Lung ultrasound and high-resolution computed tomography quantitative variations during nintedanib treatment for systemic sclerosis-associated interstitial lung disease

Objectives: Lung ultrasound (LUS) and high-resolution CT (HRCT) are commonly used for the evaluation of interstitial lung disease (ILD). Nintedanib (NIN) is an antifibrotic therapy approved for systemic sclerosis-associated ILD (SSc-ILD). We assessed LUS and quantitative HRCT changes in SSc-ILD patients treated with NIN during a 1 year follow-up, evaluating relationships between imaging variations and functional or quality-of-life outcomes.Methods: SSc-ILD patients who started NIN were enrolled and followed for 12 months. Pulmonary function tests and patient-reported outcome measures (PROMs) were assessed half-yearly and quarterly, respectively. LUS was performed quarterly evaluating the presence of B-lines (BL) and pleural line irregularities (PLI). HRCT was repeated after 1 year and quantitatively analysed with CALIPER software.Results: Ten patients (70% female, mean age 62 years) were enrolled. The mean total number of both BL and PLI was constantly decreased during NIN treatment, being significantly reduced after 12 months (from 175.1 [66.7] to 120.8 [70.3] for BL, P = 0.005; and from 50.6 [32.5] to 37.2 [22.4] for PLI, P = 0.05). Male gender, smoking habit and baseline forced vital capacity <70% predicted were associated with worse LUS outcomes. A greater reduction in both BL and PLI was observed in those who improved in PROMs, especially modified Medical Research Council dyspnoea scale (P = 0.016 and P = 0.04, respectively) and Saint George's Respiratory Questionnaire (P = 0.006 and P = 0.026, respectively). No significant changes in the CALIPER percentages of normal parenchyma or ILD elements were observed after 12 months of NIN, thus paralleling the stabilization obtained at pulmonary function tests.Conclusion: We present preliminary results on NIN effects on SSc-ILD as assessed by LUS, a useful method for frequently repeated monitoring, and CALIPER, a valid implementation whenever a HRCT is performed.