Induction of apoptosis and fibrillin 1 expression in human dermal endothelial cells by scleroderma sera containing anti–endothelial cell antibodies

Association of Systemic Markers of Inflammation with Signs and Symptoms of Dry Eye Disease and Sjogren's Syndrome in the Dry Eye Assessment and Management (DREAM©) Study

PURPOSE

To evaluate the possible role of systemic inflammation in dry eye disease (DED) via systemic inflammatory marker associations with DED signs and symptoms, and an analysis of a subgroup with Sjogren's Syndrome (SS).

METHODS

Participant serums were analyzed using line immunoassays (LIAs) for the presence of antibodies against 34 systemic inflammatory markers. Using the 2012 American College of Rheumatology definition, the 481 participants were categorized into group 1 (SS; n = 52), group 2 (autoimmune disease not including SS; n = 66), or group 3 (control, i.e. no autoimmune disease; n = 363).

RESULTS

3 markers were positive in ≥10% of participants: Ro52 (19.3%), Scl-70 (15.0%), CN-1A (14.2%). 2 markers were positively associated with symptoms: PM-Scl100 (p = 0.02), Sm (p = 0.009). 5 markers were positively associated with signs: U2SnRNP A', Ro52, La, DNA, Ro60. SS participants showed significantly higher positivity for 4 markers compared to participants with no autoimmune disease: PL-7 (p = 0.02), Ro52 (p < 0.0001), La (p < 0.0001), Ro60 (p < 0.0001). SS participants showed significantly higher positivity for 3 markers compared to participants with another autoimmune disease: Ro52 (p < 0.0001), La (p = 0.002), Ro60 (p < 0.0001).

CONCLUSIONS

This study did not show evidence of significant systemic inflammation in participants with moderate-to-severe DED, based on the markers tested. PM-Scl100 and Sm may be associated with more severe DED symptoms. U2SnRNP A', Ro52, La, DNA, and Ro60 may be associated with more severe ocular surface disease. Ro52 and PL-7 may be diagnostic markers for SS. Future research evaluating these relationships and their clinical significance is needed.

Digital gangrene in systemic sclerosis patients: not only due to the microvascular disease

OBJECTIVE

This study aims to investigate the characteristics, risk factors, and outcomes of digital gangrenes in SSc patients, and to identify whether vasculitis is one of the causes for digital gangrene.

METHODS

A retrospective case-control study was performed from February 2003 to April 2021. Forty-three SSc patients with digital gangrene admitted to Peking Union Medical College Hospital were included. One-hundred forty-six age- and sex-matched SSc patients without gangrene were selected as controls during the same period. Univariate and multivariate logistic regression analysis was used to determine risk factors.

RESULTS

Among 43 SSc patients with gangrene, 93.0% had Raynaud's phenomenon (RP) and 32.6% had current or previous digital ulcers (DU). SSc patients with digital gangrene had more ESR elevation (54.8% vs. 34.9%, p = 0.020) and higher level of high-sensitive C reactive protein (median 7.2 mg/L vs. 1.8 mg/L, p = 0.045) compared with controls. In the multivariable logistic regression analysis, smoking history (OR 4.119, p = 0.037), anti-centromere antibody positivity (OR 3.542, p = 0.016), anti-neutrophil cytoplasmic antibody positivity (OR 22.605, p = 0.037), and anti-phospholipid antibody positivity (OR 16.563, p = 0.001), as well as elevated ESR (OR 2.524, p = 0.038) were identified as independent risk factors for gangrenes. Most (79.1%) cases were treated with combination of immunosuppressive and vasodilating therapy, and four cases also got remised after treatment of only glucocorticoid and immunosuppressive agent.

CONCLUSION

Smoking history; positive-ACA, ANCA, and anti-phospholipid antibodies; and increased ESR were independent risk factors for digital gangrenes in SSc. Vasculitis and macrovascular disease may contribute to the progression of digital gangrenes. Key Points •18.6% of SSc patients with digital gangrene had macrovascular stenosis. •Smoking, positive-ACA, ANCA, aPL, and increased ESR were indicators for digital gangrenes in SSc. •Vasculitis and macrovascular disease may involve in the pathogenesis.

Research progress on mesenchymal stem cells and their exosomes in systemic sclerosis

Systemic sclerosis (SSc) is a connective tissue disease with an unknown etiology. Clinically, it is characterized by localized or diffuse skin thickening and fibrosis. The pathogenesis of SSc includes microvascular injury, autoimmune-mediated inflammation, and fibroblast activation. These processes interact and contribute to the diverse clinicopathology and presentation of SSc. Given the limited effectiveness and substantial side effects of traditional treatments, the treatment strategy for SSc has several disadvantages. Mesenchymal stem cells (MSCs) are expected to serve as effective treatment options owing to their significant immunomodulatory, antifibrotic, and pro-angiogenic effects. Exosomes, secreted by MSCs via paracrine signaling, mirror the effect of MSCs as well as offer the benefit of targeted delivery, minimal immunogenicity, robust reparability, good safety and stability, and easy storage and transport. This enables them to circumvent the limitations of the MSCs. When using exosomes, it is crucial to consider preparation methods, quality standards, and suitable drug delivery systems, among other technical issues. Therefore, this review aims to summarize the latest research progress on MSCs and exosomes in SSc, offering novel ideas for treating SSc.

Human Cytomegalovirus and Human Herpesvirus 6 Coinfection of Dermal Fibroblasts Enhances the Pro-Inflammatory Pathway Predisposing to Fibrosis: The Possible Impact on Systemic Sclerosis

Systemic sclerosis (SSc) is a severe autoimmune disease likely triggered by genetic and environmental factors, including viral infections. Human cytomegalovirus (HCMV) and human herpesvirus 6A species (HHV-6A) have been associated with SSc, based on in vivo and in vitro evidence, but the data are still inconclusive. Furthermore, despite both viruses being highly prevalent in humans and able to exacerbate each other’s effects, no data are available on their joint effects. Hence, we aimed to study their simultaneous impact on the expression of cell factors correlated with fibrosis and apoptosis in in vitro coinfected fibroblasts, representing the main target cell type in SSc. The results, obtained by a microarray detecting 84 fibrosis/apoptosis-associated factors, indicated that coinfected cells underwent higher and more sustained expression of fibrosis-associated parameters compared with single-infected cells. Thus, the data, for the first time, suggest that HCMV and HHV-6A may cooperate in inducing alterations potentially leading to cell fibrosis, thus further supporting their joint role in SSc. However, further work is required to definitively answer whether β-herpesviruses are causally linked to the disease and to enable the possible use of targeted antiviral treatments to improve clinical outcomes.

ANCA in systemic sclerosis, when vasculitis overlaps with vasculopathy: a devastating combination of pathologies

In patients with SSc, the coexistence of ANCA-associated vasculitis (SSc-AAV) has been reported to be associated with a severe disease course, including significant pulmonary and renal involvement. The presence of ANCA is not uncommon in patients with SSc, and therefore clinicians must maintain a high index of clinical suspicion about SSc-AAV. p-ANCA and anti-myeloperoxidase antibodies are the most common antibodies observed. Patients typically present with clinical features of microscopic polyangiitis or renal-limited vasculitis. There are multiple areas of potential interaction in the pathogenesis of SSc and AAV, which can exacerbate/compound vascular disease. In addition, similar patterns of major internal organ involvement (e.g. lung and kidneys) are seen in both conditions. We highlight a diagnostic approach to SSc-AAV and the paucity of data to inform management. As such, SSc-AAV is typically treated as per isolated AAV, which can potentially be hazardous in patients with SSc (e.g. due to the association between high-dose steroid and scleroderma renal crisis). We propose that this rare clinical entity warrants rigorous investigation, including definition of a therapeutic strategy to ameliorate the potentially devastating combination of pathologies in SSc-AAV.

Identification of monoclonal antibodies against human renal glomerular endothelial cells in lupus nephritis that induce endothelial interferon-alpha production

BACKGROUND

The pathogenesis of lupus nephritis (LN) remains not fully understood. In this study, we aimed to explore the pathogenic roles of autoantibodies against human renal glomerular endothelial cells (HRGEC) in LN patients.

METHODS

The serum levels of anti-HRGEC antibodies in systemic lupus erythematosus (SLE) patients without LN and LN patients were determined by cell-based enzyme-linked immunosorbent assay (ELISA). Monoclonal IgG anti-HRGEC antibodies were subsequently generated from LN patients. The binding activities of these monoclonal antibodies to HRGEC, their cross-reactivity with double-stranded DNA (dsDNA), and the ability to activate HRGEC were further evaluated.

RESULTS

LN patients had higher serum levels of IgG anti-HRGEC antibodies than SLE patients without LN and healthy controls. Four monoclonal IgG anti-HRGEC antibodies (LN1-4) were obtained; LN1 and LN2 were IgG3 while LN3 and LN4 were IgG1. Among these monoclonal antibodies, LN1-3 were cross-reactive with dsDNA. The functional assays showed that compared with IgG1/IgG3 isotype controls, LN3 had an effect on HRGEC to enhance interleukin (IL)-6 production, LN4 could enhance IL-8 and monocyte chemoattractant protein (MCP)-1 production, and LN1-3 possessed the ability to induce interferon (IFN)-α production by HRGEC. Moreover, the removal of DNA on the HRGEC surface by DNAse 1 did not interpose the binding of LN1-3 to HRGEC and the effects of LN1-3 on IFN-α induction by HRGEC.

CONCLUSIONS

Some IgG anti-HRGEC antibodies in LN patients had the ability to enhance endothelial proinflammatory cytokine (IL-6, IL-8, and MCP-1) production, and some could induce the DNA-independent production of IFN-α by HRGEC.

Association Between Centromere- and Topoisomerase-specific Immune Responses and the Degree of Microangiopathy in Systemic Sclerosis

OBJECTIVE

Autoreactive antibody responses, including the use of several isotypes of autoantibodies, have been shown to be associated with clinical outcome in several rheumatic autoimmune diseases. The goals of this study were to evaluate whether (1) anticentromere antibody (ACA)- and antitopoisomerase antibody (ATA)-specific isotype expression, and (2) organ involvement are associated with the degree of microangiopathy in systemic sclerosis (SSc).

METHODS

ACA and ATA IgG, IgM, and IgA levels were measured in baseline serum samples of ACA IgG-positive (+) and ATA IgG+ patients with SSc. The degree of microangiopathy was determined based on nailfold videocapillaroscopy (NVC) images collected at the same point in time. Logistic regression analyses with autoantibodies, clinical characteristics, isotype expression, and ACA and ATA IgG, IgM, and IgA levels as independent variables, and NVC pattern as the dependent variable were performed.

RESULTS

In 164 patients, isotype levels and degree of microangiopathy were evaluated. Logistic regression confirmed the association of the degree of microangiopathy with the presence of digital ulcers (OR 3.07, 95% CI 1.43-6.60), interstitial lung disease (OR 3.41, 95% CI 1.11-10.61), and pulmonary arterial hypertension (OR 5.58, 95% CI 2.05-17.81). ATA positivity was associated with more severe microangiopathy (OR 2.09, 95% CI 1.05-4.13). Patients who expressed solely ACA IgG showed a trend towards less severe microangiopathy compared to patients also expressing ACA IgM and/or IgA. Levels of ACA IgG and ATA IgM were found to be associated with microangiopathy severity.

CONCLUSION

We observed an association between ACA and ATA responses and the degree of microangiopathy in SSc. These findings might indicate that the breadth of the autoimmune response, as reflected by autoantibody production and microvascular damage, interacts in the pathophysiology of SSc.

Cytotoxic CD4+ T lymphocytes may induce endothelial cell apoptosis in systemic sclerosis

Systemic sclerosis (SSc) is an autoimmune fibrotic disease whose pathogenesis is poorly understood and lacks effective therapies. We undertook quantitative analyses of T cell infiltrates in the skin of 35 untreated patients with early diffuse SSc and here show that CD4+ cytotoxic T cells and CD8+ T cells contribute prominently to these infiltrates. We also observed an accumulation of apoptotic cells in SSc tissues, suggesting that recurring cell death may contribute to tissue damage and remodeling in this fibrotic disease. HLA-DR-expressing endothelial cells were frequent targets of apoptosis in SSc, consistent with the prominent vasculopathy seen in patients with this disease. A circulating effector population of cytotoxic CD4+ T cells, which exhibited signatures of enhanced metabolic activity, was clonally expanded in patients with systemic sclerosis. These data suggest that cytotoxic T cells may induce the apoptotic death of endothelial and other cells in systemic sclerosis. Cell loss driven by immune cells may be followed by overly exuberant tissue repair processes that lead to fibrosis and tissue dysfunction.

Anti-nuclear autoantibodies in systemic sclerosis : News and perspectives

Systemic sclerosis is a connective tissue disorder characterized by microvascular damage and excessive fibrosis of the skin and internal organs. One hallmark of the immunological abnormalities in systemic sclerosis is the presence of anti-nuclear antibodies, which are detected in more than 90% of patients with systemic sclerosis. Anti-centromere antibodies, anti-DNA topoisomerase I antibodies, and anti-RNA polymerase III antibodies are the predominant anti-nuclear antibodies found in systemic sclerosis patients. Other systemic sclerosis-related anti-nuclear antibodies include those targeted against U3 ribonucleoprotein, Th/To, U11/U12 ribonucleoprotein, and eukaryotic initiation factor 2B. Anti-U1 ribonucleoprotein, anti-Ku antibodies, anti-PM-Scl, and anti-RuvBL1/2 antibodies are associated with systemic sclerosis overlap syndrome. Anti-human upstream binding factor, anti-Ro52/TRIM21, anti-B23, and anti-centriole antibodies do not have specificity to systemic sclerosis, but are sometimes detected in sera from patients with systemic sclerosis. Identification of each systemic sclerosis-related antibody is useful to diagnose and predict organ involvement, since the particular type of systemic sclerosis-related antibodies is often predictive of clinical features, severity, and prognosis. The clinical phenotypes are largely influenced by ethnicity. Currently, an immunoprecipitation assay is necessary to detect most systemic sclerosis-related antibodies; therefore, the establishment of an easy, reliable, and simple screening system is warranted.

CXCL13 produced by macrophages due to Fli1 deficiency may contribute to the development of tissue fibrosis, vasculopathy and immune activation in systemic sclerosis

CXCL13, a chemokine for B cells, follicular T cells, T helper 17 cells, and regulatory T cells, is reported to contribute to the development of systemic sclerosis (SSc), reflecting aberrant activation of immune system. To better understand the role of CXCL13 in SSc, we investigated the influence of Fli1 deficiency, a potential predisposing factor of this disease, on CXCL13 expression and assessed the clinical correlation of serum CXCL13 levels by multivariate regression analysis. Haploinsufficient loss of Fli1 remarkably induced CXCL13 expression in murine peritoneal macrophages, while gene silencing of FLI1 did not affect the expression of CXCL13 in human dermal fibroblasts and human dermal microvascular endothelial cells. Serum CXCL13 levels were elevated in SSc patients compared with healthy controls and correlated positively with skin score and negatively with pulmonary function test results. SSc patients with elevated serum CXCL13 levels had longer disease duration, diffuse cutaneous involvement, interstitial lung disease (ILD), heart involvement, pulmonary arterial hypertension, Raynaud's phenomenon, pitting scars, digital ulcers, telangiectasia, and high serum IgG levels more frequently than the other patients. In particular, serum CXCL13 levels were associated with ILD and digital ulcers by multivariate regression analysis. Taken together, these results indicate that CXCL13 expression is upregulated by Fli1 deficiency in macrophages, potentially contributing to the development of tissue fibrosis, vasculopathy and immune activation in SSc, especially ILD and digital ulcers.

Oxidative stress in the pathogenesis of systemic scleroderma: An overview

Systemic sclerosis (SSc) is a rare disorder of the connective tissue characterized by fibrosis of the skin, skeletal muscles and visceral organs. Additional manifestations include activation of the immune system and vascular injury. SSc causes disability and death as the result of end‐stage organ failure. Two clinical subsets of the SSc are accepted: limited cutaneous SSc (lc‐SSc) and diffuse cutaneous SSc (dc‐SSc). At present, the aetiology and pathogenesis of SSc remain obscure, and consequently, disease outcome is unpredictable. Numerous studies suggest that reactive oxidizing species (ROS) play an important role in the pathogenesis of scleroderma. Over the years, several reports have supported this hypothesis for both lc‐SSc and dc‐SSc, although the specific role of oxidative stress in the pathogenesis of vascular injury and fibrosis remains to be clarified. The aim of the present review was to report and comment the recent findings regarding the involvement and role of oxidative stress in SSc pathogenesis. Biomarkers proving the link between ROS and the main pathological features of SSc have been summarized.

Angiogenesis Dysregulation in the Pathogenesis of Systemic Sclerosis

Systemic sclerosis is a chronic autoimmune connective tissue disease characterized by vascular injury and fibrosis and by an impaired angiogenesis which cannot ensure an efficient vascular recovery. Vascular injury is responsible for hypoxia and tissual ischemia which are the primary triggers for angiogenesis and are not able to induce a compensatory angiogenesis. This review article is focused on current knowledge on the mechanisms responsible for angiogenesis dysregulation in systemic sclerosis.

The role of endothelial cells in the vasculopathy of systemic sclerosis: A systematic review

INTRODUCTION

Systemic sclerosis (SSc) is an autoimmune connective tissue disorder characterized by fibroproliferative vasculopathy, immunological abnormalities and progressive fibrosis of multiple organs including the skin. In this study, all English speaking articles concerning the role of endothelial cells (ECs) in SSc vasculopathy and representing biomarkers are systematically reviewed and categorized according to endothelial cell (EC) (dys)function in SSc.

METHODS

A sensitive search on behalf of the EULAR study group on microcirculation in Rheumatic Diseases was developed in Pubmed, The Cochrane Library and Web of Science to identify articles on SSc vasculopathy and the role of ECs using the following Mesh terms: (systemic sclerosis OR scleroderma) AND pathogenesis AND (endothelial cells OR marker). All selected papers were read and discussed by two independent reviewers. The selection process was based on title, abstract and full text level. Additionally, both reviewers further searched the reference lists of the articles selected for reading on full text level for supplementary papers. These additional articles went through the same selection process.

RESULTS

In total 193 resulting articles were selected and the identified biomarkers were categorized according to description of EC (dys)function in SSc. The most representing and reliable biomarkers described by the selected articles were adhesion molecules for EC activation, anti-endothelial cell antibodies for EC apoptosis, vascular endothelial growth factor (VEGF), its receptor VEGFR-2 and endostatin for disturbed angiogenesis, endothelial progenitors cells for defective vasculogenesis, endothelin-1 for disturbed vascular tone control, Von Willebrand factor for coagulopathy and interleukin (IL)-33 for EC-immune system communication. Emerging, relatively new discovered biomarkers described in the selected articles, are VEGF₁₆₅b, IL-17A and the adipocytokines. Finally, myofibroblasts involved in tissue fibrosis in SSc can derive from ECs or epithelial cells through a process known as endothelial-to-mesenchymal transition.

CONCLUSION

This systematic review emphasizes the growing evidence that SSc is primarily a vascular disease where EC dysfunction is present and prominent in different aspects of cell survival (activation and apoptosis), angiogenesis and vasculogenesis and where disturbed interactions between ECs and various other cells contribute to SSc vasculopathy.

Current perspectives on the immunopathogenesis of systemic sclerosis

Systemic sclerosis (SSc or scleroderma) is a progressive and highly debilitating autoimmune disorder characterized by inflammation, vasculopathy, and extensive fibrosis. SSc is highly heterogeneous in its clinical presentation, extent and severity of skin and internal organ involvement, and clinical course and has the highest fatality rate among connective tissue diseases. While clinical outcomes have improved in recent years, no current therapy is able to reverse or slow the natural progression of SSc, a reflection of its complex pathogenesis. Although activation of the immune system has long been recognized, the mechanisms responsible for the initiation of autoimmunity and the role of immune effector pathways in the pathogenesis of SSc remain incompletely understood. This review summarizes recent progress in disease pathogenesis with particular focus on the immunopathogenetic mechanisms of SSc.

Pathogenesis of Systemic Sclerosis

Systemic scleroderma (SSc) is one of the most complex systemic autoimmune diseases. It targets the vasculature, connective tissue-producing cells (namely fibroblasts/myofibroblasts), and components of the innate and adaptive immune systems. Clinical and pathologic manifestations of SSc are the result of: (1) innate/adaptive immune system abnormalities leading to production of autoantibodies and cell-mediated autoimmunity, (2) microvascular endothelial cell/small vessel fibroproliferative vasculopathy, and (3) fibroblast dysfunction generating excessive accumulation of collagen and other matrix components in skin and internal organs. All three of these processes interact and affect each other. The disease is heterogeneous in its clinical presentation that likely reflects different genetic or triggering factor (i.e., infection or environmental toxin) influences on the immune system, vasculature, and connective tissue cells. The roles played by other ubiquitous molecular entities (such as lysophospholipids, endocannabinoids, and their diverse receptors and vitamin D) in influencing the immune system, vasculature, and connective tissue cells are just beginning to be realized and studied and may provide insights into new therapeutic approaches to treat SSc.

The Pathogenesis of Systemic Sclerosis

Systemic sclerosis is a multisystem disorder with a high associated mortality. The hallmark abnormalities of the disease are in the immune system, vasculature, and connective tissue. Systemic sclerosis occurs in susceptible individuals and is stimulated by initiating events that are poorly understood at present. In order for the disease phenotype to appear there is dysfunction in the homoeostatic mechanisms of immune tolerance, endothelial physiology, and extracellular matrix turnover. The progression of disease is not sequential but requires simultaneous dysfunction in these normal regulatory mechanisms. Better understanding of the interplay of these factors is likely to contribute to improved treatment options.

Autoantibodies in systemic sclerosis: unanswered questions

Systemic sclerosis (SSc) is an autoimmune disease characterized by vascular abnormalities, and cutaneous and visceral fibrosis. Serum autoantibodies directed to multiple intracellular antigens are present in more than 95% of patients and are considered a hallmark of SSc. They are helpful biomarkers for the early diagnosis of SSc and are associated with distinctive clinical manifestations. With the advent of more sensitive, multiplexed immunoassays, new and old questions about the relevance of autoantibodies in SSc are emerging. In this review, we discuss the clinical relevance of autoantibodies in SSc emphasizing the more recently published data. Moreover, we will summarize recent advances regarding the stability of SSc autoantibodies over the course of disease, whether they are mutually exclusive and their potential roles in the disease pathogenesis.

Evaluation of nail fold capillaroscopy findings in patients with primary biliary cirrhosis

AIM

Some patients with primary biliary cirrhosis (PBC) experience Raynaud's phenomenon. The objective of this study was to clarify the relationships between nail fold capillaroscopy findings and clinical presentations of PBC.

METHODS

A total of 70 patients with PBC and 57 patients with non-PBC liver diseases, including 44 patients with chronic viral hepatic disease, eight with autoimmune hepatitis and five with non-alcoholic fatty liver disease, were included in this study. Nail fold capillaroscopy findings were classified as normal or abnormal and were further graded as mild, moderate or severe, and the relationships between frequency of abnormal blood vessel and their clinical presentations were examined.

RESULTS

The frequency of abnormal nail fold capillaroscopy findings was significantly higher in PBC patients (54.3%) than in patients with non-PBC liver disease (13.8%) (P < 0.01). These abnormal findings observed in PBC patients were graded as mild in 15 patients, moderate in 18 patients and severe in five patients. Significantly more PBC patients with abnormal capillaroscopy findings (19/38, 50%) were positive for anticentromere antibody than were those with normal capillaroscopy findings (3/32, 9.4%) (P < 0.01).

CONCLUSION

PBC patients had significantly higher frequency of abnormal nail fold capillaroscopy findings than did patients with non-PBC liver disease.

Digital gangrene associated with anticentromere antibodies

Anticentromere antibodies have been associated with peripheral vascular occlusive disease, but then it is mostly accompanied by sclerodactyly in the context of a connective tissue disorder. We report a case of digital gangrene in a 75 year old lady with no other associations except positive anticentromere antibodies.

Pathophysiology and recent findings of primary biliary cirrhosis complicated by systemic sclerosis

Primary biliary cirrhosis (PBC) can be complicated by systemic sclerosis (SSc) and, more specifically, limited cutaneous SSc (lcSSc), which was previously called CREST syndrome. Moreover, combined PBC and SSc has been described in many case reports. Although neither the etiology of PBC nor that of SSc has been elucidated, some genetic and immunological factors are known to be shared. Both disorders are autoimmune fibrotic diseases characterized by increased levels of profibrotic cytokines transforming growth factor β (TGFβ) and interleukin-6, which have recently been suggested to influence T-helper 17 cells and regulatory T cells involved in acquired immunity. lcSSc is accompanied by CREST symptoms, although complete CREST cases are rare, with relatively high prevalence of Raynaud's phenomenon, sclerodactyly and telangiectasia, and lower prevalence of calcinosis and esophageal dysmotility. Because patients with anticentromere antibody positive PBC-SSc are at a high risk of developing portal hypertension, particular attention should be paid to the management of gastroesophageal varices. In addition, the management of SSc-related non-hepatic disorders, such as pulmonary fibrosis, pulmonary hypertension, heart disorder, infection and malignancy, is also important for improved outcomes. Because PBC is often complicated by rheumatic disease, hepatologists should keep the possibility of systemic disorder in mind when examining PBC patients.

Autoantibodies by line immunoassay in patients with primary biliary cirrhosis

OBJECTIVES

We attempted to measure multiple autoantibodies simultaneously using line immunoassay (LIA) in patients with primary biliary cirrhosis (PBC) with or without anti-mitochondrial antibody (AMA) and patients with PBC-autoimmune hepatitis (AIH) overlap, and we examined the clinical significance of measuring these autoantibodies.

METHODS

The study population consisted of 80 patients with PBC (including 12 AMA-negative patients), 16 patients with PBC-AIH overlap and 40 patients with AIH as controls. Nine antibodies (AMA-M2, M2-3E, Sp100, PML, gp210, Ro-52, LKM-1, LC-1 and SLA/LP) were detected by LIA, and AMA-M2 and anti-centromere antibody (ACA) were detected by ELISA. We examined the relationship between these autoantibodies and clinical findings.

RESULTS

The positive prevalence of each autoantibody and ACA in the PBC group, as determined by LIA, was as follows: 13.8% for anti-Sp100, 8.7% for anti-PML, 40% for anti-gp210 and 27.5% for anti-Ro-52 antibodies and 32.5% for ACA. In the PBC-AIH overlap group, the prevalence of anti-gp210 antibody (68.7%) and that of anti-Ro-52 antibody (81.2%) were significantly higher than those in the PBC and AIH groups. Only a few patients were positive for 2 or more autoantibodies. Nine patients were determined to be negative for all autoantibodies by LIA, of whom 7 were positive for ACA. Patients positive for anti-gp210 antibody included more patients classified as stage 4 on histology than did the negative group. Those positive for ACA included more patents with varices than did the negative group.

CONCLUSION

LIA can measure multiple autoantibodies simultaneously and thus is considered useful in diagnosing PBC and PBC-AIH overlap. In addition, ACA is a useful marker for identifying AMA-negative PBC.

Acupuncture-based modalities: novel alternative approaches in the treatment of gastrointestinal dysmotility in patients with systemic sclerosis

BACKGROUND

The gastrointestinal (GI) dysmotility of systemic sclerosis (SSc, scleroderma) patients requires careful evaluation and intervention. The lack of effective prokinetic drugs motivate researchers to search for alternative treatments.

OBJECTIVES

We present an overview of the pathophysiology of SSc GI dysmotility and the advances in its management, with particular focus on acupuncture-related modalities and innovative therapies.

DATA SOURCES

Original research articles were identified based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline methodology. We have searched the MEDLINE database using Medical Subject Heading (MeSH) for all English and non-English articles with an English abstract from 2005 to October 2012.

RESULTS

Only four original articles of various study designs were found studying Complementary and Alternative Medicine (CAM) therapies for SSc patients. Despite the small patient study numbers, CAM treatments, acupressure, and transcutaneous electroacupuncture, showed self-reported and physiologic evidence of improvement of GI functioning and/or symptoms in SSc patients.

CONCLUSIONS

CAM therapies include experimental modalities with the potential to offer relief of symptoms from GI dysmotility. Larger studies are needed to investigate their optimal use in patient subsets to tailor therapies to patient needs.

Agonistic anti-ICAM-1 antibodies in scleroderma: activation of endothelial pro-inflammatory cascades

Background

Scleroderma (SSc) is a complex autoimmune disorder that can be characterised by the presence 2of circulating autoantibodies to nuclear, cytoplasmic and cell surface antigens. In particular antibodies directed against endothelial cell antigens (anti-endothelial cell antibodies; AECA) have been detected.

ICAM-1 is an adhesion molecule expressed on the surface of human endothelial cells. We have previously shown that cross-linking ICAM-1 with monoclonal antibodies leads to pro-inflammatory activation of human endothelial and vascular smooth muscle cells and that cardiac transplant recipients with transplant associated vasculopathy make antibodies directed against ICAM-1.

Objectives

To determine whether SSc patients make antibodies directed against ICAM-1 and whether these antibodies induce pro-inflammatory activation of human endothelial cells in vitro.

Methods

Using recombinant ICAM-1 as capture antigen, an ELISA was developed to measure ICAM-1 antibodies in sera from SSc patients. Antibodies were purified using ICAM-1 micro-affinity columns. HUVEC were incubated with purified anti-ICAM-1 antibodies and generation of reactive oxygen species, and expression of VCAM-1 was measured.

Results

Significantly elevated levels of anti-ICAM-1 antibodies were detected in patients with diffuse (dSSc; 10/31 32%) or limited (lSSc; 14/36 39%) scleroderma. Cross-linking of HUVEC with purified anti-ICAM-1 antibodies caused a significant increase in ROS production (2.471 ± 0.408 fold increase above untreated after 150 min p < 0.001), and significant increase in VCAM-1 expression (10.6 ± 1.77% vs 4.12 ± 1.33%, p < 0.01).

Conclusion

AECA from SSc patients target specific endothelial antigens including ICAM-1, and cause pro-inflammatory activation of human endothelial cells, suggesting that they are not only a marker of disease but that they contribute to its progression.

An innovative method to identify autoantigens expressed on the endothelial cell surface: serological identification system for autoantigens using a retroviral vector and flow cytometry (SARF)

Autoantibodies against integral membrane proteins are usually pathogenic. Although anti-endothelial cell antibodies (AECAs) are considered to be critical, especially for vascular lesions in collagen diseases, most molecules identified as autoantigens for AECAs are localized within the cell and not expressed on the cell surface. For identification of autoantigens, proteomics and expression library analyses have been performed for many years with some success. To specifically target cell-surface molecules in identification of autoantigens, we constructed a serological identification system for autoantigens using a retroviral vector and flow cytometry (SARF). Here, we present an overview of recent research in AECAs and their target molecules and discuss the principle and the application of SARF. Using SARF, we successfully identified three different membrane proteins: fibronectin leucine-rich transmembrane protein 2 (FLRT2) from patients with systemic lupus erythematosus (SLE), intercellular adhesion molecule 1 (ICAM-1) from a patient with rheumatoid arthritis, and Pk (Gb3/CD77) from an SLE patient with hemolytic anemia, as targets for AECAs. SARF is useful for specific identification of autoantigens expressed on the cell surface, and identification of such interactions of the cell-surface autoantigens and pathogenic autoantibodies may enable the development of more specific intervention strategies in autoimmune diseases.

Antiendothelial cells antibodies in patients with systemic sclerosis in relation to pulmonary hypertension and lung fibrosis

Although scleroderma is generally considered a fibrosing disease, it is now recognized that the underlying vascular pathology is playing a fundamental role in its pathogenesis. The present study was aimed at testing the prevalence of anti-endothelial cell antibodies (AECA) in systemic scleroderma (SSc) patients with and without pulmonary hypertension (PH) and in relation to the presence of pulmonary fibrosis. Fifty four SSc patients (50 females and 4 male, mean age 55.7 ± 16.3 years) were prospectively screened. All patients underwent transthoracic echocardiography with the estimation of pulmonary artery pressure (PAP) and tricuspid regurgitant peak gradient (TRPG). All patients suspected to have pulmonary hypertension were referred for right heart catheterization. Restrictive lung disease was confirmed by HRCT. A healthy control group included (n = 27; 7 men and 20 women, mean age 49.8 ± 12.1 years). The study of AECA was performed using the indirect immunofluorescence method on commercially available human umbilical vein endothelial cells. The HRCT scans in patients with suspected interstitial lung disease revealed signs of lung fibrosis in 15 (out of the 36 examined patients). TRPG at rest of 31 mmHg was demonstrated in 14 (21%) patients. During cardiac catheterization, arterial PH was found in two patients. Resting venous PH was found in one patient and an excessive post capillary PAP elevation at rest was demonstrated in 11 patients. At the baseline, 14/54 patients (26%) were positive for AECA. In the control group, the frequency of the antibodies was 3/27 (11%). No statistical correlation between antibody titter and the presentation of the disease existed. AECA were highly prevalent in a subgroup of patients suffering from interstitial pulmonary fibrosis. Out of the 15 patients suffering from lung fibrosis, 7 were AECA positive. The presence of AECA correlated very well with antinuclear antibodies (ANA), but was not related to the profile of ANA. Our findings support evidence that endothelial cell damage is involved in SSc, as there was increased prevalence of circulating AECA of the IgG isotype in SSc patients. AECA may also be related to the complications of SSc, like pulmonary fibrosis.

4F decreases IRF5 expression and activation in hearts of tight skin mice

The apoAI mimetic 4F was designed to inhibit atherosclerosis by improving HDL. We reported that treating tight skin (Tsk^−/+) mice, a model of systemic sclerosis (SSc), with 4F decreases inflammation and restores angiogenic potential in Tsk^−/+ hearts. Interferon regulating factor 5 (IRF5) is important in autoimmunity and apoptosis in immune cells. However, no studies were performed investigating IRF5 in myocardium. We hypothesize that 4F differentially modulates IRF5 expression and activation in Tsk^−/+ hearts. Posterior wall thickness was significantly increased in Tsk^−/+ compared to C57Bl/6J (control) and Tsk^−/+ mice with 4F treatment assessed by echoradiography highlighting reduction of fibrosis in 4F treated Tsk^−/+ mice. IRF5 in heart lysates from control and Tsk/+ with and without 4F treatment (sc, 1 mg/kg/d, 6–8 weeks) was determined. Phosphoserine, ubiquitin, ubiquitin K⁶³ on IRF5 were determined on immunoprecipitates of IRF5. Immunofluorescence and TUNEL assays in heart sections were used to determine positive nuclei for IRF5 and apoptosis, respectively. Fluorescence-labeled streptavidin (SA) was used to determine endothelial cell uptake of biotinylated 4F. SA-agarose pulldown and immunoblotting for IRF5 were used to determine 4F binding IRF5 in endothelial cell cytosolic fractions and to confirm biolayer interferometry studies. IRF5 levels in Tsk^−/+ hearts were similar to control. 4F treatments decrease IRF5 in Tsk^−/+ hearts and decrease phosphoserine and ubiquitin K⁶³ but increase total ubiquitin on IRF5 in Tsk^−/+ compared with levels on IRF5 in control hearts. 4F binds IRF5 by mechanisms favoring association over dissociation strong enough to pull down IRF5 from a mixture of endothelial cell cytosolic proteins. IRF5 positive nuclei and apoptotic cells in Tsk^−/+ hearts were increased compared with controls. 4F treatments decreased both measurements in Tsk^−/+ hearts. IRF5 activation in Tsk^−/+ hearts is increased. 4F treatments decrease IRF5 expression and activation in Tsk^−/+ hearts by a mechanism related to 4F’s ability to bind IRF5.

A novel autoantibody against fibronectin leucine-rich transmembrane protein 2 expressed on the endothelial cell surface identified by retroviral vector system in systemic lupus erythematosus

Introduction

Anti-endothelial cell antibodies (AECAs) are thought to be critical for vasculitides in collagen diseases, but most were directed against molecules localized within the cell and not expressed on the cell surface. To clarify the pathogenic roles of AECAs, we constructed a retroviral vector system for identification of autoantigens expressed on the endothelial cell surface.

Methods

AECA activity in sera from patients with collagen diseases was measured with flow cytometry by using human umbilical vein endothelial cells (HUVECs). A cDNA library of HUVECs was retrovirally transfected into a rat myeloma cell line, from which AECA-positive clones were sorted with flow cytometry. cDNA of the cells was analyzed to identify an autoantigen, and then the clinical characteristics and the functional significance of the autoantibody were evaluated.

Results

Two distinct AECA-positive clones were isolated by using serum immunoglobulin G (IgG) from a patient with systemic lupus erythematosus (SLE). Both clones were identical to cDNA of fibronectin leucine-rich transmembrane protein 2 (FLRT2). HUVECs expressed FLRT2 and the prototype AECA IgG bound specifically to FLRT2-transfected cells. Anti-FLRT2 antibody activity accounted for 21.4% of AECAs in SLE. Furthermore, anti-FLRT2 antibody induced complement-dependent cytotoxicity against FLRT2-expressing cells.

Conclusions

We identified the membrane protein FLRT2 as a novel autoantigen of AECAs in SLE patients by using the retroviral vector system. Anti-FLRT2 antibody has the potential to induce direct endothelial cell cytotoxicity in about 10% of SLE patients and could be a novel molecular target for intervention. Identification of such a cell-surface target for AECAs may reveal a comprehensive mechanism of vascular injury in collagen diseases.

Induction of elastin expression in vascular endothelial cells relates to hepatoportal sclerosis in idiopathic portal hypertension: possible link to serum anti-endothelial cell antibodies

Hepatoportal sclerosis accompanied by dense elastic fibre deposition is generally regarded as the primary lesion in the development of idiopathic portal hypertension (IPH). This study was performed to clarify the mechanism of elastic fibre deposition in the peripheral portal tracts of IPH liver in relation to serum anti-endothelial cell antibodies (AECA). In-vitro experiments were performed using human dermal microvascular endothelial cells (HMVEC) and patients' sera. The presence of serum AECA was assayed by a cell-based enzyme-linked immunosorbent assay (ELISA) using HMVEC. Immunohistochemical analysis of elastin was performed using liver tissue sections of IPH patients. IPH sera contained one or more AECA that could bind to the vascular endothelial cells of the peripheral portal tracts of the liver. When the value of AECA greater than the mean ± 2 standard deviations of healthy controls was regarded as positive, the positive detection rate of either immunoglobulin (Ig)G, IgA or IgM AECA in IPH sera was 30% (10 of 33 cases). IPH sera induced the expression of elastin in HMVEC, which appeared to be associated with the presence of AECA. Apoptosis was also induced in HMVEC by the stimulation with IPH sera. In vivo, elastin expression was observed in the endothelial cells of the peripheral portal tracts of IPH livers in a proportion of cases. The disease pathogenesis of IPH seems to be heterogeneous, and this study elucidated a possible contribution of the induction of elastin expression in the portal vessels to hepatoportal sclerosis of IPH, which might be linked to serum AECA as a causative factor.

Novel insights on the role of the innate immune system in systemic sclerosis

Over the last several years the involvement of the innate immune system in the pathogenesis of autoimmune diseases such as systemic lupus erythematosus (SLE) has become well established. As systemic sclerosis (SSc; scleroderma) shares clinical features and autoantibodies with SLE, investigation has recently focused on the role of innate immunity in SSc. This has been supported by recent genetic studies. However, unlike SLE and other related autoimmune diseases, SSc patients suffer from pathologic fibrosis of skin and internal organs. The fibrotic component of SSc shares several features with syndromes following environmental exposures to agents such as organic solvents, silica dust and bleomycin. Recent work in SSc and these related fibrotic diseases have identified several areas in which innate immunity can stimulate inflammation as well as fibrosis. This article will focus on the recent discoveries identifying a prominent role of cells of the innate immune system, pattern recognition receptors, and activation of dendritic cells in the pathogenesis of SSc.

Apoptosis modulation as a promising target for treatment of systemic sclerosis

Diffuse systemic sclerosis (SSc) is a fatal autoimmune disease characterized by an excessive ECM deposition inducing a loss of function of skin and internal organs. Apoptosis is a key mechanism involved in all the stages of the disease: vascular damage, immune dysfunction, and fibrosis. The purpose of this paper is to gather new findings in apoptosis related to SSc, to highlight relations between apoptosis and fibrosis, and to identify new therapeutic targets.

Thrombospondin 1 in hypoxia-conditioned media blocks the growth of human microvascular endothelial cells and is increased in systemic sclerosis tissues

Background

Systemic sclerosis (SSc) is a chronic inflammatory autoimmune disease characterised by vascular dysfunction and damage, excess collagen deposition and subsequent organ manifestations. Vasculopathy is an early feature of the disease which leads to a chronic hypoxic environment in the tissues. Paradoxically, there is a lack of angiogenesis. We hypothesised that this may in part be due to a nonphysiological, overriding upregulation in antiangiogenic factors produced by the hypoxic tissues. We considered thrombospondin 1 (TSP-1) as a candidate antiangiogenic factor.

Results

Conditioned media from human microvascular endothelial cells cultured in both normoxic and hypoxic environments were able to block endothelial cell proliferation, with the latter environment having a more profound effect. Filtration to remove > 100-kDa proteins or heparin-binding proteins from the conditioned media eliminated their antiproliferative effect. TSP-1 was expressed in high concentrations in the hypoxic media, as was vascular endothelial growth factor (VEGF). Depletion of TSP-1 from the media by immunoprecipitation reduced the antiproliferative effect. We then show that, in a dose-dependent fashion, recombinant TSP-1 blocks the proliferation of endothelial cells. Immunohistochemistry of skin biopsy material revealed that TSP-1 expression was significantly higher throughout the skin of patients with SSc compared with healthy controls.

Conclusions

Despite the environment of chronic tissue hypoxia in SSc, there is a paradoxical absence of angiogenesis. This is thought to be due in part to aberrant expression of antiangiogenic factors, including TSP-1. We have demonstrated that TSP-1 is released in high concentrations by hypoxic endothelial cells. The conditioned media from these cells is able to block proliferation and induce apoptosis in microvascular endothelial cells, an effect that is reduced when TSP-1 is immunoprecipitated out. Further, we have shown that recombinant TSP-1 is able to block proliferation and induce apoptosis at concentrations consistent with those found in the plasma of patients with SSc and that its effect occurs in the presence of elevated VEGF levels. Taken together, these data are consistent with a model wherein injured microvascular cells in SSc fail to repair because of dysregulated induction of TSP-1 in the hypoxic tissues.

Antiendothelial cell antibodies induce apoptosis of bone marrow endothelial progenitors in systemic sclerosis

OBJECTIVE

Patients with systemic sclerosis (SSc) have significantly fewer and functionally impaired endothelial progenitor cells (EPC) in peripheral blood and bone marrow; further, endothelial apoptosis seems to play a primary role in the pathogenesis of vascular damage. We investigated whether the failure of bone marrow EPC is related to their apoptotic phenotype and analyzed the possible mechanisms inducing apoptosis.

METHODS

The presence of apoptotic cells was investigated in bone marrow aspirates taken from patients with SSc; microvessel density (MVD) and the immunohistochemical expression of vascular endothelial growth factor (VEGF) were also measured in bone marrow biopsies. A correlation between EPC apoptosis and the presence of antiendothelial cell antibodies (AECA) was also investigated.

RESULTS

We confirmed the presence of bone marrow EPC dysfunction in SSc, while hematopoiesis was not impaired. Bone marrow studies showed a high percentage of apoptotic progenitors, no signs of fibrosis or an altered MVD, and an increased VEGF index. The patients' bone marrow plasma showed significant titers of AECA, and their presence correlated with that of apoptotic progenitors. These findings were further confirmed by an in vitro assay in which the apoptosis of normal progenitors was induced by the addition of AECA+ purified IgG.

CONCLUSION

Our results showed that apoptosis in patients with SSc involves the source compartment of endothelial progenitors and correlates with AECA activity. These findings support the hypothesis that AECA may play a pathogenetic role by affecting the bone marrow EPC machinery that should repair the peripheral vascular lesions.

Digital gangrene associated with anticentromere antibodies: a case report

Introduction

Anticentromere antibodies have been associated with peripheral vascular occlusive disease, most frequently accompanied by sclerodactyly in the context of a connective tissue disorder. We report a case of digital gangrene with no other clinical associations except positive anticentromere antibodies.

Case presentation

Our patient, a 53-year-old Caucasian woman, non-smoker, presented with progressive pain and blackening of the distal right third finger over the preceding five weeks. No sclerodactyly was evident. She was anticentromere antibody positive at greater than 100 U/mL. Angiography revealed diffuse distal vasculopathy in both upper extremities. Other investigations were unremarkable.

Conclusions

It is rare for anticentromere antibody-associated digital necrosis to develop without concomitant sclerodactyly. However, this patient's case illustrates the need to consider an autoimmune contribution to the pathogenesis of digital ischemia even in the absence of a recognizable connective tissue disease.

Pharmacotherapy of systemic sclerosis

IMPORTANCE OF THE FIELD

Systemic sclerosis (SSc) is an uncommon autoimmune disease with variable degrees of fibroproliferation in blood vessels and certain organs of the body. There is currently no cure. The purpose of this article is to review the current literature regarding pathogenesis and treatment of complications of SSc.

AREAS COVERED IN THIS REVIEW

All available articles regarding research related to SSc pathogenesis and treatment listed in the PubMed database were searched; relevant articles were then reviewed and used as sources of information for this review.

WHAT THE READER WILL GAIN

This review attempts to highlight for the reader some current thought regarding mechanisms of SSc pathogenesis and how autoimmunity relates to vascular changes and fibrogenesis of the disease, as well as providing a review of results of completed clinical trials and current ongoing clinical trials that address organ-specific or global therapies for this disease. This can aid physicians who provide medical care for patients with SSc.

TAKE HOME MESSAGE

SSc is a complex autoimmune disease, the pathogenesis of which, although not completely understood, is under active study; new insights into pathogenesis are continually being discovered. Although there is no effective disease-modifying treatment for patients with SSc, quality of life, morbidity and mortality can be improved by using targeted therapy directed at affecting the consequences of damage to lungs, blood vessels, kidneys and the gastrointestinal tract. Innovative approaches to treating SSc are under intense investigation.

The complexity of managing systemic sclerosis: screening and diagnosis

The difficulties inherent in diagnosing, screening and treating SSc are reflected by the complex pathology of the disease, which involves the development of severe organ-based complications that reduce both quality of life and overall survival. Early detection and prompt treatment of such complications depend upon a successful and timely screening strategy, which, in turn, requires cooperation between disciplines and good collaborative links at all stages of the disease. Establishment of a disease registry for SSc may also be of benefit, as such registries facilitate longitudinal observation of trends in disease presentation, management and outcome. They may also help to determine potential risk factors and identify those patient subgroups that face the highest risk of developing disease. In patients with known or suspected SSc, a panel of disease-specific markers--such as autoantibodies, cell activation markers and markers of organ involvement--may help to establish the diagnosis and assess prognosis; however, changes in serum levels of such markers throughout the course of SSc should be interpreted with caution, as they may not always correlate with disease activity. Nail-fold capillaroscopy is a promising tool for SSc assessment and may provide useful diagnostic and prognostic information, although further research is required to clarify its role in evaluating disease evolution.

The microvascular endothelium in scleroderma

Vascular endothelial injury in SSc leads to a host of pathological changes in the blood vessels that adversely impact the physiology of many organ systems and eventually results in a state of chronic tissue ischaemia. Current hypotheses in SSc vascular disease pathogenesis suggest a possible infectious or chemical trigger(s) that activates both cellular and humoral immunity. Products of immune activation may lead to vascular injury possibly through the production of autoantibodies and the release of products of activated T cells that can directly damage the endothelium. Knowledge of the initial trigger of immune activation in SSc may offer an opportunity to develop a multiple step strategy for therapeutic intervention.

Is scleroderma a vasculopathy?

Described as an autoimmune collagen vascular disease, the most striking feature of scleroderma may be a systemic vasculopathy. This vasculopathy includes characteristic noninflammatory macrovascular and microvascular changes with dramatic and possibly occlusive formation of a thickened neointima. Scleroderma vessels also have an unusual endothelial phenotype, with loss of normal markers including vascular endothelial (VE)-cadherin. These endothelial cells express type 1 interferon and regulator of G protein signaling 5 (RGS5), two molecules associated with vascular rarefaction. These genes may be important because tissue is hypoxic with high levels of vascular endothelial growth factor (VEGF), especially early in the disease. The combination of VEGF and rarefaction is not necessarily paradoxical. VEGF-mediated angiogenesis creates labile vessels that may not survive unless the vessel acquires a smooth muscle coat. The combination of interferon and RGS5 is consistent with an antiangiogenic phenotype. We offer a hypothesis that places vascular injury at the center of this disease and also suggest possible clinical approaches for arresting and/or reversing the disease.

Is scleroderma a vasculopathy?

Described as an autoimmune collagen vascular disease, the most striking feature of scleroderma may be a systemic vasculopathy. This vasculopathy includes characteristic noninflammatory macrovascular and microvascular changes with dramatic and possibly occlusive formation of a thickened neointima. Scleroderma vessels also have an unusual endothelial phenotype, with loss of normal markers including vascular endothelial (VE)-cadherin. These endothelial cells express type 1 interferon and regulator of G protein signaling 5 (RGS5), two molecules associated with vascular rarefaction. These genes may be important because tissue is hypoxic with high levels of vascular endothelial growth factor (VEGF), especially early in the disease. The combination of VEGF and rarefaction is not necessarily paradoxical. VEGF-mediated angiogenesis creates labile vessels that may not survive unless the vessel acquires a smooth muscle coat. The combination of interferon and RGS5 is consistent with an antiangiogenic phenotype. We offer a hypothesis that places vascular injury at the center of this disease and also suggest possible clinical approaches for arresting and/or reversing the disease.