Mechanistic studies on the regulation of systemic sclerosis progression by imbalance in angiogenic T cell subsets.

Systemic sclerosis (SSc) is a systemic autoimmune disease characterized by widespread fibrosis affecting the skin, internal organs, and vasculature. However, there are currently no systemic, disease-modifying therapies available for the treatment of the overall condition, and the outcomes remain poor. Studies into disease pathogenesis have identified several pathways that are dysregulated in SSc, and novel targeted therapies are currently being developed. In this special issue, we invited authors to submit original research articles, review articles, or case reports/case series describing preclinical, translational, or clinical studies related to new therapies for SSc. A set of papers in this special issue focuses on identification of new therapeutic targets in preclinical and translational studies. V. J. Moulin's paper is a review article describing the role of apoptosis in the initiation and maintenance of disease in SSc, through effects on the immune system, vascular damage, and fibroblast proliferation. This report discusses potential therapies targeting apoptosis and the Fas/FasL pathway that could be investigated in patients with SSc. Other paper describes vascular changes in the bleomycin-induced mouse model of SSc. The authors discuss the use of this mouse model to investigate targeting fibrosis, apoptosis, and cellular adhesion molecules for the treatment of vascular disease in SSc. The paper by T. Radstake et al. reviews the evidence that hypoxia contributes to the pathogenesis of SSc, with a focus on the role of hypoxia inducible factor (HIF)-1 alpha in the vasculopathy, immune dysregulation, and fibrosis in SSc. This paper summarizes potential therapeutic interventions to bypass the dysfunctional hypoxic pathway in SSc. The paper by R. De Vries et al. describes an original research study evaluating the accumulation of advanced glycation end products (AGE) in the skin of patients with SSc compared with controls using a technique called skin autofluorescence. Although this study did not find a significant difference in AGE accumulation in SSc skin compared with control samples, use of angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers in the SSc patients may have confounded the results. The paper by E. G. Kroon et al. is an original research article evaluating the expression of Types I and III interferons (IFNs) and interferon-stimulated genes (ISG) in peripheral blood mononuclear cells from SSc patients compared with controls. This study confirmed the increased basal expression of Type I IFNs and the ISG 2′5′OAS in SSc, but found no induction of Type III IFNs. This paper provides further evidence that targeting the IFN pathway may be useful in the treatment of SSc. The paper by S. M. Violette et al. reviews the preclinical data supporting the role of the integrin αvβ6 in the activation of fibrosis via the transforming growth factor (TGF)-β pathway. This paper summarizes in vivo evidence of the utility of blocking αvβ6 for the treatment of lung fibrosis and provides rationale for pursuing this therapeutic approach in patients with SSc-associated interstitial lung disease. Another set of articles includes reviews of novel therapies that are currently being evaluated for the treatment of SSc. The paper by M. Anderson et al. reviews the role of interleukin-6 (IL-6) in SSc, summarizing evidence of effects on B cells, inflammation, fibrogenesis, and endothelial cell activation. The paper reviews the rationale for ongoing clinical trials of agents blocking IL-6 transsignaling for the treatment of SSc. The paper by S.-N. Liossis et al. reviews the published literature supporting the role of B cells in SSc, summarizing data from animal models and human studies. The authors then review the results of four clinical trials assessing the effects of B cell depletion with rituximab therapy on skin disease and lung function in patients with SSc. The paper by R. F. Spiera and J. Gordon reviews the preclinical and clinical studies of tyrosine kinase inhibitors, with a focus on experience with imatinib, in the treatment of SSc and related fibrotic conditions. The authors conclude that interpretation of the results from the completed proof-of-concept studies is difficult due to the small size and heterogeneity of the populations studied and the open-label designs. The review article by K. Phillips et al. describes published studies investigating the utility of phosphodiesterase-5 inhibitors (PDE-5-I) in the treatment of Raynaud's phenomenon (RP) and/or digital ulcers (DU), detailing results of studies using sildenafil, vardenafil, and tadalafil. The authors also list the ongoing clinical studies of PDE-5-I for RP and DU. The paper by D. F. Fiorentino et al. reviews the role of endothelin-1 in the pathogenesis of SSc-associated vascular disease and summarizes the published reports evaluating the use of endothelin receptor antagonists in the treatment of RP and DU. One of the sets in this special issue includes two articles describing rare clinical manifestations of SSc, gastric antral vascular ectasias and primary biliary cirrhosis, and management strategies for these entities. The paper B. Markewitz et al. is a case series describing the tolerability and efficacy of naltrexone for the treatment of pruritus and gastrointestinal symptoms in three patients with SSc. The paper by K. Nikolov and M. Baleva reviews the rationale for using intravenous immunoglobulins (IVIG) in the treatment of SSc. The authors also summarize the published case reports and series supporting the potential efficacy of IVIG in the treatment of skin sclerosis in SSc. In summary, this special issue provides an interesting compilation of articles addressing potential emerging therapies for the treatment of SSc, including information gleaned from preclinical, translational, and clinical studies. We, the guest editors, hope readers find that the manuscripts included herein offer a comprehensive summary of the current status of drug development and promising therapies for SSc. Lorinda Chung Oliver Distler Laura Hummers Eswar Krishnan Virginia Steen

Systemic sclerosis (SSc) is an autoimmune disorder with clinical manifestations resulting from immune activation, fibrosis development and damage of small blood vessels. Although there have been no established treatments for SSc, lots of new treatments targeting organ and pathogenesis are in the process of development. Transforming growth factor (TGF)-beta is a major cytokine involved in the pathogenesis of fibrosis in SSc. The blockade of cell surface molecules capable of activating latent TGF-beta, blockade of ligand by the pan-isoform-specific antibody, soluble TGF-beta receptors and a recombinant latency associated peptide, as well as inhibitors for ALK5 and Smad3 are the potential strategies to abolish the pathological activation of TGF-beta signaling in SSc fibroblasts. Besides TGF-beta, connective tissue growth factor (CTGF)/CCN2, platelet-derived growth factor (PDGF) and endothelin-1 are the candidates for the new therapeutic targets. As for immune dysfunction in SSc, i.v. immunoglobulin infusion, stem cell transplantation and B-cell depletion are potential new therapies under or awaiting a randomized, double-blind, placebo-controlled trial, although their efficacies are still controversial. Phosphodiesterase-5 inhibitors, endothelin receptor antagonists and inhibitors for serotonin signaling are the new therapeutic targets for Raynaud's phenomenon, digital ulceration and pulmonary arterial hypertension in SSc. Imatinib mesylate may be a novel new therapy for fibrosis and vasculopathy in SSc because it reverses the expression levels of Fli1, which is a transcription factor downregulated in SSc through an epigenetic mechanism and is likely to be involved in the development of fibrosis and vasculopathy in this disease. Potential therapeutic targets other than those described above are also reviewed.

SP0176 Role of Endothelial To Mesenchymal Transition in The Pathogenesis of The Vascular Alterations in Systemic Sclerosis

ObjectivesNeutrophils and neutrophil extracellular traps (NETs) contribute to the vascular complications of multiple diseases, but their role in systemic sclerosis (SSc) is understudied. We sought to test the hypothesis that NETs are implicated in SSc vasculopathy and that treatment with prostacyclin analogs may ameliorate SSc vasculopathy not only through vasodilation but also by inhibiting NET release.MethodsBlood from 125 patients with SSc (87 diffuse cutaneous SSc and 38 limited cutaneous SSc) was collected at a single academic medical center. Vascular complications such as digital ulcers, pulmonary artery hypertension, and scleroderma renal crisis were recorded. The association between circulating NETs and vascular complications was determined using in vitro and ex vivo assays. The impact of the synthetic prostacyclin analog epoprostenol on NET release was determined.ResultsNeutrophil activation and NET release were elevated in patients with SSc-associated vascular complications compared to matched patients without vascular complications. Neutrophil activation and NETs positively correlated with soluble E-selectin and VCAM-1, circulating markers of vascular injury. Treatment of patients with digital ischemia with a synthetic prostacyclin analog boosted neutrophil cyclic AMP, which was associated with the blunting of NET release and reduced NETs in circulation.ConclusionOur study demonstrates an association between NETs and vascular complications in SSc. We also identified the potential for an additional therapeutic benefit of synthetic prostacyclin analogs, namely to reduce neutrophil hyperactivity and NET release in SSc patients.

Endothelial to mesenchymal transition (EndoMT) in the pathogenesis of Systemic Sclerosis-associated pulmonary fibrosis and pulmonary arterial hypertension. Myth or reality?

Lipocalin-2 is an adipocytokine implicated in apoptosis, innate immunity, angiogenesis, and the development of chronic kidney disease. To investigate the role of lipocalin-2 in systemic sclerosis (SSc). Serum lipocalin-2 levels were determined by enzyme-linked immunosorbent assay in 50 patients with SSc and 19 healthy subjects. Lipocalin-2 expression was evaluated in the skin of patients with SSc and bleomycin (BLM)-treated mice and in Fli1-deficient endothelial cells by reverse transcriptase-real time polymerase chain reaction, immunoblotting and/or immunohistochemistry. Although serum lipocalin-2 levels were comparable between patients with SSc and healthy controls, the prevalence of scleroderma renal crisis was significantly higher in patients with SSc with elevated serum lipocalin-2 levels than in those with normal levels. Furthermore, serum lipocalin-2 levels inversely correlated with estimated glomerular filtration rate in patients with SSc with renal dysfunction. Among patients with SSc with normal renal function, serum lipocalin-2 levels positively correlated with skin score in patients with diffuse cutaneous SSc with disease duration of <3years and inversely correlated with estimated right ventricular systolic pressure in total patients with SSc. Importantly, in SSc lesional skin, lipocalin-2 expression was increased in dermal fibroblasts and endothelial cells. In BLM-treated mice, lipocalin-2 was highly expressed in dermal fibroblasts, but not in endothelial cells. On the other hand, the deficiency of transcription factor Fli1, which is implicated in SSc vasculopathy, induced lipocalin-2 expression in cultivated endothelial cells. Lipocalin-2 may be involved in renal dysfunction and dermal fibrosis of SSc. Dysregulated matrix metalloproteinase-9/lipocalin-2-dependent angiogenesis due to Fli1 deficiency may contribute to the development of pulmonary arterial hypertension associated with SSc.

Digital ulcers in patients with systemic sclerosis are associated with pain and poor quality of life. Endothelin-1 promotes vasculopathy in systemic sclerosis after macitentan, an endothelin-1 blocker. To evaluate the efficacy of macitentan in reducing the number of new digital ulcers in patients with systemic sclerosis. Two international, randomized, double-blind, placebo-controlled trials (DUAL-1, DUAL-2) were conducted between January 2012 and February 2014. Participants were patients with systemic sclerosis and active digital ulcers at baseline. Target enrollment for each study was 285 patients. Patients were randomized (1:1:1) to receive oral doses of 3 mg of macitentan, 10 mg of macitentan, or placebo once daily and stratified according to number of digital ulcers at baseline (≤3 or >3). The primary outcome for each trial was the cumulative number of new digital ulcers from baseline to week 16. Treatment effect was expressed as the ratio between treatment groups. In DUAL-1, among 289 randomized patients (mean age 51.2 years; 85.8% women), 226 completed the study. The adjusted mean number of new digital ulcers per patient over 16 weeks was 0.94 in the 3-mg macitentan group (n = 95) and 1.08 in the 10-mg macitentan group (n = 97) compared with 0.85 in the placebo group (n = 97) (absolute difference, 0.09 [95% CI, -0.37 to 0.54] for 3 mg of macitentan vs placebo and 0.23 [-0.27 to 0.72] for 10 mg of macitentan vs placebo). Among 265 patients randomized in DUAL-2 (mean age 49.6 years; 81.9% women), 216 completed the study. In DUAL-2, the adjusted mean number of new digital ulcers was 1.44 in the 3-mg macitentan group (n = 88) and 1.46 in the 10-mg macitentan group (n = 88) compared with 1.21 in the placebo group (n = 89) (absolute difference, 0.23 [95% CI, -0.35 to 0.82] for 3 mg of macitentan vs placebo and 0.25 [95% CI, -0.34 to 0.84] for 10 mg of macitentan vs placebo). Adverse events more frequently associated with macitentan than with placebo were headache, peripheral edema, skin ulcer, anemia, upper respiratory tract infection, diarrhea, and nasopharyngitis. Among patients with systemic sclerosis and active ischemic digital ulcers, treatment with macitentan did not reduce new digital ulcers over 16 weeks. These results do not support the use of macitentan for the treatment of digital ulcers in this patient population. clinicaltrials.gov Identifiers: NCT01474109, NCT01474122.

Digital ulcers represent a severe manifestation of digital vasculopathy in systemic sclerosis, occasionally with the contribution of microtrauma and calcinosis. These ulcers are often challenging to heal and extremely painful. Regarding analgesic approaches, there is a lack of consensus on best practices, leading to physician experience-guided approaches rather than standardized protocols. To assess the published evidence on the effectiveness of oral and topical analgesics and local anaesthetics for pain reduction in digital ulcer of systemic sclerosis, we conducted a PRISMA-driven systematic review. A search in PubMed and Cochrane databases was performed using the keyword search terms 'digital ulcers', 'finger ulcers', 'systemic sclerosis', 'scleroderma', 'pain management', 'analgesics', 'anaesthetics' and 'painkillers', with the Boolean terms 'AND' and 'OR'. Original studies and case reports were considered for inclusion. Results were screened by title, abstract and full-text. We identified a total of 26 results, of which 5 original papers were included: 2 prospective observational studies, 1 prospective case series, 1 retrospective case series and 1 case report. The evaluated pharmacological strategies were digital nerve block with lidocaine and mepivacaine (one study), oral extended-release oxycodone (two studies), local lidocaine (one study), local lidocaine and prilocaine, local morphine and sublingual morphine (one study). Overall, digital nerve block appeared to provide complete or near-complete pain relief. Oral and topical strategies resulted in reduced pain intensity, although levels remained in the mild-to-moderate range. Concerning adverse outcomes, all strategies were generally well tolerated, with only mild effects reported across studies. Despite limitations, the available evidence suggests that the evaluated analgesics and anaesthetics may provide pain relief for digital ulcer in patients with systemic sclerosis. Future larger-scale studies employing standardized protocols are necessary to further assess the efficacy, optimal dosing and long-term outcomes of these interventions.

Fli1 deficiency and beyond: a unique pathway linking peripheral vasculopathy and dermal fibrosis in systemic sclerosis

POS0869 PREDICTIVE VALUE OF ANTI-INTERFERON-INDUCIBLE PROTEIN 16 ANTIBODIES FOR DIGITAL ULCERS OF SYSTEMIC SCLEROSIS

Systemic sclerosis (SSc) is a relatively rare collagenosis manifested as microvasculopathy, excessive cutaneous and visceral fibrosis in a background of autoimmune alteration. Autoimmune vasculopathy in SSc occurs early and begins with endothelial cell activation followed by blood vessel intimal proliferation in a context of defective angiogenesis. The alteration of peripheral micro and macrocirculation in SSc is evident through vascular lesions, such as Raynaud's phenomenon, telangiectasias, acrocyanosis, digital ulcers, gangrene, peripheral pulse deficiency. Our paper details the results of the study on the association between telangiectasias and other types of immune-mediated peripheral vascular lesions that can be identified in SSc. The presence of these peripheral vascular lesions can provide information about the magnitude of the peripheral vasculopathy. A total of 37 patients diagnosed with SSc, recruited from a university clinic in Bucharest between February 2019 and March 2020, were enrolled in an observational study. We evaluated the presence of telangiectasias, as a stigma of autoimmune microvasculopathy, and their association with other immune-mediated peripheral vascular lesions that may be present in SSc. The presence of telangiectasias was identified in the absence, but especially in the presence of acrocyanosis and digital ulcerations, and patients with peripheral pulse deficiency almost always had telangiectasias. Less than a quarter of the patients with digital ulcers progressed unfavorably to gangrene, and only one required amputation, telangiectasias being present not only in the patient with amputation but in all patients with gangrene. We appreciate that telangiectasias may be the clinical expression of peripheral vasculopathy characteristic of SSc, they can often be present in association with other peripheral vascular lesions and may represent a valuable indicator for the gangrene risk of digital ulcerations in SSc.

Interstitial lung disease occurs in the majority of patients with systemic sclerosis. Although interstitial lung disease is the number one cause of death in systemic sclerosis, interstitial lung disease progression rates vary considerably among patients with systemic sclerosis. Some patients with systemic sclerosis-associated interstitial lung disease have sub-clinical disease and may not derive benefit from immunosuppression, while others have a more aggressive interstitial lung disease phenotype. Reliable predictors of interstitial lung disease progression are lacking. The present review describes our current approach to monitoring systemic sclerosis-associated interstitial lung disease progression in clinical practice. To illustrate the marked heterogeneity that exists in interstitial lung disease progression rates in systemic sclerosis, this review presents the individual disease course of five unique patients with systemic sclerosis-associated interstitial lung disease who participated in the Scleroderma Lung Study II. These cases illustrate that treatment response rates vary in systemic sclerosis-associated interstitial lung disease and more research is needed to determine how to predict treatment response in systemic sclerosis-associated interstitial lung disease and to develop personalized treatment approaches for patients with this devastating disease.

To evaluate endothelial dysfunction and microvascular damage in secondary Raynaud Phenomenon (SRP) and Systemic sclerosis (SSc)-associated patients as possible predictors of ischemic fingertip digital ulcers (DU) in a 3-year clinical follow-up. Flow-mediated dilatation (FMD), nailfold videocapillaroscopy (NVC), endothelin-1 (ET-1) and asymmetric dimethylarginine (ADMA) were analysed in a 3-year observational cohort study of 77 SRP patients with systemic sclerosis. The primary outcome was the occurrence of a new DU. Risk factors for DU at baseline were low FMD% (p < 0.001), NVC pattern (p < 0.001), high microangiopathy evolution score (MES) (p < 0.001), increased ET-1 (p < 0.001) and increased ADMA serum levels (p = 0.001). Median time to the occurrence of a new DU was 4.50 (1.25-16.25) months. The risk factors for the occurrence of at least one new DU episode in follow-up included a history of at least one DU before enrolment (p < 0.001), autoantibody anti-scleroderma-70 (p = 0.012), NVC late pattern (p < 0.001), high MES score (p < 0.001), low FMD% (p < 0.001) and increased ET-1 serum levels (p < 0.001).We used univariate Cox regression analysis to show that FMD >9.41% (HR: 0.37 95% CI: 0.14-0.99) and ET-1 >11.85 pmol/L (HR: 3.81 95% CI: 1.41-10.26) and NVC (HR: 2.29 95% CI: 0.97-5.38) were predictors of DU recurrence. In terms of first DU event in naïve DU patients at baseline, late NVC pattern (HR: 12.66 95% CI: 2.06-77.89) and MES score (HR: 1.693 95% CI: 1.257-2.279) were independent predictors. This study identified endothelium dysfunction biomarkers (FMD and ET-1) and severe microvascular damage in NVC as strong predictors of new DU in SSc patients.

Systemic sclerosis (SSc) is associated with interstitial lung disease (ILD) and pulmonary hypertension (PH). This study was undertaken to determine the prevalence, characteristics, treatment, and outcomes of PH in a cohort of patients with SSc-associated ILD. Patients with SSc-associated ILD on high-resolution computed tomography (HRCT) were included in a prospective observational cohort. Patients were screened for PH based on a standardized screening algorithm and underwent right-sided heart catheterization (RHC) if indicated. PH classification was based on hemodynamic findings and the extent of ILD on HRCT. Summary statistics and survival using the Kaplan-Meier method were calculated. Of the 93 patients with SSc-associated ILD included in the study, 76% were women and 65.6% had diffuse cutaneous SSc. The mean age was 54.9 years, and the mean SSc disease duration was 8 years. Twenty-nine patients (31.2%) had RHC-proven PH; of those 29 patients, 24.1% had PAH, 55.2% had World Health Organization (WHO) Group III PH, 34.5% had WHO Group III PH with pulmonary vascular resistance >3.0 Wood units, 48.3% had a PH diagnosis within 7 years of SSc onset, 82.8% received therapy for ILD, and 82.8% received therapy for PAH. The survival rate 3 years after SSc-associated ILD diagnosis for all patients was 97%. The survival rate 3 years after PH diagnosis for those with SSc-associated ILD and PH was 91%. In a large cohort of patients with SSc-associated ILD, a significant proportion of patients had coexisting PH, which often occurs early after SSc diagnosis. Most patients were treated with ILD and PAH therapies, and survival was good. Patients with SSc-associated ILD should be evaluated for coexisting PH.

SAT0206 Vascular Evaluation of The Hand by Power Doppler Ultrasonography Provides New Predictive Markers of Ischaemic Digital Ulcers in Systemic Sclerosis