Pulmonary ultrasonography was shown to accurately detect interstitial lung disease (ILD) in patients with rheumatoid arthritis (RA), according to study findings published in Joint Bone Spine.
Researchers conducted a clinical study at tertiary medical centers in Argentina and Mexico to assess the feasibility of pulmonary ultrasonography for detecting ILD. Patients with a clinical diagnosis of RA underwent ILD screening with both ultrasonography and high-resolution computed tomography (HRCT). Individuals without RA were recruited from the surrounding communities for the control group. Results from ultrasonography were compared with results from HRCT, as well as data from other pulmonary measures.
A total of 148 patients (74 patients with RA and 74 control participants) were enrolled in the study. On ultrasonography, 30 patients with RA (40.5%) and 3 control participants (4.1%) displayed signs of ILD (P <.01). HRCT detected ILD in 27 patients (36.4%) with RA. The concordance between ultrasonography and HRCT was 90%. Among the 30 study patients with ultrasonography-identified ILD, 17 (56.6%) were symptomatic for ILD on pulmonary examination. The estimated sensitivity and specificity of ultrasonography was 92% and 89%, respectively, indicating low false positive and negative rates.
Ultrasonography results were strongly correlated with certain measures of RA disease severity, including Disease Activity Score-28, anti-cyclic citrullinated peptide levels, and rheumatoid factor positivity (all P <.01). However, no substantial association was detected between ultrasonography and chest radiography results, though chest radiography is often unable to detect early ILD. The mean time required to perform pulmonary ultrasonography was 7.8 ± 1.2 minutes, suggesting high feasibility.
Study limitations included the small cohort size and the exclusion of participants with concomitant pulmonary conditions, such as those caused by smoking. These factors may limit the generalizability of results.
The study authors concluded, “Future research should be focused on validity of pulmonary [ultrasonography] in detecting ILD in the early RA stages, its accuracy in assessing the eventual response to therapy, the correct timing of pulmonary [ultrasonography] for diagnosis and follow-up, and its potential in monitoring the progression of RA-ILD.”
Gutiérrez M, Ruta S, Clavijo-Cornejo D, Fuentes-Moreno G, Reyes-Long S, Bertolazzi C. The emerging role of ultrasound in detecting interstitial lung disease in patients with rheumatoid arthritis. Joint Bone Spine. Published online May 7, 2022. doi:10.1016/j.jbspin.2022.105407