ILD patients, but there was no difference in the prevalence of biological DMARDs. In HRCT findings of RA-ILD patients, usual interstitial pneumonia (UIP) and non-specific interstitial pneumonia (NSIP) dominant patterns were common, followed by organizing pneumonia (OP), and overlapping patterns combined with NSIP or UIP.

Conclusion: We found that RA-ILD patients showed higher disease activity, male predominance and older age than those without ILD. Treatment patterns were different in the use of MTX or OCs. In our HUMANISM cohort, common HRCT findings of RA-ILD patients were UIP and NSIP.