Safety and tolerability of pirfenidone in asbestosis: a prospective multicenter study.

BACKGROUND: Pirfenidone slows down disease progression in idiopathic pulmonary fibrosis (IPF). Recent studies suggest a treatment effect in progressive pulmonary fibrosis other than IPF. However, the safety and effectiveness of pirfenidone in asbestosis patients remain unclear. In this study, we aimed to investigate the safety, tolerability and efficacy of pirfenidone in asbestosis patients with a progressive phenotype. METHODS: This was a multicenter prospective study in asbestosis patients with progressive lung function decline. After a 12-week observational period, patients were treated with pirfenidone 801 mg three times a day. Symptoms and adverse events were evaluated weekly and patients completed online patient-reported outcomes measures. At baseline, start of therapy, 12 and 24 weeks, in hospital measurement of lung function and a 6 min walking test were performed. Additionally, patients performed daily home spirometry measurements. RESULTS: In total, 10 patients were included of whom 6 patients (66.7%) experienced any adverse events during the study period. Most frequently reported adverse events were fatigue, rash, anorexia and cough, which mostly occurred intermittently and were reported as not very bothersome. No significant changes in hospital pulmonary function (forced vital capacity (FVC), diffusion capacity of the lung for carbon monoxide (DLCO), 6 min walking test or patient-reported outcomes measures before and after start of pirfenidone were found. Home spirometry demonstrated a FVC decline in 12 weeks before start of pirfenidone, while FVC did not decline during the 24 week treatment phase, but this difference was not statistically significant. CONCLUSIONS: Treatment with pirfenidone in asbestosis has an acceptable safety and tolerability profile and home spirometry data suggest this antifibrotic treatment might attenuate FVC decline in progressive asbestosis. Trial registration MEC-2018-1392; EudraCT number: 2018-001781-41.

Smoothelin-B deficiency results in reduced arterial contractility, hypertension, and cardiac hypertrophy in mice.

BACKGROUND: Smoothelins are actin-binding proteins that are abundantly expressed in healthy visceral (smoothelin-A) and vascular (smoothelin-B) smooth muscle. Their expression is strongly associated with the contractile phenotype of smooth muscle cells. Analysis of mice lacking both smoothelins (Smtn-A/B(-/-) mice) previously revealed a critical role for smoothelin-A in intestinal smooth muscle contraction. Here, we report on the generation and cardiovascular phenotype of mice lacking only smoothelin-B (Smtn-B(-/-)). METHODS AND RESULTS: Myograph studies revealed that the contractile capacity of the saphenous and femoral arteries was strongly reduced in Smtn-B(-/-) mice, regardless of the contractile agonist used to trigger contraction. Arteries from Smtn-A/B(-/-) compound mutant mice exhibited a similar contractile deficit. Smtn-B(-/-) arteries had a normal architecture and expressed normal levels of other smooth muscle cell-specific genes, including smooth muscle myosin heavy chain, alpha-smooth muscle actin, and smooth muscle-calponin. Decreased contractility of Smtn-B(-/-) arteries was paradoxically accompanied by increased mean arterial pressure (20 mm Hg) and concomitant cardiac hypertrophy despite normal parasympathetic and sympathetic tone in Smtn-B(-/-) mice. Magnetic resonance imaging experiments revealed that cardiac function was not changed, whereas distension of the proximal aorta during the cardiac cycle was increased in Smtn-B(-/-) mice. However, isobaric pulse wave velocity and pulse pressure measurements indicated normal aortic distensibility. CONCLUSIONS: Collectively, our results identify smoothelins as key determinants of arterial smooth muscle contractility and cardiovascular performance. Studies on mutations in the Smtn gene or alterations in smoothelin levels in connection to hypertension in humans are warranted.