Lung Ultrasound as a Screening Tool for Subclinical Rheumatoid Arthritis-Associated Interstitial Lung Disease

The screening strategy for interstitial lung disease (ILD) in rheumatoid arthritis (RA) patients without respiratory symptoms is still a subject of debate. This study aimed to assess the performance of lung ultrasonography (LUS) as a screening tool for RA-ILD and compare it with spirometry and DLCO. <bold>Methods:</bold> A multinational cross-sectional study conducted between June and December 2023 enrolled consecutively selected RA patients aged 17 or older without respiratory symptoms from Argentina, Greece, France, and Mexico. High-resolution Computed Tomography (HRCT) served as the gold standard for ILD diagnosis, performed within 30 days of LUS and pulmonary function tests. Investigators, blinded to HRCT results and clinical data, conducted LUS by exploring 14 areas, considering it positive when the sum of B lines was ≥ 5. <bold>Results:</bold> Of the 199 patients (78.9% women, median age 63, 52-70 years), with a median time from RA diagnosis to study inclusion of 10 (4-18) years, 48% were past or current smokers, and 76% were seropositive. A total of 53 (26.6%; 95% CI: 20.6-33.3) patients had HRCT-confirmed ILD diagnosis. The negative predictive value of LUS was 93% (87%-97%). The performance of other diagnostic tests is detailed in the table. <bold>Conclusions:</bold> In 93 out of 100 RA patients without respiratory symptoms, ILD could be ruled out with LUS, proving to be an accurate diagnosic tool for ILD screening. <fig><object-id>erj;64/suppl_68/OA3785/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig>