Improvement of vascular endothelial function using the oral endothelin receptor antagonist bosentan in patients with systemic sclerosis

Endothelial Function in Pulmonary Arterial Hypertension: From Bench to Bedside

Pulmonary arterial hypertension is a complex pathology whose etiology is still not completely well clarified. The pathogenesis of pulmonary arterial hypertension involves different molecular mechanisms, with endothelial dysfunction playing a central role in disease progression. Both individual genetic predispositions and environmental factors seem to contribute to its onset. To further understand the complex relationship between endothelial and pulmonary hypertension and try to contribute to the development of future therapies, we report a comprehensive and updated review on endothelial function in pulmonary arterial hypertension.

Molecular Mechanisms and Therapeutic Implications of Endothelial Dysfunction in Patients with Heart Failure

Heart failure is a complex medical syndrome that is attributed to a number of risk factors; nevertheless, its clinical presentation is quite similar among the different etiologies. Heart failure displays a rapidly increasing prevalence due to the aging of the population and the success of medical treatment and devices. The pathophysiology of heart failure comprises several mechanisms, such as activation of neurohormonal systems, oxidative stress, dysfunctional calcium handling, impaired energy utilization, mitochondrial dysfunction, and inflammation, which are also implicated in the development of endothelial dysfunction. Heart failure with reduced ejection fraction is usually the result of myocardial loss, which progressively ends in myocardial remodeling. On the other hand, heart failure with preserved ejection fraction is common in patients with comorbidities such as diabetes mellitus, obesity, and hypertension, which trigger the creation of a micro-environment of chronic, ongoing inflammation. Interestingly, endothelial dysfunction of both peripheral vessels and coronary epicardial vessels and microcirculation is a common characteristic of both categories of heart failure and has been associated with worse cardiovascular outcomes. Indeed, exercise training and several heart failure drug categories display favorable effects against endothelial dysfunction apart from their established direct myocardial benefit.

Factors Behind the Higher COVID-19 Risk in Diabetes: A Critical Review

Diabetes mellitus (DM) and coronavirus disease 2019 (COVID-19) are public health issues worldwide, and their comorbidities trigger the progress to severe disease and even death in such patients. Globally, DM has affected an estimated 9.3% adults, and as of April 18, 2021, the World Health Organization (WHO) has confirmed 141,727,940 COVID-19 confirmed cases. The virus is spread via droplets, aerosols, and direct touch with others. Numerous predictive factors have been linked to COVID-19 severity, including impaired immune response and increased inflammatory response, among others. Angiotensin receptor blockers and angiotensin converting enzyme 2 have also been identified as playing a boosting role in both susceptibility and severity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Specifically, in DM patients, both their control and management during this pandemic is herculean as the restriction periods have markedly hampered the maintenance of means to control glycemia, hypertension, and neuroendocrine and kidney diseases. In addition, as a result of the underlyin cardio-metabolic and immunological disorders, DM patients are at a higher risk of developing the severe form of COVID-19 despite other comorbidities, such as hypertension, also potentially boosting the development of higher COVID-19 severity. However, even in non-DM patients, SARS-CoV-2 may also cause transient hyperglycemia through induction of insulin resistance and/or pancreatic β-cell injury. Therefore, a strict glucose monitoring of DM patients with COVID-19 is mandatory to prevent life-threatening complications.

Endothelin receptor antagonists for pulmonary arterial hypertension

BACKGROUND

Pulmonary arterial hypertension is a devastating disease that leads to right heart failure and premature death. Endothelin receptor antagonists have shown efficacy in the treatment of pulmonary arterial hypertension.

OBJECTIVES

To evaluate the efficacy of endothelin receptor antagonists (ERAs) in pulmonary arterial hypertension.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and the reference sections of retrieved articles. The searches are current as of 4 November 2020.

SELECTION CRITERIA

We included randomised trials and quasi-randomised trials involving participants with pulmonary arterial hypertension.

DATA COLLECTION AND ANALYSIS

Two of five review authors selected studies, extracted data and assessed study quality according to established criteria. We used standard methods expected by Cochrane. The primary outcomes were exercise capacity (six-minute walk distance, 6MWD), World Health Organization (WHO) or New York Heart Association (NYHA) functional class, Borg dyspnoea scores and dyspnoea-fatigue ratings, and mortality.

MAIN RESULTS

We included 17 randomised controlled trials involving a total of 3322 participants. Most trials were of relatively short duration (12 weeks to six months). Sixteen trials were placebo-controlled, and of these nine investigated a non-selective ERA and seven a selective ERA.   We evaluated two comparisons in the review: ERA versus placebo and ERA versus phosphodiesterase type 5 (PDE5) inhibitor. The abstract focuses on the placebo-controlled trials only and presents the pooled results of selective and non-selective ERAs. After treatment, participants receiving ERAs could probably walk on average 25.06 m (95% confidence interval (CI) 17.13 to 32.99 m; 2739 participants; 14 studies; I² = 34%, moderate-certainty evidence) further than those receiving placebo in a 6MWD. Endothelin receptor antagonists probably improved more participants' WHO functional class (odds ratio (OR) 1.41, 95% CI 1.16 to 1.70; participants = 3060; studies = 15; I² = 5%, moderate-certainty evidence) and probably lowered the odds of functional class deterioration (OR 0.43, 95% CI 0.26 to 0.72; participants = 2347; studies = 13; I² = 40%, moderate-certainty evidence) compared with placebo. There may be a reduction in mortality with ERAs (OR 0.78, 95% CI 0.58, 1.07; 2889 participants; 12 studies; I² = 0%, low-certainty evidence), and pooled data suggest that ERAs probably improve cardiopulmonary haemodynamics and may reduce Borg dyspnoea score in symptomatic patients. Hepatic toxicity was not common, but may be increased by ERA treatment from 37 to 67 (95% CI 34 to 130) per 1000 over 25 weeks of treatment (OR 1.88, 95% CI 0.91 to 3.90; moderate-certainty evidence). Although ERAs were well tolerated in this population, several cases of irreversible liver failure caused by sitaxsentan have been reported, which led the licence holder for sitaxsentan to withdraw the product from all markets worldwide.  As planned, we performed subgroup analyses comparing selective and non-selective ERAs, and with the exception of mean pulmonary artery pressure, did not detect any clear subgroup differences for any outcome.

AUTHORS' CONCLUSIONS

For people with pulmonary arterial hypertension with WHO functional class II and III, endothelin receptor antagonists probably increase exercise capacity, improve WHO functional class, prevent WHO functional class deterioration, result in favourable changes in cardiopulmonary haemodynamic variables compared with placebo. However, they are less effective in reducing dyspnoea and mortality. The efficacy data were strongest in those with idiopathic pulmonary hypertension. The irreversible liver failure caused by sitaxsentan and its withdrawal from global markets emphasise the importance of hepatic monitoring in people treated with ERAs. The question of the effects of ERAs on pulmonary arterial hypertension has now likely been answered.. The combined use of ERAs and phosphodiesterase inhibitors may provide more benefit in pulmonary arterial hypertension; however, this needs to be confirmed in future studies.

Exploring molecular pathology of chronic kidney disease in systemic sclerosis by analysis of urinary and serum proteins

Objective.

Renal involvement is common in systemic sclerosis (scleroderma; SSc) and includes chronic kidney disease (CKD). We have performed analysis of urinary proteins to gain insight into local molecular pathology of CKD in SSc and identify candidate markers for use in clinical trials.

Methods.

To evaluate urinary proteins that might specifically reflect SSc-related CKD, patients were recruited with confirmed SSc and stratified for the presence or absence of CKD. Controls included patients with CKD and no SSc, in addition to healthy volunteers. Candidate markers were measured in serum and urine by multiplex immunoassay testing for IL6, IL18, TNF-α, monocyte chemoattractant protein 1 (MCP1), monocyte chemoattractant protein 3 (MCP3), VEGF and the soluble adhesion molecules vascular cell adhesion molecule 1 (VCAM-1) and intercellular adhesion molecule 1 (ICAM-1).

Results.

One hundred and two subjects were examined, including patients with SSc with no evidence of CKD (n = 40), SSc with CKD (n = 39), non-SSc CKD (n = 11) and healthy volunteers (n = 12). Urinary levels of IL6, MCP1, TNF-α, MCP3, IL18 and ICAM-1 were elevated in SSc patients compared with healthy controls. The most significant differences were for MCP1 and ICAM-1 (both P < 0.0001), and these analytes also showed the most significant differences between groups overall (P = 0.003 for MCP1 and P < 0.0001 for ICAM-1). These markers showed a trend (MCP1, P = 0.0868) or a significant difference (ICAM-1, P = 0.0134) between SSc–CKD and SSc with normal renal function.

Conclusion.

Urinary levels of candidate molecular markers appear to reflect SSc–CKD more than serum markers. MCP1 and ICAM-1 are promising molecular markers for SSc–CKD and might be potential biomarkers of SSc renal involvement. This might be explored in future prospective analyses.

Hypertension, Thrombosis, Kidney Failure, and Diabetes: Is COVID-19 an Endothelial Disease? A Comprehensive Evaluation of Clinical and Basic Evidence

The symptoms most commonly reported by patients affected by coronavirus disease (COVID-19) include cough, fever, and shortness of breath. However, other major events usually observed in COVID-19 patients (e.g., high blood pressure, arterial and venous thromboembolism, kidney disease, neurologic disorders, and diabetes mellitus) indicate that the virus is targeting the endothelium, one of the largest organs in the human body. Herein, we report a systematic and comprehensive evaluation of both clinical and preclinical evidence supporting the hypothesis that the endothelium is a key target organ in COVID-19, providing a mechanistic rationale behind its systemic manifestations.

Endocan Levels and Endothelial Dysfunction in Patients With Sarcoidosis

A systemic inflammatory reaction is a common feature of both sarcoidosis and atherosclerosis. Endothelial-cell specific molecule 1 (endocan) is a marker of vascular pathology which also shows a correlation with inflammation, endothelial dysfunction, and atherosclerosis. The objective of this study was to evaluate the vascular involvement in sarcoidosis using serum endocan levels and brachial artery flow–mediated dilation (FMD), a marker of endothelial dysfunction. We included 53 patients with sarcoidosis without conventional cardiovascular risk factors and 40 healthy controls. Endothelial function was assessed using FMD. Endocan concentrations were measured using a commercially available enzyme-linked immunoassay. Patients with sarcoidosis had significantly higher endocan levels (306 [68] ng/mL vs 269 [73] ng/mL; P = .039) and lower FMD (2.7% [2.3%-3.2%] vs 8% [5%-13%]; P < .001) compared with the healthy group. A negative correlation was found between endocan levels and FMD in the sarcoidosis group ( r = −.325, P < .007). We conclude that sarcoidosis is associated with high levels of endocan and lower FMD values, which may indicate endothelial dysfunction and an early stage of atherosclerosis.

Increased serum levels of adhesion molecules ICAM-1 and VCAM-1 in systemic sclerosis are not specific for pulmonary manifestations

Studies suggest elevated serum intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) levels may be markers of pulmonary arterial hypertension in systemic sclerosis (SSc-PAH). We sought to evaluate whether ICAM-1 and VCAM-1 levels are useful screening biomarkers for incident SSc-PAH. In this cross-sectional study, four groups were selected from the Australian Scleroderma Cohort Study: group 1 (n = 15) had definite PAH; group 2 (n = 19) had interstitial lung disease (ILD); group 3 (n = 30) were SSc-controls; and group 4 (n = 34) were healthy controls. Serum ICAM-1 and VCAM-1 levels were measured using the Millipore Milliplex MAP Human 2-Plex Panel. There were no differences in ICAM-1 levels in the PAH versus ILD group (263.0 ± 85.4 vs 380.4 ± 168.3 ng/mL, p = 0.136), SSc-controls (263.0 ± 85.4 vs 253.1 ± 98.0 ng/mL, p = 1.00), or healthy controls (263.0 ± 85.4 vs 201.8 ± 57.2 ng/mL, p = 0.093). Similarly, there were no differences in VCAM-1 level in PAH versus ILD groups (1476.2 ± 434.9 vs 1424.8 ± 527.6 ng/mL, p = 1.00) and SSc-controls (1476.2 ± 434.9 vs 1409.5 ± 341.1 ng/mL, p = 1.00). SSc subjects had significantly higher levels of ICAM-1 (297.4 ± 134.0 vs 201.8 ± 57.2 ng/mL, p < 0.0001) and VCAM-1 compared to healthy controls (1432.7 ± 427.4 vs 1125.6 ± 273.4 ng/mL, p < 0.0001). Neither ICAM-1 nor VCAM-1 is a specific screening biomarker of SSc-PAH. Instead, increased levels of these adhesion molecules in SSc, irrespective of pulmonary complications, suggest that they may play a role in SSc pathogenesis.

COPD as an endothelial disorder: endothelial injury linking lesions in the lungs and other organs? (2017 Grover Conference Series)

Chronic obstructive pulmonary disease (COPD) is characterized by chronic expiratory airflow obstruction that is not fully reversible. COPD patients develop varying degrees of emphysema, small and large airway disease, and various co-morbidities. It has not been clear whether these co-morbidities share common underlying pathogenic processes with the pulmonary lesions. Early research into the pathogenesis of COPD focused on the contributions of injury to the extracellular matrix and pulmonary epithelial cells. More recently, cigarette smoke-induced endothelial dysfunction/injury have been linked to the pulmonary lesions in COPD (especially emphysema) and systemic co-morbidities including atherosclerosis, pulmonary hypertension, and chronic renal injury. Herein, we review the evidence linking endothelial injury to COPD, and the pathways underlying endothelial injury and the "vascular COPD phenotype" including: (1) direct toxic effects of cigarette smoke on endothelial cells; (2) generation of auto-antibodies directed against endothelial cells; (3) vascular inflammation; (4) increased oxidative stress levels in vessels inducing increases in lipid peroxidation and increased activation of the receptor for advanced glycation end-products (RAGE); (5) reduced activation of the anti-oxidant pathways in endothelial cells; (6) increased endothelial cell release of mediators with vasoconstrictor, pro-inflammatory, and remodeling activities (endothelin-1) and reduced endothelial cell expression of mediators that promote vasodilation and homeostasis of endothelial cells (nitric oxide synthase and prostacyclin); and (7) increased endoplasmic reticular stress and the unfolded protein response in endothelial cells. We also review the literature on studies of drugs that inhibit RAGE signaling in other diseases (angiotensin-converting enzyme inhibitors and angiotensin receptor blockers), or vasodilators developed for idiopathic pulmonary arterial hypertension that have been tested on cell culture systems, animal models of COPD, and/or smokers and COPD patients.

Points to consider for skin ulcers in systemic sclerosis

This article discusses points to consider when undertaking a clinical trial to test therapy for skin ulcers in SSc. A validated definition of skin ulcers should be used if available. Defining a uniform SSc patient population, including consideration of disease duration, history of digital ulcers and capillaroscopic patterns, is important. Excluding confounding factors such as infection, calcinosis and trauma should be strongly considered, or at least accounted for, in defining patients. Outcome measures such as time to healing, prevention of new ulcers, function, pain and objective measures such as US, laser Doppler and thermography can be considered as outcome measures, although their validation has not yet been achieved and efforts may be needed to validate them before use. Likewise, biomarkers should be considered or consideration should be given to storing serum, plasma or cells for possible future analysis. A pre-planned analysis is important and should include consideration of missing data.

Efficacy of bosentan in patients with refractory thromboangiitis obliterans (Buerger disease): A case series and review of the literature

The cornerstone of therapy in thromboangiitis obliterans (TAO) is complete abstinence from tobacco. In addition to discontinuation of cigarette smoking, very few pharmacological and surgical options of controversial efficacy are available to date. New therapeutic options with greater efficacy are clearly needed to properly manage these patients.In this preliminary study, we assessed the effectiveness and safety of bosentan in a case series of 8 adults with TAO and severe ischemic ulceronecrotic lesions who were treated with bosentan after inadequate response to platelet inhibitors, vasodilators, and intravenous alprostadil. Additionally, we reviewed 18 well-documented patients with refractory TAO treated with bosentan, which was previously reported (PubMed 1965-2015). These 26 patients formed the basis of our present analysis. All were current smokers.The median duration of bosentan treatment (SD) was 4.5 ± 4 months (range 3-16). Eleven patients (42%) were unable to completely abstain from smoking during their follow-up. With bosentan treatment, no new ischemic lesions were observed in the target extremities. A complete therapeutic response was achieved in 80% of patients, whereas a partial response was observed in 12%. Two patients (8%) ultimately required amputation despite treatment.After discontinuation of bosentan, patients were followed for a median of 20 ± 14 months (range 3-60). Two patients whose trophic lesions had healed relapsed.When comparing patients who gave up smoking with those who were unable to completely abstain from smoking during follow-up, no significant differences were found in efficacy outcomes. Four patients (15%) developed adverse events, requiring bosentan discontinuation in 1 case.These preliminary data suggest that bosentan may be considered a therapeutic option for treatment of cases of severe TAO refractory to conventional treatment, and merit further evaluation in larger controlled, randomized clinical studies.

Possible vasculoprotective role of linagliptin against sodium arsenite-induced vascular endothelial dysfunction

Vascular endothelial dysfunction (VED) interrupts the integrity and function of endothelial lining through enhanced markers of oxidative stress and decrease endothelial nitric oxide synthase (eNOS) expression. The main aim of the present study has been designed to investigate the possible vasculoprotective role of linagliptin against sodium arsenite-induced VED. Sodium arsenite (1.5 mg/kg, i.p., 2 weeks) abrogated the acetylcholine-induced, endothelium-dependent vasorelaxation by depicting the decrease in serum nitrite/nitrate concentration, reduced glutathione level, and simultaneously enhance the thiobarbituric acid reactive substances (TBARS) level, superoxide level, and tumor necrosis factor-alpha. These elevated markers interrupt the integrity of endothelial lining of thoracic aorta which was assessed histologically. The study elicits dose dependent effect of linagliptin (1.5 mg/kg, i.p. and 3 mg/kg, i.p.) or atorvastatin (30 mg/kg, p.o.) treatment, improved the endothelium-dependent independent relaxation, improve the integrity of endothelium lining which was assessed histologically by enhancing the serum nitrite/nitrate level, reduced glutathione level and simultaneously decreasing the TBARS level, superoxide anion level and tumor necrosis factor-alpha (TNF-α) level. L-NAME (25 mg/kg, i.p.), eNOS inhibitor, abrogated the ameliorative potential of linagliptin. However, the ameliorative potential of linagliptin has been enhanced by l-arginine (200 mg/kg, i.p.) which elicits that ameliorative potential of linagliptin was through eNOS signaling cascade and it may be concluded that linagliptin 3 mg/kg, i.p. has more significantly activated the eNOS and decreased the oxidative markers than linagliptin 1.5 mg/kg, i.p. and prevented sodium arsenite-induced VED.

Effects of bosentan on peripheral endothelial function in patients with pulmonary arterial hypertension or chronic thromboembolic pulmonary hypertension

Endothelin receptor antagonists (ERAs) have been shown to improve the prognosis of patients with pulmonary arterial hypertension (PAH). However, the effect of the oral dual ERA bosentan on peripheral endothelial dysfunction (PED), as assessed by flow-mediated vasodilation (FMD), in patients with pulmonary hypertension is not well characterized. We investigated the effect of bosentan on PED in patients with PAH or inoperable chronic thromboembolic pulmonary hypertension (CTEPH). A total of 18 patients with PAH and 8 with CTEPH were treated with bosentan. All patients underwent FMD assessment before and after 3 months of bosentan treatment. Whereas FMD increased from 6.01% ± 2.42% at baseline to 8.07% ± 3.18% after 3 months (P < 0.0001) in patients with PAH, those with CTEPH showed no change in FMD after bosentan therapy. In addition, FMD at baseline showed no correlation with pulmonary vascular resistance (r = 0.09) or plasma brain natriuretic peptide levels (r = -0.23) in patients with PAH. Bosentan treatment ameliorated PED in patients with PAH but not in those with inoperable CTEPH. In addition, FMD did not correlate with PAH severity.

Evaluation of the effect of ambrisentan on digital microvascular flow in patients with systemic sclerosis using laser Doppler perfusion imaging: a 12-week randomized double-blind placebo controlled trial

INTRODUCTION

In patients with systemic sclerosis (SSc), digital ischemia results from an occlusive microvasculopathy that may not respond adequately to conventional vasodilators. Endothelin receptor antagonists can potentially modify the fibroproliferative vascular remodeling in SSc, and hence their use may be justified in the management of digital ischemia. The objective of this clinical trial was to evaluate the effect of ambrisentan, a selective endothelin type A receptor antagonist, on microvascular blood flow in patients with limited systemic sclerosis (SSc) using laser Doppler perfusion imaging (LDPI).

METHODS

In this randomized, double-blind, placebo controlled study we enrolled 20 patients with limited SSc. Fifteen patients received ambrisentan 5 mg daily for one month and then 10 mg daily for two months, and five received a placebo. There were three visits: weeks 0 (baseline), one and 12. Three patient-oriented questionnaires were completed at each visit: Scleroderma-Health Assessment Questionnaire (S-HAQ), Raynaud Condition Score (RCS), and Pain-Visual Analog Scale (P-VAS). At each visit, LDPI was used to obtain three blood flow readings involving regions of interest in second to fifth fingers of the non-dominant hand at room temperature (25°C) and after cooling (10°C) for two minutes.

RESULTS

There were 16 females (80%); mean age was 50 years. None of the differences in blood flow (as measured by LDPI) were significant both at baseline and after cooling. However, patients in the ambrisentan group showed significant improvement in the patient-oriented outcomes: RCS (P=0.001) and S-HAQ score (P=0.005).

CONCLUSIONS

This pilot study did not show evidence of significant increase in digital blood flow over time; however, there was an improvement in RCS and S-HAQ score. We conclude that continuous use of ambrisentan for three months does not seem to significantly improve digital blood flow in SSc patients.

TRIAL REGISTRATION

Clinicaltrials.gov NCT01072669. Registered 19 February 2010.

Cardiovascular disease in systemic sclerosis

Cardiovascular (CV) system involvement is a frequent complication of autoimmune diseases such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). It still remains unclear if a premature atherosclerosis (ATS) occurs even in systemic sclerosis (SSc). Although microvascular disease is a hallmark of SSc, in the last few years a number of studies highlighted a higher prevalence of macrovascular disease in SSc patients in comparison to healthy individuals and these data have been correlated with a poorer prognosis. The mechanisms promoting ATS in SSc are not fully understood, but it is believed to be secondary to multi-system organ inflammation, endothelial wall damage and vasculopathy. Both traditional risk factors and endothelial dysfunction have been proposed to participate to the onset and progression of ATS in such patients. In particular, endothelial cell injury induced by anti-endothelial antibodies, ischemia/reperfusion damage, immune-mediated cytotoxicity represent the main causes of vascular injury together with an impaired vascular repair mechanism that determine a defective vasculogenesis. Aim of this review is to analyse both causes and clinical manifestations of macrovascular involvement and ATS in SSc.

Systemic sclerosis induces pronounced peripheral vascular dysfunction characterized by blunted peripheral vasoreactivity and endothelial dysfunction

Systemic sclerosis (SSc) vasculopathy can result in a digital ulcer (DU) and/or pulmonary arterial hypertension (PAH). We hypothesized that bedside brachial artery flow-mediated dilation (FMD) testing with duplex ultrasound could be used in SSc patients to identify features of patients at risk for DU or PAH. Thirty-eight SSc patients were compared to 52 age-matched healthy controls from the VAMC Utah Vascular Research Laboratory. Peripheral hemodynamics, arterial structure, and endothelial function were assessed by duplex ultrasound. A blood pressure cuff was applied to the forearm and 5-min ischemia was induced. Post-occlusion, brachial artery vascular reactivity (peak hyperemia/area under the curve [AUC]), shear rate, and endothelial function (FMD) were measured. SSc patients had smaller brachial artery diameters (p < 0.001) and less reactive hyperemia (p < 0.001), peak shear rate (p = 0.03), and brachial artery FMD (p < 0.001) compared with healthy controls. Brachial artery FMD was lower (p < 0.05) in SSc patients with DU. Tertile analysis suggested the 2 lower FMD tertiles (<5.40 %) had a 40-50 % chance of presenting with DU while the SSc patients with highest FMD tertile (>5.40 %) had less than 15 % chance of DU. All brachial artery FMD measurements were similar between SSc patients with and without PAH (all p > 0.05). Compared to healthy controls, SSc patients had significantly smaller brachial artery diameter and blunted peripheral vascular reactivity and endothelial function. SSc patients with DU have even greater impairments in endothelial function compared to those without DU. FMD testing has clinical utility to identify SSc patients at risk for DU.

Novel photoplethysmography cardiovascular assessments in patients with Raynaud's phenomenon and systemic sclerosis: a pilot study

OBJECTIVE

Multisite photoplethysmography (PPG) cardiovascular assessments can evaluate endothelial, peripheral autonomic and arterial dysfunction. The aim of this pilot study was to investigate the potential clinical utility of the technology in assessing patients with SSc and primary RP (PRP).

METHODS

Multisite PPG pulse measurements, a reference ankle brachial pressure index (ABPI) and a full clinical assessment were undertaken for three subject groups: SSc, PRP and controls. Endothelial and autonomic function and arterial disease measures were obtained using pulse wave analysis.

RESULTS

Nineteen SSc, 19 PRP and 23 control subjects were assessed and compared. Endothelial function was significantly impaired in SSc (P < 0.02), but with no difference between controls and PRP. Receiver operating characteristic-based classification accuracy was 81% (sensitivity 90%, specificity 74%) for separating SSc from controls and 82% (sensitivity 84%, specificity 79%) for separating SSc from PRP. SSc patients with digital ulcers had significantly lower endothelial function compared with those without ulcers (P < 0.05). Autonomic dysfunction was suggested in both SSc and PRP and was most exaggerated in patients with diffuse SSc. All groups had overall normal ABPI and arterial stiffness timing measures. Bilateral timing differences at the toes, which represents peripheral occlusive arterial disease, did show increased asymmetry in SSc (P < 0.02).

CONCLUSION

Multisite PPG pulse technology showed potential diagnostic ability. By using measures of endothelial function, it differentiated SSc from control and PRP subjects with an accuracy of at least 81%. Objective pulse-derived measures of autonomic function and arterial disease in SSc have also been reported in this pilot study.

Retrospective analysis of the frequency of centrofacial telangiectasia in systemic sclerosis patients treated with bosentan or ilomedin

Background

Bosentan is a dual endothelin receptor antagonist initially introduced for the treatment of pulmonary arterial hypertension and recently approved for the treatment of digital ulcers in patients with systemic sclerosis (SSc). Our clinical observations indicate that bosentan therapy may be associated with an increased frequency of centrofacial telangiectasia (TAE). Here, we sought to analyze the frequency of TAE in patients with SSc who were treated with either bosentan or the prostacyclin analog iloprost.

Methods

We conducted a retrospective analysis in 27 patients with SSc undergoing therapy with either bosentan (n = 11) or iloprost (n = 16). Standardized photodocumentations of all patients (n = 27) were obtained at a time point ten months after therapy initiation and analyzed. A subgroup of patients (bosentan: n = 6; iloprost: n = 6) was additionally photodocumented prior to therapy initiation, enabling an intraindividual analysis over the course of therapy.

Results

After ten months of therapy patients with SSc receiving bosentan showed a significantly (P = 0.0028) higher frequency of centrofacial TAE (41.6 ± 27.8) as compared to patients with SSc receiving iloprost (14.3 ± 13.1). Detailed subgroup analysis revealed that the frequency of TAE in the bosentan group (n = 6 patients) increased markedly and significantly (P = 0.027) by 44.4 after ten months of therapy (TAE at therapy initiation: 10.8 ± 5.1; TAE after ten months of therapy: 55.2 ± 29.8), whereas an only minor increase of 1.9 was observed in the iloprost group (n = 6 patients; TAE at therapy initiation: 18.3 ± 14.5; TAE after ten months of therapy: 20.2 ± 15.5), yet without reaching statistical significance (P = 0.420).

Conclusions

The use of bosentan may be associated with an increased frequency of TAE in patients with SSc. Patients should be informed about this potential adverse effect prior to therapy. Treatment options may include camouflage or laser therapy.

A reduction of 3 g/day from a usual 9 g/day salt diet improves endothelial function and decreases endothelin-1 in a randomised cross_over study in normotensive overweight and obese subjects

BACKGROUND AND AIM

It is unclear if a modest reduction in dietary salt intake has beneficial effects on vascular function. The aim was to compare the effects of 9 g salt/day with 6 g salt/day intake on measures of vascular function and explore mechanisms of effect in overweight and obese adults.

METHODS

Twenty-five overweight/obese subjects (BMI 27-40 kg/m(2)) completed a randomised cross-over study of 6 weeks each on a reduced salt (RS) (6 g/day) and usual salt diet (US) (9 g/day). Flow-mediated-dilatation (FMD), 24 h blood pressure (BP), augmentation index (AIx), pulse wave velocity (PWV), plasma and urinary nitrate/nitrite, asymmetric dimethylarginine (ADMA), renin, aldosterone and endothelin-1 and vascular adhesion molecules were measured after 2 days and 6 weeks. Adherence to the diets was determined from two 24 h urine collections.

RESULTS

Urinary sodium excretion was 155 ± 58 mmol/24 h US vs 113 ± 45 mmol/24 h RS (p = 0.002). Following the RS diet there was a significant improvement in FMD from 3.5 ± 2.8% to 5.6 ± 2.8% (P < 0.001) and decrease in serum endothelin-1 from 1.45 ± 0.38 pg/ml to 1.25 ± 0.39 pg/ml (P < 0.05). Endothelium-independent vasodilatation was also significantly different between treatments (P < 0.05). AIx, PWV, serum ADMA and plasma and urinary nitrate/nitrite concentrations were not different between treatments. Change in FMD was related to the urinary sodium: creatinine ratio (r = -0.47, P < 0.05) and was independent of blood pressure. Aldosterone and renin were unchanged.

CONCLUSIONS

A small reduction in dietary salt intake of 3 g/day improves endothelial function in normotensive overweight and obese subjects. This response may be mediated by serum endothelin-1. This small reduction in salt had no effect on aldosterone and renin concentrations. This trial was registered with the Australian and New Zealand Clinical Trials Registry Unique Identifier: ACTRN12609000321246 http://www.anzctr.org.au/ACTRN12609000321246.aspx.

Renal involvement in autoimmune connective tissue diseases

Connective tissue diseases (CTDs) are a heterogeneous group of disorders that share certain clinical presentations and a disturbed immunoregulation, leading to autoantibody production. Subclinical or overt renal manifestations are frequently observed and complicate the clinical course of CTDs. Alterations of kidney function in Sjögren syndrome, systemic scleroderma (SSc), auto-immune myopathies (dermatomyositis and polymyositis), systemic lupus erythematosus (SLE), antiphospholipid syndrome nephropathy (APSN) as well as rheumatoid arthritis (RA) are frequently present and physicians should be aware of that.In SLE, renal prognosis significantly improved based on specific classification and treatment strategies adjusted to kidney biopsy findings. Patients with scleroderma renal crisis (SRC), which is usually characterized by severe hypertension, progressive decline of renal function and thrombotic microangiopathy, show a significant benefit of early angiotensin-converting-enzyme (ACE) inhibitor use in particular and strict blood pressure control in general. Treatment of the underlying autoimmune disorder or discontinuation of specific therapeutic agents improves kidney function in most patients with Sjögren syndrome, auto-immune myopathies, APSN and RA.In this review we focus on impairment of renal function in relation to underlying disease or adverse drug effects and implications on treatment decisions.

Clinical correlation of brachial artery flow-mediated dilation in patients with systemic sclerosis

OBJECTIVE: To investigate the clinical significance of flow-mediated dilation (FMD) in systemic sclerosis (SSc). METHODS: Thirty-three SSc patients and 12 healthy controls were studied. Ultrasound assessment of the brachial artery FMD was performed on all subjects. The results were expressed as the percentage of increase in brachial artery diameter following hyperemia. RESULTS: Limited cutaneous SSc (lcSSc) patients had significantly lower FMD values than healthy controls (5.3 ± 2.7 versus 7.7 ± 2.0 %, p < 0.05), while the values in diffuse cutaneous SSc (dcSSc) patients (6.7 ± 4.0 %) were comparable to those in lcSSc patients and healthy controls. Although FMD values did not correlate with any clinical features in dcSSc patients, there was an inverse correlation between FMD values and disease duration in lcSSc patients (r = -0.64, p < 0.05). Furthermore, lcSSc patients with decreased FMD values showed significantly higher prevalence of digital ulcers and elevated right ventricular systolic pressure than those with normal values (for each; 75 versus 10 %, p < 0.05). CONCLUSION: The FMD values represent the severity of vascular damages, which progress along with disease duration and lead to digital ulcers and pulmonary arterial hypertension, in lcSSc patients.

Asymmetric dimethylarginine as a surrogate marker of endothelial dysfunction and cardiovascular risk in patients with systemic rheumatic diseases

The last few decades have witnessed an increased life expectancy of patients suffering with systemic rheumatic diseases, mainly due to improved management, advanced therapies and preventative measures. However, autoimmune disorders are associated with significantly enhanced cardiovascular morbidity and mortality not fully explained by traditional cardiovascular disease (CVD) risk factors. It has been suggested that interactions between high-grade systemic inflammation and the vasculature lead to endothelial dysfunction and atherosclerosis, which may account for the excess risk for CVD events in this population. Diminished nitric oxide synthesis—due to down regulation of endothelial nitric oxide synthase—appears to play a prominent role in the imbalance between vasoactive factors, the consequent impairment of the endothelial hemostasis and the early development of atherosclerosis. Asymmetric dimethylarginine (ADMA) is one of the most potent endogenous inhibitors of the three isoforms of nitric oxide synthase and it is a newly discovered risk factor in the setting of diseases associated with endothelial dysfunction and adverse cardiovascular events. In the context of systemic inflammatory disorders there is increasing evidence that ADMA contributes to the vascular changes and to endothelial cell abnormalities, as several studies have revealed derangement of nitric oxide/ADMA pathway in different disease subsets. In this article we discuss the role of endothelial dysfunction in patients with rheumatic diseases, with a specific focus on the nitric oxide/ADMA system and we provide an overview on the literature pertaining to ADMA as a surrogate marker of subclinical vascular disease.

Treatment of thromboangiitis obliterans (Buerger's disease) with bosentan

BACKGROUND

This study assessed the effectiveness and safety of bosentan when administered to thromboangiitis obliterans (Buerger's disease) patients.

METHODS

A clinical pilot study was designed in which patients with ulcer and/or pain at rest were treated with bosentan p.o. at a dose of 62.5 mg twice daily during the first month, which was thereafter up-titrated to 125 mg twice daily. The study endpoints were clinical improvement rate, major or minor amputation rate, haemodynamic changes, changes in endothelial function and angiographic changes.

RESULTS

Seven out of 12 patients were male (58%). Median age was 39 years (range 29-49). The median follow-up was 20 months (range 11-40). All patients were smokers. With bosentan treatment, new ischaemic lesions were observed in only one patient. Overall, clinical improvement was observed in 12 of the 13 extremities (92%). Only two out of 13 extremities underwent amputation (one major and one minor) after bosentan treatment. After being assessed by digital arteriography with subtraction or angio-magnetic resonance imaging, an increase of distal flow was observed in 10 out of the 12 patients. All patients experienced a statistically significant improvement in their BAFMD values (mean: 1.8 at baseline; 6.6 at the end of the treatment; 12.7 three months after the end of the treatment; p < 0.01).

CONCLUSION

Bosentan treatment may result in an improvement of clinical, angiographic and endothelial function outcomes. Bosentan should be investigated further in the management of TAO patients. Larger studies are required to confirm these results.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01447550.

Improvement of endothelial function in parallel with the amelioration of dry cough and dyspnea due to interstitial pneumonia by intravenous cyclophosphamide pulse therapy in patients with systemic sclerosis: a preliminary report of two cases

Intravenous cyclophosphamide pulse therapy (IVCY) exerts its efficacy against interstitial lung disease (ILD) associated with systemic sclerosis (SSc) by restoring vascular injuries as well as aberrant immune activation. We recently experienced two patients with SSc-ILD in whom the values of brachial flow-mediated dilation (FMD) reflected the efficacy of IVCY. We herein report the details of these cases and discuss the potential of FMD to predict and evaluate the effect of IVCY on SSc-ILD.

Acute effect of sildenafil is maintained in pulmonary arterial hypertension patients chronically treated with bosentan

The chronic use of bosentan has been reported to reduce the plasma concentration of sildenafil. However, it remains unclear how sildenafil exerts the effect at reduced concentrations in pulmonary arterial hypertension (PAH) patients chronically treated with bosentan.We examined the hemodynamic effects of sildenafil (50 mg) in 8 Japanese patients with PAH, and simultaneously measured the plasma concentration of sildenafil ([Sil]) and its major metabolite, desmethylsildenafil ([Des]).The overall effects of sildenafil were 12.4% decrease in mean pulmonary arterial pressure, 19.9% increase in cardiac index (CI), and 25% reduction in derived pulmonary vascular resistance (PVR). When the patients were divided into two groups, a group with bosentan pretreatment [BOS (+), n = 4] and a group without bosentan pretreatment [BOS (-), n = 4], both [Sil] and [Des] were lower at the peak concentration (C(max)) and the area under the plasma concentration versus time curve (AUC(0-6h)), and the time to reach C(max) was longer in BOS (+), although only the difference in AUC(0-6h) of [Des] reached statistical significance (P = 0.02). In spite of lower concentration, the effect of sildenafil on CI was maintained in the BOS (+) group, while the decrease in PVR was less marked.Sildenafil acutely dilated the pulmonary artery and increased CI in the PAH patients. These effects were still observed or maintained in the PAH patients chronically treated with bosentan, even when [Sil] was reduced.

The effect of different doses of aerobic exercise training on endothelial function in postmenopausal women with elevated blood pressure: results from the DREW study

OBJECTIVES

The aim of this study was to examine the effect of three different doses of aerobic exercise training (corresponding to approximately 50%, 100% and 150% of the National Institutes of Health consensus guidelines) on endothelial function in sedentary obese postmenopausal women with elevated blood pressure. Aerobic exercise training improves endothelial function in individuals with cardiovascular risk; however, it is unknown whether these adaptations occur in a dose-dependent manner.

METHODS

Obese postmenopausal women (n=155) with elevated blood pressure (systolic blood pressure between 120 and 159.0 mm Hg) were randomly assigned to one of four groups: 4, 8 or 12 kilocalories per kilogram of energy expenditure per week (kcal/kg/week) or a non-exercise control group for 6 months. Endothelial function was assessed via flow-mediated dilation (FMD) at baseline and post-intervention.

RESULTS

After exercise training, there was a similar improvement (1.02-1.5%) in FMD in all three exercise groups (p<0.05) compared with control (-0.5%). Change in FMD after exercise training was significantly correlated with FMD at baseline (r= -0.35, p<0.001). Post hoc analyses found a significant improvement in FMD in exercisers (all exercise groups combined) with endothelial dysfunction (FMD < 5.5%) at baseline (1.8%, 95% CI: 1.17 to 2.38; p<0.001) compared with exercisers with normal endothelial function (FMD ≥ 5.5%) (-1.2%; 95% CI: -1.17 to 0.69; p=0.60).

CONCLUSIONS

Aerobic exercise training was associated with improved FMD in postmenopausal women with elevated blood pressure. In addition, exercise training may be more efficacious in improving endothelial function in postmenopausal women with endothelial dysfunction than individuals with normal endothelial function at baseline.

Cardiovascular disease in systemic sclerosis--an emerging association?

Microvascular disease is a prominent feature of systemic sclerosis (SSc) and leads to Raynaud's phenomenon, pulmonary arterial hypertension, and scleroderma renal crisis. The presence of macrovascular disease is less well established, and, in particular, it is not known whether the prevalence of coronary heart disease in SSc is increased. Furthermore, in terms of cardiac involvement in SSc, there remains conjecture about the relative contributions of atherosclerotic macrovascular disease and myocardial microvascular disease. In this review, we summarize the literature describing cardiovascular disease in SSc, discuss the pathophysiological mechanisms common to SSc and atherosclerosis, and review the surrogate markers of cardiovascular disease which have been examined in SSc. Proposed mediators of the vasculopathy of SSc which have also been implicated in atherosclerosis include endothelial dysfunction, a reduced number of circulating endothelial progenitor cells, and an increased number of microparticles. Excess cardiovascular risk in SSc is suggested by increased arterial stiffness and carotid intima thickening and reduced flow-mediated dilatation. Cohort studies of adequate size are required to resolve whether this translates into an increased incidence of cardiovascular events in patients with SSc.

Evaluation of the effect of Bosentan treatment on proinflammatory cytokine serum levels in patients affected by Systemic Sclerosis

Systemic sclerosis (SSc) is a connective tissue disease characterized by vascular and fibrotic changes in the skin and in internal organs. Endothelin-1 (ET-1) is a peptide that has a role in promoting both vascular injury and the fibrotic process in SSc; indeed, patients with systemic sclerosis have higher levels of ET-1 compared with healthy subjects. Moreover, ET-1 enhances expression of pro-inflammatory cytokines in animal model. Bosentan is a dual endothelin receptor antagonist approved for the treatment of pulmonary arterial hypertension and digital ulcers in scleroderma patients. In animal models and in vitro models, after treatment with Bosentan, a significant reduction of cytokine (TNF α, IFN γ,IL-8, IL-4) levels was observed. The aim of the study is to verify whether Bosentan treatment in SSc patients can reduce circulating cytokines levels. We enrolled 10 patients affected by SSc with digital ulcers and/or pulmonary hypertension, treated with Bosentan 125 mg twice daily. Patients were tested for cytokines and ET-1 level before treatment and after 12 months. The cytokines tested were IL-10, IL-2, IL-4, IL-5, IL-6, IL-8, GM-CSF, IFN-γ and TNF. Levels of ET-1, IL-10, IL-4, IL-5, GM-CSF and TNFalpha did not show consistent modification during treatment with Bosentan in respect to baseline, while IL-2, IL-6, IL-8 and IFN-γ were significantly decreased. Bosentan significantly reduced IL-2, IL-6, IL-8 and IFN- γ levels in SSc patients, probably slowing progression to fibrosis and vascular damage. This is the first report showing a decrease of profibrotic and proinflammatory cytokines levels in humans during treatment with Bosentan.

Pilot study of circulating prolactin levels and endothelial function in men with hypertension

BACKGROUND

Hyperprolactinemia has been recently associated with hypertension and endothelial dysfunction in humans, confirming animal studies performed in the 1970s that showed high prolactin levels to exert positive chronotropic and vasoconstrictive effects. Whether prolactin affects endothelial function, in the absence of hyperprolactinemia, remains unknown. Considering that secretion of prolactin presents circadian rhythmicity, we tested the hypothesis that in patients with hypertension, who present diurnal variation in their endothelial function as well, prolactin levels correlate with endothelial function and/or blood pressure.

METHODS

Endothelial function, assessed by flow-mediated dilatation (FMD) and serum prolactin were examined successively at 12 PM, 9 PM, and 7 AM in 27 nonhyperprolactinemic men with newly diagnosed, untreated essential hypertension.

RESULTS

Both FMD and prolactin presented 24-h variation (P < 0.01). FMD reached its lowest values at 7 AM (2.1 ± 1.8%, mean ± s.d.); concurrently prolactin levels peaked (7.18 ng/ml, median). Across the three time points, prolactin changes inversely interacted with FMD changes (P = 0.002). Systolic and diastolic blood pressure also varied significantly but no interaction with prolactin changes was evident.

CONCLUSIONS

Diurnal fluctuations of prolactin levels are associated with decreased endothelial function that occurs early in the morning in men with hypertension, although this study did not assess causality. Additional studies are required to determine whether these responses differ from normotensive individuals.

Bosentan treatment for Raynauds phenomenon and skin fibrosis in patients with Systemic Sclerosis and pulmonary arterial hypertension: an open-label, observational, retrospective study

Raynaud?s phenomenon (RP) and cutaneous fibrosis are the distinctive manifestations of scleroderma, in which Endothelin-1 plays a fundamental pathogenetic role. Bosentan, an Endothelin-1 receptor antagonist used for the treatment of pulmonary arterial hypertension, retards the beginning of new sclerodermic digital ulcers (DU). This open-label, observational, retrospective study verified the effect of Bosentan on RP and skin fibrosis in sclerodermic outpatients affected by pulmonary arterial hypertension without DU. Fourteen subjects (13 women, 1 man; mean age 60 ± 7.5 years; ten with limited and four with diffuse scleroderma) were observed at baseline (T0) and after four (T1), twelve (T2), twenty-four (T3) and forty-eight (T4) weeks during treatment with Bosentan. They were evaluated for daily quantity and duration of RP attacks and skin thickness (using modified Rodnan total skin score, MRSS). Videocapillaroscopic evaluation was performed at T0 and T4. Bosentan decreased significantly the number and duration of RP attacks, beginning at T2 (p<0.05). Videocapillaroscopy showed significant improvement of microcirculatory patterns at T4 (p<0.05). MRSS decreased throughout the study, reaching the statistical significance at T3 and T4 (p<0.01) in the whole cohort. The present data suggest that Bosentan is effective in stabilizing the microcirculation involvement and in improving skin fibrosis irrespective of scleroderma patterns.

Atherosclerosis and macrovascular involvement in systemic sclerosis: myth or reality

Systemic sclerosis (SSc) is a chronic disease of unknown etiology, characterized by enhanced fibrosis, and microvascular abnormalities. During the past several decades, the death rates due to cardiovascular disease or cerebrovascular disease in SSc patients substantially increased and are currently responsible for 20-30% of mortality. Various autoimmune rheumatic diseases such as rheumatoid arthritis and systemic lupus erythematosus accelerate atherosclerosis. Although microvascular disease is a hallmark of SSc, an ongoing debate exists regarding the presence and extent of macrovascular diseases and the presence of accelerated atherosclerosis in SSc patients. Despite conflicting results as to intima-media thickness (IMT) in SSc patients, the most recent and largest study has found no difference in either plaque occurrence or IMT. Additionally, abnormal coronary flow reserve in SSc patients appears to be due to microvascular involvement rather than atherosclerosis of the epicardial coronary arteries. Angiographic findings as well as computed tomography studies have generated conflicting reports as to coronary atherosclerosis in SSc. Herein, we review the current knowledge of macrovascular involvement and atherosclerosis in SSc. The differences between SSc and other autoimmune rheumatic diseases in the presence and extent of atherosclerosis need to be further investigated.

Efficacy of tadalafil in secondary Raynaud's phenomenon resistant to vasodilator therapy: a double-blind randomized cross-over trial

OBJECTIVE

To evaluate the efficacy of tadalafil as add-on therapy in secondary RP resistant to vasodilators.

METHODS

Patients with scleroderma and MCTD having four or more RP attacks per week despite being on vasodilators were randomized to receive either placebo or tadalafil (20 mg) on alternate days as add-on therapy to their current vasodilators for 6 weeks. After a 7-day washout, patients were crossed over to the other arm. Primary endpoints were improvement in the daily frequency and duration of RP episodes and RP condition score (RCS). Secondary outcome measures were healing of existing and appearance of new digital ulcers (DUs) and improvement in scleroderma-specific HAQ (SHAQ), quality of life (QoL), flow-mediated dilatation (FMD), patient and physician global assessment.

RESULTS

Twenty-four of 25 recruited patients completed the study. All the patients were receiving calcium channel blockers and in addition 18 were receiving other vasodilators. During tadalafil therapy significant improvement in mean daily frequency, mean daily duration of RP and mean daily RCS were observed as compared with baseline and placebo. All the 24 digital lesions healed during tadalafil therapy as compared with 3/13 during the placebo treatment (P<0.0001). One new DU was reported during tadalafil therapy vs 13 during placebo therapy (P=0.0005). QoL, SHAQ, FMD, patient and physician global assessment significantly improved while on tadalafil. No serious adverse event was observed.

CONCLUSION

Tadalafil as add-on therapy improves symptoms of RP, heals and prevents new DUs and improves QoL in patients with resistant secondary RP.

TRIAL REGISTRATION

Clinicaltrials.gov, http://clinicaltrials.gov/, identifier: NCT00626665.

Bosentan Improves Skin Perfusion of Hands in Patients with Systemic Sclerosis with Pulmonary Arterial Hypertension

Objective.

Our aim was to investigate effects of bosentan on hand perfusion in patients with systemic sclerosis (SSc) with pulmonary arterial hypertension (PAH), using laser Doppler perfusion imaging (LDPI).

Methods.

We enrolled 30 SSc patients with PAH, 30 SSc patients without PAH, and 30 healthy controls. In SSc patients and healthy controls at baseline, skin blood flow of the dorsum of the hands was determined with a Lisca laser Doppler perfusion imager. The dorsal surface of the hands was divided into 3 regions of interest (ROI). ROI 1 included 3 fingers of the hand from the second to the fourth distally to the proximal interphalangeal finger joint. ROI 2 included the area between the proximal interphalangeal and the metacarpophalangeal joint. ROI 3 included only the dorsal surface of the hand without the fingers. LDPI was repeated in SSc patients and controls after 4, 8, and 16 weeks of treatment. In SSc patients, nailfold videocapillaroscopy and Raynaud Condition Score (RCS) were performed at baseline and at 4, 8, and 16 weeks.

Results.

SSc patients with PAH enrolled in the study received treatment with bosentan as standard care for PAH. In these patients with PAH, after 8 and 16 weeks of treatment, bosentan improved minimum, mean, and maximum perfusion and the perfusion proximal-distal gradient. Bosentan seems to be most effective in patients with the early and active capillaroscopic pattern than in patients with the late pattern. Bosentan improved skin blood flow principally in the ROI 1 compared to the ROI 2 and ROI 3. Bosentan restored the perfusion proximal-distal gradient in 57% of SSc patients with the early capillaroscopic pattern. No significant differences from baseline were observed in the RCS in SSc patients with PAH.

Conclusion.

Bosentan improved skin perfusion in SSc patients with PAH, although it did not ameliorate symptoms of Raynaud’s phenomenon. Skin blood perfusion increased in SSc patients with PAH, particularly in the skin region distal to the proximal interphalangeal joint, and in patients with the early/active capillaroscopic pattern. Double-blind randomized clinical trials are needed to evaluate the effects of bosentan on skin perfusion of SSc patients without PAH and with active digital ulcers.

Digital ischemia in scleroderma spectrum of diseases

Systemic Sclerosis (Scleroderma, SSc) is a disease of unknown etiology characterized by widespread vasculopathy and extracellular matrix deposition leading to fibrosis and autoimmune processes. Digital ischemia (digital ulcers (DUs)) is the hallmark of SSc-related vasculopathy and is characterized by endothelial dysfunction leading to intimal proliferation and thrombosis. It happens frequently (30% of the patients each year) and it is associated with significant morbidity. This paper summarizes the current information regarding pathogenesis, definitions, management, and exploratory therapies in DUs associated with SSc.

Systemic vasculopathy with altered vasoreactivity in a transgenic mouse model of scleroderma

Introduction

Vasculopathy, including altered vasoreactivity and abnormal large vessel biomechanics, is a hallmark of systemic sclerosis (SSc). However, the pathogenic link with other aspects of the disease is less clear. To assess the potential role of transforming growth factor beta (TGF-β) overactivity in driving these cardiovascular abnormalities, we studied a novel transgenic mouse model characterized by ligand-dependent activation of TGF-β signaling in fibroblasts.

Methods

The transgenic mouse strain Tβ RIIΔk-fib is characterized by balanced ligand-dependent upregulation of TGF-β signaling. Aortic and cardiac tissues were examined with histologic, biochemical, and isolated organ bath studies. Vascular and perivascular architecture was examined by hematoxylin and eosin (H&E) and special stains including immunostaining for TGF-β1 and phospho-Smad2/3 (pSmad2/3). Confirmatory aortic smooth muscle cell proliferation, phenotype, and functional assays, including signaling responses to exogenous TGF-β and endothelin-1, were performed. Aortic ring contractile responses to direct and receptor-mediated stimulation were assessed.

Results

Aortic ring contractility and relaxation were diminished compared with wild-type controls, and this was associated with aortic adventitial fibrosis confirmed histologically and with Sircol assay. TGF-β1 and pSmad 2/3 expression was increased in the adventitia and smooth muscle layer of the aorta. Aortic smooth muscle cells from transgenic animals showed significant upregulation of TGF-β- responsive genes important for cytoskeletal function, such as transgelin and smoothelin, which were then resistant to further stimulation with exogenous TGF-β1. These cells promoted significantly more contraction of free floating type I collagen lattices when compared with the wild-type, but were again resistant to exogenous TGF-β1 stimulation. Aortic ring responses to receptor-mediated contraction were reduced in the transgenic animals. Specifically, bosentan reduced endothelin-mediated contraction in wild-type animals, but had no effect in transgenic animals, and endothelin axis gene expression was altered in transgenic animals. Transgenic mice developed cardiac fibrosis.

Conclusions

The histologic, biochemical, and functional phenotype of this transgenic mouse model of scleroderma offers insight into the altered biomechanical properties previously reported for large elastic arteries in human SSc and suggests a role for perturbed TGF-β and endothelin activity in this process.

Advances in the treatment of Raynaud's phenomenon

Raynaud's phenomenon is a common condition characterized by vasospasm of the digital arteries and resulting cyanosis and redness. It often does not require pharmacologic management, but in some cases symptoms are severe and pharmacologic management is necessary. Calcium channel blockers are often used first-line, but in some patients are ineffective. Patients with severe symptoms or intolerance to available therapies have prompted exploration of alternative therapies, including endothelin antagonists, phosphodiesterase-5 inhibitors, antioxidants, newer vasodilators, statins, and botulinum toxin. These newer therapies provide the focus for this review.

Bosentan: in pediatric patients with pulmonary arterial hypertension

Bosentan is a dual endothelin-1 (ET-1) receptor antagonist that has affinity for ET-1 receptors A and B. In the EU, oral bosentan (Tracleer) is indicated to improve exercise capacity and symptoms in patients with pulmonary arterial hypertension (PAH) of WHO functional class III; benefits have also been seen in patients with WHO functional class II PAH. Bosentan is available as film-coated tablets, and a new dispersible formulation of bosentan has also recently been approved in the EU for the treatment of PAH in children aged > or =2 years. A noncomparative, multicenter, phase III trial (FUTURE-1), which was primarily designed to investigate the pharmacokinetics of dispersible bosentan in pediatric patients, demonstrated that increasing the dosage of bosentan from 2 to 4 mg/kg twice daily was unlikely to result in increased exposure to bosentan. Exploratory measures of efficacy in FUTURE-1 demonstrated that target dosages of twice-daily dispersible bosentan 4 mg/kg (in patients weighing <30 kg) or 120 mg (in patients weighing > or =30 kg) for 12 weeks were beneficial in pediatric patients (aged > or =2 to <12 years) with WHO functional class II or III PAH. Film-coated bosentan 31.25, 62.5, or 125 mg (in pediatric patients weighing 10-20, >20-40, or >40 kg, respectively) twice daily for 12 weeks significantly (p < 0.05) improved the majority of hemodynamic measures evaluated as an exploratory measure in pediatric patients (aged 3-15 years) with WHO functional class II or III PAH in another noncomparative, multicenter, pharmacokinetic trial (BREATHE-3). However, there was no significant change in peak oxygen consumption or mean walk distance in those patients capable (i.e. children aged > or =8 years) of performing the 6-minute walk test. Bosentan was generally well tolerated in clinical trials of pediatric patients with PAH, with most adverse events being mild or moderate in severity and resolving with continued treatment.