Endothelin-1 as a Candidate Biomarker of Systemic Sclerosis: A GRADE-Assessed Systematic Review and Meta-Analysis With Meta-Regression

Background

There is an ongoing search for novel biomarkers of vascular dysfunction, extent of fibrosis and organ involvement in systemic sclerosis (SSc).

Objectives

We critically appraised the studies investigating the circulating concentrations of endothelin-1 in SSc patients and healthy controls.

Design

This was a systematic review with meta-analysis.

Data sources and methods

We searched electronic databases (PubMed, Scopus, and Web of Science) from inception to 15 June 2024. We assessed the risk of bias and the certainty of evidence using the JBI Critical Appraisal Checklist and GRADE, respectively.

Results

Endothelin-1 concentrations were significantly higher in SSc patients than in controls (26 studies; standardised mean difference, SMD = 0.98, 95% CI 0.73-1.23, P < .001; moderate certainty of evidence). In SSc patients, there were no significant differences in endothelin-1 concentrations between those with limited and diffuse cutaneous SSc (10 studies; SMD = 0.32, 95% CI -0.07 to 0.71 P = .11; very low certainty), and with and without digital ulcers (5 studies; SMD = 0.82, 95% CI -0.06 to 1.69, P = .066; very low certainty), pulmonary arterial hypertension (7 studies; SMD = 0.22, 95% CI -0.01 to 0.45, P = .066; very low certainty) or interstitial lung disease (3 studies; SMD = 0.09, 95% CI -0.18 to 0.35, P = .51; very low certainty). There was limited evidence in SSc patients with different video capillaroscopy pattern and telangiectasias. Subgroup and meta-regression analyses showed significant associations between the effect size and geographical location (studies investigating SSc patients and controls), year of publication (studies investigating SSc patients with limited and diffuse cutaneous SSc), and biological matrix assessed (studies investigating SSc patients with and without digital ulcers).

Conclusion

The results of this systematic review and meta-analysis highlight the potential role of endothelin-1 as a candidate biomarker of SSc. Further research is warranted to determine the utility of measuring endothelin-1 in SSc subgroups with different extent of fibrosis and organ involvement.

Registration

PROSPERO registration number - CRD42024566461.

An overview of the role of chemokine CX3CL1 (Fractalkine) and CX3C chemokine receptor 1 in systemic sclerosis

INTRODUCTION

Systemic sclerosis (SSc) is a complex autoimmune disease characterized by fibrosis, vascular damage, and immune dysregulation. Fractalkine or chemokine (C-X3-C motif) ligand 1 (CX3CL1), a chemokine and adhesion molecule, along with its receptor CX3CR1, have been implicated in the inflammatory processes of SSc. CX3CL1 functions as both a chemoattractant and an adhesion molecule, guiding immune cell trafficking. This systematic review examines the role of CX3CL1 and its receptor CX3CR1 in the pathogenesis of SSc, with a focus on pulmonary and vascular complications.

METHODS

A systematic literature search was conducted across databases including PubMed, Scopus, and Web of Science from inception to November 2020. The search focused on studies investigating the CX3CL1/CX3CR1 axis in the context of SSc.

RESULTS

The review identified elevated CX3CL1 expression in SSc patients, particularly in the skin and lungs, where CX3CR1 is expressed on infiltrating immune cells. Higher levels of CX3CL1 were correlated with the severity of interstitial lung disease in SSc patients, indicating a potential predictive marker for disease progression. CX3CR1-positive monocytes and NK cells were recruited to inflamed tissues, contributing to fibrosis and tissue damage. Animal studies showed that inhibition of the CX3CL1/CX3CR1 axis reduced fibrosis and improved vascular function.

CONCLUSION

The CX3CL1/CX3CR1 axis plays a key role in immune cell recruitment and fibrosis in SSc. Elevated CX3CL1 levels are associated with lung and vascular complications, making it a potential biomarker for disease progression and a promising therapeutic target.

Autoantibodies Targeting G-Protein-Coupled Receptors: Pathogenetic, Clinical and Therapeutic Implications in Systemic Sclerosis

Systemic sclerosis (SSc) is a multifaceted connective tissue disease whose aetiology remains largely unknown. Autoimmunity is thought to play a pivotal role in the development of the disease, but the direct pathogenic role of SSc-specific autoantibodies remains to be established. The recent discovery of functional antibodies targeting G-protein-coupled receptors (GPCRs), whose presence has been demonstrated in different autoimmune conditions, has shed some light on SSc pathogenesis. These antibodies bind to GPCRs expressed on immune and non-immune cells as their endogenous ligands, exerting either a stimulatory or inhibitory effect on corresponding intracellular pathways. Growing evidence suggests that, in SSc, the presence of anti-GPCRs antibodies correlates with specific clinical manifestations. Autoantibodies targeting endothelin receptor type A (ETAR) and angiotensin type 1 receptor (AT1R) are associated with severe vasculopathic SSc-related manifestations, while anti-C-X-C motif chemokine receptors (CXCR) antibodies seem to be predictive of interstitial lung involvement; anti-muscarinic-3 acetylcholine receptor (M3R) antibodies have been found in patients with severe gastrointestinal involvement and anti-protease-activated receptor 1 (PAR1) antibodies have been detected in patients experiencing scleroderma renal crisis. This review aims to clarify the potential pathogenetic significance of GPCR-targeting autoantibodies in SSc, focusing on their associations with the different clinical manifestations of scleroderma. An extensive examination of functional autoimmunity targeting GPCRs might provide valuable insights into the underlying pathogenetic mechanisms of SSc, thus enabling the development of novel therapeutic strategies tailored to target GPCR-mediated pathways.

Cellular Transdifferentiation: A Crucial Mechanism of Fibrosis in Systemic Sclerosis

Systemic Sclerosis (SSc) is a systemic autoimmune disease of unknown etiology with a highly complex pathogenesis that despite extensive investigation is not completely understood. The clinical and pathologic manifestations of the disease result from three distinct processes: 1) Severe and frequently progressive tissue fibrosis causing exaggerated and deleterious accumulation of interstitial collagens and other extracellular matrix molecules in the skin and various internal organs; 2) extensive fibroproliferative vascular lesions affecting small arteries and arterioles causing tissue ischemic alterations; and 3) cellular and humoral immunity abnormalities with the production of numerous autoantibodies, some with very high specificity for SSc. The fibrotic process in SSc is one of the main causes of disability and high mortality of the disease. Owing to its essentially universal presence and the severity of its clinical effects, the mechanisms involved in the development and progression of tissue fibrosis have been extensively investigated, however, despite intensive investigation, the precise molecular mechanisms have not been fully elucidated. Several recent studies have suggested that cellular transdifferentiation resulting in the phenotypic conversion of various cell types into activated myofibroblasts may be one important mechanism. Here, we review the potential role that cellular transdifferentiation may play in the development of severe and often progressive tissue fibrosis in SSc.

Efficacy of adjunctive ambrisentan treatment for digital ulcers in patients with systemic sclerosis: a case series study

Purpose: The efficacy of adjunctive ambrisentan treatment in patients with systemic sclerosis (SSc) suffering from digital ulcers (DUs) was investigated.Material and methods: Patients (4 males, 7 females) diagnosed with SSc at our hospital between 2017 and 2022 were enrolled. Ten of them had diffuse SSc, while one had limited SSc. These patients received daily 5 mg doses of ambrisentan in addition to their regular SSc treatment for 16 weeks. Parameters including the total number and size of existing and new DUs, Visual Analog Score (VAS), frequency of Raynaud's phenomenon (RP) attacks, and any adverse effects were assessed.Results: At baseline, the median number and size of DUs was 3.0 (interquartile range (IQR): 2.0-4.0 cm) and 0.4 cm (IQR: 0.3-0.5 cm), respectively. Following the intervention, seven patients with a median of 2.0 DUs and a size of 0.35 cm (IQR: 0.15-0.45 cm) at baseline achieved complete healing. Significant improvements were also observed in other patients. VAS scores decreased from a baseline median of 5.0-0.0 (IQR: 0.0-1.0), and both the frequency and duration of RP attacks notably reduced.Conclusion: Adjunctive ambrisentan therapy proved effective in promoting DU healing and preventing new DUs in SSc patients.

Molecular Pathways of Breast Cancer in Systemic Sclerosis: Exploratory Immunohistochemical Analysis from the Sclero-Breast Study

Several authors reported an increased risk of cancer in SSc patients, including breast cancer (BC). Nevertheless, the mechanisms underlying this association have not yet been clarified. SSc and BC share several molecular pathways, which seem to play a common etiopathogenetic role. The previously published Sclero-Breast study demonstrated the development of BC with a good prognosis among these patients, which could be explained by an autoimmune background as a possible mechanism for limiting tumor extension. Here, we report the results of an IHC analysis of molecular pathways known to be common drivers for both diseases, with the aim to better define the mechanisms underlying a good prognosis of BC in patients affected by SSc. The analysis demonstrated higher TILs rates in all BC subgroups, with a high rate of PD-L1 expression especially in TNBC and HER2-positive BC, suggesting a less aggressive behavior in these patients compared to the general population. These results support a possible de-escalation strategy of cancer therapies in these fragile patients. These data could represent a starting point for future prospective studies based on the clinical application of these biomarkers with a larger sample size to promote a personalized and targeted oncological treatment for this specific subset of patients.

The role of endothelin and RAS/ERK signaling in immunopathogenesis-related fibrosis in patients with systemic sclerosis: an updated review with therapeutic implications

Systemic sclerosis (SSc) is a disease of connective tissue with high rate of morbidity and mortality highlighted by extreme fibrosis affecting various organs such as the dermis, lungs, and heart. Until now, there is no specific cure for the fibrosis occurred in SSc disease. The SSc pathogenesis is yet unknown, but transforming growth factor beta (TGF-β), endothelin-1 (ET-1), and Ras-ERK1/2 cascade are the main factors contributing to the tissue fibrosis through extracellular matrix (ECM) accumulation. Several studies have hallmarked the association of ET-1 with or without TGF-β and Ras-ERK1/2 signaling in the development of SSc disease, vasculopathy, and fibrosis of the dermis, lungs, and several organs. Accordingly, different clinical and experimental studies have indicated the potential therapeutic role of ET-1 and Ras antagonists in these situations in SSc. In addition, ET-1 and connective tissue growth factor (CTGF) as a cofactor of the TGF-β cascade play a substantial initiative role in inducing fibrosis. Once initiated, TGF-β alone or in combination with ET-1 and CTGF can activate several kinase proteins such as the Ras-ERK1/2 pathway that serve as the fundamental factor for developing fibrosis. Furthermore, Salirasib is a synthetic small molecule that is able to inhibit all Ras forms. Therefore, it can be used as a potent therapeutic factor for fibrotic disorders. So, this review discusses the role of TGF-β/ET-1/Ras signaling and their involvement in SSc pathogenesis, particularly in its fibrotic situation.

Systemic Sclerosis Portends Increased Risk of Conduction and Rhythm Abnormalities at Diagnosis and During Disease Course: A US Population-Based Cohort

Objectives

To study the incidence, risk factors and outcomes of conduction and rhythm disorders in a population-based cohort of patients with systemic sclerosis (SSc) vs. non-SSc comparators.

Methods

An incident cohort of patients with SSc (1980-2016) from Olmsted County, MN was compared to age- and sex-matched non-SSc subjects (1:2). Electrocardiograms (ECGs), Holter ECGs, and need for cardiac interventions were reviewed to determine the occurrence of any conduction or rhythm abnormalities.

Results

78 incident SSc cases and 156 comparators were identified (mean age 56 y, 91% female). The prevalence of any conduction disorder prior to SSc diagnosis compared to non-SSc subjects was 15% vs. 7% (p=0.06), and any rhythm disorder was 18% vs. 13% (p=0.33). During a median follow-up of 10.5 years in patients with SSc and 13.0 years in non-SSc comparators, conduction disorders developed in 25 patients with SSc with cumulative incidence of 20.5% (95% CI: 12.4-34.1%) vs. 28 non-SSc patients with cumulative incidence of 10.4% (95% CI: 6.2-17.4%) (HR: 2.57; 95% CI: 1.48-4.45), while rhythm disorders developed in 27 patients with SSc with cumulative incidence of 27.3% (95% CI: 17.9-41.6%) vs. 43 non-SSc patients with cumulative incidence of 18.0% (95% CI: 12.3-26.4%) (HR: 1.62; 95% CI: 1.00-2.64). Age, pulmonary hypertension and smoking were identified as risk factors.

Conclusion

Patients with SSc have an increased risk of conduction and rhythm disorders both at disease onset and over time, compared to non-SSc patients. These findings warrant increased vigilance and screening for ECG abnormalities in SSc patients with pulmonary hypertension.

Clinical Relevance of Liver Involvement in the Clinical Course of Systemic Sclerosis

Liver involvement in systemic sclerosis (SSc) is rare. We evaluated the prevalence of liver fibrosis and hepatic autoimmunity in SSc patients in a retrospective observational cohort (97 SSc or mixed connective tissue disease with sclerodermic manifestations patients undergoing transient elastography, evaluating liver stiffness (LS) and controlled attenuation parameter (CAP), due to clinical indications along with biochemistry assessments and major antibodies associated to liver autoimmunity). Among them, 11 had LS ≥ 7.5 kPa and 5 showed an LS compatible with cirrhosis (LS ≥ 12.5 kPa). Predictors of LS ≥ 7.5 fibrosis were alcohol consumption (>14 or >7 alcoholic units/week for men and women, respectively), waist circumference (>102 or >88 cm for men and women, respectively), elevated alkaline phosphatase, and anti-La and anti-mitochondrial antibody (AMA) positivity. Six patients had CAP values compatible with severe steatosis (≥280 dB/m). Waist circumference, body mass index and diabetes mellitus were significant predictors of steatosis. Out of 97 patients, 19 were positive for AMA, 4 for anti-Sp100, 1 for anti-Gp210 and 7 were diagnosed with primary biliary cholangitis. Among SSc patients, hepatic fibrosis biomarkers and AMA prevalence are relatively high, suggesting the opportunity of performing a transient elastography and a screening for hepatic autoimmunity at diagnosis and/or during disease progression.

Autoantibodies Targeting AT1- and ETA-Receptors Link Endothelial Proliferation and Coagulation via Ets-1 Transcription Factor

Scleroderma renal crisis (SRC) is an acute life-threatening manifestation of systemic sclerosis (SSc) caused by obliterative vasculopathy and thrombotic microangiopathy. Evidence suggests a pathogenic role of immunoglobulin G (IgG) targeting G-protein coupled receptors (GPCR). We therefore dissected SRC-associated vascular obliteration and investigated the specific effects of patient-derived IgG directed against angiotensin II type 1 (AT1R) and endothelin-1 type A receptors (ETAR) on downstream signaling events and endothelial cell proliferation. SRC-IgG triggered endothelial cell proliferation via activation of the mitogen-activated protein kinase (MAPK) pathway and subsequent activation of the E26 transformation-specific-1 transcription factor (Ets-1). Either AT1R or ETAR receptor inhibitors/shRNA abrogated endothelial proliferation, confirming receptor activation and Ets-1 signaling involvement. Binding of Ets-1 to the tissue factor (TF) promoter exclusively induced TF. In addition, TF inhibition prevented endothelial cell proliferation. Thus, our data revealed a thus far unknown link between SRC-IgG-induced intracellular signaling, endothelial cell proliferation and active coagulation in the context of obliterative vasculopathy and SRC. Patients' autoantibodies and their molecular effectors represent new therapeutic targets to address severe vascular complications in SSc.

Dental implants in patients suffering from systemic sclerosis: a retrospective analysis of clinical outcomes in a case series with 24 patients

PURPOSE

Patients with systemic sclerosis (SSc) often suffer from premature tooth loss. This is a retrospective case series of patients with systemic sclerosis who were treated with dental implants.

METHODS

SSc patients treated with at least one dental implant between 5 August 1998 and 31 December 2018 were included in this long-term retrospective study. The primary study variables were the plaque index (PLI), sulcus bleeding index (SBI), peri-implant pocket depth (PPD) and interincisal distance (ID). The test for marginal homogeneity analysed whether the SBI and PLI values changed between examination and follow-up. A linear regression was performed for the PPD measurement. The rank correlation coefficient compared the SBI with the PLI and the PPD with the PLI. The survival rate data for the implants were analysed by the Kaplan-Meier procedure. P < .05 was considered significant.

RESULTS

Twenty-four patients [(age: mean 59.6 years (SD ± 13.08)] received a total of 72 implants. ID resulted in a mean value of 29.54 mm (SD ± 6.4 mm). The mean value of the PPD was between 2.4 mm and 2.8 mm. A comparison of the SBI with the PLI and the PPD with the PLI showed a significantly positive correlation between the SBI and the PLI and between the PPD and the PLI. The correlation between the PPD and the PLI (Spearman rho: 0.36, p < 0.001) was less pronounced than that between the SBI and the PLI (Spearman rho: 0.61, p < 0.001). Kaplan-Meier analysis showed a post-10-year implant survival rate of 87.6% (95%-KI: 75.5-94.0).

CONCLUSION

Implant-supported oral rehabilitation can be carried out and maintained successfully in SSc patients.

A preliminary study of possible fibrotic role of meprin metalloproteases in scleroderma patients

OBJECTIVES

This study aims to investigate the possible fibrotic role of meprin metalloproteases and possible fibrotic effects of activator protein-1 (AP-1) in scleroderma patients.

PATIENTS AND METHODS

Between April 2018 and April 2019, a total of 85 scleroderma patients (9 males, 76 females; mean age: 54.9 years; range, 22 to 80 years) who met the 2013 American College of Rheumatology/European League Against Rheumatism criteria and 80 healthy control individuals (10 males, 70 females; mean age 42.9 years; range, 19 to 65 years) were included. Patients' data and blood samples were collected. Messenger ribonucleic acid expressions of interleukin (IL)-6, AP-1 subunits, and tumor necrosis factor-alpha (TNF-α) were analyzed by quantitative real-time polymerase chain reaction. Serum meprin alpha and beta protein levels were analyzed using the enzyme-linked immunosorbent assay.

RESULTS

Meprin alpha and meprin beta protein levels increased in scleroderma patients. The AP-1 subunits (c-Fos, c-Jun), IL-6, and TNF-α increased in scleroderma patients, compared to controls.

CONCLUSION

Our results provide evidence showing that increased meprins levels may be related to AP-1 levels and increased meprins levels may responsible for increased inflammatory TNF-α and IL-6 levels. All these data suggest meprins as promising therapeutic targets to restore the balance between inflammation and extracellular matrix deposition in scleroderma.

Myocardial Involvement Detected Using Cardiac Magnetic Resonance Imaging in Patients with Systemic Sclerosis: A Prospective Observational Study

Introduction and objectives: Cardiac involvement in systemic sclerosis (SSc) patients affects mortality. Cardiac magnetic resonance (CMR) is capable of detecting structural changes, including diffuse myocardial fibrosis that may develop over time. Our aim was to evaluate myocardial structure and function changes using CMR in patients with SSc without known cardiac disease during a 5-year follow-up and find possible correlations with selected biomarkers. Methods: A total of 25 patients underwent baseline and follow-up CMR examinations according to a pre-specified protocol. Standard biochemistry, five biomarkers (hsTnI, NT-proBNP, galectin-3, sST2, and GDF-15), and disease-specific functional parameters enabling the classification of disease severity were also measured. Results: After five years, no patient suffered from manifest heart disease. Mean extracellular volume (ECV) and T1 mapping values did not change significantly (p ≥ 0.073). However, individual increases in native T1 time and ECV correlated with increased galectin-3 serum levels (r = 0.56; p = 0.0050, and r = 0.71; p = 0.0001, respectively). The progression of skin involvement assessed using the Rodnan skin score and a decrease in the diffusing capacity of the lungs were associated with increased GDF-15 values (r = 0.63; p = 0.0009, and r = −0.51; p = 0.011, respectively). Conclusions: During the 5-year follow-up, there was no new onset of heart disease observed in patients with SSc. However, in some patients, CMR detected progression of sub-clinical myocardial fibrosis that significantly correlated with elevated galectin-3 levels. GDF-15 values were found to be associated with disease severity progression.

The relationship of ocular parameters with clinical parameters and disease-related quality of life in patients with systemic sclerosis: A cross-sectional study

OBJECTIVE

To evaluate choroidal thickness (CT), corneal parameters, and scleral thickness (ST) in patients with systemic sclerosis (SSc) and to determine their relationship with disease-related quality of life (QoL).

METHODS

The study included 38 patients with SSc and 40 healthy controls. A detailed ocular examination was performed on all participants. Corneal parameters such as K1, K2, Km, corneal volume (CV), central corneal thickness (CCT), and ST at a distance of 1000, 2000, and 3000 μm from the scleral spur were measured. CT was measured at five points, including the subfoveal area and the temporal and nasal points at radii of 750.0 and 1500.0 μm. The scleroderma health assessment questionnaire (SHAQ) was administered to SSc patients to investigate the disease-related QoL.

RESULTS

Individuals with SSc had thicker ST at all distances from the scleral spur (P=0.008, P=0.001, P=0.002, respectively). All corneal parameters were significantly lower in the SSc group than in the control group (P < 0.05). Moreover, SSc patients had significantly lower median CT at N750.0, N1500.0, T750.0, and T1500.0 points and thinner subfoveal CT than healthy controls (P < 0.05). There was a weak-moderate negative correlation between ST and the components of the SHAQ scale and SHAQ-global.

CONCLUSION

Despite not having ocular involvement, SSc patients had thicker ST but thinner CT and corneal parameters than healthy controls. This may indicate subclinical inflammation in patients with SSc. Only ST was affected by organ involvement and QoL among the ocular parameters.

Serum resistin is predictive marker of development of new digital ulcers in systemic sclerosis

Systemic sclerosis (SSc) is autoimmune disease characterized by endothelial dysfunction and microvascular damage. Resistin has been implied in microvascular dysfunction. Objective of this study is to evaluate the association between baseline resistin and development of new digital ulcers (DUs) in SSc patients. At baseline, serum resistin has been assessed in 70 female SSc patients and 26 healthy controls (HC). In SSc patients, clinical assessment was performed at baseline and after a 52-weeks follow-up. Serum resistin level was increased in SSc patients compared to HC [5.89 ng/ml (2.5 ng/ml–8.1 ng/ml) vs 2.3 ng/ml (0.4 ng/ml–2.4 ng/ml), p = 0.0004)]. Resistin was lower (p = 0.005) in SSc patients with early capillaroscopic pattern than patients with active or late capillaroscopic pattern [2.49 ng/ml (0.89 ng/ml–5.81 ng/ml) vs 7.11 ng/ml (3.48 ng/ml–11.35 ng/ml) and 6.49 ng/ml (3.35 ng/ml–8.87 ng/ml), respectively]. After a 52-weeks follow-up, 34 (48.6%) patients developed new DUs. Median serum resistin was significantly higher in patients with new DUs than in patients without new DUs [6.54 ng/ml (3.35 ng/ml–11.02 ng/ml) vs 4.78 ng/ml (1.06 ng/ml–7.6 ng/ml), p = 0.019]. Kaplan–Meier curves show a significantly reduced free survival from DUs in patients with increased resistin (p = 0.002). In multivariate analysis, resistin is associated with the development of new DUs. Increased serum resistin level is a predictive marker of new DUs in SSc.

TGFβ-1 Induced Cross-Linking of the Extracellular Matrix of Primary Human Dermal Fibroblasts

Excessive cross-linking is a major factor in the resistance to the remodelling of the extracellular matrix (ECM) during fibrotic progression. The role of TGFβ signalling in impairing ECM remodelling has been demonstrated in various fibrotic models. We hypothesised that increased ECM cross-linking by TGFβ contributes to skin fibrosis in Systemic Sclerosis (SSc). Proteomics was used to identify cross-linking enzymes in the ECM of primary human dermal fibroblasts, and to compare their levels following treatment with TGFβ-1. A significant upregulation and enrichment of lysyl-oxidase-like 1, 2 and 4 and transglutaminase 2 were found. Western blotting confirmed the upregulation of lysyl hydroxylase 2 in the ECM. Increased transglutaminase activity in TGFβ-1 treated ECM was revealed from a cell-based assay. We employed a mass spectrometry-based method to identify alterations in the ECM cross-linking pattern caused by TGFβ-1. Cross-linking sites were identified in collagens I and V, fibrinogen and fibronectin. One cross-linking site in fibrinogen alpha was found only in TGFβ-treated samples. In conclusion, we have mapped novel cross-links between ECM proteins and demonstrated that activation of TGFβ signalling in cultured dermal fibroblasts upregulates multiple cross-linking enzymes in the ECM.

Pain chronification and the important role of non-disease-specific symptoms in patients with systemic sclerosis

Background

Pain is a frequent, yet inadequately explored challenge in patients with systemic sclerosis (SSc). This study aimed to conduct an extensive pain assessment, examining pain chronification and its association with disease manifestations.

Methods

Consecutive SSc patients attending their annual assessment were included. SSc-specific features were addressed as defined by the European Scleroderma Trials and Research (EUSTAR) guidelines. Pain analysis included intensity, localization, treatment, chronification grade according to the Mainz Pain Staging System (MPSS), general well-being using the Marburg questionnaire on habitual health findings (MFHW) and symptoms of anxiety and depression using the Hospital Anxiety and Depression Scale (HADS).

Results

One hundred forty-seven SSc patients completed a pain questionnaire, and 118/147 patients reporting pain were included in the analysis. Median pain intensity was 4/10 on a numeric rating scale (NRS). The most frequent major pain localizations were hand and lower back. Low back pain as the main pain manifestation was significantly more frequent in patients with very early SSc (p = 0.01); those patients also showed worse HADS and MFHW scores. Regarding pain chronification, 34.8% were in stage I according to the MPSS, 45.2% in stage II and 20.0% in stage III. There was no significant correlation between chronification grade and disease severity, but advanced chronification was significantly more frequent in patients with low back pain (p = 0.024). It was also significantly associated with pathological HADS scores (p < 0.0001) and linked with decreased well-being and higher use of analgesics.

Conclusions

Our study implies that also non-disease-specific symptoms such as low back pain need to be considered in SSc patients, especially in early disease. Since low back pain seems to be associated with higher grades of pain chronification and psychological problems, our study underlines the importance of preventing pain chronification in order to enhance the quality of life.

Association Between DNA Damage Response, Fibrosis and Type I Interferon Signature in Systemic Sclerosis

Increased endogenous DNA damage and type I interferon pathway activation have been implicated in systemic sclerosis (SSc) pathogenesis. Because experimental evidence suggests an interplay between DNA damage response/repair (DDR/R) and immune response, we hypothesized that deregulated DDR/R is associated with a type I interferon signature and/or fibrosis extent in SSc. DNA damage levels, oxidative stress, induction of abasic sites and the efficiency of DNA double-strand break repair (DSB/R) and nucleotide excision repair (NER) were assessed in peripheral blood mononuclear cells (PBMCs) derived from 37 SSc patients and 55 healthy controls; expression of DDR/R-associated genes and type I interferon-induced genes was also quantified. Endogenous DNA damage was significantly higher in untreated diffuse or limited SSc (Olive tail moment; 14.7 ± 7.0 and 9.5 ± 4.1, respectively) as well as in patients under cytotoxic treatment (15.0 ± 5.4) but not in very early onset SSc (5.6 ± 1.2) compared with controls (4.9 ± 2.6). Moreover, patients with pulmonary fibrosis had significantly higher DNA damage levels than those without (12.6 ± 5.8 vs. 8.8 ± 4.8, respectively). SSc patients displayed increased oxidative stress and abasic sites, defective DSB/R but not NER capacity, downregulation of genes involved in DSB/R (MRE11A, PRKDC) and base excision repair (PARP1, XRCC1), and upregulation of apoptosis-related genes (BAX, BBC3). Individual levels of DNA damage in SSc PBMCs correlated significantly with the corresponding mRNA expression of type I interferon-induced genes (IFIT1, IFI44 and MX1, r=0.419-0.490) as well as with corresponding skin involvement extent by modified Rodnan skin score (r=0.481). In conclusion, defective DDR/R may exert a fuel-on-fire effect on type I interferon pathway activation and contribute to tissue fibrosis in SSc.

Translational engagement of lysophosphatidic acid receptor 1 in skin fibrosis: from dermal fibroblasts of patients with scleroderma to tight skin 1 mouse

Background and Purpose

Genetic deletion and pharmacological studies suggest a role for lysophosphatidic acid (LPA₁) receptor in fibrosis. We investigated the therapeutic potential in systemic sclerosis (SSc) of a new orally active selective LPA₁ receptor antagonist using dermal fibroblasts from patients and an animal model of skin fibrosis.

Experimental Approach

Dermal fibroblast and skin biopsies from systemic sclerosis patients were used. Myofibroblast differentiation, gene expression and cytokine secretion were measured following LPA and/or SAR100842 treatment. Pharmacolgical effect of SAR100842 was assessed in the tight skin 1 (Tsk1) mouse model.

Key Results

SAR100842 is equipotent against various LPA isoforms. Dermal fibroblasts and skin biopsies from patients with systemic sclerosis expressed high levels of LPA₁ receptor. The LPA functional response (Ca²⁺) in systemic sclerosis dermal fibroblasts was fully antagonized with SAR100842. LPA induced myofibroblast differentiation in systemic sclerosis dermal and idiopathic pulmonary fibrosis lung fibroblasts and the secretion of inflammatory markers and activated Wnt markers. Results from systemic sclerosis dermal fibroblasts mirror those obtained in a mouse Tsk1 model of skin fibrosis. Using a therapeutic protocol, SAR100842 consistently reversed dermal thickening, inhibited myofibroblast differentiation and reduced skin collagen content. Inflammatory and Wnt pathway markers were also inhibited by SAR100842 in the skin of Tsk1 mice.

Conclusion and Implications

The effects of SAR100842 on LPA‐induced inflammation and on mechanisms linked to fibrosis like myofibroblast differentiation and Wnt pathway activation indicate that LPA₁ receptor activation plays a key role in skin fibrosis. Our results support the therapeutic potential of LPA₁ receptor antagonists in systemic sclerosis.

Anti-annexin V autoantibodies and vascular abnormalities in systemic sclerosis: a longitudinal study

BACKGROUND

Annexins are a group of conserved proteins which exert several regulatory functions on various cellular activities. Increased frequency and levels of antibodies against annexin V have already been observed in several autoimmune diseases including systemic sclerosis (SSc), but their role as a vascular biomarker is unknown. The aim of this study was to determine the serum levels and the dynamical behavior of anti-annexin V antibodies over a 24 months follow-up in patients with SSc.

METHODS

In this bicentric cross-sectional study, 70 patients with SSc were consecutively selected from March 2016 to April 2017. Demographic and clinical features, including the presence of active DUs, were collected. Serum anti-annexin V IgG and IgM antibodies were measured at baseline and after 6, 12 and 24 months of follow-up. Videocapillaroscopy was performed in all patients.

RESULTS

Among the 70 SSc patients included anti-annexin V IgG was found in 11 patients (15.7%) (range of 15.88-39.48 U/mL) and anti-annexin V IgM in 10 patients (14.3%) (range of 14.16-22.69 U/mL) at baseline. During follow-up, the number of patients who were positive for anti-annexin V IgG and IgM remained stable over 24 months. Among the patients with positive anti-annexin V IgG at baseline the frequency of patients with necrosis or amputation of extremities, forced vital capacity less than 70% and pulmonary arterial hypertension (PAH) was significantly higher than in patients with negative anti-annexin V IgG antibodies. Patients with anti-annexin V IgG had also a higher Raynaud's Condition Score and a higher Health Assessment Questionnaire Disability Index (HAQ-DI) than patients without these antibodies at baseline. Patients with positive anti-annexin V IgM at baseline presented a higher frequency of PAH, compared to those with negative anti-annexin V IgM at baseline.

CONCLUSIONS

Anti-annexin V antibodies are stable and do not change their positivity during a 24 month follow-up in SSc patients. Anti-annexin V IgG was associated with more severe interstitial lung involvement and digital microangiopathy, and patients with anti-annexin V IgG or IgM had a higher occurrence of PAH indicating an association of these biomarker with more severe disease.

'Narrow-sense' and 'broad-sense' vascular abnormalities of systemic sclerosis

Systemic sclerosis (SSc) induces skin thickening and numerous symptoms involving the entire body. Collagen deposition, immune disorder, and vascular abnormalities is currently estimated to be three major causal factors involved in the respective conditions. Vascular abnormalities usually develop in the initial phase of this disease, and may exist in all phases; therefore, they markedly influence the patient's quality of life. This article reviews recent findings about 'narrow-sense' vascular lesions (including Raynaud's phenomenon, skin ulcers, nailfold bleedings, pitting scars, telangiectasia, and pulmonary hypertension) and 'broad-sense' vascular lesions (such as calcinosis or erectile dysfunction). Affected blood vessels can be classified into arteriole/small artery and capillary blood vessels. Furthermore, pathological changes include the proliferation of the vascular endothelial or smooth muscle cells, lumen stenosis by collagen accumulation of the vascular intima, vasodilation or fragility, and apoptosis. There may be interaction between vascular lesions, autoimmune disorder, and collagen deposition. Thus, various symptoms of this disease may be controlled through the treatment of vascular lesions.

Plasma Glycosaminoglycan Profiles in Systemic Sclerosis: Associations with MMP-3, MMP-10, TIMP-1, TIMP-2, and TGF-Beta

The aim of the study was to determine whether plasma levels of total glycosaminoglycans (GAGs), matrix metalloproteinases (MMPs) (MMP-3, MMP-10), and their tissue inhibitors (TIMPs) (TIMP-1, TIMP-2) as well as transforming growth factor β (TGF-β) differ in the patients with systemic sclerosis (SSc) in relation to the healthy subjects. Plasma samples were obtained from 106 people (64 patients with SSc and 42 healthy individuals) and measured for MMP-3, MMP-10, TIMP-1, TIMP-2, and TGF-β levels using ELISA methods. GAGs isolated from plasma samples were quantified using a hexuronic acid assay. The plasma levels of total GAGs, TIMP-1, TIMP-2, and TGF-β were significantly higher, while MMP-3 was significantly decreased in SSc patients compared to the controls. We have revealed a significant correlation between plasma GAGs and TGF-β (r = -0.47) and TIMP-2 (r = 0.38), respectively. The results of this study revealed that remodeling of the extracellular matrix, reflected by quantitative changes in plasma glycosaminoglycans, occurs during systemic sclerosis. Thus, the alterations in GAG metabolism connected with SSc may lead to systemic changes in the properties of the connective tissue extracellular matrix.

Electrocardiographic markers for the prediction of ventricular arrhythmias in patients with systemic sclerosis

SSc is an autoimmune disease characterized by microvascular damage, endothelial dysfunction and fibrosis of the skin and the internal organs. Cardiac manifestation in patients with SSc is one of the major organ involvements. Approximately 20% of SSc patients suffer from primary cardiovascular disease and another 20% may have secondary cardiac involvement. Although cardiac arrhythmias are mostly linked to myocardial fibrosis, atrioventricular conduction abnormalities are secondary to the fibrosis of the pulse conduction system. Despite the severe consequences of ventricular rhythm disturbances in patients with SSc, the exact role of electrocardiographic markers in the prediction of these arrhythmias has not yet been clearly elucidated. Therefore, the question is whether certain ECG parameters reflecting ventricular repolarization may help to recognize scleroderma patients with increased risk for ventricular arrhythmias and sudden cardiac death.

Toll-like receptors in mediating pathogenesis in systemic sclerosis

Toll-like receptors (TLRs) are evolutionarily conserved receptors essential for the host defence against pathogens. Both immune and non-immune cells can express TLRs, although at different levels. Systemic sclerosis (SSc) is a chronic disease in which autoimmunity, dysregulated profibrotic mediator release and activation of fibroblasts lead to dysregulated collagen deposition and fibrosis. There is now increasing knowledge that the innate immune system and, in particular, TLRs take a part in SSc pathogenesis. The list of endogenous ligands that can stimulate TLRs in SSc is growing: these ligands represent specific danger-associated molecular patterns (DAMPs), involved either in the initiation or the perpetuation of inflammation, and in the release of factors that sustain the fibrotic process or directly stimulate the cells that produce collagen and the endothelial cells. This review reports evidences concerning TLR signalling involvement in SSc. We report the new DAMPs, as well as the TLR-linked pathways involved in disease, with emphasis on type I interferon signature in SSc, the role of plasmacytoid dendritic cells (pDCs) and platelets. The dissection of the contribution of all these pathways to disease, and their correlation with the disease status, as well as their values as prognostic tools, can help to plan timely intervention and design new drugs for more appropriate therapeutic strategies.

Analysis of gene expression profiles and protein-protein interaction networks in multiple tissues of systemic sclerosis

Background

Systemic sclerosis (SSc), a multi-organ disorder, is characterized by vascular abnormalities, dysregulation of the immune system, and fibrosis. The mechanisms underlying tissue pathology in SSc have not been entirely understood. This study intended to investigate the common and tissue-specific pathways involved in different tissues of SSc patients.

Methods

An integrative gene expression analysis of ten independent microarray datasets of three tissues was conducted to identify differentially expressed genes (DEGs). DEGs were mapped to the search tool for retrieval of interacting genes (STRING) to acquire protein–protein interaction (PPI) networks. Then, functional clusters in PPI networks were determined. Enrichr, a gene list enrichment analysis tool, was utilized for the functional enrichment of clusters.

Results

A total of 12, 2, and 4 functional clusters from 619, 52, and 119 DEGs were determined in the lung, peripheral blood mononuclear cell (PBMC), and skin tissues, respectively. Analysis revealed that the tumor necrosis factor (TNF) signaling pathway was enriched significantly in the three investigated tissues as a common pathway. In addition, clusters associated with inflammation and immunity were common in the three investigated tissues. However, clusters related to the fibrosis process were common in lung and skin tissues.

Conclusions

Analysis indicated that there were common pathological clusters that contributed to the pathogenesis of SSc in different tissues. Moreover, it seems that the common pathways in distinct tissues stem from a diverse set of genes.

Systemic sclerosis patients are at higher risk of hyperthyroidism and have a worse survival than those without hyperthyroidism: A nationwide population-based cohort study

BACKGROUND

A high prevalence of thyroid disorders has been reported in patients with autoimmune diseases. The link between hyperthyroidism and systemic sclerosis (SSc) has been relatively overlooked, and only a few studies utilizing small samples or case reports have been reported so far.

OBJECTIVES

To investigate the association between SSc and hyperthyroidism.

METHODS

We designed a case-control study utilizing the medical database of the Clalit Health Services. Chi-square and t tests were used for univariate analysis, and a logistic regression model was used for multivariate analysis.

RESULTS

The study included 2,431 SSc patients and 12,710 age- and sex-matched controls. The mean age of the study population was 63.32 ± 18.06 years (median 66 years), and female-to-male ratio was 4.5:1. Age (P < .0001, OR 1.03 [95% CI 1.02-1.04]), female sex (P = .0015, OR 1.86 [95% CI 1.27- 2.74]) and diagnosis of SSc (P = .0011, OR 1.81[95% CI 1.27-2.58]) were all independently associated with hyperthyroidism. Patients with SSc and hyperthyroidism had 1.54-fold increase of mortality rates during a mean follow-up of 17 years than SSc patients without hyperthyroidism, even though at the Cox multivariate survival analysis, only age (HR 1.06 [95% CI 1.06-1.07], P < .0001) and diagnosis of SSc (HR 2.35 [CI 2.06 to 2.69], P < .0001) resulted associated with a higher risk of mortality.

CONCLUSIONS

Hyperthyroidism is highly prevalent among SSc patients and can negatively impact on their survival rates. Therefore, a pre-emptive screening may be warranted in all SSc patients. Further studies are needed to evaluate whether tight control and optimal treatment for hyperthyroidism may lead to a reduction of all-cause mortality in patients with SSc.

Arterial stiffness correlates with progressive nailfold capillary microscopic changes in systemic sclerosis: results from a cross-sectional study

BACKGROUND

While microangiopathy is well-documented in systemic sclerosis (SSc), a potential link between SSc and macrovascular disease is highly debated and remains to be established. The aim of the present study is to investigate the association between micro- and macrovascular involvement in the setting of SSc.

METHODS

Consecutive, consenting SSc patients were assessed by nailfold video-capillaroscopy (NVC) to evaluate the microcirculation. The number of capillaries per mm² and the capillaroscopic skin ulcer risk index (CSURI) were measured, and findings were also classified into three scleroderma patterns (i.e., early, active, and late). Carotid intima-media thickness (IMT), aortic augmentation index corrected for a heart rate of 75 beats per minute (AIx-75), carotid-femoral pulse wave velocity (PWV), and central systolic and diastolic blood pressure were also determined to assess macrovascular function.

RESULTS

A total of 37 patients were studied. A significant correlation was observed between AIx and the average number of capillaries per mm² (r = - 0.34, p = 0.047) and between AIx and CSURI (r = 0.35, p = 0.044). Patients with the "early" scleroderma pattern had lower AIx values compared with "active" (20.5 ± 11.4 vs 34.1 ± 11.5%, p = 0.02) and "late" (20.5 ± 11.4 vs 33.4 ± 8.8%, p = 0.05) patterns. No other significant correlations were found between macrovascular biomarkers (PWV, carotid IMT, systolic and diastolic central blood pressure) and the capillaroscopic measurements.

CONCLUSIONS

These data suggest that arterial stiffness (as assessed by AIx-75) correlates with microvascular damage in patients with SSc.

[Cancers in systemic sclerosis : risk factors, impact on survival and literature review]

INTRODUCTION

Patients with systemic sclerosis (SSc) have an increased risk of malignancy. In this study, we aimed to analyze the prevalence of cancer, the risk factors and the impact on overall survival.

PATIENTS AND METHODS

We analyzed clinical (history of cancer, toxic exposition, organ involvement), immunological and treatment data in a monocentric cohort of SSc patients followed between January 2004 and December 2017.

RESULTS

Two hundred and ten patients with SSc were included. During the follow-up, twenty-one patients (10 %) were diagnosed with malignancies. The underlying malignancies were breast adenocarcinoma (n=6, 28%), lung cancer (n=6, 28%), colorectal (colic adenocarcinoma, carcinoid tumor of the appendix), ovarian and cervix uteri, melanoma, kidney and papillary thyroid carcinoma (one of each). The median time between the first visit and the diagnosis of cancer was 4 [2-10] years. The overall survival in SSc patients with cancer was not significantly different from patients without cancer, with median survival during the first quartile (75%) at 12 years for patients with cancer and 11.6 years for those without cancer (P=0.9). The history of renal scleroderma crisis (HR 10.99, IC95% [1.95-62.07]; P=0.006) and the presence of anti-topoisomerase I antibodies (HR 5.5, IC95% [1.40-21.67]; P=0.01) were associated with an increased risk of cancer, whereas the presence of gastroesophageal reflux was inversely associated with the cancer occurrence (HR 0.22, IC95% [0.056-0.867]; P=0.03).

CONCLUSION

The history of renal scleroderma crisis and the positivity of anti-topoisomerase I antibodies were associated with an increased risk of cancer in SSc patients in this monocentric study.

Scleroderma renal crisis: a review for emergency physicians

Scleroderma renal crisis (SRC) remains a high-risk clinical presentation, and many patients require emergency department (ED) management for complications and stabilization. This narrative review provides an evidence-based summary of the current data for the emergency medicine evaluation and management of SRC. While SRC remains a rare clinical presentation, surveillance data suggest an overall incidence between 4 and 6% of patients with scleroderma. The diagnostic criteria for SRC include a new onset blood pressure > 150/85 mm Hg OR increase ≥ 20 mm Hg from baseline systolic blood pressure, along with a decline in renal function, defined as an increase serum creatinine of ≥ 10% and supportive features. There are many risk factors for SRC, including diffuse and rapidly progressive skin thickening, palpable tendon friction rubs, and new anemia or cardiac events. Critical patients should be evaluated in the resuscitation bay, and consultation with the nephrology team for appropriate patients improves patient outcomes.

Abnormalities of heart rate turbulence and heart rate variability as indicators of increased cardiovascular risk in patients with systemic sclerosis

Introduction

Systemic sclerosis (SSc) is a connective tissue disease manifested by progressive fibrosis of many internal organs including the cardiovascular system and development of autonomic disorders with sympathetic predominance. These abnormalities can increase cardiovascular mortality.

Aim

To evaluate heart rate turbulence (HRT) and variability (HRV) parameters (indicator of autonomic imbalance) obtained from 24-hour ECG Holter monitoring, as predictors of the increased cardiovascular risk in patients with scleroderma.

Material and methods

Thirty-twoscleroderma patients and 30 healthy people were included. After clinical examination, ECG, routine laboratory tests and echocardiography, participants performed 24-hour Holter-ECG at home. For HRT assessment, turbulence onset (To) and turbulence slope (Ts) parameters were used. Both time and frequency domain analysis of HRV was used. The HRV circadian rhythm was also evaluated.

Results

Time domain: SDNN, SDNN-ix, SDANN and frequency domain: LF, VLF, ULF, NHF, NLF, parameters were lower, while p50NN was higher in SSc as compared to the control group. There was also a loss of the circadian rhythm for r-MSSD and p50NN present in the control group. Abnormal HRT parameters To and/or Ts occurred in the SSc group only. The median value of To = –1.24% and Ts = 11.13 ms/RR did not differ significantly as compared to the control group.

Conclusions

The study confirmed the presence of HRV disturbances, including HRV circadian rhythm, as it may seem at an early stage of SSc. The HRT disorders may be characterized by the increasing changes with advancing disease. This indicates the presence of autonomic imbalance and an increased cardiovascular risk.

Ocular involvement in systemic sclerosis: A systematic literature review, it's not all scleroderma that meets the eye

OBJECTIVES

Systemic sclerosis (SSc) is a rare and complex autoimmune disorder characterized by microvascular damage and progressive fibrosis which affects the skin and multiple other organs. Much of the published data concerning SSc and the eye consists of single case reports or small case studies. This systematic review aims to provide an overview of the current level of evidence for SSc-related ocular changes.

MATERIALS AND METHODS

A systematic literature review was conducted using 3 electronic databases, according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. A combination of following keywords was used: "Systemic Sclerosis" and ophthalmology-related search terms, including the keywords "Eye", "Ocular" and "Ophthalmic". All articles were screened by 2 independent reviewers at title, abstract and full text level. We solely included case-control studies that investigated specific ocular findings in SSc patients compared to healthy controls.

RESULTS

Nine of 270 articles were retained. Dry eye symptoms are associated with SSc, whereas objective signs (Schirmer I testing) show conflicting results. There is insufficient evidence of SSc-related changes to the central corneal thickness. In terms of posterior segment involvement, choroidal vasculature appears to be affected to greater extent than the retinal microcirculation. However, the limited number of patients included in the studies renders it hazardous to draw overall conclusions.

CONCLUSIONS

There is a paucity of well-designed case-control studies investigating possible ocular involvement in SSc. Our systematic review demonstrates limited proven associations between SSc and ocular abnormalities, mainly in terms of dry eye symptoms and choroidal thickness. Future standardized prospective studies are needed to clarify the impact of the disease on the eye.

Mutations of FAM111B gene are not associated with Systemic Sclerosis

Systemic sclerosis (SSc) is a prototypic systemic fibrotic disease with unclearly characterized genetic basis. We have discovered that mutations in family with sequence similarity 111, member B (FAM111B) gene cause hereditary fibrosing poikiloderma with tendon contractures, myopathy, and pulmonary fibrosis, a multisystem fibrotic condition with clinical similarities to SSc. This observation has established FAM111B as a candidate gene for SSc.

PATIENTS AND METHODS

Demographic and clinical characteristics of consenting adults with definite SSc were recorded. Blood DNA analysis was performed using the High-Resolution Melt technique, and samples with abnormal electropherograms were selected for Sanger sequencing to identify mutations. Ethnically-matched controls from the general South African population were used to verify the frequency of variants in FAM111B. Public databases such as 1000 Genomes and ExAC were also used to verify the frequency of variants in FAM111B.

RESULTS

Of 131 patients, 118 (90.1%) were female, and 78 (59.5%) were black Africans. Genetic analysis revealed two FAM111B genetic variants. The c.917 A > G variant (rs200497516) was found in one SSc patients, and one control, and was classified as a missense variant of unknown significance. The c.988 C > T variant (rs35732637) occurred in three SSc patients and 42/243 (17.3%) of healthy controls, and is a known polymorphism.

CONCLUSION

One rare variant was found in a patient with SSc but has no functional or structural impact on the FAM111B gene. In this cohort, FAM111B gene mutations are not associated with SSc.

A Paradigmatic Interplay between Human Cytomegalovirus and Host Immune System: Possible Involvement of Viral Antigen-Driven CD8+ T Cell Responses in Systemic Sclerosis

Human cytomegalovirus (HCMV) is a highly prevalent opportunistic agent in the world population, which persists as a latent virus after a primary infection. Besides the well-established role of this agent causing severe diseases in immunocompromised individuals, more recently, HCMV has been evoked as a possible factor contributing to the pathogenesis of autoimmune diseases such as systemic sclerosis (SSc). The interplay between HCMV and immune surveillance is supposed to become unbalanced in SSc patients with expanded anti-HCMV immune responses, which are likely involved in the exacerbation of inflammatory processes. In this study, blood samples from a cohort of SSc patients vs. healthy subjects were tested for anti-HCMV immune responses (IgM, IgG antibodies, and T cells to peptide pools spanning the most immunogenic HCMV proteins). Statistically significant increase of HCMV-specific CD8+ T cell responses in SSc patients vs. healthy subjects was observed. Moreover, significantly greater HCMV-specific CD8+ T cell responses were found in SSc patients with a longer disease duration and those with higher modified Rodnan skin scores. Given the known importance of T cells in the development of SSc and that this virus may contribute to chronic inflammatory diseases, these data support a relevant role of HCMV-specific CD8+ T cell responses in SSc pathogenesis.

Effects of epigallocatechin-3-gallate (EGCG) on a scleroderma model of fibrosis

Objective

The aim of the present study was to evaluate the potential protective effects of epigallocatechin-3-gallate (EGCG) on fibrosis in bleomycin induced scleroderma model.

Materials and methods

Thirty-two healthy female Balb-c mice with the average body weight of 22±5 g were used in this study. The mice were randomly divided into four groups as control (n=8), Bleomycin (n=8), Bleomycin+EGCG (n=8) and EGCG (n=8). Skin tissue samples were collected to quantify matrix metalloproteinases (MMP-1, MMP-8, MMP-13), p-SMAD 2/3 and SMAD 2/3 in protein homogenates by western blotting. TGF-β1 expression was determined by real-time PCR. Immunohistopathological and histopathological examinations of skin tissues were also done.

Results

When measured with Masson Trichrome, EGCG treatment was found to decrease fibrosis in connective tissue compared to the BLM injected control. EGCG was decreased dermal fibrosis. Bleomycin+EGCG group showed a significant reduction in fibrosis at the dermal surface area using hematoxylin measurements compared with the BLM group. MMP-1, MMP-8 protein levels were increased and p-SMAD 2/3 protein level was decreased. TGF-β mRNA expression was decreased in the EGCG+BLM group compared with the BLM group.

Conclusion

These results suggest an antifibrotic role for EGCG.

Biomarkers for Pulmonary Vascular Remodeling in Systemic Sclerosis: A Pathophysiological Approach

Pulmonary arterial hypertension (PAH) is a severe complication of systemic sclerosis (SSc) associated with high morbidity and mortality. There are several biomarkers of SSc-PAH, reflecting endothelial physiology, inflammation, immune activation, extracellular matrix, metabolic changes, or cardiac involvement. Biomarkers associated with diagnosis, disease severity and progression have been identified, however, very few have been tested in a prospective setting. Some antinuclear antibodies such as nucleosome antibodies (NUC), anti-centromere antibodies (CENP-A/B) and anti-U3-ribonucleoprotein (anti-U3-RNP) are associated with PAH while anti-U1-ribonucleoprotein (anti-U1-RNP) is associated with a reduced PAH risk. Anti-endothelin receptor and angiotensin-1 receptor antibodies might be good markers of SSc-PAH and progression of pulmonary vasculopathy. Regarding the markers reflecting immune activation and inflammation, there are many inconsistent results. CXCL-4 was associated with SSc progression including PAH and lung fibrosis. Growth differentiation factor (GDF)-15 was associated with PAH and mortality but is not specific for SSc. Among the metabolites, kynurenine was identified as diagnostic marker for PAH, however, its pathologic role in the disease is unclear. Endostatin, an angiostatic factor, was associated with heart failure and poor prognosis. Established heart related markers, such as N-terminal fragment of A-type natriuretic peptide/brain natriuretic peptide (NT-proANP, NT-proBNP) or troponin I/T are elevated in SSc-PAH but are not specific for the right ventricle and may be increased to the same extent in left heart disease. Taken together, there is no universal specific biomarker for SSc-PAH, however, there is a pattern of markers that is strongly associated with a risk of vascular complications in SSc patients. Further comprehensive, multicenter and prospective studies are warranted to develop reliable algorithms for detection and prognosis of SSc-PAH.

Scleroderma Renal Crisis: A Reversible Cause of Left Ventricular Dysfunction

We report a case of acute left ventricular dysfunction due to myocarditis, in the setting of a scleroderma renal crisis. The case is particularly intriguing for the favorable outcome of both symptoms and heart function following immunosuppressive therapy. We also highlight the changes observed over time with image techniques as well as in electrocardiograms.

What can we learn from Fli1-deficient mice, new animal models of systemic sclerosis?

Systemic sclerosis is a complex multifactorial disease characterized by autoimmunity, vasculopathy, and selective organ fibrosis. A series of genetic and epidemiological studies have demonstrated that environmental influences play a central role in the onset of systemic sclerosis, while genetic factors determine the susceptibility to and the severity of this disease. Therefore, the identification of predisposing factors related to environmental influences would provide us with an informative clue to better understand the pathological process of this disease. Based on this concept, the deficiency of transcription factor Friend leukemia virus integration 1, which is epigenetically suppressed in systemic sclerosis, seems to be a potential candidate acting as the predisposing factor of this disease. Indeed, Fli1-mutated mice serve as a set of useful disease models to disclose the complex pathology of systemic sclerosis. This article overviews the recent advancement in systemic sclerosis animal models associated with Friend leukemia virus integration 1 deficiency.

Friends or Foes? Host defense (antimicrobial) peptides and proteins in human skin diseases

Host defense peptides/proteins (HDPs), also known as antimicrobial peptides/proteins (AMPs), are key molecules in the cutaneous innate immune system. AMPs/HDPs historically exhibit broad-spectrum killing activity against bacteria, enveloped viruses, fungi and several parasites. Recently, AMPs/HDPs were shown to have important biological functions, including inducing cell proliferation, migration and differentiation; regulating inflammatory responses; controlling the production of various cytokines/chemokines; promoting wound healing; and improving skin barrier function. Despite the fact that AMPs/HDPs protect our body, several studies have hypothesized that these molecules actively contribute to the pathogenesis of various skin diseases. For example, AMPs/HDPs play crucial roles in the pathological processes of psoriasis, atopic dermatitis, rosacea, acne vulgaris, systemic lupus erythematosus and systemic sclerosis. Thus, AMPs/HDPs may be a double-edged sword, promoting cutaneous immunity while simultaneously initiating the pathogenesis of some skin disorders. This review will describe the most common skin-derived AMPs/HDPs (defensins, cathelicidins, S100 proteins, ribonucleases and dermcidin) and discuss the biology and both the positive and negative aspects of these AMPs/HDPs in skin inflammatory/infectious diseases. Understanding the regulation, functions and mechanisms of AMPs/HDPs may offer new therapeutic opportunities in the treatment of various skin disorders.

Phenotypic Alterations Involved in CD8+ Treg Impairment in Systemic Sclerosis

Systemic sclerosis (SSc) is a connective tissue disease characterized by tissue fibrosis, vasculopathy, and autoimmunity. Although the exact pathogenetic mechanisms behind SSc remain to be fully elucidated, a great deal of evidence suggests the existence of an unbalanced ratio between the effector and regulatory arms of the immune system. With regard to the T regulatory (Treg) compartment, we observed that CD8+ Treg subsets display functional defects in SSc-affected patients. Since CD127 down-modulation and CD39 upregulation have been observed on Treg subsets, the phenotypic expression of these molecules was analyzed on the CD8+CD28− Treg precursors and on CD8+ Treg cells generated in vitro through interleukin-10 commitment. Immunophenotypic data from SSc patients were compared to those obtained from healthy subjects. The analyses performed on ex vivo-isolated CD8+CD28− Treg precursors did not show any significant differences in CD39 or CD127 expression as compared to values obtained from healthy donors. On the contrary, in vitro-generated CD8+ Tregs obtained from SSc patients displayed reduced expression of the CD39 molecule as compared to controls. Moreover, the percentage of CD127+ cells was significantly higher in in vitro-generated CD8+ Tregs from SSc patients compared to CD8+ Tregs obtained from healthy donors. Taken together, these findings may indicate an impairment of maturation processes affecting CD8+ Treg cells in SSc patients. This impairment of maturation involves phenotypic alterations that are mainly characterized by a deficient CD39 upregulation and a lack of down-modulation of the CD127 molecule.

T and NK Cell Phenotypic Abnormalities in Systemic Sclerosis: a Cohort Study and a Comprehensive Literature Review

Scleroderma (SSc) is a rare and heterogeneous immune-mediated disease involving the connective tissue and microvasculature whose pathogenesis remains unclear. Data concerning T and natural killer (NK) cell abnormalities and cytokine levels in the peripheral blood (PB) from patients with SSc are scarce, and the results are contradictory. The present study aimed to analyze the changes of T lymphocytes, NK cells, and T helper (Th)-related cytokines in the PB of patients with SSc in comparison to healthy individuals and its relation to disease subtype and stage, organ involvement, and nailfold capillaroscopic changes. A non-random convenience sample of 57 scleroderma patients was utilized. Fifty-five out of the 57 patients studied were women (97 %); 10 patients presented pre-scleroderma (pre-SSc) and 47 SSc: 34 limited cutaneous SSc (lcSSc) and 13 diffuse cutaneous SSc (dcSSc). Patients with SSc were classified in early (n = 7), intermediate (n = 10), and late (n = 30) disease. Blood samples were analyzed by flow cytometry for total T cells, CD4+ and CD8+ T cell subsets, total NK cells, and CD56+low and CD56+high NK cell subsets. T cells were further analyzed for the expression of the CD56 adhesion molecule and activation-related markers (HLA-DR, CD45RO). In addition, the serum levels of Th1-, Th2-, and Th17-related cytokines were measured by flow cytometry. Twenty-five healthy individuals recruited from the blood bank were used as controls. Patients had lower numbers of total lymphocytes and T cells comparing to healthy controls. Both CD4+ and CD8+ T cells were decreased, but differences were statistically significant only for CD8+ and CD8+ CD45RO+ T cells. These alterations were seen in patients with SSc but not in patients with pre-SSc, and, in general, they were more pronounced in patients with dcSSc than in patients with lcSSc, in patients with vascular involvement than in those without, as well as in patients having active and late nailfold capillaroscopic patterns. CD56+ T cells were also decreased in SSc patients, especially in those with active/late capillaroscopic patterns or with severe lung disease. Diminished numbers of circulating NK cells were also observed in patients with lcSSc and in those with early disease. No statistically significant changes were found in serum cytokine levels, as compared with controls. Patients with SSc had major alterations in circulating CD8+ and CD56+ T cells, as well as in NK cells, suggesting that these cells may play a relevant role in SSc pathogenesis, probably operating at different phases and/or at different organs. In addition, the serum levels of Th1, Th2, and Th17 cytokines did not provide useful information for evaluating T cell polarization in SSc.

Progranulin: A key player in autoimmune diseases

Autoimmune disease encompasses an array of conditions with a variety of presentations and the involvement of multiple organs. Though the etiologies of many autoimmune conditions are unclear, uncontrolled inflammatory immune response is believed to be a major cause of disease development and progression. Progranulin (PGRN), an anti-inflammatory molecule with therapeutic effect in inflammatory arthritis, was identified as an endogenous antagonist of TNFα by competitively binding to TNFR. PGRN exerts its anti-inflammatory activity through multiple pathways, including induction of T_reg differentiation and IL-10 expression and inhibition of chemokine release from macrophages. In addition, the protective role of PGRN has also been demonstrated in osteoarthritis, inflammatory bowel disease, and psoriasis. Intriguingly, PGRN was reported to contribute to development of insulin resistance in high-fat diet induced diabetes. Emerging evidences indicate that PGRN may also be associated with various autoimmune diseases, including systemic lupus erythematous, systemic sclerosis, multiple sclerosis and Sjogren's syndrome. This review summarizes recent studies of PGRN as a novel target molecule in the field of autoimmune disease, and provides updated information to inspire future studies.

A critical view on cardiovascular risk in systemic sclerosis

Systemic Sclerosis (SSc) is an autoimmune disorder characterized by microvascular injury and diffuse fibrosis of the skin and internal organs. While macrovascular disease and higher risk for cardiovascular events are well documented in other systemic rheumatic diseases such as rheumatoid arthritis and systemic lupus erythematosus, the presence and extent of atherosclerosis among patients with SSc is yet to be established. Primary cardiac involvement, due to impairment of coronary microvascular circulation and myocardial fibrosis, considerably affects prognosis and life expectancy of individuals with SSc, representing one of the leading causes of death in this population. On the other hand the existence and prevalence of atherosclerotic coronary disease remains an issue of debate as studies comparing structural and morphological markers of atherosclerosis and cardiovascular events between SSc patients and the general population have yielded controversial results. The aim of this review is to summarize recent literature about the prevalence of cardiovascular disease in SSc, review the surrogate markers of CVD that have been evaluated and examine whether common pathogenic mechanisms exist between SSc and macrovascular disease.

Serum adropin level and ENHO gene expression in systemic sclerosis

Adropin, a secreted protein, is encoded by the energy homeostasis associated (ENHO) gene. It has been implicated in the several physiological and pathological processes such as angiogenesis and apoptosis. Therefore, the aim of present study was to investigate serum adropin levels and ENHO gene expressions in systemic sclerosis (SSc) characterized by vasculopathy, inflammation, and progressive fibrosis of the skin and internal organs. The study includes 27 patients with SSc, 39 patients with Behçet's disease (BD), and 20 healthy controls (HC). Serum adropin levels and ENHO gene expressions by peripheral blood mononuclear cells were analyzed by ELISA method and by real-time PCR, respectively. The serum adropin levels were higher in the SSc and BD groups than in the HC group (p = 0.023 and p < 0.001, respectively). However, there were no significant differences among the groups in terms of ENHO gene expressions (p ANOVA = 0.149). There was no significant difference between the limited and diffuse cutaneous subtypes of SSc in terms of serum adropin level and ENHO gene expression. Moreover, serum adropin level and ENHO gene expression were not associated with the disease activity and severity indexes. ENHO gene expression was correlated with the triglyceride levels in the BD group (r = -0.426, p = 0.027). The augmented serum adropin levels may be expected in the chronic inflammatory disease and seem not to be characteristic of only SSc. However, further studies are needed to explain the precise role of adropin in SSc.

Post-occlusive reactive hyperaemia (POHR) in systemic sclerosis: very early disease (VEDOSS) represents a separate entity compared to established disease

OBJECTIVES

Vascular involvement is a key feature of systemic sclerosis (SSc). Vascular changes are central to the pathogenesis of the disease and the assessment of vascular involvement has a prognostic value. This assessment therefore has a pivotal role in the management of SSc patients. The aim of our study was to evaluate post-occlusive reactive hyperaemia (PORH) in consecutive SSc patients and to test whether a PORH test might be a useful tool for the early diagnosis of SSc.

METHOD

Between April 2011 and April 2015, 60 consecutive SSc patients (mean age 56 ± 15 years, females:males = 18:1) were enrolled in the study. The patients were divided into those with full-blown SSc (n = 50) and those with very early diagnosis of SSc (VEDOSS) (n = 10) according to the literature. Laser speckle contrast analysis (LASCA) was used to assess PORH.

RESULTS

A statistically significant difference was detected in the post-ischaemic hyperaemic peak flow between VEDOSS and established SSc (424% vs. 137%, p = 0.0011). PORH peak flow decreased according to the capillaroscopic pattern (early = 419%, active = 163%, late = 145%, p = 0.0027). Moreover, a correlation between capillary density and peak flow was revealed (rho = 0.33, p < 0.01).

CONCLUSIONS

These data show a different pattern of vascular involvement in VEDOSS compared to established disease that mirrors capillaroscopic changes. Functional features of very early and established disease seem to be the physiological counterpart of abnormalities detected by capillaroscopy. The POHR test might be a useful aid for further characterization of vascular involvement in SSc. In particular, blunted POHR might prove a tool to separate pre-clinical from full-blown SSc.

Vasculopathy in scleroderma

Systemic sclerosis (SSc) is a multisystem connective tissue disorder featured by vascular injury and fibrosis of the skin and various internal organs with autoimmune background. Although the pathogenesis of SSc still remains elusive, it is generally accepted that initial vascular injury due to autoimmunity and/or environmental factors causes structural and functional abnormalities of vasculature which eventually result in the constitutive activation of fibroblasts in various organs. Structural alterations consist of destructive vasculopathy (loss of small vessels) and proliferative obliterative vasculopathy (occlusion of arterioles and small arteries with fibro-proliferative change) caused by impaired compensatory vasculogenesis and angiogenesis. Impaired function of SSc vasculature includes the altered expression of cell adhesion molecules predominantly inducing Th2 and Th17 cell infiltration, endothelial dysfunction primarily due to the low availability of nitric oxide, the activated endothelial-to-mesenchymal transition leading to fibro-proliferative vascular change and tissue fibrosis, and the impaired coagulation/fibrinolysis system promoting the formation of intravascular fibrin deposits. Recent new insights into the therapeutic mechanisms of intravenous cyclophosphamide pulse and bosentan and the establishment of a new SSc animal model (Klf5 (+/-);Fli1 (+/-) mice) provide us useful clues to further understand the development of vascular alterations characteristic of SSc. This article overviewed the present understanding of the pathogenesis of SSc vasculopathy.