Interstitial lung disease in patients with systemic sclerosis: relationships between functional, radiological and ultrasound data

<bold>Background:</bold> Interstitial lung disease (ILD) is a common manifestation of systemic sclerosis (SS) associated with poor prognosis and low quality of life. The semiquantitative evaluation of radiological involvement by high-resolution computed tomography (HRCT) (Warrick score) provides information about the extension of pulmonary damage and is often used to monitor the disease progression. Integrating aspects related to lung images and function in the follow-up of ILD-SS patients could reduce the possibility of exposure with resource sparing. <bold>Objective:</bold> To explore the relationships between data related to pulmonary function tests (PFTs), HRCT, and thoracic ultrasound (US) in ILD-SS patients. <bold>Methods:</bold> Our prospective study enrolled 26 patients (23 females). We collected data about PFTs, with measures of forced vital capacity (FVC), total lung capacity (TLC) and the diffusing capacity of the lungs for carbon monoxide (DLCO). The Warrick score at HRCT and B-lines scores on the thoracic US were also collected. <bold>Results:</bold> The median age of patients was 58 years (range 26-79). Baseline values of FVC, TLC, DLCO, Warrick score and B-lines score were in median 111% (range 42-172), 98 % (range 48-144), 70 % (range 32-101), 8.5 (range 0-29), and 1.35 (range 0-4.6), respectively. Strong and inverse correlations were observed between the Warrick score and FVC (Spearman ρ-0.609; p<0.001), TLC (ρ -0.620; p<0.001), and DLCO (ρ -0.527; p=0.007). Moreover, a direct correlation was found between the Warrick and B-lines scores (ρ 0.792; p<0.001). <bold>Conclusion:</bold> We highlight the role of PFTs and thoracic US as monitoring methods to reduce radiation exposure and maximise resource management.