Initial predictors of skin thickness progression in patients with diffuse cutaneous systemic sclerosis: Results from a multicentre prospective cohort in Japan.

OBJECTIVE: To identify initial parameters that predict worsening of skin thickening in patients with diffuse cutaneous systemic sclerosis (dcSSc) using a multicentre, prospective, observational cohort in Japan. METHODS: A total of 171 patients with dcSSc were selected from a prospective cohort database based on the following criteria: dcSSc, modified Rodnan total skin thickness score (mRSS) ≥7, disease duration <60 months, and valid mRSS data at one year. Worsening of skin thickness was defined as an increase in mRSS ≥3 points and an increase ≥25% from baseline to one year. Initial demographic and clinical parameters useful for predicting the progression of skin thickness were identified using univariate and multivariable analysis, and prediction models of skin thickening progression were built based on combinations of independent predictive parameters. RESULTS: Only 23 patients (13.5%) experienced worsening mRSSs at one year. Short disease duration, low mRSS, absence of nailfold bleeding, arthritis, and a high erythrocyte sedimentation rate at diagnosis were identified as predictors of subsequent worsening of the mRSS even after adjusting for the treatment. Assessment of the best predictive model revealed that patients with a disease duration ≤12 months and mRSS ≤19 had a risk of mRSS worsening within one year, with a sensitivity of 73.9% and specificity of 81.1%. CONCLUSION: Identification of predictors of subsequent worsening of skin thickness in dcSSc patients is useful for identifying patients who require intensive treatment with potential disease-modifying agents and for improving clinical trial design by characterizing eligible progressors in the Japanese population.

Clinical course of Japanese patients with early systemic sclerosis: A multicenter, prospective, observational study.

OBJECTIVES: To investigate the clinical course of Japanese patients with early diffuse cutaneous systemic sclerosis (dcSSc) and early SSc with interstitial lung disease (ILD). METHODS: We prospectively analyzed the clinical features of 207 Japanese patients with early dcSSc (n = 150) and limited cutaneous SSc (lcSSc) with ILD (n = 57) in 10 medical centers every year for 7 consecutive years. RESULTS: Mean modified Rodnan total skin thickness score (mRSS) was 18.3 and 67.4% of the cohort had ILD. Most patients started immunosuppressive therapy and vasodilators during 7 years (83.4% and 87.9%, respectively). Mean value of mRSS of total patients was significantly reduced from the initial registration after the first year. However, other parameters for physical function associated with skin sclerosis including fist closure, hand extension, and oral aperture were not so ameliorated during the study period. Health Assessment Questionnaire-disability index and serum KL-6 levels were constant throughout the course. Percent vital capacity and the presence of ILD, clinically suspected pulmonary arterial hypertension, and digital ulcers were gradually exacerbated during the period. CONCLUSION: In Japanese early dcSSc patients and SSc patients with ILD, mRSS was continuously reduced during 7 years of follow-up, but there was little improvement of physical disability and organ involvement.

Prediction of organ involvement in systemic sclerosis by serum biomarkers and peripheral endothelial function.

OBJECTIVES: To identify prognostic factors among serum biomarkers and endothelial vasodilator function findings in patients with systemic sclerosis (SSc). METHODS: This is a clinical observational study. We assessed 60 consecutive SSc patients (44 limited cutaneous-type, 16 diffuse cutaneous-type). Circulating growth differentiation factor-15 (GDF-15), placenta growth factor (PlGF), endostatin, vascular endothelial growth factor (VEGF), and pentraxin 3 (PTX3) were measured by ELISA. Peripheral endothelial function was measured by forearm blood dilatation response to brachial artery occlusion using noninvasive plethysmography (EndoPAT2000), which is associated with nitric-oxide-dependent vasodilatation and yields a reactive hyperemia index (RHI). We evaluated whether abnormalities in these values were associated with type of SSc - namely, diffuse cutaneous SSc (dcSSc) or limited cutaneous SSc (lcSSc) - or organ involvement including interstitial lung disease (ILD), digital ulcer (DU) and estimated right ventricular systolic pressure (RVSP) by echocardiography >30 mmHg. RESULTS: SSc patients showed significantly elevated serum GDF-15, PlGF, endostatin and VEGF but not PTX3 compared with controls. GDF-15 and PlGF were high in dcSSc patients. EndoPAT-RHI was low, and incidence of RVSP >30 mmHg was high in dcSSc. Multivariate analysis revealed that elevated GDF-15 was highly predictive of dcSSc, ILD or RVSP >30 mmHg. PlGF for DU was also found. Conversely, a low EndoPAT-RHI value was predictive of the presence of dcSSc, ILD or DU. CONCLUSIONS: This is the first study to inclusively investigate the relationships among biomarkers, EndoPAT-RHI and organ involvement in patients with SSc. Our data suggest a complex pathological progression of SSc through fibrotic impairment and microvascular damage.

Myositis-specific anti-155/140 autoantibodies target transcription intermediary factor 1 family proteins.

OBJECTIVE: To identify the 140-kd autoantigen recognized by anti-155/140 autoantibodies that are associated with adult cancer-associated dermatomyositis (DM) and juvenile DM and to determine the clinical relevance of anti-155/140 antibodies in a large cohort. METHODS: Sera from 456 DM patients were assessed for the presence of anti-155/140 antibodies by immunoprecipitation using K562 cell extracts as substrate. Using immunoprecipitation and Western blotting, we then examined whether anti-155/140-positive sera recognized transcription intermediary factor 1α (TIF-1α), TIF-1ß, and TIF-1γ. The clinical associations of antigen reactivity were also evaluated. RESULTS: Anti-155/140-positive sera reacted with 140-kd TIF-1α in addition to 155-kd TIF-1γ. Among sera from 456 DM patients, 52 were reactive with both TIF-1α and TIF-1γ, while another 25 were reactive with TIF-1γ alone. Additionally, 7 were reactive with TIF-1ß. Malignancy was more frequently found in adult patients with both anti-TIF-1α and anti-TIF-1γ antibodies than in those with anti-TIF-1γ antibodies alone (73% versus 50%; P < 0.05). In addition to juvenile DM patients and middle-aged and older DM patients with high percentages of malignancy, 8 "young adult" DM patients without malignancy had these autoantibodies. CONCLUSION: Anti-155/140 antibodies target TIF-1 family proteins, TIF-1α and TIF-1ß, in addition to TIF-1γ. Since TIF-1 proteins have significant roles in oncogenesis, these antibodies may be produced during misdirected antitumor immunity.

Serum chemokine levels as prognostic markers in patients with early systemic sclerosis: a multicenter, prospective, observational study.

OBJECTIVE: To assess the utility of serum chemokine levels as a prognostic indicator of disease progression in systemic sclerosis (SSc) patients with early onset disease. METHODS: Seventy Japanese patients with early onset SSc presenting with diffuse skin sclerosis and/or interstitial lung disease were registered in a multicenter, observational study. Concentrations of CCL2, CCL5, CXCL8, CXCL9, and CXCL10 in serum samples from all patients were measured using cytometric beads array. In 33 patients, chemokine levels were measured each year for 4 years. The ability of baseline chemokine levels to predict changes in clinical features were evaluated statistically by multiple regression analysis. RESULTS: At their first visit, serum levels of CCL2, CCL5, CXCL8, CXCL9, and CXCL10 were significantly elevated in patients with SSc compared with healthy controls. There were significant associations between CCL2 and CXCL8 levels and between CXCL9 and CXCL10 levels in patients. The initial serum CXCL8 levels were significantly associated with the HAQ-DI at the fourth year while the %VC of baseline tended to be negatively associated with HAQ-DI at the fourth year. Initial chemokine levels were not associated with other clinical features including skin thickness score and the respiratory function. CONCLUSION: Serum CXCL8 level may serve as a prognostic indicator of the physical dysfunction in SSc. Further longitudinal studies of larger populations are needed to confirm these findings.

Investigation of prognostic factors for skin sclerosis and lung function in Japanese patients with early systemic sclerosis: a multicentre prospective observational study.

OBJECTIVE: To clarify the clinical course of SSc in Japanese patients with early-onset disease. It is well known that ethnic variations exist in the clinical features and severity of SSc. However, neither the clinical course nor prognostic factors have been thoroughly investigated in the Japanese population. METHODS: Ninety-three Japanese patients of early-onset SSc (disease duration: <3 years) with diffuse skin sclerosis and/or interstitial lung disease were registered in a multi-centre observational study. All patients had a physical examination with laboratory tests at their first visit and at each of the three subsequent years. Factors that could predict the severity of skin sclerosis and lung involvement were examined statistically by multiple regression analysis. RESULTS: Two patients died from SSc-related myocardial involvement and four patients died from other complications during the 3-year study. Among various clinical data assessed, the initial modified Rodnan total skin thickness score (MRSS) and maximal oral aperture were associated positively and negatively with MRSS at Year 3, respectively. Additionally, initial ESR tended to be associated with final MRSS. Pulmonary vital capacity (VC) in the third year was significantly associated with initial %VC. Furthermore, patients with anti-topo I antibody tended to show reduced %VC at Year 3. CONCLUSIONS: Several possible prognostic factors for skin sclerosis and lung function were detected in Japanese patients with early SSc. Further longitudinal studies of larger populations will be needed to confirm these findings.

Attenuation of an adult T-cell leukemia skin lesion after treatment of a concomitant herpes simplex infection: a case study.

We report the development and treatment of eczema herpeticum in a 51-year-old male suffering from adult T-cell leukemia (ATL). Lesions of eczema herpeticum coexisted with the skin lesions of ATL. Treatment of eczema herpeticum resulted in a concomitant improvement in the symptoms of ATL, including a reduction in the size of the ATL plaques, for over 2 months before relapse.

The specific free radical scavenger edaravone suppresses fibrosis in the bleomycin-induced and tight skin mouse models of systemic sclerosis.

OBJECTIVE: Patients with systemic sclerosis (SSc) exhibit enhanced production of free radicals due to ischemia and reperfusion injury following Raynaud's phenomenon, an initial clinical manifestation. Oxidative stress induces cytokine production, inflammatory cell recruitment, and tissue injury in several inflammatory diseases. The aim of this study was to examine the effect of edaravone, a free radical scavenger, on the development of fibrosis and autoimmunity in two different mouse models of SSc. METHODS: The bleomycin-induced SSc model in mice and the tight skin mouse model were used to evaluate the effect of edaravone on fibrosis and immunologic abnormalities. To assess the reaction of fibroblasts to stimulation with free radicals, fibroblasts from these mice were cultured with NONOate, a nitric oxide-releasing agent, and hydrogen peroxide. RESULTS: Treatment with edaravone reduced fibrosis in mice with bleomycin-induced SSc and in TSK/+ mice. The production of free radicals was also attenuated by edaravone in both models. In addition, production of fibrogenic cytokines such as interleukin-6 and transforming growth factor ß1, production of anti-topoisomerase I antibody, and the degree of hypergammaglobulinemia were reduced by edaravone. Furthermore, bleomycin induced the production of H2O2 and nitric oxide from inflammatory cells, and collagen production was increased in fibroblasts cultured with H2O2 and NONOate. CONCLUSION: This study is the first to show that edaravone has a significant inhibitory effect on fibrosis both in the bleomycin-induced SSc model and in TSK/+ mice. These results indicate that edaravone should be further evaluated for potential use as an antifibrotic agent in SSc.

Cell adhesion molecules regulate fibrotic process via Th1/Th2/Th17 cell balance in a bleomycin-induced scleroderma model.

Mice s.c. injected with bleomycin, an experimental model for human systemic sclerosis, develop skin and lung fibrosis, which is mediated by inflammatory cell infiltration. This process is highly regulated by multiple adhesion molecules and does not require Ag sensitization. To assess the role of adhesion molecules in this pathogenetic process, bleomycin-induced fibrosis was examined in mice lacking adhesion molecules. L-selectin and/or ICAM-1 deficiency inhibited skin and lung fibrosis with decreased Th2 and Th17 cytokines and increased Th1 cytokines. In contrast, P-selectin deficiency, E-selectin deficiency with or without P-selectin blockade, or P-selectin glycoprotein ligand 1 (PSGL-1) deficiency augmented the fibrosis in parallel with increased Th2 and Th17 cytokines and decreased Th1 cytokines. Furthermore, loss of L-selectin and/or ICAM-1 reduced Th2 and Th17 cell numbers in bronchoalveolar lavage fluid, whereas loss of P-selectin, E-selectin, or PSGL-1 reduced Th1 cell numbers. Moreover, Th1 cells exhibited higher PSGL-1 expression and lower expression of LFA-1, a ligand for ICAM-1, whereas Th2 and Th17 cells showed higher LFA-1 and lower PSGL-1 expression. This study suggests that L-selectin and ICAM-1 regulate Th2 and Th17 cell accumulation into the skin and lung, leading to the development of fibrosis, and that P-selectin, E-selectin, and PSGL-1 regulate Th1 cell infiltration, resulting in the inhibition of fibrosis.

Elevated serum interleukin-27 levels in patients with systemic sclerosis: association with T cell, B cell and fibroblast activation.

OBJECTIVE: To determine serum levels of interleukin 27 (IL-27) in patients with systemic sclerosis (SSc) and relate the results to the clinical features of SSc. METHODS: Serum levels of IL-27 in 91 patients with SSc and the production of IL-27 by isolated monocytes were examined by ELISA. The expression of IL-27 receptor in the skin fibroblasts, B cells and T cells was quantified by real-time PCR. The effect of IL-27 on immunoglobulin G (IgG) production of B cells, IL-17 production of CD4 T cells and proliferation and collagen synthesis of fibroblasts was also analysed. RESULTS: Serum IL-27 levels were raised in patients with SSc compared with healthy controls and correlated positively with the extent of skin and pulmonary fibrosis and immunological abnormalities. IL-27 levels also correlated positively with serum levels of hyaluronan, recently identified as an endogenous ligand for Toll-like receptors. The retrospective longitudinal analysis showed a tendency for serum IL-27 levels to be attenuated during the follow-up period. IL-27 production by cultured monocytes was increased by hyaluronan stimulation. IL-27 receptor expression was upregulated in the affected skin fibroblasts, B cells and CD4 T cells of patients with SSc. Moreover, IL-27 stimulation increased IgG production of B cells, IL-17 production of CD4 T cells and proliferation and collagen synthesis of fibroblasts in patients with SSc compared with those in healthy controls. CONCLUSION: These results suggest that IL-27 and its signalling in B cells, T cells and fibroblasts contributes to disease development in patients with SSc.

Platelets control leukocyte recruitment in a murine model of cutaneous arthus reaction.

Platelets have been shown to be important in inflammation, but their role in the cutaneous Arthus reaction remains unclear. To assess the role of platelets in this pathogenetic process, the cutaneous Arthus reaction was examined in wild-type mice and mice lacking E-selectin, P-selectin, or P-selectin glycoprotein ligand-1 (PSGL-1) with or without platelet depletion by busulfan, a bone marrow precursor cell-specific toxin. Edema and hemorrhage induced by immune complex challenge significantly decreased in busulfan-treated wild-type mice compared with untreated mice. Busulfan treatment did not affect edema and hemorrhage in P-selectin- or PSGL-1-deficient mice, suggesting that the effect by busulfan is dependent on P-selectin and PSGL-1 expression. The inhibited edema and hemorrhage paralleled reduced infiltration of neutrophils and mast cells and reduced levels of circulating platelets. Increased cutaneous production of interleukin-6, tumor necrosis factor-alpha, and platelet-derived chemokines during Arthus reaction was inhibited in busulfan-treated wild-type mice relative to untreated mice, which paralleled the reduction in cutaneous inflammation. Flow cytometric analysis showed that immune complex challenge generated blood platelet-leukocyte aggregates that decreased by busulfan treatment. In thrombocytopenic mice, the cutaneous inflammation after immune complex challenge was restored by platelet infusion. These results suggest that platelets induce leukocyte recruitment into skin by forming platelet-leukocyte aggregates and secreting chemokines at inflamed sites, mainly through the interaction of P-selectin on platelets with PSGL-1 on leukocytes.

Involvement of L-selectin in contact hypersensitivity responses augmented by auditory stress.

Stress affects the pathophysiology of cutaneous immune reactions, including contact hypersensitivity (CH) in individuals sensitized with sensitizing hapten, where local endothelial cell activation plays a critical role. To clarify the effects of stress in cutaneous immune reactions, we selected a CH model using annoying sound as a stress. Furthermore, we conducted the stress experiments by using selectin-deficient mice to determine the involvement of selectin molecules regarding local endothelial activation. Auditory stress augmented CH responses in the present study. Namely, ear thickness and mast cell numbers were significantly increased in stressed CH mice. mRNA expression of preprotachykinin-A, a precursor of substance-P; interferon-gamma; interleukin (IL)-4; IL-6; and tumor necrosis factor-alpha significantly increased in stressed CH mice. Furthermore, stressed L-selectin-deficient mice showed significant decreases in all parameters mentioned above relative to stressed wild-type mice in CH response. Meanwhile, treatment with anti-L-selectin Ab resulted in a significant decrease in ear thickness and mRNA levels of interferon-gamma, IL-4, IL-6, and tumor necrosis factor-alpha, but failed to significantly reduce preprotachykinin-A mRNA levels and mast cell numbers. Our results indicated that auditory stress enhances CH response and that the augmentation of this CH response might be mediated through L-selectin, but not through P- or E-selectin pathways.

Treatment with rapamycin prevents fibrosis in tight-skin and bleomycin-induced mouse models of systemic sclerosis.

OBJECTIVE: Rapamycin, a novel macrolide immunosuppressive drug, is increasingly used as an agent for posttransplant immunosuppression and treatment of autoimmune disease. The molecular mechanism related to rapamycin-mediated immunosuppression is that rapamycin binds to FK-506 binding protein 12, and the formed complex inhibits the function of the mammalian target of rapamycin (mTOR), which in turn reduces protein phosphorylation, cell cycle progression, and cytokine production. The aim of this study was to examine the effect of rapamycin against the development of fibrosis and autoimmunity in 2 different types of systemic sclerosis (SSc) model mice. METHODS: Tight skin (TSK/+) mice and bleomycin- induced SSc model mice were used to evaluate the effect of rapamycin on fibrosis and immunologic abnormalities. Furthermore, the antifibrotic effect of rapamycin was assessed using TSK/+ mouse fibroblasts. RESULTS: Treatment with rapamycin reduced skin fibrosis of TSK/+ mice and skin and lung fibrosis of bleomycin-induced SSc model mice. The production of fibrogenic cytokines, such as interleukin-4 (IL-4), IL-6, IL-17, and transforming growth factor beta1, was attenuated by rapamycin. Hypergammaglobulinemia and anti-topoisomerase I antibody production were also reduced by rapamycin treatment in TSK/+ mice. In addition, mTOR expression levels were increased in TSK/+ mouse fibroblasts compared with those in wild-type mouse fibroblasts. Rapamycin treatment inhibited proliferation and collagen production of TSK/+ mouse fibroblasts in a dose-dependent manner. CONCLUSION: This study is the first to show that rapamycin has a significant inhibitory effect on fibrosis in both TSK/+ and bleomycin-induced SSc model mice. These results suggest that rapamycin might be an attractive candidate for clinical trials in SSc patients.

A portable dermatoscope for easy, rapid examination of periungual nailfold capillary changes in patients with systemic sclerosis.

Microvascular lesions are a predominant feature in systemic sclerosis (SSc) and seem to play a central pathogenic role. The presence of nailfold capillary abnormalities is useful in diagnosing SSc. Capillaroscopy, however, usually requires special equipment and may be time consuming. Dermatoscope has been presented as a new diagnostic tool for quick and efficient examination of nailfold capillaries for circumstances when standard microscope equipment is not available. To assess the practical utility of dermatoscope for assessment of capillary morphology in patients with SSc, 83 Japanese patients with SSc (68 women, 15 men) and 68 healthy controls were examined in the study. Twenty-one patients (16 women, 5 men) had diffuse cutaneous SSc and 62 (52 women, 10 men) had limited cutaneous SSc. Enlarged capillaries and hemorrhages were evaluated in all 10 fingers with either naked eyes or DermLite(®) DL100 dermatoscope. Enlarged capillaries and hemorrhages were significantly more frequently detected with dermatoscope than without it. These findings were observed most frequently in the fourth finger. The presence of two or more enlarged capillaries in one or more fingers showed 83.1% sensitivity and 100% specificity for SSc. Among patients with SSc with anti-topoisomerase I antibody, the disease duration correlated negatively with the dermatoscopic number of enlarged capillaries and hemorrhages. Dermatoscope allows the easy and rapid identification of capillary nailfold morphological changes in SSc and should be routinely used for diagnosing SSc.

Establishment of experimental eosinophilic vasculitis by IgE-mediated cutaneous reverse passive arthus reaction.

Prominent eosinophil infiltration is a characteristic of some forms of vasculitis, such as Churg-Strauss syndrome, also known as allergic granulomatous vasculitis. In the current study, we established a mouse model of cutaneous eosinophilic vasculitis by the cutaneous reverse passive Arthus reaction using IgE injection instead of IgG. Wild-type C57BL/6 mice were injected with IgE anti-trinitrophenyl antibodies, followed immediately by intravenous administration of trinitrophenyl bovine serum albumin. IgE-mediated immune complex challenge induced substantial hemorrhage with marked infiltration of eosinophils in which neutrophils, mast cells, and macrophages were also mixed. This finding contrasted remarkably with the neutrophil-dominant infiltration pattern in IgG-mediated immune complex challenge. In the lesion, the expression level of monocyte chemotactic protein-3 was increased, and anti-monocyte chemotactic protein-3 treatment resulted in a significant but incomplete blockade of eosinophil recruitment. Furthermore, mice lacking E-selectin, P-selectin, L-selectin, or intercellular adhesion molecule-1, as well as wild-type mice that received anti-vascular cell adhesion molecule-1-blocking antibodies were assessed for the IgE-mediated Arthus reaction. After 24 hours, the loss of P-selectin resulted in a significant reduction in eosinophil accumulation compared with both wild-type mice and other mouse mutants. Collectively, the Fc class of immunoglobulins, which forms these immune complexes, critically determines the disease manifestation of vasculitis. The IgE-mediated cutaneous reverse passive Arthus reaction may serve as an experimental model for cutaneous eosinophilic infiltration in vasculitis as well as in other diseases.

CD19, a response regulator of B lymphocytes, regulates wound healing through hyaluronan-induced TLR4 signaling.

Immune cells are critical to the wound-healing process, through both cytokine and growth factor secretion. Although previous studies have revealed that B cells are present within wound tissue, little is known about the role of B cells in wound healing. To clarify this, we investigated cutaneous wound healing in mice either lacking or overexpressing CD19, a critical positive-response regulator of B cells. CD19 deficiency inhibited wound healing, infiltration of neutrophils and macrophages, and cytokine expression, including basic and acidic fibroblast growth factor, interleukin-6, platelet-derived growth factor, and transforming growth factor-beta. By contrast, CD19 overexpression enhanced wound healing and cytokine expression. Hyaluronan (HA), an endogenous ligand for toll-like receptor (TLR)-4, stimulated B cells, which infiltrates into wounds to produce interleukin-6 and transforming growth factor-beta through TLR4 in a CD19-dependent manner. CD19 expression regulated TLR4 signaling through p38 activation. HA accumulation was increased in injured skin tissue relative to normal skin, and exogenous application of HA promoted wound repair in wild-type but not CD19-deficient mice, suggesting that the beneficial effects of HA to the wound-healing process are CD19-dependent. Collectively, these results suggest that increased HA accumulation in injured skin induces cytokine production by stimulating B cells through TLR4 in a CD19-dependent manner. Thus, this study is the first to reveal a critical role of B cells and novel mechanisms in wound healing.

Autoantibody against caspase-3, an executioner of apoptosis, in patients with systemic sclerosis.

The objective of the study was to determine the presence or levels of antibodies (Abs) against caspase-3 and their clinical relevance in systemic sclerosis (SSc). Anti-caspase-3 Ab was examined by enzyme-linked immunosorbent assay and immunoblotting. IgG anti-caspase-3 Ab levels in SSc patients were higher than in normal controls. SSc patients positive for IgG anti-caspase-3 Ab had significantly longer disease duration, more frequent presence of decreased %VC and %DLco, and elevated levels of serum immunoglobulin and erythrocyte sedimentation rates. IgG anti-caspase-3 Ab levels correlated positively with serum IgG levels, renal vascular resistance, and serum levels of 8-isoprostane. Immunoblotting analysis confirmed the presence of anti-caspase-3 Ab in sera from SSc patients. Caspase-3 enzymatic activity was inhibited by IgG isolated from SSc sera containing IgG anti-caspase-3 Ab. These results suggest that autoantibody against caspase-3 is generated in SSc and that this Ab is related to the severity of pulmonary fibrosis, vascular damage, and inflammation.

Clinical significance of serum HMGB-1 and sRAGE levels in systemic sclerosis: association with disease severity.

INTRODUCTION: The high mobility group box 1 protein (HMGB-1)/advanced glycation end products (RAGE) system is recently shown to play an important part in immune/inflammatory disorders. However, the association of this system in systemic sclerosis (SSc) remains unknown. MATERIALS AND METHODS: To determine clinical association of serum levels of HMGB-1 and soluble RAGE (sRAGE) in patients with SSc, sera from 70 patients with SSc and 25 healthy controls were examined by enzyme-linked immunosorbent assay. Sera from tight-skin mice and bleomycin-induced scleroderma mice, animal models for SSc, were also examined. Skin HMGB-1 and RAGE expression was assessed by immunohistochemistry. RESULTS AND DISCUSSION: Serum HMGB-1 and sRAGE levels in SSc were higher than those in controls. Similarly, HMGB-1 and sRAGE levels in animal SSc models were higher than those in control mice. SSc patients with elevated HMGB-1 and sRAGE levels had more frequent involvement of several organs and immunological abnormalities compared to those with normal levels. Furthermore, HMGB-1 and sRAGE levels correlated positively with modified Rodnan total skin thickness score and negatively with pulmonary function test. CONCLUSIONS: HMGB-1 and sRAGE expression in the sclerotic skin was more intense than normal skin. These results suggest that elevated serum HMGB-1 and sRAGE levels are associated with the disease severity and immunological abnormalities in SSc.

CD19 regulates skin and lung fibrosis via Toll-like receptor signaling in a model of bleomycin-induced scleroderma.

Mice subcutaneously injected with bleomycin, in an experimental model of human systemic sclerosis, develop cutaneous and lung fibrosis with autoantibody production. CD19 is a general "rheostat" that defines signaling thresholds critical for humoral immune responses, autoimmunity, and cytokine production. To determine the role of CD19 in the bleomycin-induced systemic sclerosis model, we investigated the development of fibrosis and autoimmunity in CD19-deficient mice. Bleomycin-treated wild-type mice exhibited dermal and lung fibrosis, hyper-gamma-globulinemia, autoantibody production, and enhanced serum and skin expression of various cytokines, including fibrogenic interleukin-4, interleukin-6, and transforming growth factor-beta1, all of which were inhibited by CD19 deficiency. Bleomycin treatment enhanced hyaluronan production in the skin, lung, and sera. Addition of hyaluronan, an endogenous ligand for Toll-like receptor (TLR) 2 and TLR4, stimulated B cells to produce various cytokines, primarily through TLR4; CD19 deficiency suppressed this stimulation. These results suggest that bleomycin induces fibrosis by enhancing hyaluronan production, which activates B cells to produce fibrogenic cytokines mainly via TLR4 and induce autoantibody production, and that CD19 deficiency suppresses fibrosis and autoantibody production by inhibiting TLR4 signals.

Reduced red blood cell velocity in nail-fold capillaries as a sensitive and specific indicator of microcirculation injury in systemic sclerosis.

OBJECTIVE: To assess red blood cell velocity in finger nail-fold capillaries using video capillaroscopy in patients with SSc and other collagen diseases. METHODS: This study included 127 patients with SSc as well as patients with SLE (n = 33), DM/PM (n = 21), RA (n = 13) and APS (n = 12), and 20 healthy subjects. Red blood cell velocity was evaluated using frame-to-frame determination of the position of capillary plasma gaps. RESULTS: The mean red blood cell velocity was significantly decreased in patients with SSc compared to healthy controls (63.0% reduction) and patients with other conditions. Mean blood velocity was similar between patients with dcSSc and lcSSc. Importantly, even SSc patients with normal or non-specific nail-fold video capillaroscopic (NVC) patterns or a scleroderma early NVC pattern exhibited a significantly lower red blood cell velocity compared to healthy controls (51.7 and 61.4% reduction, respectively) or patients with other conditions, despite normal or mild capillary changes. Patients with the scleroderma active and late NVC pattern showed a more decreased blood velocity (65.5 and 66.2% reduction, respectively). This reduced blood velocity was significantly associated with NVC findings, including capillary ramification and capillary loss. Although remarkably reduced velocity was observed in SSc patients with intractable digital ulcers (72.1% reduction), it was significantly improved by lipo-prostaglandin E(1) (lipo-PGE(1)) infusion. CONCLUSION: Our results suggest that reduced blood velocity is a hallmark of SSc. Furthermore, measurement of red blood cell velocity may be useful in evaluating therapeutic effects on microcirculation.