Evaluation of non-invasive techniques for the diagnosis of pulmonary complications in systemic sclerosis and scleroderma-like overlap syndromes: role of lung ultrasound.

BACKGROUND AND AIM: Pulmonary arterial hypertension (PAH) and interstitial lung disease (ILD) are the leading cause of death in Systemic Sclerosis (SSc) and severely affect patients' quality of life. Early, accurate, and non-invasive diagnostic tools are essential for timely treatment. This study investigates the role of lung ultrasonography (LUS) as a screening method for detecting pulmonary involvement in SSc.

METHODS

A monocentric cross-sectional study was conducted on 72 patients diagnosed with SSc. Lung ultrasound was performed using a 1-5 MHz convex probe across 14 lung fields. B-lines were quantified using the Total Thoracic Ultrasound Score (TTUS). Echocardiographic data, pulmonary function tests, and visual score on high resolution computed tomography (HRCT) were also collected.

RESULTS

TTUS scores showed significant correlation with the presence of ILD and PAH (p = 0.001). TTUS positively correlated with pulmonary arterial pressure, Goh score, visual HRCT score, and inversely correlated with DLCO and 6-min walk test performance. LUS demonstrated good diagnostic performance: fewer than 6 B-lines ruled out PAH with 100% sensitivity (specificity 38.8%; AUC 0.77 [0.64-0.90]). The presence of fewer than 5 B-lines excluded ILD with 100% sensitivity. Conversely, more than 15 B-lines indicated ILD (sensitivity 88.9%; specificity 82.5%; accuracy 91.4%; AUC 0.88 [0.79-0.97]).

CONCLUSIONS

LUS is a reliable, non-invasive tool for detecting pulmonary involvement in SSc: its high negative predictive value allows it to be adopted as a first-line imaging to rule out PAH and ILD.