Endothelin-1 release from cultured endothelial cells induced by sera from patients with systemic lupus erythematosus

Association between endothelin-1 and systemic lupus erythematosus: insights from a case-control study

Systemic lupus erythematosus (SLE) is a chronic rheumatic disorder. Endothelin-1, a vasoconstrictor, belongs to the endothelin family and is associated with vascular-related damages. To date, association between ET-1 and pathogenesis of SLE remains unclear. This case-control study was carried out by 314 SLE, 252 non-SLE diseases patients and 500 healthy controls. Serum ET-1, CCN3, IL-28B levels were detected by ELISA, and ET-1 gene polymorphisms (rs5369, rs5370, rs1476046, rs2070699, rs2071942, rs2071943, rs3087459, rs4145451, rs6458155, rs9369217) were genotyped with Kompetitive Allele-Specific PCR. SLE patients had high levels of ET-1, which were correlated with some clinical, laboratory features. Serum CCN3, IL-28B levels were higher in SLE patients, and ET-1 levels were positively correlated with the two cytokines. Rs5370, rs1476046, rs2070699, rs2071942, rs2071943, rs3087459, rs6458155 and rs2070699 were associated with SLE risk. Rs2070699 (T, TT) was related to SLE patients with alopecia. Rs5370 (T, TT, TG), rs1476046 (G,GA), rs2071942 (G,GA) and rs2071943 (G,GA) were associated with SLE patients with pericarditis, pyuria and fever manifestation, respectively. Rs3087459 (CC) and rs9369217 (TC) were related to SLE patients with positive anti-SSB antibody. Rs5369 (AA) was associated with IgG and CRP levels in SLE patients. In conclusion, elevated serum ET-1 in SLE patients may be a potential disease marker, and its gene polymorphisms were related to SLE susceptibility.

Serum Biomarkers in Connective Tissue Disease-Associated Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a life-threatening complication of connective tissue diseases (CTDs) characterised by increased pulmonary arterial pressure and pulmonary vascular resistance. CTD-PAH is the result of a complex interplay among endothelial dysfunction and vascular remodelling, autoimmunity and inflammatory changes, ultimately leading to right heart dysfunction and failure. Due to the non-specific nature of the early symptoms and the lack of consensus on screening strategies-except for systemic sclerosis, with a yearly transthoracic echocardiography as recommended-CTD-PAH is often diagnosed at an advanced stage, when the pulmonary vessels are irreversibly damaged. According to the current guidelines, right heart catheterisation is the gold standard for the diagnosis of PAH; however, this technique is invasive, and may not be available in non-referral centres. Hence, there is a need for non-invasive tools to improve the early diagnosis and disease monitoring of CTD-PAH. Novel serum biomarkers may be an effective solution to this issue, as their detection is non-invasive, has a low cost and is reproducible. Our review aims to describe some of the most promising circulating biomarkers of CTD-PAH, classified according to their role in the pathophysiology of the disease.

Endothelin receptor antagonism improves glucose tolerance and adipose tissue inflammation in an experimental model of systemic lupus erythematosus

Endothelin-1 (ET-1) is elevated in patients with systemic lupus erythematosus (SLE), an autoimmune disease characterized by high rates of hypertension, renal injury, and cardiovascular disease. SLE is also associated with an increased prevalence of obesity and insulin resistance compared to the general population. In the present study, we tested the hypothesis that elevated ET-1 in SLE contributes to obesity and insulin resistance. For these studies, we used the NZBWF1 mouse model of SLE, which develops obesity and insulin resistance on a normal chow diet. To test this hypothesis, we treated control (NZW) and SLE (NZBWF1) mice with vehicle, atrasentan (ETA receptor antagonist, 10 mg/kg/day), or bosentan (ETA/ETB receptor antagonist, 100 mg/kg/day) for 4 wk. Neither treatment impacted circulating immunoglobulin levels, but treatment with bosentan lowered anti-dsDNA IgG levels, a marker of SLE disease activity. Treatment with atrasentan and bosentan decreased glomerulosclerosis, and atrasentan lowered renal T-cell infiltration. Body weight was lower in SLE mice treated with atrasentan or bosentan. Endothelin receptor antagonism also improved hyperinsulinemia, homeostatic model assessment for insulin resistance, and glucose tolerance in SLE mice. Adipose tissue inflammation was also improved by endothelin receptor blockade. Taken together, these data suggest a potential therapeutic benefit for SLE patients with obesity and insulin resistance.NEW & NOTEWORTHY SLE is an autoimmune disease that is associated with obesity, insulin resistance, and elevated endothelin-1. The present study demonstrated that pharmacological inhibition of endothelin receptors decreased body weight, insulin resistance, and adipose tissue inflammation in a murine model of SLE. The therapeutic potential of endothelin receptor antagonists to treat obesity-related diseases and pathophysiological conditions, such as autoimmune diseases and insulin resistance, has become increasingly clear.

Retrobulbar blood flow velocity in systemic lupus erythematosus assessed by color Doppler imaging

OBJECTIVE

To analyze the blood flow in retrobulbar vessels in systemic lupus erythematosus (SLE) by color Doppler imaging (CDI) and to investigate the associations between immunological markers, retinal abnormalities, disease activity, and vascular parameters.

METHODS

We examined 30 patients with SLE who were aged 32.1 ± 11.6 years with a disease duration of 68.0 ± 55.6 months and 30 participants in a control group. The peak systolic velocity (PSV), end diastolic velocity (EDV), pulsatility index (PI), and resistive index (RI) of the ophthalmic artery (OA), central retinal artery (CRA), and posterior ciliary arteries (PCAs) were determined. Physical and ophthalmic examinations with assessments of immunological markers were performed. All parameters were compared between SLE patients and normal controls while the correlations among parameters were analyzed.

RESULTS

In the SLE group, CDI confirmed blood flow abnormalities in the CRA and PCAs, with significantly lower blood flow velocities and increased RI and PI (p < 0.05). There was a significantly negative correlation between disease duration and EDV in the CRA, PCA, and OA (p = 0.0423, 0.0453, 0.0448). There was also a significant relationship between the SLE Disease Activity Index and the PI of the OA (p = 0.0367). The patients who had received biological agents (Rituximab) had lower EDV in the CRA and PCA (p = 0.0026, 0.028). SLE patients with kidney or CNS involvement had a significant increase in the PI in the OA (p = 0.0287). The PSV and EDV in the CRA were significantly related to creatinine (p = 0.0007 and 0.0418). We also noted a significant decreased EDV in the CRA and an increased RI in the OA among participants positive for anti-dsDNA antibodies (p = 0.0331 and 0.0228).

CONCLUSIONS

Retrobulbar circulatory disturbances were detected in SLE patients by CDI. These findings seem likely to affect smaller vessels like the CRA and PCA. However, the presence of measurable changes in the OA is generally indicative of a coexistent nephropathy or central nervous system (CNS) vasculitis. Creatinine, the disease activity index, being positive for anti-dsDNA, and receiving biological agents were associated with measurable changes on the retrobulbar blood flow.

Proliferative Glomerulonephritis: Risk Factor for Hypertension in Lupus

Studies report a high prevalence of hypertension in lupus, reaching up to 74%. The incidence of hypertension in SLE patients is increased with the severity of the kidney damage. This work was carried out with the objective of determining the prevalence of hypertension in lupus nephritis and to seek the existence of an association between the presence of a proliferative glomerulonephritis and hypertension. Patients and Methods. This was a case-control study, carried out in the nephrology department of the Aristide Le Dantec University Hospital in Dakar. All records of patients with lupus nephritis over a 10-year period, from January 01, 2007, to December 31, 2016, were included. Results. During the study period, out of 64 lupus nephritis records collected, 28 patients had hypertension, for a hospital prevalence of 43.75%. The mean age of the patients was 30.64 years ± 10.44. There were 24 women and 4 men. The mean systolic blood pressure was 156 mmHg (110–220) and the mean diastolic blood pressure was 100 mmHg (80–130). The mean serum creatinine was 29.48 mg/l ± 24.99. The mean proteinuria was 4.50 g/24 h ± 2.87. Hypertriglyceridemia was observed in one patient. Hypercholesterolemia was present in 3 patients. HDL levels were normal in all patients and elevated LDL levels were noted in all 4 patients. None of our patients had diabetes. Class III was found in 11 cases, class IV in 14 cases, pure class V in 2 cases, and class II in 1 case. Hypertension was associated with the presence of proliferative glomerulonephritis (odds ratio, 7.45; 95% CI, 1.9 to 29.1; p=0.002). Conclusion. Hypertension is common in lupus nephritis. The presence of a proliferative glomerulonephritis is a risk factor for the development of arterial hypertension. Screening and adequate management of hypertension are essential for the prevention of the progression of chronic kidney disease in lupus.

Endothelin-targeted new treatments for proteinuric and inflammatory glomerular diseases: focus on the added value to anti-renin-angiotensin system inhibition

Chronic kidney disease (CKD) is the main cause of end-stage renal disease worldwide arising as a frequent complication of diabetes, obesity, and hypertension. Current therapeutic options, mainly based of inhibition of the renin-angiotensin system (RAS), provide imperfect renoprotection if started at an advanced phase of the disease, and treatments that show or even reverse the progression of CKD are needed. The endothelin (ET) system contributes to the normal renal physiology; however, robust evidence suggests a key role of ET-1 and its cognate receptors, in the progression of CKD. The effectiveness of ET receptor antagonists in ameliorating renal hemodynamics and fibrosis has been largely demonstrated in different experimental models. A significant antiproteinuric effect of ET receptor antagonists has been found in diabetic and non-diabetic CKD patients even on top of RAS blockade, and emerging evidence from ongoing clinical trials highlights their beneficial effects on a wide range of kidney disorders.

Microvascular Disease and Small-Vessel Disease: The Nexus of Multiple Diseases of Women

Microvascular disease, or small-vessel disease, is a multisystem disorder with a common pathophysiological basis that differentially affects various organs in some patients. The prevalence of small-vessel disease in the heart has been found to be higher in women compared with men. Additionally, other diseases prominently affecting women, including heart failure with preserved ejection fraction, Takotsubo cardiomyopathy, cerebral small-vessel disease, preeclampsia, pulmonary arterial hypertension (PAH), endothelial dysfunction in diabetes, diabetic cardiomyopathy, rheumatoid arthritis, systemic lupus erythematosus, and systemic sclerosis, may have a common etiologic linkage related to microvascular disease. To the best of our knowledge this is the first article to investigate this potential linkage. We sought to identify various diseases with a shared pathophysiology involving microvascular/endothelial dysfunction that primarily affect women, and their potential implications for disease management. Advanced imaging technologies, such as magnetic resonance imaging and positron-emission tomography, enable the detection and increased understanding of microvascular dysfunction in various diseases. Therapies that improve endothelial function, such as those used in PAH, may also be associated with benefits across the full spectrum of microvascular dysfunction. A shared pathology across multiple organ systems highlights the need for a collaborative, multidisciplinary approach among medical subspecialty practitioners who care for women with small-vessel disease. Such an approach may lead to accelerated research in diseases that affect women and their quality of life.

Coronary flow reserve in patients with primary biliary cholangitis

BACKGROUND

It is still not clear whether primary biliary cholangitis (PBC) is associated with abnormalities of the cardiovascular system. We aimed to assess the relationship between PBC and coronary flow reserve (CFR).

METHODS

Our inclusion criterion was a diagnosis of PBC with no clinical evidence of heart disease or metabolic syndrome. Coronary flow velocity in the left anterior descending coronary artery was measured using transthoracic Doppler echocardiography at rest (DFVr), and during adenosine infusion (DFVh). The corrected CFR (cCFR) was defined as the ratio of DFVh to DFVr corrected for cardiac workload (cDFVr). Microvascular resistance was also assessed in baseline (BMR) and hyperemic conditions (HMR).

RESULTS

37 PBC patients and 37 sex- and age-matched controls were considered. The cCFR was significantly lower in PBC patients (2.8 ± 0.7 vs. 3.7 ± 0.7, p < 0.0001), and abnormal (≤2.5) in 13 (35%) of them, but in none of the controls (p < 0.0001). The cDFVr was higher in patients with abnormal cCFR (29.0 ± 6.0 vs. 20.4 ± 4.5 cm/sec, p < 0.0001). The CFR and cCFR did not correlate with any characteristics of PBC, comorbidities or Framingham risk scores. The BMR and HMR correlated with time since PBC diagnosis and duration of symptoms.

CONCLUSION

The CFR is reduced in PBC, apparently due to mechanisms correlating with the time since diagnosis. In particular, the higher cDFVr with a lower basal resistance in patients with cCFR ≤ 2.5 suggests a compensatory mechanism against any cardiomyocyte bioenergetics impairment.

REDD1/autophagy pathway promotes thromboinflammation and fibrosis in human systemic lupus erythematosus (SLE) through NETs decorated with tissue factor (TF) and interleukin-17A (IL-17A)

OBJECTIVES

The release of neutrophil extracellular traps (NETs) represents a novel neutrophil effector function in systemic lupus erythematosus (SLE) pathogenesis. However, the molecular mechanism underlying NET release and how NETs mediate end-organ injury in SLE remain elusive.

METHODS

NET formation and NET-related proteins were assessed in the peripheral blood and biopsies from discoid lupus and proliferative nephritis, using immunofluorescence, immunoblotting, quantitative PCR and ELISA. Autophagy was assessed by immunofluorescence and immunoblotting. The functional effects of NETs in vitro were assessed in a primary fibroblast culture.

RESULTS

Neutrophils from patients with active SLE exhibited increased basal autophagy levels leading to enhanced NET release, which was inhibited in vitro by hydroxychloroquine. NETosis in SLE neutrophils correlated with increased expression of the stress-response protein REDD1. Endothelin-1 (ET-1) and hypoxia-inducible factor-1α (HIF-1α) were key mediators of REDD1-driven NETs as demonstrated by their inhibition with bosentan and L-ascorbic acid, respectively. SLE NETs were decorated with tissue factor (TF) and interleukin-17A (IL-17A), which promoted thrombin generation and the fibrotic potential of cultured skin fibroblasts. Notably, TF-bearing and IL-17A-bearing NETs were abundant in discoid skin lesions and in the glomerular and tubulointerstitial compartment of proliferative nephritis biopsy specimens.

CONCLUSIONS

Our data suggest the involvement of REDD1/autophagy/NET axis in end-organ injury and fibrosis in SLE, a likely candidate for repositioning of existing drugs for SLE therapy. Autophagy-mediated release of TF-bearing and IL-17A-bearing NETs provides a link between thromboinflammation and fibrosis in SLE and may account for the salutary effects of hydroxychloroquine.

Endothelins in inflammatory neurological diseases

Endothelins were discovered more than thirty years ago as potent vasoactive compounds. Beyond their well-documented cardiovascular properties, however, the contributions of the endothelin pathway have been demonstrated in several neuroinflammatory processes and the peptides have been reported as clinically relevant biomarkers in neurodegenerative diseases. Several studies report that endothelin-1 significantly contributes to the progression of neuroinflammatory processes, particularly during infections in the central nervous system (CNS), and is associated with a loss of endothelial integrity at the blood brain barrier level. Because of the paucity of clinical trials with endothelin-1 antagonists in several infectious and non-infectious neuroinflammatory diseases, it remains an open question whether the 21 amino acid peptide is a mediator/modulator rather than a biomarker of the progression of neurodegeneration. This review focuses on the potential roles of endothelins in the pathology of neuroinflammatory processes, including infectious diseases of viral, bacterial or parasitic origin in which the synthesis of endothelins or its pharmacology have been investigated from the cell to the bedside in several cases, as well as in non-infectious inflammatory processes such as neurodegenerative disorders like Alzheimers Disease or central nervous system vasculitis.

Relationship between serum vascular cell adhesion molecule-1 and endothelin-1 levels with organ involvement and disease activity in systemic lupus erythematosus patients

Background

Endothelial dysfunction plays an important role in pathogenesis of systemic lupus erythematosus (SLE). Considering the importance of serum soluble vascular cell adhesion molecule-1 as the most abundant of the circulating adhesion molecules increased as a result of endothelial dysfunction and the role of endothelin-1 in pathophysiology of SLE, this study aimed to evaluate serum soluble vascular cell adhesion molecule-1 and endothelin-1 levels in SLE patients compared to healthy subjects.

Methods

In this cross-sectional study, 60 SLE patients according to the Systemic Lupus International Collaborating Clinics classification criteria for SLE and 40 age and sex-matched healthy controls were included. In patients, clinical examination was performed and SLE disease activity index was assessed. Serum endothelin-1 and soluble vascular cell adhesion molecule-1 levels were measured using ELISA kits.

Results

The mean ± standard deviation age of patients and controls was 31.91 ± 7.66 and 33.20 ± 10.08 years, respectively. Compared to healthy controls, serum soluble vascular cell adhesion molecule-1 (1023.8 ± 352.96 vs. 866.06 ± 109.91) and endothelin-1 (77.83 ± 16.27 vs. 54.45 ± 12.01) was significantly higher in SLE patients ( P = 0.003 and P < 0.001, respectively). The most common organs involved in patients were skin, joint and kidney. There were no significant differences in serum soluble vascular cell adhesion molecule-1 and endothelin-1 levels according to organ involvement, activity of disease and the conventional serum markers of disease activity ( P > 0.05). There was no significant correlation between disease activity, organ involvement and negative or positivity of autoantibodies as well as serum complement with endothelin-1 and vascular cell adhesion molecule-1 levels ( P > 0.05).

Conclusions

Although our study revealed higher serum soluble vascular cell adhesion molecule-1 and endothelin-1 levels in SLE patients compared to healthy controls, there were no significant correlations between their serum levels with organ involvement and disease activity.

The relationship between serum rheumatoid factor level and no-reflow phenomenon in patients with acute ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention

OBJECTIVE

This study aimed to evaluate the relationship between serum rheumatoid factor (RF) levels and no-reflow phenomenon in patients with acute ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI).

METHODS

This single-center, cross-sectional study included a total of 318 consecutive patients who were diagnosed with STEMI and underwent primary PCI within 12 hours of the onset of symptoms. Baseline serum RF levels of all patients were measured. The diagnosis of no-reflow phenomenon was defined as a flow of TIMI II or less without the presence of dissection, mechanical obstruction, significant residual stenosis, or other plausible causes. The patients were divided into reflow group (n = 283) and no-reflow group (n = 46) regarding the angiographic features of thrombolysis in myocardial infarction (TIMI) flow of the infarct-related artery.

RESULTS

No-reflow phenomenon was observed in 13.8% of the patients. Median RF level was significantly higher in no-reflow group than in reflow group (18.5 (7.0-27.6) vs 8.0 (4.6-50.8), P < .001). Forward conditional logistic regression analysis demonstrated that body mass index (OR = 0.845, 95% CI: 0.765 to 0.933, P = .001), diabetes mellitus (OR = 5.257, 95% CI: 1.124 to 24.587, P = .035), baseline RF level (OR = 1.198, 95% CI: 1.108 to 1.295, P < .001), and SYNTAX score I (OR = 1.065, 95% CI: 1.025 to 1.107, P = .001) were the independent predictors of no-reflow phenomenon.

CONCLUSION

Baseline serum RF concentrations are independently associated with the no-reflow phenomenon in patients undergoing primary PCI for acute STEMI.

From microvasculature to fibroblasts: Contribution of anti-endothelial cell antibodies in systemic sclerosis

Systemic sclerosis (SSc) is an autoimmune disease characterized by skin and internal organ fibrosis, caused by microvascular dysfunction. In recent years, the hypothesis that anti-endothelial cell antibodies (AECA) play a key role in microvascular damage seems to be increasingly convincing. In fact, AECA can induce antibody-dependent cellular apoptosis and stimulate the microvasculature to release pro-inflammatory and pro-fibrotic cytokines. Human-microvascular-endothelial-cells (MVECs) were stimulated with SSc sera (with and without AECA) and with sera from healthy donors. The conditioned MVEC culture media were then added to fibroblast cultures obtained from control skin (CTR), non-affected skin of SSc patients (NA), and affected skin of the same sclerodermic (SSc) patients, respectively. AECA contributed to the MVEC increased release of endothelin-1 (ET-1) in the culture medium and to MVEC apoptosis. Fibroblast (CTR, NA, and SSc) proliferation was increased after treatment with AECA-positive conditioned media, compared to AECA-negative and control conditioned media. Furthermore, both AECA-positive (in major contribution) and AECA-negative conditioned media were responsible for alpha-smooth-muscle-actin (αSMA) over-expression in all fibroblast cultures, compared to control conditioned media. Fibroblast type I collagen synthesis was upregulated by both SSc conditioned media (with and without AECA). Finally, the synthesis of fibroblast transforming-growth-factor-beta (TGF-β) was statistically higher in AECA-positive conditioned media, compared to AECA-negative and control conditioned media. These findings support the concept that AECA may mediate the crosstalk between endothelial damage and dermal-fibroblast activation in SSc.

The effects of hydroxychloroquine on endothelial dysfunction

Hydroxychloroquine is an anti-malarial drug which, due to its anti-inflammatory and immunomodulatory effects, is widely used for the treatment of autoimmune diseases. In a model of systemic lupus erythematosus hydroxychloroquine has been shown to exert protective endothelial effects. In this study, we aimed to investigate whether hydroxychloroquine was endothelial protective in an in vitro model of TNF-α and preeclamptic serum induced dysfunction. We showed that hydroxychloroquine significantly reduced the production of TNF-α and preeclamptic serum induced endothelin-1 (ET-1). Hydroxychloroquine also significantly mitigated TNF-α induced impairment of angiogenesis. These findings support the further assessment of hydroxychloroquine as an adjuvant therapy in preeclampsia.

Increased aortic pulse wave velocity in middle aged women with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a connective tissue disease where inflammatory activity affects several organ systems. An increased risk of cardiovascular disease has been identified in these patients, even after correction for traditional risk factors. The aim of the present study was to evaluate arterial stiffness and central hemodynamics in women with SLE in comparison to controls.

Arterial tonometry was used to measure aortic (carotid-femoral) and arm (carotid-radial) pulse wave velocity (PWV), reflected pressure waves, and aortic augmentation index (AIx) in 27 women with SLE (52 to 68 years) and 27 controls. Aortic PWV was higher in women with SLE than controls, 9.8 m/s versus 8.2 m/s ( P 0.01), after correction for mean arterial pressure and body mass index, 9.5 m/s versus 8.5 m/s ( P 0.05). Other parameters were similar, arm PWV, 8.4 versus 8.5 m/s, AIx 34 versus 33% and calculated central aortic pulse pressure 48 versus 43 mmHg, in SLE and controls, respectively (NS). Aortic PWV was positively associated to C-reactive protein (CRP) and complement factor 3 (C3).

Women with SLE have increased stiffness of their elastic central arteries. This may be one factor contributing to the increased cardiovascular risk seen in this cohort.

Understanding mechanisms of hypertension in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder that predominately affects women of reproductive age. Hypertension is an important cardiovascular risk factor that is prevalent in this patient population. Despite the high incidence of hypertension in women with SLE, the pathophysiological mechanisms underlying the development of hypertension remain poorly understood. This review will focus on disease-related factors, including inflammation, autoantibodies, and sex hormones that may contribute to hypertension in patients with SLE. In addition, we will highlight studies performed by our laboratory using the female NZBWF1 (F1 hybrid of New Zealand Black and New Zealand White strains) mouse model, a spontaneous model of SLE that mimics human disease and develops hypertension and renal injury. Specifically, using female NZBWF1 mice, we have demonstrated that multiple factors contribute to the pathogenesis of hypertension, including the inflammatory cytokine, tumor necrosis factor (TNF)-α, oxidative stress, as well as B-cell hyperactivity and autoantibody production.

The increased cardiovascular risk in patients affected by autoimmune diseases: review of the various manifestations

Cardiovascular and autoimmune diseases are among major health concerns in developed countries, and both represent a significant source of morbidity, mortality and economic costs. Despite they are thought to affect subjects at different ages, most of the deaths of patients affected by autoimmune diseases are represented by cardiovascular deaths. Several manifestations of cardiovascular diseases can be observed in patients with autoimmune diseases, such as endothelial dysfunction, accelerated atherosclerosis and an increase in the rate of acute coronary syndromes. Thus, people with autoimmune diseases have an increased cardiovascular risk and a worse outcome in the case of cardiovascular events. In this review, we will describe the correlations between the two spectra of diseases.

[Assessment of endothelial function in autoimmune diseases]

Numerous autoimmune-inflammatory rheumatic diseases have been associated with accelerated atherosclerosis or other types of vasculopathy leading to an increase in cardiovascular disease incidence. In addition to traditional cardiovascular risk factors, endothelial dysfunction is an important early event in the pathogenesis of atherosclerosis, contributing to plaque initiation and progression. Endothelial dysfunction is characterized by a shift of the actions of the endothelium toward reduced vasodilation, a proinflammatory and a proadhesive state, and prothrombic properties. Therefore, assessment of endothelial dysfunction targets this vascular phenotype using several biological markers as indicators of endothelial dysfunction. Measurements of soluble adhesion molecules (ICAM-1, VCAM-1, E-selectin), pro-thrombotic factors (thrombomodulin, von Willebrand factor, plasminogen activator inhibitor-1) and inflammatory cytokines are most often performed. Regarding the functional assessment of the endothelium, the flow-mediated dilatation of conduit arteries is a non-invasive method widely used in pathophysiological and interventional studies. In this review, we will briefly review the most relevant information upon endothelial dysfunction mechanisms and explorations. We will summarize the similarities and differences in the biological and functional assessments of the endothelium in different autoimmune diseases.

Inflammatory mechanisms in the pathogenesis of pulmonary arterial hypertension

Inflammation is a prominent feature of human and experimental pulmonary hypertension (PH) as suggested by infiltration of various inflammatory cells and increased expression of certain cytokines in remodeled pulmonary vessels. Macrophages, T and B lymphocytes, and dendritic cells are found in the vascular lesions of idiopathic pulmonary arterial hypertension (PAH) as well as in PAH associated with connective tissue diseases or infectious etiologies such as HIV. In addition, PAH is often characterized by the presence of circulating chemokines and cytokines, increased expression of growth (such as VEGF and PDGF) and transcriptional (e.g., nuclear factor of activated T cells or NFAT) factors, and viral protein components (e.g., HIV-1 Nef), which directly contribute to further recruitment of inflammatory cells and the pulmonary vascular remodeling process. These inflammatory pathways may thus serve as potential specific therapeutic targets. This article provides an overview of inflammatory pathways involving chemokines and cytokines as well as growth factors, highlighting their potential role in pulmonary vascular remodeling and the possibility of future targeted therapy.

Improving cardiovascular outcomes in rheumatic diseases: therapeutic potential of circulating endothelial progenitor cells

Patients with Rheumatoid Arthritis (RA) and Systemic Lupus Erythematosus (SLE) have a significantly increased risk of cardiovascular disease (CVD). The reason for this is unclear but may be due, at least in part, to the failure of endothelial repair mechanisms. Over the last 15 years there has been much interest in the mechanisms of endothelial renewal and its potential as a therapy for CVD. In the circulation there are two distinct populations of cells; myeloid angiogenic cells (MACs) which augment repair by the paracrine secretion of angiogenic factors, and outgrowth endothelial cells (OECs) which are true endothelial progenitor cells (EPCs) and promote vasculogenesis by differentiating into mature endothelium. There are marked abnormalities in the number and function of these cells in patients with RA and SLE. Inflammatory cytokines including interferon-alpha (IFNα) and tumour-necrosis factor alpha (TNFα) both impair MAC and OEC function ex vivo and may therefore contribute to the CVD risk in these patients. Whilst administration of mononuclear cells, MACs and other progenitors has improved cardiovascular outcomes in the acute setting, this is not a viable option in chronic disease. The pharmacological manipulation of MAC/OEC function in vivo however has the potential to significantly improve endothelial repair and thus reduce CVD in this high risk population.

Differential expression of functional Fc-receptors and additional immune complex receptors on mouse kidney cells

The precise mechanisms by which circulating immune complexes accumulate in the kidney to form deposits in glomerulonephritis are not well understood. In particular, the role of resident cells within glomeruli of the kidney has been widely debated. Immune complexes have been shown to bind one glomerular cell type (mesangial cells) leading to functional responses such as pro-inflammatory cytokine production. To further assess the presence of functional immunoreceptors on resident glomerular cells, cultured mouse renal epithelial, endothelial, and mesangial cells were treated with heat-aggregated mouse IgG or preformed murine immune complexes. Mesangial and renal endothelial cells were found to bind IgG complexes, whereas glomerular epithelial cell binding was minimal. A blocking antibody for Fc-gamma receptors reduced binding to mesangial cells but not renal endothelial cells, suggesting differential immunoreceptor utilization. RT-PCR and immunostaining based screening of cultured renal endothelial cells showed limited low-level expression of known Fc-receptors and Ig binding proteins. The interaction between mesangial cells and renal endothelial cells and immune complexes resulted in distinct, cell-specific patterns of chemokine and cytokine production. This novel pathway involving renal endothelial cells likely contributes to the predilection of circulating immune complex accumulation within the kidney and to the inflammatory responses that drive kidney injury.

Pulmonary hypertension in rheumatic diseases: epidemiology and pathogenesis

The focus of this review is to increase awareness of pulmonary arterial hypertension (PAH) in patients with rheumatic diseases. Epidemiology and pathogenesis of PAH in rheumatic diseases is reviewed, with recommendations for early screening and diagnosis and suggestion of possible role of immunosuppressive therapy in treatment for PAH in rheumatic diseases. A MEDLINE search for articles published between January 1970 and June 2012 was conducted using the following keywords: pulmonary hypertension, scleroderma, systemic sclerosis, pulmonary arterial hypertension, connective tissues disease, systemic lupus erythematosus, mixed connective tissue disease, rheumatoid arthritis, Sjogren's syndrome, vasculitis, sarcoidosis, inflammatory myopathies, dermatomyositis, ankylosing spondylitis, spondyloarthropathies, diagnosis and treatment. Pathogenesis and disease burden of PAH in rheumatic diseases was highlighted, with emphasis on early consideration and workup of PAH. Screening recommendations and treatment were touched upon. PAH is most commonly seen in systemic sclerosis and may be seen in isolation or in association with interstitial lung disease. Several pathophysiologic processes have been identified including an obliterative vasculopathy, veno-occlusive disease, formation of microthrombi and pulmonary fibrosis. PAH in systemic lupus erythematosus is associated with higher prevalence of antiphospholipid and anticardiolipin antibodies and the presence of Raynaud's phenomenon. Endothelial proliferation with vascular remodeling, abnormal coagulation with thrombus formation and immune-mediated vasculopathy are the postulated mechanisms. Improvement with immunosuppressive medications has been reported. Pulmonary fibrosis, extrinsic compression of pulmonary arteries and granulomatous vasculitis have been reported in patients with sarcoidosis. Intimal and medial hyperplasia with luminal narrowing has been observed in Sjogren's syndrome, mixed connective tissue disease and inflammatory myopathies. Pulmonary arterial hypertension (PAH) associated with rheumatic diseases carries a particularly grim prognosis with faster progression of disease and poor response to therapy. Though largely associated with systemic sclerosis, it is being increasingly recognized in other rheumatic diseases. An underlying inflammatory component may explain the poor response to therapy in patients with rheumatic diseases and is a rationale for consideration of immunosuppressive therapy in conjunction with vasodilator therapy in treatment for PAH. Further studies identifying pathogenetic pathways and possible targets of therapy, especially the role of immunomodulatory medications, are warranted.

A histopathological study of pulmonary hypertension in connective tissue disease

Connective tissue diseases (CTD), such as systemic sclerosis (SSc), systemic lupus erythematosus (SLE), and mixed connective tissue disease (MCTD), develop pulmonary hypertension (PH). Generally all PH cases associated with any CTD are classified into the same PH group. However, histological examination shows both common and specific lesions for each disease. In patients with SLE, fibrosis is generally rare and mild. The findings of PH in SLE are similar to those in primary pulmonary hypertension. Many cases of SSc are accompanied by fibrosis. MCTD is rather close to SSc. Arterial and arteriolar lesions of MCTD are characterized by fibrous intimal thickening. In this review, we describe the pathological features of PH associated with each CTD.

Prognostic factors for survival in systemic lupus erythematosus associated pulmonary hypertension

Objective: Pulmonary hypertension (PH) is a rare but severe manifestation of systemic lupus erythematosus (SLE) that can ultimately result in death. The identification of factors that prognosticate survival in SLE-PH is necessary for appropriate monitoring, timing of therapeutics and lung transplantation. The primary objective of this study was to identify prognostic factors for survival in SLE-PH through review of the literature. The methodological quality of the prognostic studies was also evaluated .Methods: A systematic review of the literature was performed to identify studies evaluating prognostic factors for survival in SLE-PH. Medline, EMBASE, CINAHL, and Cochrane Central Registry of Controlled Trials (inception – week 2 2010) were searched. A standardized abstraction form was used by two independent reviewers to extract prognostic factors. Methodological quality was evaluated using a validated quality index. Results: Twenty-three observational studies from 375 citations were evaluated. Elevated mean pulmonary artery pressure, Raynaud’s phenomenon, thrombocytopenia, plexiform lesion, infection, thrombosis, pregnancy, pulmonary vasculitis and anticardiolipin antibodies were associated with decreased survival. Lupus disease activity, nephritis and central nervous system disease were not associated with survival. The sample sizes were small and methodological quality of the studies was variable. Conclusion: This study summarizes factors that may be associated with decreased survival in SLE-PH. The small sample sizes and variable methodological quality preclude definitive conclusions. This study provides the groundwork for further research using large cohorts.

[Pulmonary arterial hypertension in systemic lupus erythematosus]

Pulmonary hypertension (PH) is a serious complication of connective tissue diseases. The prevalence of PH in systemic lupus erythematosus (SLE) ranges from 0.5 to 17.5%, depending on whether echocardiography or right heart catheterization is used as the gold standard for diagnosis. The recent guidelines for the diagnosis and treatment of pulmonary hypertension include several potential causes of PH in SLE, including: a primary vasculopathy similar to idiopathic pulmonary arterial hypertension (PAH); left heart diseases; post-thromboembolic disease; hypoxia and fibrosis resulting from interstitial lung disease; and the infrequent SLE-associated pulmonary veno-occlusive disease. The pathogenesis of PAH associated with lupus is yet unclear, but likely includes a role for the genetic background, the presence of antiphospholipid antibodies, and some level of endothelial dysfunction. The evolution of SLE-associated PH is highly variable and difficult to elicit because the published series have used heterogeneous inclusion criteria. Optimal therapeutic management of PAH associated with lupus is unclear because no dedicated randomized controlled trial is yet available. Treatment usually includes arterial pulmonary vasodilators and immunosuppressive agents when the patients have NYHA functional class II, III or IV dyspnea.

Analysis of correlations between selected endothelial cell activation markers, disease activity, and nailfold capillaroscopy microvascular changes in systemic lupus erythematosus patients

The aim of the study was to evaluate the correlation between selected serum endothelial cell activation markers such as vascular endothelial growth factor (VEGF), endothelin-1 (ET-1), soluble thrombomodulin (sTM), soluble E-selectin (sE-selectin), disease activity, and microvascular changes determined by nailfold capillaroscopy in patients with systemic lupus erythematosus (SLE). Serum levels of VEGF, ET-1, sTM, and sE-selectin were determined by an enzyme-linked immunosorbent assay in 80 SLE patients. The disease activity was measured with Systemic Lupus Erythematosus Disease Activity Index score. Nailfold capillaroscopy was performed in all patients. Positive correlation was found between VEGF and both ET-1 (r = 0.294, p < 0.01) and sE-selectin (r = 0.274, p < 0.05) serum levels as well as between sTM and ET-1 (r = 0.273, p < 0.05) serum concentrations. We noticed also positive correlation between VEGF (r = 0.224, p < 0.05) and ET-1 (r = 0.471, p < 0.001) serum levels and disease activity, and also between VEGF serum concentration and grade of morphological changes observed by nailfold capillaroscopy (r = 0.458, p < 0.001). There was also positive correlation between capillaroscopic score and disease activity (r = 0.339, p < 0.01). Our data suggest that correlation between VEGF and both ET-1 and E-selectin serum levels as well as between sTM and ET-1 serum concentrations may reflect their participation in the pathogenesis of SLE. VEGF seems to reflect changes in microcirculation in the course of SLE, visualised by nailfold capillaroscopy. The relationship between changes in nailfold capillaroscopy, endothelial cell activation markers, and the clinical activity of SLE points to an important role of microvascular abnormalities in the clinical manifestation of the disease.

Rosiglitazone decreases blood pressure and renal injury in a female mouse model of systemic lupus erythematosus

Women with systemic lupus erythematosus (SLE) exhibit a high prevalence of hypertension and renal injury. Rosiglitazone (Rosi), a peroxisome proliferator activator receptor gamma (PPARgamma) agonist, has renal protective and antihypertensive effects. We tested whether Rosi ameliorates hypertension and renal injury in a female mouse model of SLE (NZBWF1). Thirty-week-old SLE and control (NZW/LacJ) mice (n > or = 6/group) were fed Rosi (5 mg.kg(-1).day(-1) in standard chow) or standard chow for 4 wk. SLE mice had increased blood pressure (BP in mmHg) compared with controls (139 +/- 4 vs. 111 +/- 4, P < 0.05). Rosi treatment lowered BP in SLE mice (127 +/- 4, P < 0.05) but not in controls (111 +/- 4). Urinary albumin (mug/mg creatinine) was increased in SLE mice compared with controls (12,396 +/- 6,525 vs. 50 +/- 6) and reduced with Rosi treatment (148 +/- 117). Glomerulosclerosis (% of glomeruli with sclerosis) was reduced in Rosi-treated SLE mice (4.2 +/- 1.6 vs. 0.4 +/- 0.3, P < 0.05). Renal monocyte/macrophage numbers (cell number/1,320 points counted) were reduced in SLE mice treated with Rosi (32.6 +/- 11.0 vs. 10.6 +/- 3.6, P < 0.05) but unchanged in controls (3.7 +/- 1.6 vs. 3.7 +/- 2.0). Renal osteopontin expression, a cytokine-regulating macrophage recruitment, was reduced in Rosi-treated SLE mice. Urinary endothelin (in pg/mg creatinine) was increased in SLE mice compared with controls (1.9 +/- 0.59 vs. 0.6 +/- 0.04, P < 0.05) and reduced in SLE mice treated with Rosi (0.8 +/- 0.11, P < 0.05). PPARgamma protein expression in the renal cortex was significantly lower in SLE mice compared with controls and was unaffected by Rosi. These data suggest that Rosi may be an important therapeutic option for the treatment of SLE hypertension and renal injury.

The pathophysiology of hypertension in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune inflammatory disorder that predominantly affects women during their reproductive years. Although SLE can affect any organ system, the kidneys are prominently involved in the form of immune complex glomerulonephritis. In addition, in women with SLE, risk for the development of cardiovascular disease is dramatically increased. Hypertension is a major risk factor for cardiovascular disease and is highly prevalent in women with SLE. Nevertheless, there has been little exploration of the pathophysiological mechanisms that promote SLE hypertension. This review discusses the role of several mechanisms, with an emphasis on the kidney, in SLE hypertension. These mechanisms include the renin-angiotensin system, endothelin, oxidative stress, sex steroids, metabolic changes, peroxisome proliferator-activated receptor-gamma, and, perhaps most importantly, chronic inflammation and cytokines. Growing evidence suggests a link between chronic inflammation and hypertension. Therefore, elucidation of mechanisms that promote SLE hypertension may be of significant value not only for patients with SLE, but also for a better understanding of the basis for essential hypertension.

Increased levels of asymmetric dimethylarginine (ADMA) in patients with ankylosing spondylitis

OBJECTIVE

Endothelial dysfunction is present in ankylosing spondylitis (AS). However, the etiology of events is still unclear. The aim of the present study was to investigate whether there are abnormalities in nitric oxide (NO) metabolism and endothelin-1 (ET-1) in AS patients.

METHODS

Subjects without any classical cardiovascular (CV) risk factors were studied. Fasting glucose, serum lipids, high sensitive CRP (hsCRP), ESR, asymmetric dimethylarginine (ADMA) and ET-1 were studied. Patients were also evaluated with the Bath Ankylosing Spondylitis Metrology Index, Bath Ankylosing Spondylitis Functional Index, and the Bath Ankylosing Spondylitis Disease Activity Index.

RESULTS

A total of 48 AS patients (38.6+/-10.6 years; 36M/12F) and 38 controls (36.4+/-11.1 years; 27M/11F) were studied. Acute phase reactants including hsCRP, and ESR were significantly increased in the patients group (p<0.05). Serum ADMA concentrations were also significantly higher in AS than in controls. Plasma levels of ET-1 did not differ between the groups (p>0.05). Comparison of three groups (conventional and anti-TNF treatment groups and controls) revealed that ADMA was significantly higher in the conventional treated AS than in controls. The levels of ADMA were not different between anti-TNF group and healthy subjects. Plasma ET-1 concentrations were similar between groups (p>0.05). Correlation analysis yielded significant correlations between ADMA, hsCRP, LDL cholesterol, HDL cholesterol and triglycerides (p<0.05).

CONCLUSION

The increased ADMA levels obtained in a group of relatively young AS patients who did not have classical CV risk factors suggest that NO metabolism is impaired in AS. On the other hand, anti-TNF treatments may have a beneficial effect on vascular function in AS.

Endothelin: 20 years from discovery to therapy

Since its identification as an endothelial cell-derived vasoconstrictor peptide in 1988, endothelin-1, the predominant member of the endothelin peptide family, has received considerable interest in basic medical science and in clinical medicine, which is reflected by more than 20 000 scientific publications on endothelin research in the past 20 years. The story of endothelin is unique as the gene sequences of endothelin receptors and the first receptor antagonists became available within only 4 years of the identification of the peptide sequence. The first clinical study in patients with congestive heart failure was published only 3 years thereafter. Yet, despite convincing experimental evidence of a pathogenetic role for endothelin in development, cell function, and disease, many initial clinical studies on endothelin antagonism were negative. In many of these studies, study designs or patient selection were inadequate. Today, for diseases such as pulmonary hypertension, endothelin antagonist treatment has become reality in clinical medicine, and ongoing clinical studies are evaluating additional indications, such as renal disease and cancer. Twenty years after the discovery of endothelin, its inhibitors have finally arrived in the clinical arena and are now providing us with new options to treat disease and prolong the lives of patients. Possible future indications include resistant arterial hypertension, proteinuric renal disease, cancer, and connective tissue diseases.

An update in pulmonary hypertension in systemic lupus erythematosus – do we need to know about it?

Pulmonary hypertension (PH) is a serious form of pulmonary complication that occurs less frequently in lupus than in other connective tissue diseases like scleroderma; however, it is likely that it is under-recognized in lupus. The symptoms of PH in lupus are non-specific (dyspnea, fatigue, impaired exercise tolerance) and can also be caused by other factors such as pleural or pericardial effusions, interstitial lung disease and many more, making it possible to miss the diagnosis. There are several potential causes of PH in lupus including thromboembolic disease, pulmonary vasculitis, and hypoxia and fibrosis from interstitial lung disease. Endothelin-1 is elevated in lupus and may be associated with PAH. In some studies, pulmonary arterial hypertension (PAH) has been found to be a major cause of mortality in lupus patients. Echocardiograms are a screening tool, but may yield false positives, and a right heart catheterization must be performed to confirm PAH. Early identification is important and can alter the natural history of this dangerous complication of lupus. Treatment of PAH associated with lupus includes standard PAH treatment as well as immunosuppression.

Mechanisms of ET-1-induced endothelial dysfunction

There is now increasing evidence that endothelial dysfunction is an early event in the pathophysiology of cardiovascular diseases and can be corrected with certain therapies such as angiotensin converting enzyme inhibitors angiotensin type I receptor antagonists and stains independently of blood pressure lowering effects. Restoring endothelial function appears to be a crucial target since endothelial dysfunction predicts cardiovascular events in various situations such as coronary artery disease peripheral artery disease, or hypertension and in patients undergoing vascular surgery. Preclinical and clinical data strongly support that endothelin receptor antagonists belong to this restricted class of pharmacological agents able to act on the endothelium, and offer a potential therapeutic approach for numerous diseases associated with endothelial dysfunction. The purpose of this review will be therefore, 1) to propose mechanisms by which ET-1 can cause endothelial dysfunction; 2) to provide an overview of pathological situations associated with endothelial dysfunction related to ET-1; and 3) to assemble evidence on efficacy of endothelin receptor antagonists for improvement of endothelial function.

Collagen Vascular Diseases and Disorders of Connective Tissue

The collagen vascular diseases, also referred to as connective tissue diseases, are a diverse group of systemic inflammatory disorders thought to be immunologically mediated. The concept of collagen vascular disease began to take shape in the 1930s, when it was recognized that rheumatic fever and rheumatoid arthritis can affect connective tissues throughout the body.1,2 During the following decade, as conditions such as systemic lupus erythematosus (SLE) and scleroderma came to be viewed as systemic diseases of connective tissue, the terms diffuse connective disease and diffuse collagen disease were proposed.3,4 During the same period, the designation of diffuse vascular disease was proposed for diseases such as scleroderma, polymyositis, SLE, and polyarteritis nodosa, which featured widespread vascular involvement.5 With the realization that many of these entities can exhibit both systemic connective tissue manifestations and vascular abnormalities, the unifying designation of collagen vascular disease was introduced.6

Pathogenic mechanisms of anti-endothelial cell antibodies (AECA): their prevalence and clinical relevance

Anti‐endothelial cell antibodies (AECA) represent a heterogeneous family of autoantibodies directed against structural endothelial proteins, as well as antigens adhering to endothelial cells. Although AECA immunoassays still show a high‐interlaboratory variability, several findings suggest a pathogenic role of these autoantibodies in diseases characterized by endothelial damage. In this chapter, we analyze the knowledge about AECA prevalence, clinical relevance, and their pathogenic role in autoimmune diseases focusing in particular on systemic lupus erythematosus, antiphospholipid syndrome, systemic sclerosis (SSc), and systemic vasculitis.

Microcirculatory Hemodynamics and Endothelial Dysfunction in Systemic Lupus Erythematosus

Objective— Impaired flow-mediated dilation (FMD) occurs in disease states associated with atherosclerosis, including SLE. The primary hemodynamic determinant of FMD is wall shear stress, which is critically dependent on the forearm microcirculation. We explored the relationship between FMD, diastolic shear stress (DSS), and the forearm microcirculation in 32 patients with SLE and 19 controls.

Methods and Results— DSS was calculated using (mean diastolic velocity×8×blood viscosity)/baseline brachial artery diameter. Doppler velocity envelopes from the first 15 seconds of reactive hyperemia were analyzed for resistive index (RI), and interrogated in the frequency domain to assess forearm microvascular hemodynamics. FMD was significantly impaired in SLE patients (median, 2.4%; range, −2.1% to 10.7% versus median 5.8%; range, 1.9% to 14%; P <0.001). DSS (dyne/cm 2 ) was significantly reduced in SLE patients (median, 18.5; range, 3.9 to 34.0 versus median 21.8; range, 14.1 to 58.7; P =0.037). A strong correlation between FMD and DSS, r s =0.65, P =0.01 was found. Postischemic RI was not significantly different between the 2 groups; however, there were significant differences in the power-frequency spectrums of the Doppler velocity envelopes ( P <0.05).

Conclusions— These data suggest that in SLE, altered structure and function of the forearm microcirculation contributes to impaired FMD through a reduction in shear stress stimulus.

New target antigens for antiendothelial cell antibodies

Numerous connective tissue diseases, such as systemic lupus erythematosus (SLE), and infectious states, such as leprosy, are characterized by early vascular endothelial cell (EC) damage. There is substantial interest in the role of anti-EC antibodies (AECA) in such an injury. Due to the diversity of AECA-associated conditions, these autoantibodies are likely to be heterogeneous, and, therefore, identification of their antigens (Ag) to be difficult. They may be classified into three groups: membrane components, ligand-receptor complexes and Ag derived from the blood and attached to the cell surface. New technologies have been developed to sort it out, such as expression libraries and two-dimensional electrophoresis. A handful of Ag have hitherto been recognized viz. heat-shock protein 60 in SLE and leprosy, or plasminogen activator inhibitor-1 in SLE and Wegener granulomatosis. In reality, most of the target Ag for AECA remain to be identified.

A study on vascular endothelial growth factor and endothelin-1 in patients with extra-articular involvement of rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease associated with a wide range of extra-articular manifestations. Recent studies emphasise a key inflammatory role of the endothelial cells, either by overexpression of inflammatory mediators or by the proliferation of new blood vessels, in the disease process leading to the systemic organ involvement. To evaluate the relationship between internal organ manifestations and immunological markers of endothelial activation, serum levels of vascular endothelial growth factor (VEGF) and endothelin-1 (ET-1) were determined by an enzyme-linked immunosorbent assay in 64 RA patients and in 32 healthy controls. In comparison with a control group, higher serum concentrations of VEGF and ET-1 (p<0.001) in RA patients were demonstrated. A comparison between both RA groups with (20 patients) and without systemic involvement (44 patients) showed significantly higher concentrations of VEGF (p<0.05) and ET-1 (p<0.01) in the sera of patients with systemic manifestation. Moreover, a significant positive correlation between VEGF and ET-1 (r=0.475, p<0.001) in RA patients was found. A positive correlation between VEGF and Disease Activity Score (DAS) 28 index (r=0.39, p<0.005) as well as erythrocyte sedimentation rate (ESR) (r=0.564, p<0.0001) and C-reactive protein was found. ET-1 serum level correlated significantly with ESR (r=0.326, p<0.05) and DAS 28 index (r=0.307, p<0.05). These results suggest that the elevated serum levels of VEGF and ET-1 are associated with systemic organ involvement in RA patients and may play a key role in the pathogenesis of extra-articular manifestation of the disease.

Inflammatory bowel disease and endothelin-1: a review

Inflammatory bowel disease (IBD) appears to be an inappropriate response to an antigen that leads to chronic inflammation rather than repair. This review looks at the role of endothelin-1 (ET-1) as a proinflammatory agent in IBD. ET-1 antagonists in animal models reduce the incidence and severity of IBD. These antagonists may be useful for treatment of IBD in humans.

Endothelial cell-binding antibodies in patients with systemic lupus erythematosus

Abstract The implications of endothelial cell-binding IgG antibodies (EC IgG) in systemic lupus erythematosus (SLE) was evaluated by determining level of EC IgG in sera from 112 SLE patients. The serum EC IgG level was determined by the cyto-ELISA method using human umbilical vein endothelial cells (HUVEC), human microvascular endothelial cells (HMVEC), and aortic endothelial cells (HAEC) as antigens. The levels of EC IgG were significantly higher among patients with SLE than among healthy control subjects (P < 0.001), and 68% (76/112) of SLE patients were shown to be EC IgG-positive. In patients with active lupus nephritis, the level of EC IgG was statistically and significantly elevated compared with those without lupus nephritis (P < 0.05). Negative correlations between EC IgG level and levels of CH50, C3, and lymphocyte count were revealed (P < 0.05, P < 0.005, and P < 0.05, respectively). When clinical course was evaluated, the levels of EC IgG correlated with disease activity. Definitive correlations in antibody levels between HUVEC and HMVEC, and between HUVEC and HAEC were revealed (both P < 0.0001). The results of this study revealed that the EC IgG in patients with SLE was involved in the onset of clinical manifestation, especially in patients with active lupus nephritis.

Life-threatening complications of systemic sclerosis

Pulmonary arterial hypertension is common in patients with SSc. Fig. 1 shows the diagnostic and therapeutic approach to PAH in SSc. Doppler echocardiography may suggest the diagnosis, but RHC is necessary to confirm PAH and to measure vasoreactivity. Therapy is directed at the underlying connective tissue disease. Vasoreactive patients often benefit from therapy with high-dose calcium-channel [figure: see text] blockers, but most patients are not vasoreactive. Intravenous epoprostenol and oral endothelin-1 receptor antagonists improve hemodynamic measurements and symptoms in SSc-associated PAH. The therapy of right ventricular failure is focused on vasodilators, inotropes, and diuretics with careful attention to avoiding systemic hypotension. The scleroderma pulmonary-renal syndrome and the scleroderma renal crisis are distinct syndromes with different clinical presentations, histopathologic manifestations, treatments, and outcomes. The scleroderma pulmonary renal syndrome is an autoimmune vasculitis of kidney and lung associated with normal blood pressure. Treatment is supportive, and prognosis is dismal. In contrast, scleroderma renal crisis is associated with systemic hypertension, onion skinning of afferent arterioles, and response to ACE inhibition and renal replacement therapy. Pericardial effusions are common but only occasionally lead to tamponade. Esophageal dysmotility is often associated with aspiration, leading to pulmonary fibrosis, pneumonia, or ARDS. Diffuse bowel involvement may result in pseudo-obstruction, bacterial overgrowth, or malabsorption. Prokinetic agents, antibiotics, and parenteral nutrition may be required.

Vasospasm, its role in the pathogenesis of diseases with particular reference to the eye

Vasospasm can have many different causes and can occur in a variety of diseases, including infectious, autoimmune, and ophthalmic diseases, as well as in otherwise healthy subjects. We distinguish between the primary vasospastic syndrome and secondary vasospasm. The term "vasospastic syndrome" summarizes the symptoms of patients having such a diathesis as responding with spasm to stimuli like cold or emotional stress. Secondary vasospasm can occur in a number of autoimmune diseases, such as multiple sclerosis, lupus erythematosus, antiphospholipid syndrome, rheumatoid polyarthritis, giant cell arteritis, Behcet's disease, Buerger's disease and preeclampsia, and also in infectious diseases such as AIDS. Other potential causes for vasospasm are hemorrhages, homocysteinemia, head injury, acute intermittent porphyria, sickle cell disease, anorexia nervosa, Susac syndrome, mitochondriopathies, tumors, colitis ulcerosa, Crohn's disease, arteriosclerosis and drugs. Patients with primary vasospastic syndrome tend to suffer from cold hands, low blood pressure, and even migraine and silent myocardial ischemia. Valuable diagnostic tools for vasospastic diathesis are nailfold capillary microscopy and angiography, but probably the best indicator is an increased plasma level of endothelin-1. The eye is frequently involved in the vasospastic syndrome, and ocular manifestations of vasospasm include alteration of conjunctival vessels, corneal edema, retinal arterial and venous occlusions, choroidal ischemia, amaurosis fugax, AION, and glaucoma. Since the clinical impact of vascular dysregulation has only really been appreciated in the last few years, there has been little research in the according therapeutic field. The role of calcium channel blockers, magnesium, endothelin and glutamate antagonists, and gene therapy are discussed.

Antibodies to endothelial cells in borderline hypertension

BACKGROUND

Antibodies to endothelial cells (aECs) and to cardiolipin (aCLs) are implicated in autoimmune diseases like systemic lupus erythematosus vasculitis. Beta2-Glycoprotein 1 (beta2GP1) is a cofactor for aCLs. The present study investigated the possible role of aECs, aCLs, and abeta2GP1 in borderline hypertension.

METHODS AND RESULTS

Seventy-three men with borderline hypertension (BHT) and 73 age-matched normotensive (NT) men (diastolic blood pressure, 85 to 94 and <80 mm Hg, respectively) were recruited from a population screening program. Antibody levels were determined by ELISA. Presence of carotid atherosclerosis was determined by B-mode ultrasonography, and 29 individuals had atherosclerotic plaques. BHT men had significantly higher aEC and abeta2GP1 levels of IgG class than NT control subjects (P=0.029 and P=0.0001, respectively). aEC levels of IgM class were higher in BHT (P=0.012), but not abeta2GP1 levels. There was no correlation between aCL levels and BHT. Individuals with atherosclerotic plaques had significantly higher aEC levels of both IgG (P=0.042) and IgM subclasses (P=0.018) than those without plaques, but no difference was found in aCL and abeta2GP1 levels. Endothelin and aECs of IgM class were significantly associated.

CONCLUSIONS

We demonstrate the first evidence of a significant elevation of aEC and abeta2GP1 levels in borderline hypertension. These findings provide a new link between hypertension and atherosclerosis and indicate that humoral immune reactions to the endothelium may play an important role in both conditions.

Effects of anti-endothelial cell antibody in pre-eclampsia on endothelin-1 release from cultured endothelial cells

In order to investigate the pathophysiological significance of anti-endothelial cell antibody (AECA) in pre-eclampsia, the effects of AECA on endothelin-1 (ET-1) and prostaglandin I2 (PGI2) release from cultured human umbilical vein endothelial cells (HUVEC) was evaluated. Serum samples were taken from 85 pre-eclamptic and 20 normal pregnant women. Anti-endothelial cell antibody was measured by ELISA using HUVEC. The release of ET-1 and 6-keto PGF1-alpha, a stable metabolite of PGI2, from HUVEC were evaluated after incubation with IgG-AECA-positive sera and IgG isolated from AECA-positive sera. The incidence of IgG- and IgM-AECA was 24.7 and 8.2%, respectively. The release of ET-1, in the medium containing IgG-AECA-positive sera was significantly greater than in the medium containing IgG-AECA-negative sera. There was significant correlation between the levels of IgG-AECA and the release of ET-1 from endothelial cells. The ET-1 release by IgG isolated from AECA-positive sera was greater than that from AECA-negative sera. However, the release of 6-keto PGF1-alpha by AECA-positive sera was not significantly different from that of AECA-negative sera. It is concluded that IgG-AECA in pre-eclampsia increases ET-1 release from endothelial cells and that AECA may affect local vascular function in this disorder.