Background Systemic sclerosis is characterised by progressive cutaneous and organ fibrosis. Among all organs, a subclinical heart involvement is difficult to detect through conventional imaging. Design We evaluated whether speckle tracking-derived global longitudinal strain could help detect early subclinical systolic dysfunction in systemic sclerosis patients without overt clinical involvement. Methods A case-control, single-centre study on 52 systemic sclerosis patients and 52 age and gender-matched controls. Patients with structural heart disease, heart failure, atrial fibrillation and pulmonary hypertension were excluded. For every patient, standard echocardiographic and speckle tracking-derived variables for the systolic and diastolic function of the left ventricle and right ventricle were acquired. Results Traditional parameters of left and right systolic function did not differ between systemic sclerosis patients and controls (all P = ns). Left and right ventricular global longitudinal strain was significantly impaired in patients with systemic sclerosis when compared to controls (-19.2% vs. -21.1%; P = 0.009 and -18.2% vs. -22.3%; P = 0.012, respectively). Systemic sclerosis patients had a 2.5-fold increased risk of subclinical left ventricular systolic impairment (odds ratio 2.5, 95% confidence interval 1.1-5.5; P = 0.027) and a 3.3-fold increased risk of subclinical right ventricular systolic impairment when compared to controls (odds ratio 3.3, 95% confidence interval 1.4-7.7; P = 0.004). Alterations in the myocardial deformation pattern of systemic sclerosis patients were homogeneous in the right ventricle and eccentric in the left ventricle. Conclusions While traditional echocardiographic parameters are ineffective in detecting subclinical systolic impairment, reduced global longitudinal strain is common in patients with systemic sclerosis and significant for both ventricles. Global longitudinal strain could become a low-cost, non-invasive and reliable tool in order to detect early cardiac involvement in systemic sclerosis patients.

No abstract

BackgroundVascular injuriy is an early event in scleroderma (SSc). It precedes fibrosis and involves small vessels (1). The cellular changes in early lesions are loss of endothelial cells, proliferation of pericytes and vascular smooth muscle cells, and precence of immune cells in the perivascular space. We recently demonstrated that IgG isolated from sera of SSc scleroderma patients induced NOX4-derived reactive oxygen species (ROS) in smooth muscle cells (SMCs) through the activation of PDGFRα receptor (2). Modulation of ROS generation led to influence migration, proliferation and collagen production in SMCs. Mammalian target of rapamycin (mTOR) is a serine/threonine kinase that acts as a major activator of cell growth and proliferation. mTOR has also been shown to play a role in vascular SMCs proliferation and when dysregulated has been implicated in vascular remodeling (3).ObjectivesThe aim of this study was to investigate the role of mTOR as a downstream signaling of SSc IgG in SMCs activation.MethodsIgG were isolated from sera of SSc patients by affinity chromatography. SMCs from human pulmonary artery were purchased from Lonza. Total RNA was isolated, reverse-transcribed, and quantitative real-time PCR reactions were performed using SYBR-Green Master Mix. To analyzed protein expression, cells were lysed and subjected to western blot with specific antibodies. For immunocytochemistry, cells were fixed in PFA, permeabilized and labelled with specific antibodies to be evaluated through fluorescence microscopy. Migration was performed using the scratch test.ResultsSMCs were treated with various concentrations of rapamycin (1-10 nM), inhibitor of mTOR, or the same amount of vehicle (DMSO) for 48 hours, and then incubated with PDGF (15 ng/ml) or SSc IgG (200 μg/ml) for further 24 hours. Rapamycin was able to reverse the effects of PDGF and SSc IgG. Inhibition of mTOR led to a significant decrease in proliferation and migration rate (40%), and collagen expression (54%) in SMCs exposed to SSc IgG compared to untreated cells.ConclusionsOur data demonstrate that mTOR is a crucial downstream signaling of SSc IgG effects through PDGFRα pathway, and is involved in the modulation of migration, proliferation and collagen expression in SMCs. These findings support the recent observation that mTOR is largely involved in collagen regulation in SSc dermal fibroblasts (4), suggesting an important role of this serine/threonine kinase in the signaling pathways involved in the development of SSc.ReferencesGabrielli et al. N Engl J Med 2009;360:1989-2003.Amico et al. Ann Rheum Dis 2011;70(S3):491.Augusto et al. C J Cardiol 2014;30:482-484.Tamaki et al. J Dermatol Science 2014;74:251-259.Disclosure of InterestNone declared