Pathogenesis of systemic sclerosis: recent insights of molecular and cellular mechanisms and therapeutic opportunities

Current and Future Outlook on Disease Modification and Defining Low Disease Activity in Systemic Sclerosis

Systemic sclerosis (SSc) is an autoimmune rheumatic disease with heterogeneous clinical manifestations and a variable course in which the severity of the pathology dictates the disease prognosis and course. Among autoimmune rheumatic diseases, SSc has the highest mortality rate among all rheumatic diseases, though there are exciting new therapeutic targets that appear to halt the progression of SSc manifestations such as skin or lung fibrosis. In selected patients, high-intensity regimens with autologous stem cell transplantation can favorably modify the course. In what was once thought to be an untreatable disease, targeted therapies have now changed the outlook of SSc to a treatable disorder. Herein, we discuss the targeted therapies modifying the outlook on selected organ involvement and creating opportunities for future treatment. We also present a framework for defining low disease activity in SSc.

Predictors of progression in systemic sclerosis patients with interstitial lung disease

Systemic sclerosis (SSc) is a systemic autoimmune disease affecting multiple organ systems, including the lungs. Interstitial lung disease (ILD) is the leading cause of death in SSc.

There are no valid biomarkers to predict the occurrence of SSc-ILD, although auto-antibodies against anti-topoisomerase I and several inflammatory markers are candidate biomarkers that need further evaluation. Chest auscultation, presence of shortness of breath and pulmonary function testing are important diagnostic tools, but lack sensitivity to detect early ILD. Baseline screening with high-resolution computed tomography (HRCT) is therefore necessary to confirm an SSc-ILD diagnosis. Once diagnosed with SSc-ILD, patients' clinical courses are variable and difficult to predict, although certain patient characteristics and biomarkers are associated with disease progression. It is important to monitor patients with SSc-ILD for signs of disease progression, although there is no consensus about which diagnostic tools to use or how often monitoring should occur. In this article, we review methods used to define and predict disease progression in SSc-ILD.

There is no valid definition of SSc-ILD disease progression, but we suggest that either a decline in forced vital capacity (FVC) from baseline of ≥10%, or a decline in FVC of 5–9% in association with a decline in diffusing capacity of the lung for carbon monoxide of ≥15% represents progression. An increase in the radiographic extent of ILD on HRCT imaging would also signify progression. A time period of 1–2 years is generally used for this definition, but a decline over a longer time period may also reflect clinically relevant disease progression.

Lung function tests and chest imaging help predict who has SSc-associated ILD and whether it will progress. In the absence of standardised methods for doctors, we recommend a strategy that combines both lung function tests and chest imaging.http://bit.ly/2uK9ZD2

The contribution of epigenetics to the pathogenesis and gender dimorphism of systemic sclerosis: a comprehensive overview

Systemic sclerosis (SSc) is a life-threatening connective tissue disorder of unknown etiology characterized by widespread vascular injury and dysfunction, impaired angiogenesis, immune dysregulation and progressive fibrosis of the skin and internal organs. Over the past few years, a new trend of investigations is increasingly reporting aberrant epigenetic modifications in genes related to the pathogenesis of SSc, suggesting that, besides genetics, epigenetics may play a pivotal role in disease development and clinical manifestations. Like many other autoimmune diseases, SSc presents a striking female predominance, and even if the reason for this gender imbalance has yet to be completely understood, it appears that the X chromosome, which contains many gender and immune-related genes, could play a role in such gender-biased prevalence. Besides a short summary of the genetic background of SSc, in this review we provide a comprehensive overview of the most recent insights into the epigenetic modifications which underlie the pathophysiology of SSc. A particular focus is given to genetic variations in genes located on the X chromosome as well as to the main X-linked epigenetic modifications that can influence SSc susceptibility and clinical phenotype. On the basis of the most recent advances, there is realistic hope that integrating epigenetic data with genomic, transcriptomic, proteomic and metabolomic analyses may provide in the future a better picture of their functional implications in SSc, paving the right way for a better understanding of disease pathogenesis and the development of innovative therapeutic approaches.

Prognostic Value of Lung Ultrasound B-Lines in Systemic Sclerosis

BACKGROUND

A high percentage of systemic sclerosis (SSc) patients experience interstitial lung disease (ILD) during the disease course. Recent data have shown that lung ultrasound (LUS) can assess ILD by the evaluation of B-lines, the sonographic sign of pulmonary interstitial involvement.

RESEARCH QUESTION

To establish the prognostic value of B-lines in a large number of patients with SSc.

STUDY DESIGN AND METHODS

A total of 396 consecutive patients with SSc, who were enrolled at three Rheumatology Departments, underwent a comprehensive LUS examination on the anterolateral and posterior chest for a total of 58 scanning sites. All available clinical, imaging, and functional data were recorded. Patients were followed after enrolment to establish the prognostic role of LUS.

RESULTS

The median number of B-lines was higher in patients with the diffuse cutaneous subset (44 vs 17 B-lines; P < .0001), topoisomerase I autoantibodies (39 vs 16 B-lines; P < .0001), and the presence of ILD at chest high-resolution CT (45 vs 9 B-lines; P < .0001). At multivariable analysis, the number of posterior B-lines ≥5 was associated with new development or worsening ILD (hazard ratio, 3.378; 95% CI, 1.137-9.994; P = .028), with additional value over topoisomerase I positivity. The prognostic value was further confirmed in the subgroup of patients with known ILD at baseline (hazard ratio, 1.010; 95% CI, 1.003-1.018; P = .008).

INTERPRETATION

Lung ultrasound B-lines are associated with worsening or development of pulmonary deterioration. In the near future, LUS might become part of the diagnostic and prognostic armamentarium in patients with SSc, which would allow a more sustainable and user-friendly approach to this very fragile population.

Systemic sclerosis and the COVID-19 pandemic: World Scleroderma Foundation preliminary advice for patient management

Due to the frequent presence of interstitial lung disease and widespread use of immunosuppressive treatment, systemic sclerosis (SSc) patients may be considered at risk for a more severe disease course and higher mortality when they develop Severe Acute Respiratory Syndrome - Coronavirus - 2 (SARS-CoV-2) virus infection. Therefore, with World Scleroderma Foundation endorsement, experts from different specialties including rheumatology, virology and clinical immunology gathered virtually to answer to the main practical clinical questions regarding SARS-CoV-2 infection coming from both patients and physicians. This preliminary advice is aligned with other national and international recommendations, adapted for SSc patients.

The Renal Resistive Index: A New Biomarker for the Follow-up of Vascular Modifications in Systemic Sclerosis

Objective.

The aim of the present retrospective observational study was to evaluate the change of Renal Resistive Index (RRI) over time (ΔRRI) and under treatment in patients with systemic sclerosis (SSc) as well as to correlate these changes with disease complications.

Methods.

Two hundred thirty patients [29 male, median age 57 (IQR 48–67) yrs] were enrolled. At baseline and follow-up (3.43, IQR 2.81–4.45 yrs), we collected the following data: disease variables, nailfold videocapillaroscopy (NVC) pattern, forced vital capacity (FVC), diffusing lung capacity for carbon monoxide (DLCO), systolic pulmonary arterial pressure (sPAP), presence of interstitial lung disease, RRI, evaluation of glomerular filtration rate, and new onset of pulmonary arterial hypertension (PAH).

Results.

RRI value is high in SSc patients with digital ulcers and anticentromere antibodies, active and late NVC patterns, and limited cutaneous SSc. A significant correlation was observed between ΔRRI and ΔsPAP (R = 0.17, P = 0.02), with statistically higher ΔRRI (0.08 ± 0.02 vs 0.03 ± 0.05, P = 0.04) in patients complicated by PAH onset. No other new-onset complication was associated with ΔRRI. The receiver-operating characteristic curve analysis confirmed the predictive role of ΔRRI in development of new PAH (area under the curve 0.84, 95% CI 0.75–0.93, P = 0.02). In patients with SSc never exposed to sildenafil, ΔRRI was higher (0.04 ± 0.05) compared to both patients exposed to sildenafil during the study period (0.01 ± 0.05, P = 0.03) or in those exposed at the time of baseline evaluation (0.00 ± 0.05, P = 0.01).

Conclusion.

RRI and its variation in time are a reliable marker of SSc-related vasculopathy, both in renal and extrarenal compartments.

Effects of Nintedanib in an Animal Model of Liver Fibrosis

Systemic sclerosis can affect multiple internal organs, including the liver and lungs. Nintedanib, an antifibrotic approved for treatment of interstitial lung disease associated with systemic sclerosis, may have activity outside of the lungs. This study explored the effect of preventive and therapeutic nintedanib treatment in a 3-week carbon tetrachloride (CCL₄)-induced (500 mg/kg/day twice weekly for 3 weeks) model of hepatic inflammation and fibrosis in C57Bl/6 mice (aged 8 weeks, n = 5 per group). Mice also received nintedanib (30 or 60 mg/kg/day) either each day for 21 days (preventive treatment) or from day 7 or day 14 (therapeutic treatment). Preventive nintedanib treatment at both doses significantly reduced CCL₄-induced increases in myeloperoxidase (p < 0.01), hepatic collagen (p < 0.001), and interleukin (IL)-6 (p < 0.01) in the liver. Nintedanib also significantly reduced hepatic necrosis (p < 0.01 and p < 0.05), inflammation (p < 0.001 and p < 0.05), fibrosis (p < 0.001 and p < 0.05) and IL-1β (p < 0.05 and p < 0.001) at both 30 and 60 mg/kg/day, respectively. Therapeutic treatment with nintedanib at 30 and 60 mg/kg/day significantly reduced CCL₄-induced serum alanine aminotransferase from day 7 (p < 0.05 and p < 0.001) and day 14 (p < 0.01 and p < 0.05), respectively. Increases in tissue inhibitor of metalloproteinase-1 were significantly reduced by nintedanib at 60 mg/kg/day from day 7 only (p < 0.001), and nintedanib completely blocked elevation of IL-6 and IL-1β levels regardless of dose or start of treatment (p < 0.05-p < 0.001). In both the preventive and therapeutic treatment schedules of the study, nintedanib treatment was beneficial in attenuating CCL₄-induced pathology and reducing hepatic injury, inflammation, and fibrosis, demonstrating that nintedanib has antifibrotic and anti-inflammatory activity outside of the lungs.

Treatment modalities and drug survival in a systemic sclerosis real-life patient cohort

BACKGROUND

European data indicate that systemic sclerosis (SSc)-related death rates are increasing, thus raising concerns about SSc's optimal management. Herein, we describe current treatment modalities and drug survival in a real-life SSc cohort.

METHODS

Details on immunosuppressive/antiproliferative (methotrexate, mycophenolate, cyclophosphamide, azathioprine, rituximab, tocilizumab) and vasoactive agent [(endothelin receptor antagonists (ERAs), sildenafil, iloprost, and calcium channel blockers (CCB)] administration during the disease course (11.8 ± 8.4 years, mean + SD) of 497 consecutive patients examined between 2016 and 2018 were retrospectively recorded. Drug survival was assessed by Kaplan-Meier analysis.

RESULTS

Methotrexate was the most frequently administered immunosuppressive/antiproliferative agent (53% of patients), followed by cyclophosphamide (26%), mycophenolate (12%), and azathioprine (11%). Regarding vasoactive agents, CCB had been ever administered in 68%, ERAs in 38%, iloprost in 7%, and sildenafil in 7% of patients; 23% of patients with pulmonary fibrosis had never received immunosuppressive/antiproliferative agents, 33% of those with digital ulcers had never received ERAs, iloprost, or sildenafil, whereas 19% of all patients had never received either immunosuppressive/antiproliferative or other than CCB vasoactive agents. Survival rates of methotrexate, cyclophosphamide, and mycophenolate differed significantly, being 84/75%, 59/43%, and 74/63% at 12/24 months, respectively, with inefficacy being the most frequent discontinuation cause. Conversely, CCB, ERAs, and sildenafil had high and comparable retention rates of 97/91%, 88/86%, and 80/80%, respectively.

CONCLUSIONS

Existing therapeutic limitations indicate that more evidence-based treatment is warranted for successful management of SSc. Vasculopathy seems to be managed more rigorously, but the low retention rates of immunosuppressive/antiproliferative drugs suggest that effective and targeted disease-modifying agents are warranted.

Applicability of shear wave elastography for the evaluation of skin strain in systemic sclerosis

The assessment of skin fibrosis is vital for the diagnosis and monitoring of treatment in the systemic sclerosis (SSc)-a severe autoimmune disease. The elastography is a technique of skin fibrosis assessment through the evaluation of skin strain. We compared the efficacy of the shear wave elastography (SWE) and commonly used modified Rodnan skin score (RSS) in skin fibrosis assessment in SSc. The study included 40 SSc patients and 28 healthy individuals, with the exclusion of individuals with other skin/autoimmune diseases. Skin thickness using RSS and skin strain using SWE were assessed in the same 20 body localizations. Subjects' informed consent and the bioethics committee approval were obtained. Elastographic skin strain correlated positively with both partial and overall RSS values, with strong positive correlation (r ≥ 0.75) for hands and fingers localizations in particular. In SSc patients with normal RSS values, the elastographic strain was significantly higher than in healthy controls. Elastographic strain of fingers' skin evaluated in SWE is highly accurate for distinguishing SSc patients (sensitivity 0.897-0.923, specificity 0.929-0.964, positive predictive value 0.946-0.973, negative predictive value 0.867-0.900). ESW results are substantially more reproducible than those of RSS examination (intraclass correlation coefficients: 0.987 vs. 0.941). The shear wave elastography is more reproducible and has higher sensitivity than RSS in the evaluation of skin condition in SSc, especially in case of changes non-detectable on physical evaluation, indicating it might become a useful tool in SSc diagnosis.

Emerging targets of disease-modifying therapy for systemic sclerosis

Systemic sclerosis (SSc) has the highest cause-specific mortality of all the connective tissue diseases, and the aetiology of this complex and heterogeneous condition remains an enigma. Current disease-modifying therapies for SSc predominantly target inflammatory and vascular pathways but have variable and unpredictable clinical efficacy, and none is curative. Moreover, many of these therapies possess undesirable safety profiles and have no appreciable effect on long-term mortality. This Review describes the most promising of the existing therapeutic targets for SSc and places them in the context of our evolving understanding of the pathophysiology of this disease. As well as taking an in-depth look at the immune, inflammatory, vascular and fibrotic pathways implicated in the pathogenesis of SSc, this Review discusses emerging treatment targets and therapeutic strategies. The article concludes with an overview of important unanswered questions in SSc research that might inform the design of future studies of treatments aimed at modifying the course of this disease.

The role of innate immune cells in systemic sclerosis in the context of autologous hematopoietic stem cell transplantation

Systemic sclerosis (SSc) is a complex, heterogeneous autoimmune connective tissue disease. Autologous hematopoietic stem‐cell transplantation (AHSCT) has emerged as a valuable treatment option for rapidly progressive diffuse cutaneous SSc (dcSSc) patients, and thus far is the only treatment that has been shown to have a long‐term clinical benefit. AHSCT is thought to reintroduce immune homeostasis through elimination of pathogenic self‐reactive immune cells and reconstitution of a new, tolerant immune system. However, the mechanism of action underlying this reset to tolerance remains largely unknown. In this study we review the immune mechanisms underlying AHSCT for SSc, with a focus on the role of the innate immune cells, including monocytes and natural killer (NK) cells, in restoring immune balance after AHSCT.

Microparticles in systemic sclerosis, targets or tools to control fibrosis: This is the question!

Systemic sclerosis is the main systemic fibrotic disease with unknown etiology characterized by peripheral microvascular injury, activation of immune system, and wide-spread progressive fibrosis. Microparticles can be derived from any cell type during normal cellular differentiation, senescence, and apoptosis, and also upon cellular activation. Carrying along a broad range of surface cytoplasmic and nuclear molecules of originating cells, microparticles are closely implicated in inflammation, thrombosis, angiogenesis, and immunopathogenesis. Recently, microparticles have been proposed as biomarkers of endothelial injury, which is the primary event in the genesis of tissue fibrosis. Microparticles may have a role in fostering endothelial to mesenchymal transition, thus giving a significant contribution to the development of myofibroblasts, the most important final effectors responsible for tissue fibrosis and fibroproliferative vasculopathy. Thanks to potent profibrotic mediators, such as transforming growth factor beta, platelet-derived growth factor, high mobility group box 1 protein, nicotinamide adenine dinucleotide phosphate oxidase 4, and antifibrotic agents, such as matrix metalloproteinases, microparticles may play an opposite role in fibrosis.

Is biological therapy in systemic sclerosis the answer?

Systemic sclerosis is a systemic fibrosing disorder associated with significant morbidity and mortality, with no universally accepted disease-modifying therapy. Significant advances in the understanding of systemic sclerosis in recent years have guided the exploration of biological drugs in systemic sclerosis. In this narrative review, we summarize the published literature on biologic therapies in systemic sclerosis. A double-blind randomized trial, and an open label trial of tocilizumab (which antagonizes the interleukin 6 receptor), identified potential benefits in skin and lung fibrosis in systemic sclerosis; however, these differences failed to attain statistical significance. Two open-label trials compared rituximab (which depletes B lymphocytes) to conventional treatment/ cyclophosphamide in systemic sclerosis-associated interstitial lung disease (ILD), and revealed significant improvements in lung functions and skin disease with rituximab. Significant observational data also support the use of rituximab in skin, lung, muscle and joint manifestations of systemic sclerosis. Abatacept (which blocks T lymphocyte activation) has demonstrated utility for skin and joint disease in systemic sclerosis; a recent clinical trial failed to demonstrate benefits in improving skin thickness compared to placebo. Agents targeting type I interferons, interleukin 17 pathway, CD19 and plasma cells hold promise in systemic sclerosis; however, high-quality evidence is lacking. The results of different ongoing clinical trials targeting B lymphocytes, T lymphocytes, various cytokines (interleukins 6, 17, 4, 13, IL-1α), platelet-derived growth factor receptor, proteasome, integrins or oncostatin M may help guide future therapeutic regimens with biological agents in systemic sclerosis.

Increased expression of the TNF superfamily member LIGHT/TNFSF14 and its receptors (HVEM and LTßR) in patients with systemic sclerosis

OBJECTIVES

This study aimed to assess the potential role of the TNF superfamily member lymphocyte T-related inducible ligand that competes for glycoprotein D binding to herpesvirus entry mediator on T cells (LIGHT) in SSc through evaluation of: skin expression of LIGHT and its receptors, herpesvirus entry mediator and lymphotoxin ß-related receptor, and serum concentration of LIGHT in SSc patients.

METHODS

Expression of LIGHT and its receptors was investigated by immunohistochemistry and evaluated semi-quantitatively in skin biopsies from 19 SSc patients and 9 healthy controls. Serum levels of LIGHT were measured using ELISA in 329 patients with SSc and 50 control subjects.

RESULTS

Expression of LIGHT and both receptors was higher in SSc patients compared with controls (P < 0.05 for all comparisons). Patients with early SSc (⩽ 3 years from the first non-Raynaud's phenomenon symptom) showed higher expression of LIGHT and herpesvirus entry mediator compared with patients with longer disease duration (P < 0.05 for both comparisons). The mean serum concentration of LIGHT was significantly higher in SSc patients compared with the controls (P < 0.05). High serum concentration of LIGHT was associated with male sex, presence of digital ulcers, muscle involvement (defined by elevated serum creatine kinase levels), steroid treatment and lack of ACA. However, in multivariate regression analysis only presence of digital ulcers and creatine kinase elevation were independently associated with serum concentration of LIGHT.

CONCLUSION

These data provide the first evidence of overexpression of LIGHT and its receptors in SSc and suggest that the LIGHT axis might contribute to the pathogenesis of SSc. Increased serum concentrations of LIGHT seem to reflect vascular injury in SSc.

Collaborative National Quality and Efficacy Registry (CONQUER) for Scleroderma: outcomes from a multicenter US-based systemic sclerosis registry

The Collaborative National Quality and Efficacy Registry (CONQUER) for Scleroderma is a multicenter US-based longitudinal study of patients with systemic sclerosis (SSc) within 5 years of first non-Raynaud's symptom. The data collection methodology incorporates successful models from other SSc registries. The cohort is designed to provide linked bio-specimen and clinical outcomes data on a longitudinal cohort of SSc patients for validation of hypothesis-driven research and to provide a platform for studying patient-reported outcomes in scleroderma. The CONQUER registry was developed using the guidelines of the International Society for Biological Repositories, and was an iterative process between physicians with an expertise in SSc, patient stakeholders, and information technology experts. Enrollment commenced in June 2018. During the first 6 months of the CONQUER Scleroderma study, 151 SSc patients with less than 5 years of disease duration (from first non-Raynaud's symptom) have been recruited. The mean age is 51 ± 14 years, 83% are female, and 60% of patients have diffuse disease. Survey completion rates are above 88% for all patient-reported outcome surveys. Bio-specimen collection rates are over 97%, and disease severity score completion rates are over 98%. Pulmonary function test data is available on 91% of patients, and echocardiography is available 80%. The CONQUER scleroderma study provides a unique and growing resource for studying scleroderma in a longitudinal, US-based population. KEY POINTS : • The Collaborative National Quality and Efficacy Registry (CONQUER) for Scleroderma is a multicenter US-based longitudinal study of patients with systemic sclerosis (SSc) within 5 years of first non-Raynaud's symptom. • The CONQUER scleroderma study provides a unique and growing resource for studying scleroderma in a longitudinal, US-based population. • CONQUER is innovative in its design in that it is focused on prospective collection of paired clinical and patient outcome data with bio-specimens.

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.

Nintedanib: New indication for systemic sclerosis-associated interstitial lung disease

Nintedanib (Ofev™), an oral triple kinase inhibitor targeting pro-fibrotic pathways, has been used for treatment of idiopathic pulmonary fibrosis (IPF). Based on positive results from phase III, placebo-controlled, randomized comparative clinical trial conducted in patients with systemic sclerosis-associated interstitial lung disease (SSc-ILD), nintedanib received marketing approval in the United States and Japan for the treatment of SSc-ILD. Nintedanib significantly reduced the annual rate of decline in forced vital capacity over 52 weeks compared with placebo. The safety profiles observed in this trial were consistent with those reported in IPF patients, and the most common adverse events were gastrointestinal disorders, including diarrhea, nausea, and vomiting, which sometimes lead to discontinuation or permanent dose reduction of nintedanib. In contrast, serious adverse events were infrequent and were related mostly to worsening of cardiopulmonary involvement of SSc. This review summarizes the milestones in development of nintedanib leading to the approval for the treatment of SSc-ILD, and covers mechanisms of action, efficacy results and safety profiles, and future perspectives of nintedanib.

Significance of the angiotensin I/angiotensin II/angiotensin-(1-7) axis in the pathogenesis of systemic sclerosis

BACKGROUND

Systemic sclerosis (SSc) is a multisystemic disease with an extensive microvasculopathy. Previously, disturbances in plasma levels of angiotensin II (Ang II) and its antagonistic angiotensin-(1-7) (Ang-(1-7)) were found in patients with SSc. Their significance in a pathogenesis of SSc stays unclear due to discrepancies of earlier studies.

OBJECTIVES

To evaluate a significance of disturbances in production pathway of angiotensins in a development of SSc.

METHODS

There were enrolled 27 patients with established SSc, 23 subjects with very early SSc and 23 healthy controls. The diagnosis of SSc was established in patients who met EULAR/ACR 2013 classification criteria. Very early SSc described patients with Raynaud's phenomenon having SSc-specific antinuclear antibodies and SSc-like abnormalities in nailfold videocapillaroscopy. Patients were submitted to evaluation of internal organ involvement and blood sampling to assay plasma levels of angiotensin I, angiotensin II and angiotensin-(1-7) with ELISA technique.

RESULTS

Plasma level of angiotensin-(1-7) was significantly reduced in both SSc group (median = 47.2 pg/mL; P < 0.001) and ones with very early SSc (median = 102.7 pg/mL; P = 0.002) when compared to healthy controls (median = 176.1 pg/mL). A tendency to higher than in control group (median = 214 pg/mL) plasma level of angiotensin I was seen in SSc group (median = 392 pg/mL; P = 0.059). Differences in plasma level of angiotensin II were insignificant between all study groups. Those disturbances produced unfavourable angiotensin-(1-7)/angiotensin II (%) ratio in both groups of patients, which achieved statistical significance in subjects with established SSc (P < 0.001). Production pathway of angiotensins showed a dependence on a subtype of SSc, immune profile and a presence of interstitial lung disease.

CONCLUSIONS

Production of angiotensin-(1-7) was significantly reduced in both SSc patients and those ones with very early SSc, although a significant imbalance between angiotensin II and angiotensin-(1-7) occurred only in subjects with established disease.

Systemic Sclerosis Serum Significantly Impairs the Multi-Step Lymphangiogenic Process: in Vitro Evidence

In systemic sclerosis (SSc), the possible involvement of lymphatic microcirculation and lymphangiogenesis has traditionally been overshadowed by the greater emphasis placed on dysfunctional blood vascular system and angiogenesis. In the present in vitro study, we explore for the first time whether the SSc microenvironment may interfere with lymphangiogenesis, a complex, multi-step process in which lymphatic microvascular endothelial cells (LMVECs) sprout, migrate, and proliferate to generate new lymphatic capillaries. Normal human adult dermal LMVECs from three donors were treated with serum from SSc patients (n = 8), serum from healthy individuals (n = 8), or recombinant human vascular endothelial growth factor (VEGF)-C as a positive control for lymphangiogenesis. Cell proliferation, Boyden chamber Matrigel chemoinvasion, wound healing capacity, and lymphatic capillary morphogenesis on Geltrex were assayed. VEGF-C serum levels were measured by enzyme-linked immunosorbent assay. Gene and protein expression levels of the lymphangiogenic orchestrators VEGF receptor-3 (VEGFR-3)/Flt-4 and neuropilin-2 (NRP-2) were determined by real-time PCR and Western blotting, respectively. Conditioning with SSc serum significantly inhibited LMVEC proliferation, Matrigel invasion, and wound healing capacity with respect to healthy serum. The ability of LMVECs to form lymphatic tubes on Geltrex was also severely compromised in the presence of SSc serum. VEGF-C levels were comparable in SSc and healthy sera. Treatment with SSc serum resulted in a significant downregulation of both VEGFR-3/Flt-4 and NRP-2 mRNA and protein levels. In SSc, the pathologic environment severely hampers every lymphangiogenesis step, likely through the reduction of pro-lymphangiogenic VEGFR-3/NRP-2 co-receptor signaling. The impairment of the lymphangiogenic process opens a new scenario underlying SSc vascular pathophysiology, which is worth investigating further.

Toll-Like Receptor Mediated Activation of Natural Autoantibody Producing B Cell Subpopulations in an Autoimmune Disease Model

Altered expression and function of the Toll-like receptor (TLR) homologue CD180 molecule in B cells have been associated with autoimmune disorders. In this study, we report decreased expression of CD180 at protein and mRNA levels in peripheral blood B cells of diffuse cutaneous systemic sclerosis (dcSSc) patients. To analyze the effect of CD180 stimulation, together with CpG (TLR9 ligand) treatment, on the phenotype defined by CD19/CD27/IgD/CD24/CD38 staining, and function (CD69 and CD180 expression, cytokine and antibody secretion) of B cell subpopulations, we used tonsillar B cells. After stimulation, we found reduced expression of CD180 protein and mRNA in total B cells, and CD180 protein in B cell subpopulations. The frequency of CD180+ cells was the highest in the CD19+CD27+IgD+ non-switched (NS) B cell subset, and they showed the strongest activation after anti-CD180 stimulation. Furthermore, B cell activation via CD180 induced IL-6 and natural autoantibody secretion. Treatment with the combination of anti-CD180 antibody and CpG resulted in increased IL-6 and IL-10 secretion and natural autoantibody production of B cells. Our results support the role of CD180 in the induction of natural autoantibody production, possibly by NS B cells, and suggest an imbalance between the pathologic and natural autoantibody production in SSc patients.

Adipose-derived stromal/stem cells successfully attenuate the fibrosis of scleroderma mouse models

AIM

Systemic sclerosis (SSc) is an autoimmune disease characterized by skin and lung fibrosis. Although SSc has a high mortality risk, an effective treatment for the disease has not been established yet. Mesenchymal stromal/stem cells (MSCs) are multipotential nonhematopoietic progenitor cells that have the ability to regulate immune responses. Adipose-derived stromal/stem cells (ASCs), one of the types of MSCs, have the advantage of accessibility and potent immunomodulatory effects when compared with other MSCs, such as bone marrow-derived MSCs. This study aimed to investigate the antifibrotic effect of ASCs in scleroderma mouse models, including bleomycin-induced scleroderma and sclerodermatous chronic graft-versus-host disease (Scl-cGVHD) models.

METHOD

ASCs were intravenously administered to a bleomycin-induced scleroderma or Scl-cGVHD model on day 0. We compared the skin and lung fibrosis of scleroderma model mice between the ASC-treated group and control group.

RESULTS

Administration of ASCs attenuated the skin and lung fibrosis of bleomycin-induced scleroderma and Scl-cGVHD model mice compared to that in the control mice. Immunohistochemical staining showed that ASCs suppressed the infiltration of CD4⁺ , CD8⁺ T cells and macrophages into the dermis of bleomycin model mice compared to that in control mice. In addition, ASCs attenuated the messenger RNA expression of collagen and fibrogenic cytokines, such as interleukin (IL)-6 and IL-13, in the skin of bleomycin model mice. ASCs also reduced the frequency of fibrogenic cytokine-producing CD4⁺ T cells and effector B cells in the spleen of bleomycin model mice.

CONCLUSION

ASCs could prove to be a potential therapeutic agent for use in patients with SSc.

The Renal Resistive Index in systemic sclerosis: Determinants, prognostic implication and proposal for specific age-adjusted cut-offs

BACKGROUND

Renal Resistive Index (RRI), reflects changes in both renal vascular and tubular-interstitial compartments and in systemic vascular compliance related to age and comorbidities.

OBJECTIVES

a) To investigate determinants of RRI in SSc population, b) its association with SSc-related features and c) to test its prognostic impact on organ specific worsening or death.

METHODS

380 SSc patients ≥18 years were enrolled after giving informed consent. Baseline data on RRI, laboratory, instrumental and therapeutic features were retrospectively collected. Age-SSc adjusted cut-offs were created by dividing the population in age quartiles and considering RRI values >75th percentile as pathologic. Clinical follow-up was performed until last available visit or the development/worsening of specific internal organ involvement or death.

RESULTS

RRI was independently predicted by age and systolic pulmonary arterial pressure on Echo. Therefore, we created Age-SSc adjusted pathologic RRI cut-offs, which were significantly associated with various disease related skin and lung fibrotic manifestations, as well as vasculopathic complications. After a mean follow-up of 3.6 ± 2.6 years, RRI was one of the independent predictors (together with modified Rodnan skin score, interstitial lung disease, presence of dyspnoea and late nailfold-videocapillaroscopy pattern) for mortality, with 0.68 as best cut-off (sensitivity 88.5%, specificity 50.9%).

CONCLUSION

If corroborated, Renal Resistive Index cut-offs might be used to evaluate renal and extrarenal involvement in SSc and could serve as predictors of mortality.

European multicentre study validates enhanced liver fibrosis test as biomarker of fibrosis in systemic sclerosis

Objectives

To validate enhanced liver fibrosis (ELF) test and its components-amino-terminal propeptide of procollagen type III (PIIINP), tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) and HA-as biomarkers of fibrosis in SSc in an independent, international, multicentre cohort.

Methods

Two hundred and fifty-four SSc patients from six Rheumatology Centres were included. Sera were collected and stored according to EUSTAR biobanking recommendations and analysed through automated high throughput diagnostics. Statistical analysis was performed with SPSS software.

Results

Two hundred and forty-seven SSc patients (mean age 55.7 ± 13.9 years, 202 F) were analysed. ELF score, TIMP-1 and PIIINP levels were higher in males (P = 0.0197, P = 0.0107, P = 0.0108 respectively) and in dcSSc (P = 0.001, P = 0.0008, P < 0.0001 respectively). ELF score and the single markers significantly correlated with modified Rodnan skin score (r = 0.37, P < 0.0001), disease activity and severity (P < 0.0001 for all markers, except for HA P = 0.0001) and inversely with forced vital capacity, (FVC) % (TIMP-1, r = -0.21, P = 0.0012; PIIINP, r = -0.26, P = 0.0001), TLC% (ELF score, r = -0.20, P = 0.0036; TIMP-1, r = -0.32, P < 0.0001; PIIINP, r = -0.28, P < 0.0001), diffusion capacity of the lung for carbon monoxide (DLCO) % (P < 0.0001 for all markers, except for HA P = 0.0115). Multivariate analysis indicated that age (P < 0.001), modified Rodnan skin score (P < 0.001) and DLCO% (P = 0.005) were independently associated with ELF score.

Conclusion

Between the first and this validation studies, the value of the ELF score as independent marker of skin and lung involvement in SSc is confirmed in 457 patients. A longitudinal study is on-going to identify an SSc specific algorithm with predictive value for skin and lung progression.

Global skin gene expression analysis of early diffuse cutaneous systemic sclerosis shows a prominent innate and adaptive inflammatory profile

OBJECTIVES

Determine global skin transcriptome patterns of early diffuse systemic sclerosis (SSc) and how they differ from later disease.

METHODS

Skin biopsy RNA from 48 patients in the Prospective Registry for Early Systemic Sclerosis (PRESS) cohort (mean disease duration 1.3 years) and 33 matched healthy controls was examined by next-generation RNA sequencing. Data were analysed for cell type-specific signatures and compared with similarly obtained data from 55 previously biopsied patients in Genetics versus Environment in Scleroderma Outcomes Study cohort with longer disease duration (mean 7.4 years) and their matched controls. Correlations with histological features and clinical course were also evaluated.

RESULTS

SSc patients in PRESS had a high prevalence of M2 (96%) and M1 (94%) macrophage and CD8 T cell (65%), CD4 T cell (60%) and B cell (69%) signatures. Immunohistochemical staining of immune cell markers correlated with the gene expression-based immune cell signatures. The prevalence of immune cell signatures in early diffuse SSc patients was higher than in patients with longer disease duration. In the multivariable model, adaptive immune cell signatures were significantly associated with shorter disease duration, while fibroblast and macrophage cell type signatures were associated with higher modified Rodnan Skin Score (mRSS). Immune cell signatures also correlated with skin thickness progression rate prior to biopsy, but did not predict subsequent mRSS progression.

CONCLUSIONS

Skin in early diffuse SSc has prominent innate and adaptive immune cell signatures. As a prominently affected end organ, these signatures reflect the preceding rate of disease progression. These findings could have implications in understanding SSc pathogenesis and clinical trial design.

The role of high-resolution manometry in the assessment of upper gastrointestinal involvement in systemic sclerosis: a systematic review

Systemic sclerosis (SSc) affects the upper gastrointestinal (GI) system in 90% of patients. High-resolution manometry (HRM) assesses esophageal dysmotility, but its role in diagnosis and follow-up remains unclear. The objectives of this systematic review were to investigate the role of HRM in the assessment of SSc-associated upper GI involvement and to evaluate the correlation between HRM abnormalities and clinical characteristics and the effects of therapeutic interventions on HRM findings. Fifteen articles were included. Most (11/15) studies were of very good or good quality. Most studies assessed correlations between esophageal symptoms and esophageal dysmotility. Two studies assessed the effectiveness of buspirone and reported HRM findings. Studies assessing upper GI symptoms using validated questionnaires, such as the University of California Scleroderma Clinical Trial Consortium Gastrointestinal Tract 2.0 or Gastrointestinal Symptoms Severity Index score, found an association between absent contractility on HRM and upper GI symptoms, but even asymptomatic patients often have esophageal body dysmotility on HRM. Esophageal dysmotility positively correlates with the presence of interstitial lung disease on high-resolution computed tomography and reduced diffusion capacity (< 0.8 of predicted value). Trials investigating the effect of buspirone demonstrate both increased lower esophageal sphincter resting pressure and reduced upper GI symptoms. Most studies report on limited patient numbers and retrospective data. Potential bias was minimized using quality appraisal. HRM findings correlate to upper GI symptoms when assessed by validated questionnaires and can detect response to therapy in buspirone trials. Esophageal body dysmotility on HRM positively correlates with the presence of interstitial lung disease. KEY POINTS: • Esophageal body dysmotility on HRM correlates with presence of ILD. • HRM findings seem to correspond to clinical symptom alleviation in interventional trials, but data are still limited. • At present HRM, a procedure with a high negative burden to the patient, offers little to no role in the therapeutic strategy.

Detection and classification of systemic sclerosis-related interstitial lung disease: a review

PURPOSE OF REVIEW

Systemic sclerosis (SSc) is a heterogeneous disease with a variable disease course. Interstitial lung disease (ILD) is one of the leading causes of morbidity and mortality in patients with SSc. The present review highlights recent advances in the classification, diagnosis, and early detection of SSc-associated ILD (SSc-ILD).

RECENT FINDINGS

Risk stratification through measurement of disease extent on high-resolution computed tomography (HRCT) of the chest, longitudinal declines in pulmonary function tests (PFTs), and mortality prediction models have formed the basis for classifying clinically significant ILD. HRCT may be preferred over PFTs for screening, as PFTs lack sensitivity and have a high false-negative rate. Novel imaging modalities and biomarkers hold promise as adjunct methods for assessing the presence and severity of SSc-ILD, and predicting risk for progressive disease. Further validation is required prior to their use in clinical settings.

SUMMARY

Classification of SSc-ILD has shifted to a personalized approach that considers an individual patient's probability of progressive disease through identification of risk factors, measurement of disease extent on HRCT, longitudinal declines in PFTs, and mortality prediction models. There remains an unmet need to develop screening guidelines for SSc-ILD.

Altered serum level of metabolic and endothelial factors in patients with systemic sclerosis

Systemic sclerosis (SSc) is a chronic connective tissue disease characterized by progressive fibrosis, vascular impairment and immune abnormalities. In recent years, adipokines (mediators synthetized by adipose tissue) have been indicated as a possible missing link in the pathogenesis of SSc. The aim of this study was to investigate the serum concentration of metabolic adipose tissue factors: adiponectin, resistin, leptin and endothelial proteins: endothelin-1, fractalkine and galectin-3 in patients with systemic sclerosis. The study included 100 patients with confirmed SSc diagnosis and 20 healthy individuals. The concentration of respective proteins was determined by enzyme-linked immunosorbent assay. The following markers showed statistically significant increased mean concentrations in patients with SSc in comparison to healthy control: resistin (13.41 vs 8.54 ng/mL; P = 0.0012), endothelin-1 (1.99 vs 1.31 pg/mL; P = 0.0072) and fractalkine (2.93 vs 1.68 ng/mL; P = 0.0007). Elevated serum levels of galectin-3 (4.54 vs 3.26 ng/mL; P = 0.0672) and leptin (19,542 vs 14,210 pg/mL; P = 0.1817) were observed. Decreased concentration of adiponectin was found in patients with SSc (5150 vs 8847 pg/mL; P = 0.0001). Fractalkine and galectin-3 levels were significantly higher in diffuse cutaneous SSc than limited cutaneous SSc subset (3.93 ng/mL vs 2.58 ng/mL, P = 0.0018; 6.86 ng/mL vs 3.78 ng/mL, P = 0.0008, respectively) and correlated positively with modified Rodnan Skin Score in total SSc patients (r = 0.376, P = 0.0009; r = 0.236, P = 0.018, respectively). In conclusion, an increased serum level of resistin associated with increased endothelin-1 and fractalkine level and decreased adiponectin level may indicate a significant role of the adipose tissue in the development and progression of vascular abnormalities in patients with systemic sclerosis. Fractalkine and galectin-3 may participate in promoting and exacerbating the fibrotic process in SSc.

Performance of ultra-high-frequency ultrasound in the evaluation of skin involvement in systemic sclerosis: a preliminary report

Objective

High frequency ultrasound allows visualization of epidermis, dermis and hypodermis, precise measurement of skin thickness, as well as assessment of skin oedema, fibrosis and atrophy. The aim of this pilot cross-sectional observational study was to assess the performance and multiobserver variability of ultra-high-frequency (UHF) (50 MHz) ultrasound (US) in measuring skin thickness as well as the capacity of UHF-derived skin features to differentiate SSc patients from healthy controls.

Methods

Twenty-one SSc patients (16 limited and five diffuse SSc) and six healthy controls were enrolled. All subjects underwent US evaluation by three experts at three anatomical sites (forearm, hand and finger). Dermal thickness was measured and two rectangular regions of interest, one in dermis and one in hypodermis, were established for texture feature analysis.

Results

UHF-US allowed a precise identification and measurement of the thickness of the dermis. The dermal thickness in the finger was significantly higher in patients than in controls (P &lt; 0.05), while in the forearm it was significantly lower in patients than in controls (P &lt; 0.001). Interobserver variability for dermal thickness was good to excellent [forearm intraclass correlation coefficient (ICC) = 0.754; finger ICC = 0.699; hand ICC = 0.602]. Texture computed analysis of dermis and hypodermis was able to discriminate between SSc and healthy subjects (area under the curve &gt;0.7).

Conclusion

These preliminary data show that skin UHF-US allows a very detailed imaging of skin layers, a reliable measurement of dermal thickness, and a discriminative capacity between dermis and hypodermis texture features in SSc and healthy subjects.

Active roles of dysfunctional vascular endothelium in fibrosis and cancer

Chronic inflammation is the underlying pathological condition that results in fibrotic diseases. More recently, many forms of cancer have also been linked to chronic tissue inflammation. While stromal immune cells and myofibroblasts have been recognized as major contributors of cytokines and growth factors that foster the formation of fibrotic tissue, the endothelium has traditionally been regarded as a passive player in the pathogenic process, or even as a barrier since it provides a physical divide between the circulating immune cells and the inflamed tissues. Recent findings, however, have indicated that endothelial cells in fact play a crucial role in the inflammatory response. Endothelial cells can be activated by cytokine signaling and express inflammatory markers, which can sustain or exacerbate the inflammatory process. For example, the activated endothelium can recruit and activate leukocytes, thus perpetuating tissue inflammation, while sustained stimulation of endothelial cells may lead to endothelial-to-mesenchymal transition that contributes to fibrosis. Since chronic inflammation has now been recognized as a significant contributing factor to tumorigenesis, it has also emerged that activation of endothelium also occurs in the tumor microenvironment. This review summarizes recent findings characterizing the molecular and cellular changes in the vascular endothelium that contribute to tissue fibrosis, and potentially to cancer formation.

Sclerodermalike syndromes: Great imitators

Sclerodermalike syndromes (SLSs) comprise diseases with mucin deposition (eg, scleromyxedema, scleredema), with eosinophilia (eg, eosinophilic fasciitis), metabolic or biochemical abnormalities (eg, nephrogenic systemic fibrosis), or endocrine disorders (eg, POEMS syndrome, or polyneuropathy, organomegaly, endocrinopathy, monoclonal lymphoproliferative disorder, and hypothyroidism). Chronic graft-versus-host disease may also show sclerodermalike skin changes. Inherited progeria syndromes with early aging (eg, Werner syndrome) and a heterogeneous group of hereditary disorders with either skin thickening (eg, stiff skin syndrome) or atrophy and tightening (eg, acrogeria) can also imitate classic systemic sclerosis (SSc). In addition, SLSs can be provoked by several drugs, chemicals, or even physical injury (eg, trauma, vibration stress, radiation). In SLSs, the distribution of skin involvement seems to be atypical compared with SSc. The acral skin involvement is usually missing, and lack of Raynaud phenomenon, scleroderma-specific antinuclear antibodies, the absence of scleroderma capillary pattern, and internal organ manifestations indicate the presence of an SLS. Skin involvement is sometimes nodular, and the underlying tissues can also be affected. For the differential diagnosis, a skin biopsy of the deeper layers including fascia and muscle is required. Histology does not always allow differentiation between SSc and SLSs; therefore, the diagnosis is often based on the distribution, quality of cutaneous involvement, and other accompanying clinical features.

Current and future perspectives on management of systemic sclerosis-associated interstitial lung disease

Introduction: Systemic sclerosis (SSc) is a rare and complex connective tissue disease characterized by fibrosis of the skin and internal organs. Interstitial lung disease (ILD) is a common complication of SSc and the leading cause of SSc-related death. No drugs are licensed for the treatment of SSc-ILD. Areas covered: This review provides an overview of the current treatment of SSc-ILD and a perspective on investigational therapies, focusing on those studied in randomized controlled trials. Expert opinion: There is substantial room for improvement in the treatment of SSc-ILD. Current treatment focuses on immunosuppressant therapies, particularly cyclophosphamide and mycophenolate. Hematopoietic stem cell transplantation has been shown to improve long-term outcomes, but the risk of treatment-related mortality restricts its use to select patients at specialized centers. Modifying the course of disease to improve outcomes remains the goal for new therapies. Several drugs are under investigation as potential therapies for SSc-ILD, providing hope that the limited treatment armamentarium for SSc-ILD will be expanded and improved in the near future. Expert consensus is needed on how to screen for and monitor SSc-ILD and on when to initiate and escalate therapy.

A multicenter randomized, double-blind, placebo-controlled pilot study to assess the efficacy and safety of riociguat in systemic sclerosis-associated digital ulcers

Background

To determine the effect of riociguat, an oral, selective soluble guanylate cyclase stimulator, on the net digital ulcer (DU) burden in systemic sclerosis (SSc).

Methods

Participants with SSc-related active or painful indeterminate DUs were recruited in a multicenter, double-blind, randomized, placebo-controlled, proof-of-concept trial. Eligible participants were required to have at least one visible, active ischemic DU or painful indeterminate DU at screening, located at or distal to the proximal interphalangeal joint and that developed or worsened within 8 weeks prior to screening. Participants were randomized 1:1 to placebo or riociguat in individualized doses (maximum of 2.5 mg three times daily) during an 8-week titration period, followed by an 8-week stable dosing period. This was followed by an optional 16-week open-label extension phase for participants with active DU/reoccurrence of DUs within 1 month of the end of the main treatment phase. The primary endpoint was the change from baseline to week 16 in net ulcer burden (NUB), analyzed using ANCOVA. Other endpoints included plasma biomarkers and proportion of participants with treatment-emergent adverse events (AEs).

Results

Seventeen participants (eight placebo, nine riociguat) were randomized at five centers. Six participants in each group transitioned to the open-label extension. Baseline characteristics were comparable between the treatment groups, except participants randomized to placebo were older and had longer disease duration (p < 0.05). At baseline, the mean (SD) NUB was 2.5 (2.0) in the placebo and 2.4 (1.4) in the riociguat. No significant treatment difference was observed in the change from baseline to 16 weeks in NUB (adjusted mean treatment difference − 0.24, 95% CI (− 1.46, 0.99), p = 0.70). Four participants experienced five serious AE (four in riociguat and one in placebo); none was considered related to study medication. Statistically significant elevation of cGMP was observed at 16 weeks in the riociguat group (p = 0.05); no other biomarkers showed significant changes. In the open-label extension, participants in the riociguat-riociguat arm had complete healing of their DUs.

Conclusion

In participants with SSc-DU, treatment with riociguat did not reduce the number of DU net burden compared with placebo at 16 weeks. Open-label extension suggests that longer duration is needed to promote DU healing, which needs to be confirmed in a new trial.

Trial registration

ClinicalTrials.gov, NCT02915835. Registered on September 27, 2016.

Electronic supplementary material

The online version of this article (10.1186/s13075-019-1979-7) contains supplementary material, which is available to authorized users.

Pregnancy in Systemic Sclerosis: Results of a Systematic Review and Metaanalysis

OBJECTIVE

Through a systematic literature search (SLR) and metaanalysis, to determine maternal and fetal outcomes in pregnancies involving systemic sclerosis (SSc), to analyze the effect of pregnancy on disease activity, and to examine predictors of fetal and maternal outcomes.

METHODS

An SLR was performed for articles on SSc and pregnancy published between 1950 and February 1, 2018. Reviewers double-extracted articles to obtain agreement on > 95% of predefined critical outcomes.

RESULTS

Out of 461 publications identified, 16 were included in the metaanalysis. The metaanalysis showed that pregnancies involving SSc were at higher risk of miscarriage (OR 1.6, 95% CI 1.22-2.22), fetuses with intrauterine growth retardation (IUGR; OR 3.2, 95% CI 2.21-4.53), preterm births (OR 2.4, 95% CI 1.14-4.86), and newborns with low birth weight (OR 3.8, 95% CI 2.16-6.56). Patients with SSc had a 2.8 times higher chance of developing gestational hypertension (HTN; OR 2.8, 95% CI 2.28-3.39) and a 2.3 times higher chance of cesarean delivery compared to controls (OR 2.3, 95% CI 1.37-3.8). The definitions of disease worsening/new visceral organ involvement were too inexact to have any confidence in the results, although worsening or new disease manifestations during pregnancy in 44/307 cases (14.3%) and 6 months postpartum in 32/306 cases (10.5%) were reported. The data did not permit definition of predictors of disease progression and of maternal and fetal outcomes.

CONCLUSION

Pregnancies involving SSc have increased frequency of miscarriages, IUGR, preterm deliveries, and newborns with low birth weight compared to healthy controls. Women with SSc were more prone to develop gestational HTN and to undergo cesarean delivery. Disease manifestations seem to remain stable or improve in most patients.

Estrogens Counteract the Profibrotic Effects of TGF-β and their Inhibition Exacerbates Experimental Dermal Fibrosis

Systemic sclerosis primarily affects women. This sex bias raises the question on the role female hormones could play in the development of fibrosis, which is largely unknown. Our aim was to evaluate the effects of estrogens in the development of experimental dermal fibrosis, in the mouse models of bleomycin-induced dermal fibrosis and tight skin (Tsk-1) mice, and on the activation of dermal fibroblasts by transforming growth factor-β (TGF-β). Estrogen inhibition, obtained through gene inactivation for the estrogen receptor-αknockout or treatment with tamoxifen, exacerbated skin fibrosis in the bleomycin model and in the Tsk-1 mice. In the dermal fibroblasts, treatment with 17-β-estradiol significantly decreased the stimulatory effects of TGF-β on collagen synthesis and myofibroblast differentiation, decreased the activation of canonical TGF-β signaling, and markedly reduced the expression of the TGF-β target genes. Tamoxifen reversed the inhibitory effects of estrogens by restoring Smad2/3 phosphorylation and TGF-β-induced collagen synthesis. Our results demonstrate a beneficial effect of estrogens in dermal fibrosis. Estrogens reduce the TGF-β-dependent activation of dermal fibroblasts, and estrogen inhibition leads to a more severe experimental dermal fibrosis. These findings are consistent with the prominent development of systemic sclerosis in postmenopausal women and the greater severity of the disease in men.

Systemic Sclerosis Serum Steers the Differentiation of Adipose-Derived Stem Cells Toward Profibrotic Myofibroblasts: Pathophysiologic Implications

Systemic sclerosis (SSc; scleroderma) is characterized by life-threatening progressive multiorgan fibrosis orchestrated by profibrotic myofibroblasts originating from different sources. Because recent data demonstrated that the majority of myofibroblasts in a murine scleroderma model arise from adipocytic progenitors through the adipocyte-myofibroblast transition process, we sought to determine whether the SSc microenvironment may affect the differentiation potential of adipose-derived stem cells (ADSC). Normal human ADSC from three donors were treated with serum from SSc patients (n = 6), serum from healthy individuals (n = 6), or recombinant human transforming growth factor-β1 (TGFβ1) as positive control of myofibroblastic phenotype induction. ADSC were subjected to in vitro adipogenic differentiation for up to 21 days in the presence of different stimuli followed by lipid content quantification. In selected experiments, adipocytic and mesenchymal/myofibroblast marker gene and protein expression levels were assessed by Real-Time PCR, immunoblotting and immunofluorescence after administration of different stimuli for 72 and 96 h, respectively. Cell contractile phenotype was assayed by collagen gel contraction assay. Likewise stimulation with TGFβ1, SSc serum was able to significantly inhibit the adipocyte differentiation of ADSC as testified by a strong decrease in red-colored lipid droplets after 21 days of adipogenic induction. Treatment of ADSC either with SSc serum or TGFβ1 resulted in the acquisition of a myofibroblast-like phenotype characterized by a reduced expression of the adipocytic markers perilipin and adiponectin, a significant upregulation of the mesenchymal/myofibroblast markers α-SMA+ stress fibers, S100A4 and type I collagen, and an ability to effectively contract collagen gels. In SSc, the pathologic environment may favor the differentiation of ADSC into profibrotic and contractile myofibroblast-like cells. These findings strengthen the notion that the generation of myofibroblasts from ADSC may be relevant in SSc pathophysiology potentially representing a new target for the prevention/treatment of multiorgan fibrosis.

Enthesopathy and involvement of synovio-entheseal complex in systemic sclerosis: an ultrasound pilot study

Objectives

SSc is a chronic autoimmune disease characterized by inflammation of the skin and multiple internal organs. Articular involvement is one of the main features of SSc, and typical hallmarks of SpA have been found in SSc patients. The aim of the present study was to estimate the prevalence of entheseal and synovio-entheseal complex (SEC) alterations in a cohort of SSc patients.

Methods

One hundred SSc patients and 25 healthy subjects were included in this cross-sectional study. The enthesis sites of lateral epicondylar common extensor tendons (CET) and the enthesis of the Glasgow Ultrasound Enthesis Scoring System were evaluated. SEC involvement was evaluated only at CET enthesis.

Results

In SSc, the Glasgow Ultrasound Enthesis Scoring System score was significantly higher (median 4.0, interquartile range 2.0–7.0) than in controls (median 1.0, interquartile range 0.0–3.0) (P < 0.0001). CET enthesis of SSc patients showed more frequent US B-mode alterations than that of controls (χ2 = 11.47, P = 0.0007 for size; χ2 = 13.79, P = 0.0002 for cortical irregularity, χ2 = 5.24, P = 0.022 for calcification/enthesophytes). Power Doppler US signal at CET enthesis was significantly more frequent in SSc patients than in healthy controls (χ2 = 9.11, P = 0.0025), as was the concomitant SEC involvement (χ2 = 8.52, P = 0.0035).

Conclusion

These data show that SSc patients frequently present US features of enthesopathy. Moreover, CET enthesopathy was correlated with SEC inflammation, suggesting that entheseal inflammation in SSc may share the same micro-anatomical targets as found in SpA.

Macitentan in the treatment of severe digital ulcers

Digital ulcers are one of the earliest and most disabling manifestations of systemic sclerosis (SSc). We report the clinical case of a female patient with SSc and severe digital ulcers, recurrent and refractory to the classic treatments to whom it was prescribed off-label macitentan with complete resolution of the condition.

Safety and Tolerability of Thrombin Inhibition in Scleroderma-Associated Interstitial Lung Disease

Objective

Interstitial lung disease (ILD) is a frequent complication of systemic sclerosis (SSc) (scleroderma) and the leading cause of scleroderma‐related deaths. There exists an unmet need for a new drug therapy for ILD‐complicated SSc. Substantial evidence supports an important role for thrombin in the pathogenesis of SSc‐associated ILD (hereafter SSc‐ILD), and targeting thrombin with a direct thrombin inhibitor could prove to be a novel and effective treatment strategy. As a first step toward designing a clinical trial to test the efficacy of thrombin inhibition in SSc‐ILD, we conducted this study to test the safety and tolerability of dabigatran in patients with SSc‐ILD.

Methods

We performed a prospective, single‐center, open‐label treatment trial with the direct thrombin inhibitor, dabigatran, in patients with SSc‐ILD. Any patient with a history of gastrointestinal hemorrhage or gastric antral vascular ectasia was excluded. Blood monitoring was performed monthly, and patient‐reported outcomes, pulmonary function tests, and skin scores were obtained at baseline and at 3‐ and 6‐month visits. Bronchoscopy with bronchoalveolar lavage (BAL) was performed at baseline and at 6 months for measurement of lung thrombin activity.

Results

Of 15 patients with SSc‐ILD, 14 completed 6 months of treatment with dabigatran at 75 mg taken orally twice daily. Adverse events were uncommon and usually mild or unrelated to the study medication. No serious adverse event was observed. Dabigatran was well tolerated, and we observed no significant gastrointestinal, pulmonary, or other safety issues or intolerability. BAL fluid thrombin activity decreased or remained stable in 13 of 14 (92.8%) subjects.

Conclusion

Dabigatran appears to be safe and well tolerated in patients with SSc‐ILD. A larger randomized controlled trial to test the efficacy of direct thrombin inhibition with dabigatran can be considered.

Stem cell enriched lipotransfer reverses the effects of fibrosis in systemic sclerosis

Oro-facial fibrosis in systemic sclerosis (Scleroderma;SSc) has a major impact on mouth function, facial appearance, and patient quality of life. Lipotransfer is a method of reconstruction that can be used in the treatment of oro-facial fibrosis. The effect of this treatment not only restores oro-facial volume but has also been found to reverse the effects of oro-facial fibrosis. Adipose derived stem cells (ADSCs) within the engrafted adipose tissue have been shown to be anti-fibrotic in SSc and are proposed as the mechanism of the anti-fibrotic effect of lipotransfer. A cohort of 62 SSc patients with oro-facial fibrosis were assessed before and after stem cell enriched lipotransfer treatment. Clinical evaluation included assessment of mouth function using a validated assessment tool (Mouth Handicap in Systemic Sclerosis Scale-MHISS), validated psychological measurements and pre and post-operative volumetric assessment. In addition, to understand the mechanism by which the anti-fibrotic effect of ADSCs occur, SSc derived fibroblasts and ADSCs from this cohort of patients were co-cultured in direct and indirect culture systems and compared to monoculture controls. Cell viability, DNA content, protein secretion of known fibrotic mediators including growth factor- β1 (TGF β-1) and connective tissue growth factor (CTGF) using ELISA analysis and fibrosis gene expression using a fibrosis pathway specific qPCR array were evaluated. Mouth function (MHISS) was significantly improved (6.85±5.07) (p<0.0001) after treatment. All psychological measures were significantly improved: DAS 24 (12.1±9.5) (p<0.0001); HADS-anxiety (2.8±3.2) (p<0.0001), HADS-depression (2.0±3.1) (p<0.0001); BFNE (2.9 ± 4.3) (p<0.0001); VAS (3.56±4.1) (p<0.0001). Multiple treatments further improved mouth function (p<0.05), DAS (p<0.0001) and VAS (p = 0.01) scores. SSc fibroblast viability and proliferation was significantly reduced in co-culture compared to monoculture via a paracrine effect over 14 days (p < 0.0001). Protein secretion of transforming growth factor (TGF-β1) and connective tissue growth factor (CTGF) was significantly reduced in co-culture compared to monoculture (p < 0.0001). Multiple fibrosis associated genes were down regulated in SSc co-culture compared to monoculture after 14 days including Matrix metalloproteinase-8 (MMMP-8), Platelet derived growth factor-β (PDGF-β) and Integrin Subunit Beta 6 (ITG-β6). Autologous stem cell enriched lipotransfer significantly improved the effects of oro-facial fibrosis in SSc in this open cohort study. Lipotransfer may reduce dermal fibrosis through the suppression of fibroblast proliferation and key regulators of fibrogenesis including TG-β1 and CTGF. Our findings warrant further investigation in a randomised controlled trial.

Targeting very early systemic sclerosis: a case-based review

It is unknown whether treatment in very early/early systemic sclerosis (SSc) can affect long-term outcomes. A case-based review was conducted (i) to assess the effect of rituximab (RTX) in very early SSc and (ii) to explore how many clinical trials in SSc targeted early disease and whether treatment of these patients led to better clinical outcomes. We identified cases of very early SSc from our department and performed a search in MEDLINE and Scopus databases for clinical trials in SSc during 2005-2018. Two cases are reported where RTX was administered within 24 months from the appearance of Raynaud's. In the first case, there was an improvement in interstitial lung disease as indicated by the improvement in pulmonary function tests and the regression of changes in high-resolution chest computed tomography. In the second case, a good clinical response in skin fibrosis was observed. The review revealed the following: (i) only one-third of the studies were specifically designed to target early disease, (ii) there is confusion related to disease duration definition across SSc clinical trials but an obvious trend towards improvement was evident during the past years, (iii) the question of whether early implementation of therapy may lead to better clinical outcomes cannot be definitely answered based on existing data and (iv) there is still a very low level of incorporation of the new classification criteria in SSc trials. This review suggests that there may be a window of opportunity in SSc and highlights the need for clinical trials targeting very early/early disease.

Systemic sclerosis and primary biliary cholangitis: An overlapping entity?

Systemic sclerosis (SSc) is a complex autoimmune disease that may lead to skin and internal organ fibrosis. Based on skin involvement, two subsets of the disease are recognized (limited cutaneous SSc and diffuse cutaneous SSc). The new 2013 American College of Rheumatology/European League against Rheumatism classification criteria allow to identify SSc patients at the early stage of the disease that allows new research avenues. The aetiology of the disease is still unknown, but it has an important autoimmune basis and its association with other autoimmune diseases has been reproducibly reported. Among them, primary biliary cholangitis is considered the most common liver disease in SSc. The aim of this review is to provide an overview on recent findings about SSc associated to primary biliary cholangitis. Although the aetiology of the two diseases is still unknown, data suggest that these two disorders share the expression of fibrogenic cytokines, involved both in generation and function of T lymphocytes subpopulation (Th17 cells) and regulatory T lymphocytes. In addition, the relationships between SSc and primary biliary cholangitis may be closer as suggested by the presence of primary biliary cholangitis-specific antibodies in SSc patients and vice versa. Recent findings confirm a prevalence of overt primary biliary cholangitis in about 2% of SSc population, in particular in patients with limited cutaneous SSc and positive anticentromere antibodies. The prevalence increases if also patients with only primary biliary cholangitis-specific antibodies are considered. Data regarding SSc prevalence in primary biliary cholangitis patients have also been recently clarified. Altogether, stimulating results are moving the field forward regarding the relationships of these two autoimmune and fibrotic disorders that may belong to an overlapping entity.

Pleuroparenchymal fibroelastosis in patients affected by systemic sclerosis: What should the rheumatologist do?

Pleuroparenchymal fibroelastosis (PPFE) is a rare new interstitial lung disease (ILD) characterized by the fibrotic thickening of the visceral pleura and subadjacent parenchymal areas of the upper lobes This study reveals that patients with ILD-SSc associated with chest HRCT evidence of PPFE require close and recurrent follow-up with periodic evaluation of lung function parameters, DLCO and chest HRCT. Rheumatologists should be aware of this new radiological finding which is accompanied by a negative prognosis, especially when associated with a progressive course. Patients with this radiological pattern need to be monitored with particular attention.

Blockade of CCL24 with a monoclonal antibody ameliorates experimental dermal and pulmonary fibrosis

Objectives

We aimed to assess the expression of the CCL24 chemokine in systemic sclerosis (SSc) and to evaluate the possible pathogenic implications of the CCL24/CCR3 axis using both in vitro and in vivo models. We further investigated the efficacy of an anti-CCL24 monoclonal antibody (mAb), CM-101, in inhibiting cell activation as well as dermal and pulmonary inflammation and fibrosis in experimental animal models.

Methods

We used ELISA and fluorescence immunohistochemistry to determine CCL24 levels in serum and CCL24/CCR3 expression in skin biopsies of SSc patients. Skin fibroblasts and endothelial cells treated with CCL24 or SSc serum with or without CM-101 were used to follow cell activation and differentiation. Prevention and treatment in vivo bleomycin (BLM)-induced models were used to evaluate experimental dermal and pulmonary fibrosis progression following treatment with the CM-101 mAb.

Results

CCL24 circulating levels were significantly elevated in SSc patients. CCL24/CCR3 expression was strongly increased in SSc skin. Blockade of CCL24 with CM-101 significantly reduced the activation of dermal fibroblasts and their transition to myofibroblasts induced by SSc serum. CM-101 was also able to significantly inhibit endothelial cell activation induced by CCL24. In BLM-induced experimental animal models, CM-101 profoundly inhibited both dermal and pulmonary fibrosis and inflammation.

Conclusions

CCL24 plays an important role in pathological processes of skin and lung inflammation and fibrosis. Inhibition of CCL24 by CM-101 mAb can be potentially beneficial for therapeutic use in SSc patients.