FRI0049 RHEUMATOID ARTHRITIS ASSOCIATED INTERSTITIAL LUNG DISEASE: TOBACCO AND OTHER RISK FACTORS
Authors: C. Aguilera Cros, M. Gomez Vargas, R. J. Gil Velez, J. A. Rodriguez Portal
Journal: Annals of the Rheumatic Diseases (2020)

Background: Among the risk factors associated with the development of interstitial lung disease (ILD) in patients with rheumatoid arthritis (RA) are: male sex, old age, erosive RA, rheumatoid nodules, smoking and high levels of rheumatoid factor (RF) and anticitrullinated protein antibody (ACPA). The factors of poor prognosis include: HRCT (High Resolution Computed Tomography) pattern of usual interstitial pneumonia (NIU) with altered baseline functional tests (forced vital capacity FVC &lt;60%, diffusion capacity of the lung for carbon monoxide DLCO&lt;40%). RA associated UIP (RA-UIP) has an appearance that is identical to idiopathic UIP (idiopathic pulmonary fibrosis [IPF]) on HRCT. Objectives: To analyze different risk factors and poor prognosis in a cohort of patients with ILD-RA. To assess the degree of association between tobacco (smokers, ex-smokers and non-smokers) and altered baseline functional respiratory tests (FRT) (FVC &lt;80% and DLCO &lt;40%) with HRCT patterns. Methods: Descriptive study of 57 patients treated in our Hospital (1/1/2018 until 12/31/2019) with a diagnosis of RA (ACR 2010 criteria) and secondary ILD. The most recent American Thoracic Society (ATS)/European Respiratory Society (ERS)/Japanese Respiratory Society (JRS)/Latin American Thoracic Society (ALAT) guidelines define three HRCT (High Resolution Computed Tomography) patterns of fibrosing lung disease in the setting of idiopathic pulmonary fibrosis (IPF): definite UIP (traction bronchiectasis and honeycombing), possible UIP and inconsistent with UIP. The distinction between definite UIP and possible UIP in these to the presence or absence of honeycombing. Approved by the Ethics Committee. Quantitative variables are expressed as mean (SD) and dichotomous variables as percentages (%). The association between tobacco-UIP and FVC-UIP was studied using two Chi-square tests and the DLCO-UIP relationship with an exact Fisher test. Statistical analysis with SPSS version 21. Results: 21 men and 36 women were included, with a mean age of 69 ± 10 years (mean ± SD), history of smoking (smokers 14%, non-smokers 43%, ex-smokers 42%). 83% were positive RF and 70% positive ACPA. Regarding the HRCT findings: 29 (50%) had a inconsistent with UIP pattern and 28 (49%) had an UIP pattern (45% defined, 3% possible). Of the UIP patients, 14 (50%) had a smoking relationship (35% ex-smokers, 25% smokers) and 15 were male (53%). Of the sample analyzed, 8% (5 patients) have died, all ex-smoking men, the UIP pattern being the most frequent found (4 UIP, 1 inconsistent with UIP). No statistical association was observed between patients with exposure to tobacco and the UIP pattern (p = 0.438), nor among patients with baseline FVC &lt;80% and UIP (p = 0.432) and also among patients with baseline DLCO &lt;40% and UIP pattern (p = 0.459). Conclusion: Our results, in general, do not match what is published in the literature. Male sex, smoking exposure and fibrosing pattern (UIP) represent a worse prognosis for patients with ILD-RA. However, more studies are required to determine more precisely how these risk factors affect the disease. Disclosure of Interests: None declared