SAT0040 RISK FACTORS FOR DEVELOPING AND MORTALITY FOR ACUTE EXACERBATION OF RHEUMATOID ARTHRITIS-ASSOCIATED INTERSTITIAL LUNG DISEASE

Background: Among collagen vascular diseases, rheumatoid arthritis-associated interstitial lung disease (RA-ILD) is the most commonly associated with ILD with acute exacerbation (AE) [1]. One study reported that ILD diagnosis at an older age, the usual interstitial pneumonia (UIP) pattern on high-resolution computed tomography, and methotrexate (MTX) use were associated with AE in patients with RA-ILD [2]. However, because these studies included few patients, the risk factors and prognosis of AE in patients with RA-ILD remain unclear. Therefore, this study examined the characteristics of RA-ILD patients with AE, and the variables associated with mortality due to AE of RA-ILD. Objectives: To investigate the risk factors for AE and mortality of RA-ILD. Methods: We retrospectively collected the clinical data of 165 RA-ILD patients admitted to our hospital between July 2010 and October 2019. We compared clinical characteristics between patients who developed AE (AE group) and those who did not (non-AE group), and identified the variables significantly associated with AE occurrence. We also compared the admission characteristics of those who survived (survivor group) and those who died (non-survivor group) after admission for AE. AE was defined using previously proposed criteria [3], which were modified slightly for application to RA-ILD. Results: The mean patient age was 73.6 ± 9.7 years and 97 (71.9%) patients were female. Thirty (22.2%) patients developed AE, of whom thirteen (43.3%) died (mean follow-up, 64.9 months). In univariate analyses UIP pattern and MTX were not associated with AE. However, in multivariate analyses, UIP pattern was associated with AE (OR 2.68, 95% CI 1.10–6.52, p=0.03). Median age (70 vs. 80 years, p=0.003), non-use of MTX (70.6% vs. 23.1%, p =0.025), and C reactive protein level (median 9.38 vs. 18.12 mg/dL, p=0.02) on admission were significantly higher in patients who died of AE. In the Cox proportional hazard model, UIP pattern (HR 4.67, 95% CI 1.02–21.5, p=0.048) and non-use of MTX (HR 0.16, 95% CI 0.04–0.72, p=0.016) were associated with death. Conclusion: Our data suggest that the UIP pattern is related to AE, and non-use of MTX and UIP pattern are related to death due to AE of RA-ILD. References: [1] Suda T, Kaida Y, Nakamura Y et al. Acute exacerbation of interstitial pneumonia associated with collagen vascular diseases. Respir Med 2009;103:846-53. [2] Hozumi H, Nakamura Y, Johkoh T et al. Acute exacerbation in rheumatoid arthritis-associated interstitial lung disease: a retrospective case control study. BMJ Open 2013;3:e003132. [3] Collard HR, Moore BB, Flaherty KR et al. Idiopathic pulmonary fibrosis clinical research network investigators. Acute exacerbations of idiopathic pulmonary fibrosis. Am J Respir Crit Care Med 2007;176:636-43. Disclosure of Interests: None declared