Objective: To evaluate clinical associations of anti-PM/Scl antibodies in patients with SSc in a multicentre international cohort, with particular focus on unresolved issues, including scleroderma renal crisis (RC), malignancies, and functional outcome of interstitial lung disease (ILD). Methods: (1) Analysis of SSc patients from the EUSTAR database: 144 anti-PM/Scl+ without SSc-specific autoantibodies were compared with 7202 anti-PM/Scl−, and then to 155 anti-Pm/Scl+ with SSc-specific antibodies. (2) Case–control study: additional data were collected for 165 anti-PM/Scl+ SSc patients (85 from the EUSTAR registry) and compared with 257 anti-PM/Scl− SSc controls, matched for sex, cutaneous subset, disease duration and age at SSc onset. Results: Patients with isolated anti-PM/Scl+, as compared with anti-Pm/Scl−, had higher frequency of muscle involvement, ILD, calcinosis and cutaneous signs of DM, but similar frequency of SRC and malignancies (either synchronous with SSc onset or not). The presence of muscle involvement was associated with a more severe disease phenotype. Although very frequent, ILD had a better functional outcome in cases than in controls. In patients with both anti-PM/Scl and SSc-specific antibodies, a higher frequency of typical SSc features than in those with isolated anti-PM/Scl was observed. Conclusion: The analysis of the largest series of anti-PM/Scl+ SSc patients so far reported helps to delineate a specific clinical subset with muscle involvement, cutaneous DM, calcinosis and ILD characterized by a good functional outcome. SRC and malignancies do not seem to be part of this syndrome.

SSc primary heart involvement (SSc-pHI) is a significant cause of mortality. We aimed to characterize and identify predictors of subclinical SSc-pHI using cardiovascular MRI. A total of 83 SSc patients with no history of cardiovascular disease or pulmonary arterial hypertension and 44 healthy controls (HCs) underwent 3 Tesla contrast-enhanced cardiovascular MRI, including T1 mapping and quantitative stress perfusion. High-sensitivity troponin I and N-terminal pro-brain natriuretic peptide were also measured. Cardiovascular MRI revealed a lower myocardial perfusion reserve in the SSc patients compared with HCs {median (interquartile range (IQR)] 1.9 (1.6–2.4) vs 3 (2–3.6), P < 0.001}. Late gadolinium enhancement, indicating focal fibrosis, was observed in 17/83 patients but in none of the HCs, with significantly higher extracellular volume (ECV), suggestive of diffuse fibrosis, in SSc vs HC [mean (s.d.) 31 (4) vs 25 (2), P < 0.001]. Presence of late gadolinium enhancement and higher ECV was associated with skin score [odds ratio (OR) = 1.115, P = 0.048; R² = 0.353, P = 0.004], and ECV and myocardial perfusion reserve was associated with the presence of digital ulcers at multivariate analysis (R² = 0.353, P < 0.001; R² = 0.238, P = 0.011). High-sensitivity troponin I was significantly higher in patients with late gadolinium enhancement, and N-terminal pro-brain natriuretic peptide was associated with ECV (P < 0.05). Subclinical SSc-pHI is characterized by myocardial microvasculopathy, diffuse and focal myocardial fibrosis but preserved myocardial contractile function. This subclinical phenotype of SSc-pHI was associated with high-sensitivity troponin I, N-terminal pro-brain natriuretic peptide, SSc disease severity and complicated peripheral vasculopathy. These data provide information regarding the underlying pathophysiological processes and provide a basis for identifying individuals at risk of SSc-pHI.

Objective: There is still a great deal to learn about the influence of sex in systemic sclerosis (SSc). In this respect, national registries provide large and homogeneous patient cohorts for analytical studies. We therefore investigated a wide-ranging and well-characterized SSc series with the aim of identifying sex differences in disease expression, with a special focus on demographic, clinical, and serological characteristics.Methods: A multicenter SSc cohort of 2281 patients, including 247 men, was recruited in the Italian Systemic sclerosis PRogression INvestiGation (SPRING) registry. Demographic data, disease manifestations, serological profile, and internal organ involvement were compared.Results: The overall female/male ratio was 8.2:1. Female/male ratios for limited cutaneous SSc, diffuse cutaneous SSc, and SSc sine scleroderma subsets were 8.7:1, 4.9:1, and 10.7:1, respectively. A shorter time from onset of Raynaud phenomenon to SSc diagnosis, an increased prevalence of the diffuse cutaneous subset, renal crisis, and digital ulcers were found in males, whereas a significantly higher percentage of sicca syndrome, serum antinuclear antibodies, antiextractable nuclear antigens, anti-La/SSB, and anticentromere protein B was detected in the female group. Males exhibited lower left ventricular ejection fraction, as well as higher prevalence of conduction blocks, arrhythmias, ground glass, and honeycombing. Moreover, forced vital capacity and total lung capacity were medially lower in men than in women. Finally, males were more frequently treated with immunosuppressive drugs.Conclusion: Our study further supports the presence of several sex-related differences in patients with SSc. These differences were pronounced in the severity of cutaneous, peripheral vascular, and cardiopulmonary involvement for male patients, whereas an increased prevalence of sicca syndrome and a specific autoantibody profile characterized the female sex.

Skeletal muscle damage is a common clinical manifestation of systemic sclerosis (SSc). C-X-C chemokine ligand 10 (CXCL10) is involved in myopathy and cardiomyopathy development and is associated with a more severe SSc prognosis. Interestingly, the phosphodiesterase type 5 inhibitor (PDE5i) sildenafil reduces CXCL10 sera levels of patients with diabetic cardiomyopathy and in cardiomyocytes. Here, we analyzed the levels of CXCL10 in the sera of 116 SSc vs. 35 healthy subjects and explored differences in 17 SSc patients on stable treatment with sildenafil. CXCL10 sera levels were three-fold higher in SSc vs. healthy controls, independent of subset and antibody positivity. Sildenafil treatment was associated with lower CXCL10 sera levels. Serum CXCL10 strongly correlated with the clinical severity of muscle involvement and with creatine kinase (CK) serum concentration, suggesting a potential involvement in muscle damage in SSc. In vitro, sildenafil dose-dependently reduced CXCL10 release by activated myocytes and impaired cytokine-induced Signal transducer and activator of transcription 1 (STAT1), Nuclear factor-κB (NFκB) and c-Jun N-terminal kinase (JNK) phosphorylation. This was also seen in cardiomyocytes. Sildenafil-induced CXCL10 inhibition at the systemic and human muscle cell level supports the hypothesis that PDE5i could be a potential therapeutic therapy to prevent and treat muscle damage in SSc.