It is still controversial how to screen for interstitial lung disease (ILD) in patients with rheumatoid arthritis (RA). We aimed to evaluate the performance of lung ultrasonography (LUS) as screening tool of RA-associated interstitial lung disease (ILD), and to compare it with that of the physical exam, chest X-ray, and pulmonary function tests (PFTs).

Methods: cross-sectional study of consecutive patients with RA evaluated by the rheumatology clinic of the Institute of Psychophysical Rehabilitation of Buenos Aires (Argentina), from January to December 2022. High resolution Computed Tomography (HRCT) was the gold standard for ILD diagnosis, and it was performed within 30 days of the LUS, the respiratory evaluation and the PFTs. Investigators were blinded to HRCT results and patientsŽ clinical data. LUS was performed by exploring 14 areas, and assumed as positive when the sum of B lines was ? 5. 

Results: 105 patients were included, 86 (81,9%) were women, median age 62 (55-68) years. The median RA disease duration at inclusion was 14 (8-24) years. A total of 32 patients (30,5%, 95% CI: 22% - 40%) had ILD. The negative predictive value (NPV) of LUS for ILD diagnosis was 95% (85%-99%). The results of the rest of the diagnostic variables for each test are shown in figure 1.

Conclusions: Given the high negative predictive value, LUS is a useful tool to rule-out ILD in patients with RA in rheumatology clinic.