Early-stage Systemic Sclerosis Research Articles

P147 M2 macrophage associated fibrosis in early stage systemic sclerosis: an update on plasma biomarkers

Abstract Background/Aims Systemic sclerosis is an autoimmune connective tissue disease characterised by vasculopathy and fibrosis. The CCN family of matricellular proteins have a regulatory role in inflammation and fibrosis. CD206, an M2 macrophage surface marker, is cleaved by metalloproteases to release soluble form of CD206; this acts as an active disease marker in systemic sclerosis. We investigated the profile of CCN2 and CCN3 in the presence of soluble CD206 (sCD206) in patients with early and late stage diffuse systemic sclerosis (dcSSc). Methods Patients with a diagnosis of dcSSc at the UCL Centre for Rheumatology and Connective Tissue Diseases were recruited. Informed consent was obtained from patients and healthy controls (HC). Blood samples were taken from which plasma was isolated and stored at -80 °C prior to assay. Expression of CCN2, CCN3, and sCD206 was measured in these plasma samples by ELISA. Study participants were categorised into healthy controls (n = 20), early stage dcSSc (n = 20) and late dcSSc (n = 20), with early stage defined as the blood sample taken within two years since diagnosis, and late stage defined as over five years since diagnosis. Results Plasma CCN2, CCN3 and sCD206 levels were significantly higher in early dcSSc patients, when compared to HC. CCN2 was raised in early dcSSc patients (early dcSSc mean 20,221pg/ml, SD 16,503, p < 0.05) with concentration in late disease matching that of HC (late dcSSc 12,893pg/ml, HC 11,289pg/ml). CCN3 was significantly higher in early and late disease when compared to HC (early mean 16,526pg/ml, late 12,838pg/ml, HC 4,201pg/ml, p < 0.05). sCD206 levels were higher in early dcSSc (mean 5356pg/ml, SD 3154, p < 0.05), with there being no significance between levels in late dcSSc (mean 4184pg/ml, SD 3900, p > 0.05) and HC (mean 3319pg/ml, SD 1925). CCN2 expression was higher compared to that of CCN3 in early disease, with CCN2:CCN3 ratio elevated in early dcSSc (mean 3.17, SD 8.26) compared to late dcSSc (mean 1.26, SD 0.99) and HC. Conclusion This investigation demonstrates that upregulation of CCN2 and CCN3 expression has a regulatory role in fibrosis in early stage dcSSc. These biomarkers of M2 macrophage associated fibrosis are to be correlated with their clinical phenotype and have potential for a role in targeted treatment of systemic sclerosis. Disclosure L.A. Leeves: None. Z. Kannan: None. Y. Ali: None. L. Pan: None. T. Malley: None. D. Abraham: None. A. Leask: None. B. Riser: None. B. Ahmed Abdi: None. R.J. Stratton: None.

Extended autoantibody panel in Turkish patients with early-stage systemic sclerosis: Coexpressions and their influences on clinical phenotypes.

To investigate the frequency and clinical relevance of an extended autoantibody profile in patients with systemic sclerosis(SSc). In this cross-sectional study, serum from 100 consecutive patients was subjected to indirect immunofluorescence (IIF)(HEp-20-10/primate liver mosaic) and Systemic Sclerosis Profile by EUROIMMUNto evaluate anti-nuclear antibodies(ANA) and autoantibodies against 13 different autoantibodies in patients with SSc less than 3 years. Ninety-three of 100 patients were positive for ANA byIIF. Fifty-three patients showed single positivity, 26 anti-topoisomerase antibodies (anti-Scl70 ab), 16 anticentromere antibodies (ACAs), six anti-RNA polymerase III antibodies (anti-RNAPIII ab), one anti-Ku antibody, one anti-PM/Scl100 antibody, two anti-PM/Scl75 antibodies, one anti-Ro52 antibody, whereas 32 patients had multiple autoantibody positivities. Among classic SSc-specific autoantibodies, anti-Scl70 and anti-RNAPIII abs showed the highest cooccurrence (n = 4). One patient was simultaneously positive for anti-RNAPIII ab and ACA, and one was positive for ACA and anti-Scl70 ab. The clinical features were not statistically different between single and multiple autoantibody-positivity for classic SSc-specific autoantibodies (ACA, anti-Scl70 ab, and anti-RNAPIII ab), except for digital ulcer in the multiantibody positive ACA group (p = .019). Based on our results, coexpression of autoantibodies is not uncommon in SSc patients. Although autoantibodies specific to SSc in early disease show generally known clinical features, it remains to be investigated how the coexpression of autoantibodies will affect clinical presentation.

Does early systemic sclerosis really exist?

Systemic sclerosis (SSc) is an autoimmune systemic disease of unknown origin, characterized by sclerosis of the skin and internal organs associated with endothelial dysfunction, immune dysregulation, and autoantibody [1]. The most common manifestations are Raynaud's phenomenon (RP), digital ulcers, interstitial lung disease (ILD), pulmonary arterial hypertension (PAH), gastrointestinal disorders, scleroderma renal crisis (SRC), heart problems, and musculoskeletal symptoms. Nevertheless, SSc may be a clinically heterogeneous disease that ranges from a milder form to more rapid widespread internal organ involvement with different clinical features at onset. This entity is easy to diagnose in the advanced stages, but the vascular and fibrotic involvement may have started years previously. Prompt detection of the various manifestations benefits prognosis [2], but this is challenging in the early stages of the disease when most of the typical signs and symptoms are absent. Consequently, an SSc diagnosis may be delayed for years following the onset of RP, and even after the appearance of the first non-RP symptom. Thus, treatment and prognosis may be delayed until systemic involvement is evident or even irreversible [3]. Conventional classification criteria are limited in identifying early-stage SSc patients. The ACR/EULAR classification criteria specify that patients with pre-scleroderma, as defined by LeRoy and Koenig, do not have to be classified as definite SSc. However, autoimmunity can precede clinical manifestations by years [4], and efforts have been made to detect this situation before frank disease develops [5]. Nevertheless, diagnosis of early SSc can still be a challenge despite the wealth of published data and available information.

AB0146 Increased frequency of th1 and tc1 lymphocytes producing tumor necrosis factor alpha in peripheral blood of late-stage systemic sclerosis

BackgroundSubstantial evidence supports the implication of immune-activated cells, cytokines and chemokines in the pathogenesis of systemic sclerosis (SSc). The frequency of T cells expressing activation markers is increased in the...

Pulmonary blood volume indexed to lung volume is reduced in newly diagnosed systemic sclerosis compared to normals--a prospective clinical cardiovascular magnetic resonance study addressing pulmonary vascular changes.

BackgroundPulmonary involvement, manifested as pulmonary arterial hypertension or pulmonary fibrosis, is the most common cause of death in systemic sclerosis (SSc). We aimed to explore the feasibility of detecting early pulmonary involvement in SSc using recently developed non-invasive quantitative measures of pulmonary physiology using cardiovascular magnetic resonance (CMR).MethodsTwenty-seven SSc patients (9 men, 57 ± 13 years) and 10 healthy controls (3 men, 54 ± 9 years) underwent CMR to determine the pulmonary blood volume (PBV) and the PBV variation (PBVV) throughout the cardiac cycle. Patients underwent Doppler echocardiography, high-resolution computed tomography (HRCT), and pulmonary function testing by spirometry. Comparisons were performed using the unpaired t-test and linear regression analysis was performed with Pearson’s correlation coefficient (r).ResultsCompared to healthy controls, the PBV indexed to lung volume (PBVI) was lower in patients (16 ± 4 vs 20 ± 5%, p < 0.05). There was no difference in PBV (466 ± 87 vs 471 ± 122 mL, p = 0.91) or PBVV/stroke volume (45 ± 10 vs 40 ± 6%, p = 0.09). There were no significant correlations between PBVI and pulmonary artery pressure estimated by Doppler (p = 0.08) the lung’s diffusion capacity for carbon monoxide (DLCO) (p = 0.09), vital capacity (p = 0.45), or pulmonary fibrosis by HRCT (p = 0.74).ConclusionsThis study is the first to measure the PBV in humans using CMR. Compared to healthy controls, newly diagnosed SSc patients have a reduced amount of blood in the pulmonary vasculature (PBVI) but unchanged pulmonary vascular distensibility (PBVV/stroke volume). PBVI is unrelated to DLCO, pulmonary artery pressure, vital capacity, and the presence of pulmonary fibrosis. PBVI may be a novel parameter reflecting vascular lung involvement in early-stage SSc, and these findings may be consistent with pathophysiological changes of the pulmonary vasculature.

Differential expression of junctional adhesion molecules in different stages of systemic sclerosis

Systemic sclerosis (SSc) is characterized by early perivascular inflammation, microvascular endothelial cell (MVEC) activation/damage, and defective angiogenesis. Junctional adhesion molecules (JAMs) regulate leukocyte recruitment to sites of inflammation and ischemia-reperfusion injury, vascular permeability, and angiogenesis. This study was undertaken to investigate the possible role of JAMs in SSc pathogenesis. JAM-A and JAM-C expression levels in skin biopsy samples from 25 SSc patients and 15 healthy subjects were investigated by immunohistochemistry and Western blotting. Subcellular localization of JAMs in cultured healthy dermal MVECs and SSc MVECs was assessed by confocal microscopy. Serum levels of soluble JAM-A (sJAM-A) and sJAM-C in 64 SSc patients and 32 healthy subjects were examined by enzyme-linked immunosorbent assay. In control skin, constitutive JAM-A expression was observed in MVECs and fibroblasts. In early-stage SSc skin, JAM-A expression was strongly increased in MVECs, fibroblasts, and perivascular inflammatory cells. In late-stage SSc, JAM-A expression was decreased compared with controls. JAM-C was weakly expressed in control and late-stage SSc skin, while it was strongly expressed in MVECs, fibroblasts, and inflammatory cells in early-stage SSc. Surface expression of JAM-A was higher in early-stage SSc MVECs and increased in healthy MVECs stimulated with early-stage SSc sera. JAM-C was cytoplasmic in resting healthy MVECs, while it was recruited to the cell surface upon challenge with early-stage SSc sera. Early-stage SSc MVECs exhibited constitutive surface JAM-C expression. In SSc, increased levels of sJAM-A and sJAM-C correlated with early disease and measures of vascular damage. Our findings indicate that JAMs may participate in MVEC activation, inflammatory processes, and impaired angiogenesis in different stages of SSc.

Decreased secretion of MMP by non-lesional late-stage scleroderma fibroblasts after selection via activation of the apoptotic fas-pathway

Our hypothesis is that the development of lesional areas of skin in patients with systemic sclerosis (SSc) originates from the selection of profibrotic cell subpopulations within their non-lesional skin areas, due to their greater resistance to apoptosis. Sensitivity to apoptosis of early-stage or late-stage SSc fibroblasts as well as of healthy cells was compared using extrinsic or intrinsic apoptotic pathway-inducers. Subpopulations of non-lesional SSc cells and healthy cells obtained after repeated Fas-induced apoptosis were compared with respect to their fibrotic parameters such as collagen and MMP secretion. Only late-stage lesional SSc cells were more resistant to Fas-induced apoptosis than their non-lesional counterparts isolated from the same patient. This result correlated with an increase in the levels of the anti-apoptotic proteins cFLIPs and cIAP in lesional cells compared to non-lesional cells. Healthy and non-lesional cell populations could be selected to generate a subpopulation that was more resistant to apoptosis. However, only the late-stage non-lesional SSc fibroblast populations showed a significant decrease in MMP secretion, one of parameters of the fibrosis. Our results show that resistance to apoptosis is an important characteristic of the late-stage lesional SSc fibroblast phenotype. We thus hypothesized that a selection of specific fibroblast subpopulations from late-stage non-lesional SSc skin areas could be at the origin of lesional populations. These cells should become independent of any exogenous stimuli and can induce or maintain SSc skin lesions.

The fibrotic phenotype of systemic sclerosis fibroblasts varies with disease duration and severity of skin involvement: reconstitution of skin fibrosis development using a tissue engineering approach

We set out to examine the pathophysiological mechanisms of fibrosis in diffuse systemic sclerosis (SSc) using a tissue engineering approach. Skin fibroblasts were isolated from lesional skin of SSc patients with a disease duration of less than 1 year (early-stage SSc) or more than 10 years (late-stage SSc). Fibroblasts were also isolated from non-lesional skin and compared with normal fibroblasts isolated from healthy adults. Cells were cultured using a tissue engineering method to reconstruct a human dermis, and histologically observed. Dermal thickness was measured, as it reflects the global and intrinsic capacity of cells to reconstitute matrix. Collagen I, MMP-1, and MMP activity were evaluated. Cells were treated with TGFbeta1 or CTGF during dermis formation to study their fibrogenic role. Clinical severity of skin involvement was measured by a modified Rodnan score. Thickness of the dermis generated with non-lesional early-stage SSc fibroblasts was similar to normal cells. In contrast, reconstructed dermis from lesional early-stage SSc fibroblasts and non-lesional late-stage SSc cells was thinner, while lesional late-stage SSc fibroblasts made a thicker dermis. Dermis was always thicker when produced with TGFbeta1-treated cells, except when lesional late-stage SSc fibroblasts from patients with high Rodnan skin scores were used. CTGF did not affect dermal thickness. Measurements of collagen I and collagenases in the culture medium of the various reconstructed dermis could explain some of the changes observed. We conclude that the fibrotic phenotype of SSc fibroblasts varies with disease duration and with severity of skin involvement, and this is clearly visualized during in vitro dermis reconstruction.

2073 Novel quantitative measures of pulmonary arterial hypertension using MRI – a study in patients with early-stage systemic sclerosis

2073 Novel quantitative measures of pulmonary arterial hypertension using MRI – a study in patients with early-stage systemic sclerosis

Collagen turnover is diminished by different clones of skin fibroblasts from early- but not late-stage systemic sclerosis.

To investigate collagen turnover and proliferation in dermal fibroblasts from patients with systemic sclerosis (SSc) and their relationship with disease duration and cellular subpopulations, SSc patients were grouped by disease duration (less than 2.5 years or more than 7 years). Control and SSc fibroblasts were obtained from skin biopsies. Collagen biosynthesis was determined by [14C]-proline uptake. Type I/III collagens, gelatinolytic activity, and tissue inhibitors of metalloproteinases (TIMP)-1 and -2 were evaluated by electrophoresis, zymography, and enzyme-linked immunosorbent assay, respectively. Total collagen synthesis and the levels of alpha1(I), alpha2(I), and alpha1(III) chains, as well as TIMP-1 and proliferation were increased in fibroblasts only from patients with early-stage SSc. Gelatinolytic activity did not vary among the groups. This metabolic condition favors a higher local fibroblast population and is characterized by a heterogeneous clonal response in which the majority exhibited higher levels of collagen and TIMP-1 synthesis as well as an increase in their proliferation patterns involving hyper-reactive fibroblast subsets.

Monocyte chemoattractant protein 3 as a mediator of fibrosis: Overexpression in systemic sclerosis and the type 1 tight‐skin mouse

To determine the gene-expression profile in dermal fibroblasts from type 1 tight-skin (Tsk1) mice, and to examine the expression and potential fibrotic activity of monocyte chemoattractant protein 3 (MCP-3) in Tsk1 mouse and human systemic sclerosis (SSc) skin. Complementary DNA microarrays (Atlas 1.2) were used to compare Tsk1 fibroblasts with non-Tsk1 littermate cells at 10 days, 6 weeks, and 12 weeks of age. Expression of MCP-3 protein was assessed by Western blotting of fibroblast culture supernatants, and localized in the mouse and human skin biopsy samples by immunohistochemistry. Activation of collagen reporter genes by MCP-3 was explored in transgenic mouse fibroblasts and by transient transfection assays. MCP-3 was highly overexpressed by neonatal Tsk1 fibroblasts and by fibroblasts cultured from the lesional skin of patients with early-stage diffuse cutaneous SSc. Immunolocalization confirmed increased expression of MCP-3 in the dermis of 4 of 5 Tsk1 skin samples and 14 of 28 lesional SSc skin samples, compared with that in matched healthy mice (n = 5) and human controls (n = 11). Proalpha2(I) collagen promoter-reporter gene constructs were activated by MCP-3 in transgenic mice and by transient transfection assays. This response was maximal between 16 and 24 hours of culture and mediated via sequences within the proximal promoter. The effects of MCP-3 could be diminished by a neutralizing antibody to transforming growth factor beta. We demonstrate, for the first time, overexpression of MCP-3 in early-stage SSc and in Tsk1 skin, and suggest a novel role for this protein as a fibrotic mediator activating extracellular matrix gene expression in addition to promoting leukocyte trafficking. This chemokine may be an important early member of the cytokine cascade driving the pathogenesis of SSc.

Expression of Stem Cell Factor in the Lesional Skin of Systemic Sclerosis

Background and Objective: Mast cells are thought to play an important role in the pathogenesis of systemic sclerosis (SSc), although their significance is still unknown. As mast cells are increased in number in the lesional skin of the early stage of scleroderma, we addressed the question whether expression of stem cell factor (SCF), a mast cell growth factor, is upregulated in the lesional skin. Methods: Immunohistochemical analysis of SCF was performed in paraffin-embedded skin sections from the lesions of 18 patients with SSc (13 in the edematous and 5 in the sclerotic phase) and from normal skin of 5 subjects. SCF messenger RNA expression was also examined on cultured fibroblasts derived from SSc by using reverse-transcriptase polymerase chain reaction. Results: Immunostaining showed focal expression for SCF in fibroblast-like spindle-shaped cells, mast cells, keratinocytes and endothelial cells. SCF-positive spindle-shaped cells were significantly increased in the reticular dermis in the early edematous stage of SSc (33.7 ± 13.0/mm²) as compared with normal skin (18.3 ± 4.2/mm²; p <0.05); however, there was no significant difference between the sclerotic phase (18.9 ± 6.9/mm²) and normal skin. mRNA expression of SCF was detected both in cultured scleroderma-derived and normal skin-derived fibroblasts. Conclusion: These results may suggest that SCF plays a role in the fibrotic process in early-stage SSc.

Decorin and glycosaminoglycan synthesis in skin fibroblasts from patients with systemic sclerosis.

We investigated the expression of decorin and the synthesis of sulphated glycosaminoglycans (GAGs) in cultured fibroblasts from patients with early-stage systemic sclerosis (SSc). Decorin mRNA levels were 1.8-fold higher in SSc fibroblasts than in control fibroblasts. SSc fibroblasts also produced 2.3-fold more decorin core protein and 2.2-fold more sulphated GAGs including dermatan sulphate and chondroitin sulphate. Newly synthesized GAGs, in the presence of p-nitrophenyl beta-xylopyranoside, which elongates dermatan sulphate and chondroitin sulphate as an initiator, were increased tenfold and were mainly composed of dermatan sulphate and chondroitin sulphate. The rate of stimulation by the beta-xyloside was similar in SSc and control fibroblasts. These results suggest that the increased amount of dermatan/chondroitin sulphate in SSc fibroblasts reflects an enhanced expression of decorin core protein. Type I collagen mRNA levels in SSc fibroblasts were also increased together with its synthesis. Therefore, our results indicate that an altered decorin and collagen production may affect the organization of collagen fibres and the fibrotic process observed in patients with SSc.