Performance of Lung Ultrasound as a Screening Tool for Subclinical Rheumatoid Arthritis-Associated Interstitial Lung Disease: A Multicenter Study.

Abstract

Background: The screening strategy for interstitial lung disease (ILD) in patients with rheumatoid arthritis is currently debated. Although high-resolution CT (HRCT) imaging is the gold standard for diagnosing ILD, its systematic use as a screening tool is not yet recommended. The role of lung ultrasound (LUS) in assessing ILD has been previously explored.

Research question: What is the performance of LUS for ILD diagnosis in asymptomatic patients with rheumatoid arthritis?

Study design and methods: We conducted a multicenter, cross-sectional study involving 203 asymptomatic patients with rheumatoid arthritis from outpatient clinics in Argentina, Greece, France, and Mexico. Participants underwent clinical evaluations, pulmonary function tests, and LUS. An HRCT scan was performed on each patient within 30 days of the LUS. Statistical analyses included sensitivity, specificity, and predictive values for LUS and pulmonary function tests.

Results: Of the participants, 26% were diagnosed with ILD. The median age was 63 years (52-89 years), and 161 (79.3%) patients were female. The median duration from rheumatoid arthritis diagnosis to inclusion was 7 years (range, 2-16 years). LUS exhibited a sensitivity of 83% (95% CI, 70.2%-91.9%) and a specificity of 81.2% (95% CI, 74.2%-87.2%), with a negative predictive value of 93.1% (95% CI, 87.4%-96.8%) and a positive predictive value of 61.1% (95% CI, 58.9%-72.4%). LUS outperformed pulmonary function tests, underscoring its potential as a primary screening tool.

Interpretation: LUS is a promising tool for ILD screening in asymptomatic patients with rheumatoid arthritis, offering high sensitivity and negative predictive value. Its incorporation into routine clinical practice could optimize ILD screening strategies and enhance patient outcomes through early detection and intervention.