Lung Ultrasound for the Detection of Radiologic Progression of Interstitial Lung Abnormalities in Patients With Rheumatoid Arthritis.

OBJECTIVE

Interstitial lung disease (ILD) is an important extra-articular manifestation of rheumatoid arthritis (RA) associated with high mortality and morbidity. Lung ultrasonography (LUS) has recently emerged as a possible screening tool. We assessed the role of LUS in monitoring radiologic progression and the development of new interstitial lung abnormalities (ILAs).

METHODS

In this prospective pilot study, patients with RA underwent high-resolution computed tomography (HRCT), pulmonary function tests (PFTs), symptom assessment, and LUS at baseline and 12 to 18 months later. B-lines were quantified using a 72-zone protocol. Radiologic changes across longitudinal HRCTs were scored on a five-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.

RESULTS

Eighty-one patients completed the follow-up HRCT, and per-protocol LUS was performed in 95% (77/81). Radiologic progression was observed in 31% (25/81). An increase in B-lines was significantly associated with radiologic 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 (area under the curve [AUC] 0.78, 95% confidence interval [CI] 0.64-0.92). When combining LUS and change in diffusing capacity for carbon monoxide (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, 95% CI 0.44-0.74, P = 0.022).

CONCLUSION

LUS may be a useful, radiation-free tool to monitor and predict radiologic progression of ILAs in RA. These findings support further research into integrating LUS into longitudinal RA-ILD assessment, particularly as part of a multimodal approach.