Systemic Sclerosis Serum Research Articles

Lymphatic Endothelial-to-Myofibroblast Transition: A Potential New Mechanism Underlying Skin Fibrosis in Systemic Sclerosis.

At present, only a few reports have addressed the possible contribution of the lymphatic vascular system to the pathogenesis of systemic sclerosis (SSc). Based on the evidence that blood vascular endothelial cells can undertake the endothelial-to-myofibroblast transition (EndMT) contributing to SSc-related skin fibrosis, we herein investigated whether the lymphatic endothelium might represent an additional source of profibrotic myofibroblasts through a lymphatic EndMT (Ly-EndMT) process. Skin sections from patients with SSc and healthy donors were immunostained for the lymphatic endothelial cell-specific marker lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1) in combination with α-smooth muscle actin (α-SMA) as the main marker of myofibroblasts. Commercial human adult dermal lymphatic microvascular endothelial cells (HdLy-MVECs) were challenged with recombinant human transforming growth factor-β1 (TGFβ1) or serum from SSc patients and healthy donors. The expression of lymphatic endothelial cell/myofibroblast markers was measured by quantitative real-time PCR, Western blotting and immunofluorescence. Collagen gel contraction assay was performed to assess myofibroblast-like cell contractile ability. Lymphatic endothelial cells in intermediate stages of the Ly-EndMT process (i.e., coexpressing LYVE-1 and α-SMA) were found exclusively in the fibrotic skin of SSc patients. The culturing of HdLy-MVECs with SSc serum or profibrotic TGFβ1 led to the acquisition of a myofibroblast-like morphofunctional phenotype, as well as the downregulation of lymphatic endothelial cell-specific markers and the parallel upregulation of myofibroblast markers. In SSc, the Ly-EndMT might represent a previously overlooked pathogenetic process bridging peripheral microlymphatic dysfunction and skin fibrosis development.

Interleukin-36α is elevated in diffuse systemic sclerosis and may potentiate fibrosis.

Systemic sclerosis (SSc) is an autoimmune prototypical connective tissues disease that results in alterations in vasculature, inflammation and fibrosis of the skin. Interleukin-1 family cytokines has been implicated in the disease including IL-1. IL-36α is an IL-1 family member that is clearly implicated in psoriatic skin disease but its role in systemic sclerosis disease is not clear. The aim of this work is to evaluate the levels and role of IL-36α in systemic sclerosis. Early diffuse SSc patients sera was isolated along with healthy controls and IL-36 levels quantified by ELISA. In vitro analysis was also undertaken with primary dermal fibroblasts with recombinant IL-36α and keratinocyte cells were also incubated with IL-36α. Cytokines were measured by ELISA. Serum IL-36 was significantly elevated compared to healthy controls. Elevated neutrophil elastase was also elevated in the matched sera. IL-36 was not directly pro-fibrotic in dermal fibroblasts but did induce pro-inflammatory cytokines that were dependant on the MAPK pathway for their release. IL-36α also led to release of CCL20 and CCL2 in keratinocytes which may potentiate fibrosis. IL-36α is elevated in SSc serum and whilst not directly pro-fibrotic it may through keratinocytes, potentiate fibrosis through keratinocyte-immune fibroblast cross-talk.

Serum markers of cardiac complications in a systemic sclerosis cohort

Primary cardiac involvement is one of the leading causes of mortality in systemic sclerosis (SSc), but little is known regarding circulating biomarkers for cardiac SSc. Here, we aimed to investigate potential associations between cardiac SSc and candidate serum markers. Serum samples from patients of the Oslo University SSc cohort and 100 healthy controls were screened against two custom-made candidate marker panels containing molecules deemed relevant for cardiopulmonary and/or fibrotic diseases. Left (LV) and right ventricular (RV) dysfunction was assessed by protocol echocardiography, performed within three years from serum sampling. Patients suspected of pulmonary hypertension underwent right heart catheterization. Vital status at study end was available for all patients. Descriptive analyses, logistic and Cox regressions were conducted to assess associations between cardiac SSc and candidate serum markers. The 371 patients presented an average age of 57.2 (± 13.9) years. Female sex (84%) and limited cutaneous SSc (73%) were predominant. Association between LV diastolic dysfunction and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) (OR 0.41, 95% CI 0.21–0.78, p = 0.007) was identified. LV systolic dysfunction defined by global longitudinal strain was associated with angiopoietin 2 (ANGPT2) (OR 3.42, 95% CI 1.52–7.71, p = 0.003) and osteopontin (OPN) (OR 1.95, 95% CI 1.08–3.52, p = 0.026). RV systolic dysfunction, measured by tricuspid annular plane systolic excursion, was associated to markers of LV dysfunction (ANGPT2, OPN, and TRAIL) (OR 1.67, 95% CI 1.11–2.50, p = 0.014, OR 1.86, 95% CI 1.25–2.77, p = 0.002, OR 0.32, 95% CI 0.15–0.66, p = 0.002, respectively) and endostatin (OR 1.86, 95% CI 1.22–2.84, p = 0.004). In conclusion, ANGPT2, OPN and TRAIL seem to be circulating biomarkers associated with both LV and RV dysfunction in SSc.

Increased L-Selectin on Monocytes Is Linked to the Autoantibody Profile in Systemic Sclerosis.

Monocytes are known to be implicated in the pathogenesis of systemic sclerosis (SSc), as they exert prominent migratory, adhesive, and chemotactic properties. The aim of our study was to characterize the surface expression of adhesion/chemotactic molecules (CD62L, CD11b, CCR2, CCR5) on the SSc monocytes and determine correlations with the clinical presentation of SSc. We included 38 SSc patients and 36 healthy age-and sex-matched controls. Isolated monocytes, as well as in vitro serum-treated monocytes, were analyzed by flow cytometry; additionally, soluble CD62L was measured in serum. We found increased soluble CD62L in the SSc serum samples and increased CD62L on the surface of the SSc monocytes in the in the same set of patients. Among samples with determined SSc-specific autoantibodies, the surface CD62L was the lowest in patients positive for anti-PM/Scl autoantibodies and the highest in patients with anti-topoisomerase I autoantibodies (ATA). The treatment of isolated healthy monocytes with ATA-positive SSc serum resulted in increased surface CD62L expression. Moreover, surface CCR5 was reduced on the monocytes from SSc patients with interstitial lung disease but also, along with CCR2, negatively correlated with the use of analgesics/anti-inflammatory drugs and immunosuppressants. In conclusion, increased CD62L on SSc monocytes, particularly in ATA-positive patients, provides new insights into the pathogenesis of SSc and suggests CD62L as a potential therapeutic target.

Comparison of a Suggested Model of Fibrosis in Human Dermal Fibroblasts by Serum from Systemic Sclerosis Patients with Transforming Growth Factor β Induced in vitro Model.

Systemic sclerosis (SSc) is a chronic autoimmune disease, featuring fibrosis in multiple organs. The serum from SSc patients contain inflammatory mediators, contributing to SSc pathogenesis and could be used to develop cell culture models. Here, we compared the fibrotic effects of serum samples from SSc patients with TGFβ1 on human dermal fibroblasts (HDFs). HDF cells were cultured in four different culture media supplementations; 10% SSc serum, 10% healthy human serum, 10% fetal bovine serum or 10% FBS supplemented with 10 ng/Ml human TGFβ. The collagen content in cell layers was measured by spectrophotometric Picro-Sirius red staining. The mRNA expression of α-SMA, COL I and III, TGFβ1, arginase and E-Cadherin genes were determined by real time RT-PCR. TGF-β1 levels in cell culture supernatants were measured using ELISA. Cell layer collagen content was significantly increased following TGF-β1 treatment, compared with FBS group and SSc serum treatment in comparison with healthy controls. Although not statistically significant, the mRNA expression of α-SMA, COLI and III, TGFβ1, and arginase increased upon TGF-β1 treatment in comparison with FBS group, and in SSc serum treatment group in comparison with healthy controls. E-Cadherin decreased following TGF-β1 treatment and SSc serum treatment in comparison with their counterparts. TGF-β1 levels increased in cell culture supernatants of HDF cells exposed to TGF-β1 and SSc serum. An in vitro model of SSc serum-induced fibrosis using human HDF cells was evaluated in comparison to the TGF-β1 fibrosis induced model and data suggested that it may be used in documenting the role of pro-fibrotic factors in serum or plasma from SSc patients.

Multiomic study of skin, peripheral blood, and serum: is serum proteome a reflection of disease process at the end-organ level in systemic sclerosis?

BackgroundSerum proteins can be readily assessed during routine clinical care. However, it is unclear to what extent serum proteins reflect the molecular dysregulations of peripheral blood cells (PBCs) or affected end-organs in systemic sclerosis (SSc). We conducted a multiomic comparative analysis of SSc serum profile, PBC, and skin gene expression in concurrently collected samples.MethodsGlobal gene expression profiling was carried out in skin and PBC samples obtained from 49 SSc patients enrolled in the GENISOS observational cohort and 25 unaffected controls. Levels of 911 proteins were determined by Olink Proximity Extension Assay in concurrently collected serum samples.ResultsBoth SSc PBC and skin transcriptomes showed a prominent type I interferon signature. The examination of SSc serum profile revealed an upregulation of proteins involved in pro-fibrotic homing and extravasation, as well as extracellular matrix components/modulators. Notably, several soluble receptor proteins such as EGFR, ERBB2, ERBB3, VEGFR2, TGFBR3, and PDGF-Rα were downregulated. Thirty-nine proteins correlated with severity of SSc skin disease. The differential expression of serum protein in SSc vs. control comparison significantly correlated with the differential expression of corresponding transcripts in skin but not in PBCs. Moreover, the differentially expressed serum proteins were significantly more connected to the Well-Associated-Proteins in the skin than PBC gene expression dataset. The assessment of the concordance of between-sample similarities revealed that the molecular profile of serum proteins and skin gene expression data were significantly concordant in patients with SSc but not in healthy controls.ConclusionsSSc serum protein profile shows an upregulation of profibrotic cytokines and a downregulation of soluble EGF and other key receptors. Our multilevel comparative analysis indicates that the serum protein profile in SSc correlates more closely with molecular dysregulations of skin than PBCs and might serve as a reflection of disease severity at the end-organ level.

Undifferentiated connective tissue disease at risk for systemic sclerosis: Which patients might be labeled prescleroderma?

Undifferentiated Connective Tissue Disease at risk for Systemic Sclerosis (UCTD-risk-SSc), otherwise referred to as very early-early SSc (very early-early diagnosis of systemic sclerosis VEDOSS), is a condition characterized by Raynaud's phenomenon (RP) and either SSc serum marker autoantibodies or a capillaroscopic scleroderma pattern or both, but without satisfying classification criteria for SSc neither features consistent with SSc sine scleroderma. Approximately half the UCTD-risk-SSc patients develop definite SSc over 5-10years of follow-up. Identifying patients who will undergo such evolution is an unmet need. Predicting at onset which patients with RP are going to develop SSc over time has long been a research objective and still is an unaccomplished task. The present review is devoted to the critical analysis of the nosographic boundaries of the condition and of items predictive of evolution including serological, capillaroscopic and circulating markers. A weighted score, based on serum antinuclear antibody titre, serum marker antibodies positivity and avascular areas has been developed and may identify in the meanwhile patients to be labeled prescleroderma i.e. those probably developing SSc over time. Future research should be directed to investigate unexplored features, validate and improve the performance of the score and highlight the involved pathways to be contrasted in order to identify a targeted therapy hampering the development of overt SSc.

TGF\u03b2-mediated expression of TGF\u03b2-activating integrins in SSc monocytes: disturbed activation of latent TGF\u03b2?

IntroductionThe pathophysiology of systemic sclerosis (SSc) is closely linked to overactive TGFβ signaling. TGFβ is produced and circulates in latent form, making its activation crucial for signaling. This activation can be mediated via integrins. We investigated the balance between active and latent TGFβ in serum of SSc patients and investigated if this correlates with integrin expression on monocytes.MethodsA TGFβ/SMAD3- or BMP/SMAD1/5-luciferase reporter construct was expressed in primary human skin fibroblasts. Both acidified and non-acidified sera of ten SSc patients and ten healthy controls were tested on these cells to determine total and active TGFβ and BMP levels respectively. A pan-specific TGFβ1/2/3 neutralizing antibody was used to confirm TGFβ signaling. Monocytes of 20 SSc patients were isolated using CD14+ positive selection, and integrin gene expression was measured using qPCR. Integrin expression was modulated using rhTGFβ1 or a small molecule inhibitor of TGFBR1: SB-505124.ResultsSSc sera induced 50% less SMAD3-reporter activity than control sera. Serum acidification increased reporter activity, but a difference between healthy control and SSc serum was no longer observed, indicating that total TGFβ levels were not different. Addition of a pan-specific TGFβ1/2/3 neutralizing antibody fully inhibited SMAD3-reporter activity of both acidified and not-acidified control and SSc sera. Both HC and SSc sera induced similar SMAD1/5-reporter activity, and acidification increased this, but not differently between groups. Interestingly, expression of two integrin alpha subunits ITGA5 and ITGAV was significantly reduced in monocytes obtained from SSc patients. Furthermore, ITGB3, ITGB5, and ITGB8 expression was also reduced in SSc monocytes. Stimulation of monocytes with TGFβ1 induced ITGA5 and ITGAV but lowered ITGB8 expression, whereas the use of the TGFβ receptor inhibitor SB-505124 had the opposite effect.ConclusionTotal TGFβ serum levels are not different between SSc patients and controls, but TGFβ activity is. This coincides with a reduced expression of TGFβ-activating integrins in monocytes of SSc patients. Because TGFβ regulates expression of these integrins in monocytes, a negative feedback mechanism possibly underlies these observations.

The relationship of serum SCUBE-1, -2 and -3 levels with clinical findings and ultrasonographic skin thickness in systemic sclerosis patients.

This study aimed to investigate the relationship between the level of serum signal peptide-CUB-EGF domain-containing protein (SCUBE)-1, SCUBE-2 and SCUBE-3 and clinical findings and ultrasonographic skin thickness in systemic sclerosis (SSc). Thirty patients who met the American College of Rheumatology/European League against Rheumatism 2013 SSc classification criteria and 44 healthy volunteers who were compatible with the patient group in terms of age and gender were included in the study. Serum SCUBE levels were measured by enzyme-linked immunosorbent assay. Ultrasonographic skin thickness measurements were simultaneously performed. No significant difference was found between the serum SCUBE levels of SSc patients and serum SCUBE levels of the control group. A negative correlation was detected between serum SCUBE-1 level and forced expiratory volume in 1second (FEV1 ). While a positive correlation was detected between serum SCUBE-2 level and the Duruöz Hand Index and serum C4 level, a negative correlation was determined with the forced vital capacity (FVC) value. A negative correlation was determined between serum SCUBE-3 level and echocardiographic pulmonary artery pressure (PAP). A correlation could not be determined between serum SCUBE levels and ultrasonographic skin thickness. However, a positive correlation was observed between ultrasonographic skin thickness and the modified Rodnan skin score. In this study, a correlation was observed between serum SCUBE levels and some clinical and laboratory parameters (FEV1 , FVC, PAP, C4, and Duruöz Hand Index) in SSc patients. New clinical studies are needed to better understand the contribution of these molecules in the progression and pathogenesis of SSc.

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.

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.

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

ObjectivesWe 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...

The Role of Endothelial Progenitors in the Repair of Vascular Damage in Systemic Sclerosis.

Systemic sclerosis (SSc) is a connective tissue disease characterized by a complex pathological process where the main scenario is represented by progressive loss of microvascular bed, with the consequent progressive fibrotic changes in involved organ and tissues. Although most aspects of vascular injury in scleroderma are poorly understood, recent data suggest that the scleroderma impairment of neovascularization could be related to both angiogenesis and vasculogenesis failure. Particularly, compensatory angiogenesis does not occur normally in spite of an important increase in many angiogenic factors either in SSc skin or serum. Besides insufficient angiogenesis, the contribution of defective vasculogenesis to SSc vasculopathy has been extensively studied. Over the last decades, our understanding of the processes responsible for the formation of new vessels after tissue ischemia has increased. In the past, adult neovascularization was thought to depend mainly on angiogenesis (a process by which new vessels are formed by the proliferation and migration of mature endothelial cells). More recently, increased evidence suggests that stem cells mobilize from the bone marrow into the peripheral blood (PB), differentiate in circulating endothelial progenitors (EPCs), and home to site of ischemia to contribute to de novo vessel formation. Significant advances have been made in understanding the biology of EPCs, and molecular mechanisms regulating EPC function. Autologous EPCs now are becoming a novel treatment option for therapeutic vascularization and vascular repair, mainly in ischemic diseases. However, different diseases, such as cardiovascular diseases, diabetes, and peripheral artery ischemia are related to EPC dysfunction. Several studies have shown that EPCs can be detected in the PB of patients with SSc and are impaired in their function. Based on an online literature search (PubMed, EMBASE, and Web of Science, last updated December 2017) using keywords related to “endothelial progenitor cells” and “Systemic Sclerosis,” “scleroderma vasculopathy,” “angiogenesis,” “vasculogenesis,” this review gives an overview on the large body of data of current research in this issue, including controversies over the identity and functions of EPCs, their meaning as biomarker of SSc microangiopathy and their clinical potency.

Integration of microRNA and mRNA expression profiles in the skin of systemic sclerosis patients

MicroRNAs (miRNAs) play important roles in the fibrosis of systemic sclerosis (SSc). However, the underlying miRNA-mRNA regulatory network is not fully understood. A systemic investigation of the role of miRNAs would be very valuable for increasing our knowledge of the pathogenesis of SSc. Here, we combined miRNA and mRNA expression profiles and bioinformatics analyses and then performed validation experiments. we identified 21 miRNAs and 2698 mRNAs that were differentially expressed in SSc. Among these, 17 miRNAs and their 33 target mRNAs (55 miRNA-mRNA pairs) were involved in Toll-like receptor, transforming growth factor β and Wnt signalling pathways. Validation experiments revealed that miR-146b, miR-130b, miR-21, miR-31 and miR-34a levels were higher whereas miR-145 levels were lower in SSc skin tissues and fibroblasts, normal fibroblasts and endothelial cells that were stimulated with SSc serum. ACVR2B, FZD2, FZD5 and SOX2 levels were increased in SSc skin fibroblasts, normal fibroblasts and endothelial cells that were stimulated with SSc serum. We did not identify any negative correlations among these miRNA-mRNA pairs. miR-21 was specifically expressed at higher levels in SSc serum. Six miRNAs and 4 mRNAs appear to play important roles in the pathogenesis of SSc are worth investigating in future functional studies.

Tenascin-C drives persistence of organ fibrosis.

The factors responsible for maintaining persistent organ fibrosis in systemic sclerosis (SSc) are not known but emerging evidence implicates toll-like receptors (TLRs) in the pathogenesis of SSc. Here we show the expression, mechanism of action and pathogenic role of endogenous TLR activators in skin from patients with SSc, skin fibroblasts, and in mouse models of organ fibrosis. Levels of tenascin-C are elevated in SSc skin biopsy samples, and serum and SSc fibroblasts, and in fibrotic skin tissues from mice. Exogenous tenascin-C stimulates collagen gene expression and myofibroblast transformation via TLR4 signalling. Mice lacking tenascin-C show attenuation of skin and lung fibrosis, and accelerated fibrosis resolution. These results identify tenascin-C as an endogenous danger signal that is upregulated in SSc and drives TLR4-dependent fibroblast activation, and by its persistence impedes fibrosis resolution. Disrupting this fibrosis amplification loop might be a viable strategy for the treatment of SSc.

Esophageal dilatation and interstitial lung disease in systemic sclerosis: A cross-sectional study.

A patulous esophagus on high-resolution computed tomography (HRCT) of the thorax is frequently observed in patients with systemic sclerosis (SSc). Microaspiration has been purported to play a role in the development and progression of SSc interstitial lung disease (ILD), but studies examining the role of microaspiration in SSc ILD have yielded conflicting results. This study was conducted to determine the association between esophageal diameter and SSc ILD. A cross-sectional study of Northwestern Scleroderma Registry patients with available HRCT exams was conducted. The predictor variable was the widest esophageal diameter (WED) on HRCT, and the primary and secondary outcome variables were radiographic ILD and pulmonary function tests respectively. The degree of radiographic ILD was assessed using a semi-quantitative score adapted from published methods. Estimated regression coefficients adjusted for age, sex, race, body mass index, smoking; SSc disease subtype, serum autoantibodies, and disease duration; modified Rodnan skin score, proton pump inhibitor, and immune suppressant medication use and erythrocyte sedimentation rate were calculated. A total of 270 subjects were studied. In the adjusted analyses, there were positive associations between WED and total ILD score (β = 0.27; 95% CI: 0.09-0.41), fibrosis (β = 0.15; 95% CI: 0.07-0.23), and ground glass opacities (β = 0.12; 95% CI: 0.04-0.20); there were negative associations between WED and FVC % predicted (β = -0.42; 95% CI: -0.69 to -0.13), and adjusted DLCO % predicted (β = -0.45; 95% CI: -0.80 to -0.09) after adjusting for potential confounders. Increasing esophageal diameter on HRCT in patients with SSc is associated with more severe radiographic ILD, lower lung volumes, and lower DLCO % predicted. Longitudinal studies are needed to determine if esophageal dilatation is associated with the incidence and/or progression of ILD in patients with SSc.

Semaphorin 3A: an immunoregulator in systemic sclerosis

Semaphorin 3A (sema3A) plays a regulatory role in immune responses, mainly affecting the activation of regulatory T cells. It has been found to correlate with disease activity in rheumatoid arthritis and systemic lupus erythematosus (SLE). To investigate the expression of sema3A in patients with systemic sclerosis (SSc) compared to healthy controls and SLE disease controls and to correlate it with clinical characteristics, 27 SSc patients, 42 SLE patients and 28 healthy controls were enrolled. Serum level of sema3A was measured by ELISA, and expression of sema3A on regulatory T cells was evaluated by FACS analysis. SSc patients were evaluated for demographics, clinical manifestations, routine laboratory results, nailfold videocapillaroscopy, pulmonary function tests, echocardiograms, modified Rodnan skin score, and disease activity and severity scores. Serum levels of semaphorin 3A were lower in SSc compared to healthy controls 14.38±5.7 versus 27.14±8.4ng/ml, p<0.0001 and similar to SLE 15.7±4.3ng/ml. The expression of semaphorin 3A on regulatory T cells was also lower in SSc compared to healthy controls 61.7±15.7 versus 88.7±3. 7% (p<0.0001). Semaphorin 3A serum level inversely correlated with the duration of disease: r=-0.4, p=0.036 and with low C4 level r=0.66, p=0.026. SCL-70 antibody positivity was associated with a lower semaphorin 3A level (difference in mean of 3.44, p=0.06). Sema3A expression is low in SSc serum and more specifically on regulatory T cells. This may help explain the reduced activation of regulatory T cells in SSc.

A1.13 Increased presence of CD206+macrophage subset in peripheral blood of systemic sclerosis patients

Background and objectives In systemic sclerosis (SSc), the immune-inflammatory infiltrate is primarily made of macrophages and T cells. 1 Recently, alternatively activated macrophages (M2) have been shown to enhance fibrosis through the production of pro-fibrotic molecules (i.e. fibronectin, metalloproteinases and TGFβ. 2 M2 are characterised by an increased expression of specific markers, primarily CD206 (macrophage mannose receptor-1) and macrophage scavenger receptors (CD204 and CD163). The study investigated the presence of M2 in the peripheral blood (PB) of SSc patients. In addition, the capability of SSc serum to induce the expression of M2 markers and the production of pro-fibrotic metalloproteinase (MMP)-9 in cultured PB mononuclear cells (PBMCs) of healthy subjects (HS) were investigated. Materials and methods Eight SSc patients (mean age 65 ± 7 years) who fulfilled the new criteria of EULAR/ACR 3 and five age matched HS were enrolled into the study, after signing an Informed Consent. SSc patients were treated with vasodilators and endothelin-1 blockers. PB from SSc patients and HS was analysed by flow cytometry (FC) to detect the presence of cells positive for CD206, CD204 and CD14 (a marker of monocyte/macrophage lineage). PBMC-derived monocytes isolated from the enrolled HS (2 × 10 6 cells/well) were maintained for 12 h in growth medium at 10% of fetal bovine serum and then stimulated for 48 h with the serum from SSc patients and HS themselves. The expression of CD206, CD204 and CD68 (a macrophage marker) was evaluated by immunocytochemistry (ICC). MMP-9 production was evaluated by zymography. Results In the PB of SSc patients, the CD206 + cell percentage was found significantly higher than that of HS (p + cells co-expressed CD204, belonging to the monocyte/macrophage lineage due to their expression of CD14. SSc serum stimulated PBMC-derived monocytes to express CD206, CD204 and CD68 thus indicating their activation into macrophages. Conversely, serum from HS was unable to stimulate the expression of CD206 and it induced a limited expression of CD204 in these cells. Zymography showed that treatment with SSc serum induced an increased production and secretion of MMP-9 compared to the treatment with HS serum in PBMC-derived macrophages. Conclusion These preliminary results show an increased presence of the CD206 + cell subset in the PB of SSc patients. The ability of SSc serum to induce the expression of this M2 macrophage marker and to increase the production of pro-fibrotic MMP-9 might support a possible involvement of this cell subset in the pathogenesis of SSc. References Wynn TA, Ramalingam TR et al . Mechanisms of fibrosis: therapeutic translation for fibrotic disease. Nat Med 2012; 18 :1028–40. Fairweather D, Cihakova D et al . Alternatively activated macrophages in infection and autoimmunity. J Autoimmun 2009; 33 :222–30. van den Hoogen F, Khanna D, Fransen J et al . 2013 classification criteria for systemic sclerosis: an American College of Rheumatology/European League against Rheumatism collaborative initiative. Arthrit Rheum 2013; 65 :2737–47.

AB0211 Expression of M2 Macrophages in the Skin of Systemic Sclerosis Patients with Active Capillaroscopic Pattern of Microangiopathy

BackgroundRecent evidences report the involvement of macrophages in the pathogenesis of systemic sclerosis (SSc) (1). Among macrophage populations, the alternatively activated macrophages (M2) are associated with T helper type 2...

OP0257 IL-6 in scleroderma; potential implications for targeted therapy: A systematic analysis

BackgroundThe pathogenesis of Systemic sclerosis (SSc) involves fibrosis, vascular changes and autoimmunity. Some research has postulated that interleukin-6 (IL-6) a pleitropic cytokine is important in SSc. However, not all studies...