Lung ultrasonography as a tool to detect interstitial lung disease in rheumatoid arthritis: A meta-analysis of diagnostic test accuracy studies

Background: Interstitial lung disease (ILD) is a frequent pulmonary complication in rheumatoid arthritis (RA). Lung ultrasonography (LUS) provides a fast, noninvasive method for detecting RA-ILD, enabling earlier intervention and treatment. This study aimed to assess the diagnostic performance of LUS in identifying RA-ILD. Methods: Systematic review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Comprehensive database searches were carried out, including PubMed (including MEDLINE and PubMed Central), Scopus, and Cochrane, covering studies published up to September 1, 2024, without restrictions on publication date. Studies were selected based on predefined inclusion and exclusion criteria. Quality Assessment of Diagnostic Accuracy Studies-2 tool was used to evaluate the methodological quality of the studies. Relevant data on study characteristics and diagnostic performance were extracted, and statistical analyses were performed using R software. Results: Nine studies involving 845 participants were included. LUS demonstrated sensitivity, specificity, and an area under the curve (AUC) of 0.910 (95% CI: 0.837–0.953), 0.793 (95% CI: 0.509–0.934), and 0.926, respectively, for detecting RA-ILD. Meta-analysis of eight studies using the number of B-lines as the diagnostic criterion yielded pooled sensitivity and specificity of 0.906 (95% CI: 0.826–0.952) and 0.739 (95% CI: 0.439–0.911), with an AUC of 0.916. Subgroup analysis of five studies evaluating B-lines in 14 lung intercostal spaces (LIS) reported sensitivity and specificity of 0.891 (95% CI: 0.746–0.958) and 0.891 (95% CI: 0.612–0.977), respectively. Assessment of a larger number of LIS (72 LIS) yielded higher sensitivity (0.917 [95% CI: 0.798–0.968]) but lower specificity (0.564 [95% CI: 0.440–0.682]). Conclusion: LUS demonstrates high diagnostic accuracy in detecting ILD in RA patients and holds promise as a valuable screening tool for clinical use.