Lung ultrasound for the detection of radiological progression of interstitial lung abnormalities in patients with rheumatoid arthritis.

Abstract

Interstitial lung disease is an important extra-articular manifestation of rheumatoid arthritis (RA) associated with high mortality and morbidity. Lung ultrasound (LUS) has recently emerged as a possible screening tool. We assessed the role of lung ultrasound in monitoring radiological progression and the development of new interstitial lung abnormalities (ILA). In this prospective pilot study, RA patients underwent high-resolution CT (HRCT), pulmonary function tests (PFTs), symptom assessment, and LUS at baseline and 12-18 months later. B-lines were quantified using a 72-zone protocol. Radiological changes across longitudinal HRCTs were scored on a 5-point Likert scale by blinded thoracic radiologists. Six multivariable logistic regression models were built to predict HRCT progression, using combinations of LUS parameters, PFTs, symptoms, and clinical characteristics. 81 patients completed the follow-up HRCT and per-protocol LUS was performed in 95% (77/81). Radiological progression was observed in 31% (25/81). An increase in B-lines was significantly associated with radiological progression (p=0.018), and a linear trend was confirmed (p=0.026). In multivariable analysis, both baseline B-lines (p=0.029) and the change in B-lines over time (p=0.012) significantly predicted progression (AUC=0.78, 95% CI: 0.64-0.92). When combining LUS and change in DLCO (AUC=0.82, 95% CI: 0.70-0.94), the model fit remained similar, and outperformed symptom scores (AUC=0.58, 95% CI 0.40-0.75, p=0.020) and PFTs (AUC=0.59, 0.44-0.74, p=0.022). LUS may be a useful, radiation-free tool to monitor and predict radiological progression of ILA in RA. These findings support further research into integrating LUS into longitudinal RA-ILD assessment, particularly as part of a multimodal approach.