Impaired brachial artery endothelium dependent flow mediated dilation in systemic lupus erythematosus: preliminary observations

Non-Traditional Pro-Inflammatory and Pro-Atherosclerotic Risk Factors Related to Systemic Lupus Erythematosus

Cardiovascular diseases (CVD) are one of the leading causes of high mortality in patients with systemic lupus erythematosus (SLE). The Framingham risk score and other traditional risk factors do not fully reflect the CVD risk in SLE patients. Therefore, in order to stratify these high-risk patients, additional biomarkers for subclinical CVD are needed. The mechanisms of atherogenesis in SLE are still being investigated. During the past decades, many reports recognized that inflammation plays a crucial role in the development of atherosclerosis. The aim of this report is to present novel proinflammatory and pro-atherosclerotic risk factors that are closely related to SLE inflammation and which determine an increased risk for the occurrence of early cardiovascular events.

Endothelial function and endothelial progenitor cells in systemic lupus erythematosus

The observations that traditional cardiovascular disease (CVD) risk factors fail to fully account for the excessive cardiovascular mortality in patients with systemic lupus erythematosus (SLE) compared with the general population have prompted in-depth investigations of non-traditional, SLE-related risk factors that contribute to cardiovascular complications in patients with SLE. Of the various perturbations of vascular physiology, endothelial dysfunction, which is believed to occur in the earliest step of atherosclerosis, has been extensively investigated for its contribution to CVD risk in SLE. Endothelial progenitor cells (EPCs), which play a crucial part in vascular repair, neovascularization and maintenance of endothelial function, are quantitatively and functionally reduced in patients with SLE. Yet, the lack of a unified definition of EPCs, standardization of the quantity and functional assessment of EPCs as well as endothelial function measurement pose challenges to the translation of endothelial function measurements and EPC levels into prognostic markers for CVD in patients with SLE. This Review discusses factors that contribute to CVD in SLE, with particular focus on how endothelial function and EPCs are evaluated currently, and how EPCs are quantitatively and functionally altered in patients with SLE. Potential strategies for the use of endothelial function measurements and EPC quantification as prognostic markers of CVD in patients with SLE, and the limitations of their prognostication potential, are also discussed.

Botulinum toxin in the management of primary and secondary Raynaud's phenomenon

Raynaud's phenomenon (RP) is common in rheumatic diseases. In the setting of systemic sclerosis (SSc), it can be complicated by digital ischemia that includes ulceration and gangrene. Systemic adverse effects may preclude the use of oral or topical vasodilators for the treatment of RP and its complications. In this article, we review effectiveness/efficacy of botulinum toxin injection in primary and secondary RP. We discuss botulinum toxin formulations, dosage, sites of administration, and adverse effects. The evidence for botulinum toxin in the treatment of primary and SSc-associated RP is promising. Consistency across patient populations, treatment options (botulinum serotype, dose, and injection site), and outcome measures will be essential for further research.

Endothelial dysfunction and arterial stiffness in patients with systemic lupus erythematosus: A systematic review and meta-analysis

BACKGROUND AND AIMS

Non-invasive surrogates of cardiovascular (CV) disease such as endothelial dysfunction (ED) and peripheral arterial stiffness (AS) have been evaluated in systemic lupus erythematosus (SLE) patients. The aim of this study was to systematically review and meta-analyze reports of cardiovascular disease (CVD) in SLE patients, as measured by ED and AS.

METHODS

Studies analyzing the relationship of SLE with ED (flow-mediated dilatation [FMD], nitroglycerin-mediated dilatation [NMD] and peripheral arterial tonometry [PAT]) and AS (augmentation index [AIx], pulse wave velocity [PWV]) were systematically searched for in PubMed, Cochrane library, EMBASE, VHL, SciELO and Web of Science databases. Inclusion criteria included peer-review and English language. Mean differences (MD) and 95% confidence intervals (CIs) were estimated using the random effect model. The study was registered with PROSPERO, number CRD42019121068.

RESULTS

The meta-analysis included 49 studies. FMD data from 18 studies including 943 SLE subjects (mean age = 38.71 [95%CI 36.21, 41.21] years) and 644 unaffected controls (mean age = 38.63 [95%CI 36.11, 41.15] years) were included. When compared with unaffected controls, FMD in SLE subjects was decreased by 4.3% (95%CI: -6.13%, -2.47%): p < 0.001). However, NMD did not significantly differ between SLE patients and controls (MD = - 2.68%; 95% CI -6.00, 0.62; p = 0.11). A significantly increased AS between SLE patients and controls according to overall PWV (MD = 1.12 m/s; 95% CI 0.72-1.52; p < 0.001) was observed, but not for the brachial-ankle PWV. AIx was also increased in SLE patients compared with healthy controls (MD = 4.55%; 95% CI 1.48-7.63; p = 0.003).

CONCLUSIONS

Overall, SLE patients showed impaired FMD, an independent predictor of CV events. There was a higher degree of AS in SLE patients compared with controls. ED and AS in SLE should be considered when planning preventive strategies and therapies.

Systemic Lupus Erythematosus and Endothelial Dysfunction: A Close Relationship

BACKGROUND

Accelerated atherosclerosis, responsible for premature cardiovascular disease, has been estimated to develop or progress in 10% of systemic lupus erythematosus (SLE) patients each year and to be 6-fold more frequent in SLE compared with the general population. The mechanisms underlying accelerated atherosclerosis in SLE are complex and involve classical and "non-classical" cardiovascular risk factors. Subclinical and disseminated atherosclerosis is associated with endothelial dysfunction and arterial stiffness.

OBJECTIVE

The aim of this review is to analyze the association between SLE and endothelial dysfunction.

RESULTS AND CONCLUSION

Different mechanisms have been proposed to explain the prevalence of endothelial dysfunction in SLE, which are briefly reported in this review: impaired clearance of apoptotic cells, oxidative stress markers, B cell activation with different circulating autoantibodies, different subtypes of T lymphocytes, cytokine cascade. Several studies and meta-analyses show a significant trend towards a prevalence of subclinical accelerated atherosclerosis in patients with SLE compared with healthy controls, since childhood. Based on general considerations, we suggest a multidisciplinary management to assess endothelial dysfunction at the diagnosis of the disease and to periodically search for and treat the traditional cardiovascular risk factors. Prospective studies are needed to confirm the benefits of this management.

Human recombinant relaxin-2 does not attenuate hypertension or renal injury but exacerbates vascular dysfunction in a female mouse model of SLE

Systemic lupus erythematosus (SLE) is an autoimmune disease that disproportionately affects women of reproductive age and increases their risk for developing hypertension, vascular, and renal disease. Relaxin has potential beneficial therapeutic effects in cardiovascular disease through direct actions on the vasculature. The potential therapeutic benefit of relaxin on SLE-associated cardiovascular and renal risk factors like hypertension has not previously been tested. We hypothesized that relaxin would attenuate hypertension, renal injury, and vascular dysfunction in an established female mouse model of SLE (NZBWF1 mice). Serelaxin (human recombinant relaxin-2, 0.5 mg·kg^-1·day^-1) or vehicle was administered via osmotic mini-pump for 4 wk in female control (NZW) or SLE mice between 28 and 31 wk of age. Serelaxin treatment increased uterine weights in both groups, suggesting that the Serelaxin was bioactive. Mean arterial pressure, measured by carotid artery catheter, was significantly increased in vehicle-treated SLE mice compared with vehicle-treated controls, but was not changed by Serelaxin treatment. Albumin excretion rate, measured by ELISA, was similar between vehicle- and Serelaxin-treated SLE mice and between vehicle- and Serelaxin-treated control mice. Wire myography was performed using isolated carotid arteries to assess endothelial-independent and -dependent vasodilation, and data confirm that SLE mice have impaired endothelium-independent and -dependent relaxation compared with control mice. Serelaxin treatment did not affect endothelium-independent vasodilation, but exacerbated the endothelium-dependent dysfunction. These data suggest that, contrary to our hypothesis, Serelaxin infusion does not attenuate hypertension, renal injury, or vascular dysfunction in SLE, but worsens underlying vascular endothelial dysfunction in this experimental model of SLE. These data do not support the use of human recombinant relaxin-2 as an antihypertensive in the SLE patient population. NEW & NOTEWORTHY Relaxin is a peptide hormone commonly known for its role in pregnancy and for its use in recent clinical trials for the treatment of heart failure. Evidence suggests that relaxin has immunomodulatory effects; however, the potential therapeutic impact of relaxin in chronic immune mediated disease is unclear. This study tests whether recombinant human relaxin (Serelaxin) attenuates the progression of autoimmunity, and the associated cardiovascular consequences, in an experimental model of systemic lupus erythematosus.

Systemic Lupus Erythematosus and Increased Prevalence of Atherosclerotic Cardiovascular Disease in Hospitalized Patients

OBJECTIVE

To assess the prevalence of atherosclerotic cardiovascular disease (ASCVD) and its individual phenotypes of coronary artery disease (CAD), peripheral artery disease (PAD), and cerebrovascular disease by age and sex in a large US cohort of hospitalized patients with systemic lupus erythematosus (SLE).

METHODS

A nested case-control study of adults with and without SLE was conducted from the January 1, 2008, through December 31, 2014, National Inpatient Sample. Hospitalized patients with SLE were matched (1:3) by age, sex, race, and calendar year to hospitalized patients without SLE. The prevalences of CAD, PAD, and cerebrovascular disease were evaluated, and associations with SLE were determined after adjustment for common cardiovascular risk factors.

RESULTS

Among the 252,676 patients with SLE and 758,034 matched patients without SLE, the mean age was 51 years, 89% were women, and 49% were white. Patients with SLE had a higher prevalence of ASCVD vs those without SLE (25.6% vs 19.2%; OR, 1.45; 95% CI, 1.44-1.47; P<.001). After multivariable adjustment, SLE was associated with a greater odds of ASCVD (adjusted odds ratio [aOR], 1.46; 95% CI, 1.41-1.51). The association between SLE and ASCVD was observed in women and men and was attenuated with increasing age. Also, SLE was associated with increased odds of CAD (aOR, 1.42; 95% CI, 1.40-1.44), PAD (aOR, 1.25; 95% CI, 1.22-1.28), and cerebrovascular disease (aOR, 1.68; 95% CI, 1.65-1.71).

CONCLUSION

In hospitalized US patients, SLE was associated with increased ASCVD prevalence, which was observed in both sexes and was greatest in younger patients.

Atherosclerotic Vascular Events in Systemic Lupus Erythematosus: An Evolving Story

OBJECTIVE

Atherosclerotic vascular events (AVE) are a major cause of mortality and morbidity in systemic lupus erythematosus (SLE). We aimed to determine the effect of early recognition and therapy for both classic risk factors for AVE and for SLE, on the burden of AVE in SLE in recent decades.

METHODS

Inception patients who entered the University of Toronto Lupus Clinic between 1975 and 1987 followed to 1992 (Cohort 1), and between 1999 and 2011 followed to 2016 (Cohort 2) were studied. AVE attributed to atherosclerosis and occurring during the 17 years were identified. SLE disease activity and therapy as well as hypertension, hypercholesterolemia, hyperglycemia, and smoking were assessed. Analysis included descriptive statistics on baseline characteristics, traditional risk factors over the followup, outcome rates by each 100 person-years (PY), Kaplan-Meier cumulative AVE curves, as well as competing risk Cox models adjusted by inverse probability weights.

RESULTS

Of the 234 patients in Cohort 1, 26 patients (11%) had an AVE compared with 10 of 262 patients (3.8%) in Cohort 2. The rate per 100 PY of followup was 1.8 in Cohort 1 and 0.44 in Cohort 2 (p < 0.0001). Better control of all risk factors and disease activity was achieved in Cohort 2. There was a reduction of 60% in the risk for AVE in Cohort 2.

CONCLUSION

The incidence of AVE in SLE in the modern era has declined in large part owing to more effective management of classic coronary artery risk factors and of SLE.

Endothelial dysfunction in systemic lupus erythematosus - a case-control study and an updated meta-analysis and meta-regression

Endothelium-dependent flow-mediated dilation (ED-FMD), a biophysical marker of endothelial dysfunction, is apparently impaired in patients with systemic lupus erythematosus (SLE) but such observation is inconsistent. Here, we assessed and compared the brachial artery ED-FMD (baED-FMD) using ultrasonography between SLE patients without cardiovascular disease and healthy controls (HC) matched for age, gender and body mass index. We then performed a comprehensive meta-analysis of case-control studies which compared baED-FMD between SLE patients and HC by determining the effect size of baED-FMD as standardized mean difference (SMD). Factors associated with the effect size were explored by mixed-model meta-regression. Seventy one SLE patients and 71 HC were studied. SLE patients had lower baED-FMD than HC (3.72 ± 2.8% vs 4.63 ± 3.1%, p = 0.032). Meta-analysis of 25 case-control studies involving 1,313 SLE patients and 1,012 HC with the random effects model revealed lower baED-FMD in SLE patients compared to HC (SMD −1.077, p < 0.001). The presence of diabetes mellitus (p = 0.04747), higher diastolic blood pressure (p = 0.044), renal involvement (p = 0.027) and aspirin use (p = 0.001) were associated with more discrepant baED-FMD between both groups. In conclusion, SLE patients naïve of cardiovascular disease have impaired endothelial function. Diabetes mellitus, renal disease and diastolic hypertension are major contributors of endothelial dysfunction in SLE patients.

Activated Platelets Induce Endothelial Cell Activation via an Interleukin-1β Pathway in Systemic Lupus Erythematosus

OBJECTIVE

Systemic lupus erythematosus (SLE) is associated with the premature development of cardiovascular disease. The platelet-endothelium interaction is important in the pathogenesis of cardiovascular disease. In this study, we investigated the platelet phenotype from patients with SLE and matched controls, and their effect on endothelial cells.

APPROACH AND RESULTS

Platelet aggregability was measured in 54 SLE subjects off antiplatelet therapy (mean age 40.1±12.8 years; 82% female; 37% white) with age- and sex-matched controls. Platelets were coincubated with human umbilical vein endothelial cells (HUVECs) and changes to gene expression assessed by an RNA array and quantitative reverse transcription polymerase chain reaction. SLE disease activity index ranged from 0 to 22 (mean 5.1±3.9). Compared with controls, patients with SLE had significantly increased monocyte and leukocyte-platelet aggregation and platelet aggregation in response to submaximal agonist stimulation. An agnostic microarray of HUVECs cocultured with SLE platelets found a platelet-mediated effect on endothelial gene pathways involved in cell activation. Sera from SLE versus control subjects significantly increased (1) activation of control platelets; (2) platelet adhesion to HUVECs; (3) platelet-induced HUVEC gene expression of interleukin-8, and intercellular adhesion molecule 1; and (4) proinflammatory gene expression in HUVECs, mediated by interleukin-1β-dependent pathway. Incubation of SLE-activated platelets with an interleukin-1β-neutralizing antibody or HUVECs pretreated with interleukin-1 receptor antibodies attenuated the platelet-mediated activation of endothelial cells.

CONCLUSIONS

Platelet activity measurements and subsequent interleukin-1β-dependent activation of the endothelium are increased in subjects with SLE. Platelet-endothelial interactions may play a role in the pathogenesis of cardiovascular disease in patients with SLE.

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.

Chronic hydroxychloroquine improves endothelial dysfunction and protects kidney in a mouse model of systemic lupus erythematosus

Hydroxychloroquine has been shown to be efficacious in the treatment of autoimmune diseases, including systemic lupus erythematosus. Hydroxychloroquine-treated lupus patients showed a lower incidence of thromboembolic disease. Endothelial dysfunction, the earliest indicator of the development of cardiovascular disease, is present in lupus. Whether hydroxychloroquine improves endothelial function in lupus is not clear. The aim of this study was to analyze the effects of hydroxychloroquine on hypertension, endothelial dysfunction, and renal injury in a female mouse model of lupus. NZBWF1 (lupus) and NZW/LacJ (control) mice were treated with hydroxychloroquine 10 mg/kg per day by oral gavage, or with tempol and apocynin in the drinking water, for 5 weeks. Hydroxychloroquine treatment did not alter lupus disease activity (assessed by plasma double-stranded DNA autoantibodies) but prevented hypertension, cardiac and renal hypertrophy, proteinuria, and renal injury in lupus mice. Aortae from lupus mice showed reduced endothelium-dependent vasodilator responses to acetylcholine and enhanced contraction to phenylephrine, which were normalized by hydroxychloroquine or antioxidant treatments. No differences among all experimental groups were found in both the relaxant responses to acetylcholine and the contractile responses to phenylephrine in rings incubated with the nitric oxide synthase inhibitor N(G)-nitro-l-arginine methyl ester. Vascular reactive oxygen species content and mRNA levels of nicotinamide adenine dinucleotide phosphate oxidase subunits NOX-1 and p47(phox) were increased in lupus mice and reduced by hydroxychloroquine or antioxidants. Chronic hydroxychloroquine treatment reduced hypertension, endothelial dysfunction, and organ damage in severe lupus mice, despite the persistent elevation of anti-double-stranded DNA, suggesting the involvement of new additional mechanisms to improve cardiovascular complications.

Imbalance between endothelial damage and repair: a gateway to cardiovascular disease in systemic lupus erythematosus

Atherosclerosis is accelerated in patients with systemic lupus erythematosus (SLE) and it leads to excessive cardiovascular complications in these patients. Despite the improved awareness of cardiovascular disease and advent of clinical diagnostics, the process of atherogenesis in most patients remains clinically silent until symptoms and signs of cardiovascular complications develop. As evidence has demonstrated that vascular damage is already occurring before clinically overt cardiovascular disease develops in lupus patients, intervention at the preclinical stage of atherogenesis would be plausible. Indeed, endothelial dysfunction, one of the earliest steps of atherogenesis, has been demonstrated to occur in lupus patients even when they are naïve for cardiovascular disease. Currently known “endothelium-toxic” factors including type 1 interferon, proinflammatory cytokines, inflammatory cells, immune complexes, costimulatory molecules, neutrophils extracellular traps, lupus-related autoantibodies, oxidative stress, and dyslipidemia, coupled with the aberrant functions of the endothelial progenitor cells (EPC) which are crucial to vascular repair, likely tip the balance towards endothelial dysfunction and propensity to develop cardiovascular disease in lupus patients. In this review, altered physiology of the endothelium, factors leading to perturbed vascular repair contributed by lupus EPC and the impact of proatherogenic factors on the endothelium which potentially lead to atherosclerosis in lupus patients will be discussed.

Omega-3 in SLE: a double-blind, placebo-controlled randomized clinical trial of endothelial dysfunction and disease activity in systemic lupus erythematosus

Accelerated atherosclerosis remains a major cause of death in late systemic lupus erythematosus (SLE). Omega-3 has been reported to have benefit for endothelial dysfunction, one of the earliest stages of atherosclerosis, and to reduce disease activity in SLE. We performed a randomized, double-blind placebo-controlled trial to examine the effect of Omega-3 on endothelial function, disease activity, inflammatory markers and lipids in SLE. SLE patients (n = 85, mean age 47, 55% Caucasian, 38% African-American, 94% female) were randomly assigned to 3 g of Omega-3 (Lovaza, GSK) versus placebo for 12 weeks. Endothelial function was measured at baseline and at 12 weeks using flow-mediated dilation, calculated using high-resolution B-mode ultrasound of the brachial artery diameter in response to vasoactive stimuli (hyperemia). Disease activity was measured using the physician global assessment and SELENA-SLEDAI score. Inflammatory markers (sICAM-1, sVCAM-1, IL-6) and fasting lipid profile were done at baseline and 12-week follow-up. There was no difference between the treatment groups with respect to changes in flow-mediated dilation parameters or disease activity. An average increase in LDL cholesterol of 3.11 mg/dL (±21.99) was found with Omega-3 versus a decrease of 1.87 mg/dL (±18.29) with placebo (p = 0.0266). In this trial, Omega-3 did not improve endothelial function, disease activity, nor reduce inflammatory markers in SLE. Longer trials might be required if there are delayed clinical effects. There was evidence that Omega-3 may increase LDL cholesterol, but not the LDL/HDL ratio.

Circulating endothelial cells as a marker of vascular dysfunction in patients with systemic lupus erythematosus by real-time polymerase chain reaction

CONTEXT

Systemic lupus erythematosus (SLE) is associated with an increased risk of atherosclerosis; endothelial dysfunction represents the first step in its pathogenesis.

OBJECTIVE

To assess endothelial dysfunction in SLE by circulating endothelial cells (CECs) and to characterize SLE-specific factors that contribute to its appearance.

DESIGN

Case-control study was conducted on 60 subjects, divided into 2 groups: group A (30 patients with SLE) and group B (30 healthy sex- and age-matched controls). Total cholesterol, triglycerides, antinuclear antibodies, anti-double-stranded DNA antibodies, and C3 were determined in all patients. Systemic lupus erythematosus activity was assessed using the SLE Disease Activity Index. Endothelial function was assessed by means of flow-mediated dilation of the brachial artery using B-mode ultrasonography and relative quantification of CD 146 mRNA by real-time polymerase chain reaction.

RESULTS

The group of SLE patients was formed of 20 females and 10 males, with a mean age of 31.16 ± 9.69 years. The values of SLE-specific tests and SLE Disease Activity Index were represented by anti-double-stranded DNA antibodies 160 ± 40.5, C3 68.91 ± 11.91 mg/dL, total cholesterol 188.66 ± 49.63 mg/dL, triglycerides 143.41 ± 46.26 mg/dL, and SLE Disease Activity Index 12.66 ± 3.70. Values for flow-mediated dilation were 8.85% ± 2.02% (group A) and 20.33% ± 6.19% (group B), P < .001, and CECs were 300 ± 40.5 μL⁻¹ blood (group A) and 10 ± 2.5 μL⁻¹ blood (group B). The statistical analysis showed a strong inverse correlation between CECs and SLE Disease Activity Index, a strong correlation between CECs and C3, a strong correlation between CECs and anti-double-stranded DNA antibodies, and a moderate inverse correlation between CECs and total cholesterol.

CONCLUSION

Endothelial dysfunction is present in SLE patients even in the absence of traditional cardiovascular risk factors due to disease activity.

Imaging assessment of cardiovascular disease in systemic lupus erythematosus

Systemic lupus erythematosus is a multisystem, autoimmune disease known to be one of the strongest risk factors for atherosclerosis. Patients with SLE have an excess cardiovascular risk compared with the general population, leading to increased cardiovascular morbidity and mortality. Although the precise explanation for this is yet to be established, it seems to be associated with the presence of an accelerated atherosclerotic process, arising from the combination of traditional and lupus-specific risk factors. Moreover, cardiovascular-disease associated mortality in patients with SLE has not improved over time. One of the main reasons for this is the poor performance of standard risk stratification tools on assessing the cardiovascular risk of patients with SLE. Therefore, establishing alternative ways to identify patients at increased risk efficiently is essential. With recent developments in several imaging techniques, the ultimate goal of cardiovascular assessment will shift from assessing symptomatic patients to diagnosing early cardiovascular disease in asymptomatic patients which will hopefully help us to prevent its progression. This review will focus on the current status of the imaging tools available to assess cardiac and vascular function in patients with SLE.

High dietary fat promotes visceral obesity and impaired endothelial function in female mice with systemic lupus erythematosus

BACKGROUND

Inflammation contributes to metabolic and cardiovascular disease. Systemic lupus erythematosus (SLE) is a chronic autoimmune inflammatory disorder that predominantly affects young women. Cardiovascular disease is a major cause of mortality in patients with SLE. We recently reported that a model of SLE (female New Zealand Black/White F1 [NZBWF1] mice) developed characteristics of the metabolic syndrome.

OBJECTIVES

In the present study, we tested the hypothesis that high dietary fat with SLE accelerated development of cardiovascular risk factors such as central obesity and vascular dysfunction.

METHODS

Twenty-four-week-old female SLE mice (NZBWF1) were fed either a control diet (SLE, 10% kcal) or a high-fat (HF) diet (SLE + HF, 45% kcal) for a total of 14 weeks.

RESULTS

Body weight was similar between SLE (42 [1] g, n = 5) and SLE + HF (45 [2] g, n = 6) mice, and weight gain was not different in the SLE + HF mice (+18.0 [3.0]%) compared with controls (+15.8 [3.6]%); food intake was not different (SLE, 2.2 [0.3] vs SLE + HF, 2.1 [0.2] g/24 hours). At the end of the experiment, 57% of the SLE + HF mice exhibited signs of albuminuria (>100 mg/dL) compared with only 20% of the control SLE mice. Endothelial-dependent relaxation in isolated carotid arteries was impaired in the SLE + HF group compared with that in the SLE group. Ovarian fat increased in SLE + HF mice (6.6 [0.5] g) compared with that in the control SLE mice (5.4 [0.1] g, P < 0.05), and liver weight decreased in SLE + HF (1.6 [0.1] g) mice compared with that in control mice (1.9 [0.1] g, P < 0.03).

CONCLUSIONS

These data suggest that dietary fat accelerates renal injury and peripheral vascular dysfunction and promotes visceral obesity in a disease model with chronic inflammation.

Blood pressure and renal hemodynamic responses to acute angiotensin II infusion are enhanced in a female mouse model of systemic lupus erythematosus

Inflammation and immune system dysfunction contributes to the development of cardiovascular and renal disease. Systemic lupus erythematosus (SLE) is a chronic autoimmune inflammatory disorder that carries a high risk for both renal and cardiovascular disease. While hemodynamic changes that may contribute to increased cardiovascular risk have been reported in humans and animal models of SLE, renal hemodynamics have not been widely studied. The renin-angiotensin system (RAS) plays a central role in renal hemodynamic control, and although RAS blockade is a common therapeutic strategy, the role of RAS in hemodynamic function during SLE is not clear. This study tested whether mean arterial pressure (MAP) and renal hemodynamic responses to acute infusions of ANG II in anesthetized animals were enhanced in an established female mouse model of SLE (NZBWF1). Baseline MAP was not different between anesthetized SLE and control (NZWLacJ) mice, while renal blood flow (RBF) was significantly lower in mice with SLE. SLE mice exhibited an enhanced pressor response and greater reduction in RBF after ANG II infusion. An acute infusion of the ANG II receptor blocker losartan increased RBF in control mice but not in mice with SLE. Renin and ANG II type 1 receptor expression was significantly lower, and ANG II type 2 receptor expression was increased in the renal cortex from SLE mice compared with controls. These data suggest that there are fewer ANG II receptors in the kidneys from mice with SLE but that the existing receptors exhibit an enhanced sensitivity to ANG II.

Posterior reversible encephalopathy syndrome in systemic lupus erythematosus

OBJECTIVE

To study the clinical profile of posterior reversible encephalopathy syndrome (PRES) in patients with systemic lupus erythematosus (SLE) and analyze the risk factors and outcomes associated with it.

METHODS

We identified patients with SLE and PRES from January 2006 to October 2010. Data were collected on demographic details, lupus characteristics, PRES-related features, laboratory abnormalities, treatment details, and outcomes.

RESULTS

We studied 13 patients (all female) ages 14-37 years (median 23 yrs; 4 were aged < 18 yrs with juvenile SLE). Duration of lupus ranged from 1.5 to 36 months (median 6 mo). Six patients had PRES as a part of their initial presentation of lupus. All had active lupus and hypertension; 9 had nephritis. Four patients were on treatment with cyclophosphamide therapy when they developed PRES. Antihypertensives and antiepileptics were the mainstay of treatment along with supportive care. Immunosuppressive therapy was guided by lupus-related major organ manifestations. Two patients had focal neurological deficits; one had persistent hemiparesis at followup. One patient died.

CONCLUSION

PRES occurs in young lupus patients and in the early part of the disease. Focal deficits are not uncommon. It can be the presenting manifestation of lupus. Management is predominantly symptomatic. Immunosuppression is directed by other major organ manifestations. Early diagnosis and appropriate management is productive.

Endothelium-dependent but not endothelium-independent flow-mediated dilation is significantly reduced in patients with systemic lupus erythematosus without vascular events: a metaanalysis and metaregression

OBJECTIVE

To assess whether endothelium-dependent and endothelium-independent flow-mediated dilation (FMD) are impaired in patients with systemic lupus erythematosus (SLE) with no history of vascular event; and to determine factors moderating impaired FMD in SLE.

METHODS

Electronic databases were searched for case-control studies that compared endothelium-dependent and/or endothelium-independent FMD at the brachial artery between SLE patients who were naive for vascular events and matched healthy controls. Effect size as standardized mean difference (SMD) and 95% confidence intervals of FMD between SLE patients and controls was pooled using the inverse variance method. Mixed-model metaregression was performed to identify potential demographic and clinical factors associated with the effect size.

RESULTS

Thirteen relevant studies involving 580 patients and 381 matched healthy controls were included. Endothelium-dependent FMD was significantly lower in SLE patients than in controls (SMD -0.832, 95% CI -1.172 to -0.492, p < 0.001). Endothelium-independent FMD, however, did not differ between the 2 groups (SMD -0.179, 95% CI -0.433 to 0.075, p = 0.167). Metaregression revealed that increasing age (r = 0.047, p = 0.037) and duration of SLE (r = 0.008, p = 0.024) at the time of FMD measurement significantly narrowed the difference of endothelium-dependent FMD between patients and controls; whereas sex, smoking, menopause, diabetes mellitus, body mass index, blood pressure, fasting lipid profile, C-reactive protein, and prednisolone use did not.

CONCLUSION

Endothelium-dependent, but not endothelium-independent FMD is significantly impaired in lupus patients who are naive for vascular events. Increasing age and longer disease duration may limit the potential of endothelial reactivity as an indicator of early atherosclerosis in SLE.

Arterial wall dysfunction in systemic lupus erythematosus

Carotid-radial pulse wave velocity (PWV), aortic augmentation index (AIx) and endothelium-dependent flow-mediated dilatation (FMD) have been repeatedly showed to be related to premature atherosclerosis and cardiovascular diseases in different settings of population. The increased arterial stiffness and endothelium dysfunction may add to premature aging of the arteries in systemic lupus erythematosus (SLE) patients. Still data about arterial stiffness and endothelium function in inflammatory rheumatic diseases are not well described. The aim of this study was to determine the PWV, its derivate marker AIx and FMD and factors possibly influencing them in young SLE women without significant organ damage. Thirty women between 23 and 55 years with an established SLE diagnosis and 66 healthy women were consequently included in the study and both groups were comparable according to age, body mass index (BMI), serum lipid profile and creatinine. PWV was determined by measuring carotid-radial pulse wave transit time with the help of applanation tonometry and AIx, its derivate marker, was calculated as a difference between two waveform peaks expressed as a percentage of the pulse pressure. The FMD was performed by obtaining the repeated scans of the brachial artery at rest and during reactive hyperemia. In SLE women, PWV and AIx were significantly higher and FMD was not different from controls. In linear multiple stepwise regression analysis if patients and controls were both considered, PWV was weakly related to mean blood pressure (MBP), AIx was mostly predicted by age and MBP and FMD was predicted by the diameter of blood vessel, BMI, high density lipoproteins. If the sole SLE setting was analyzed, PWV was not related to any of the pending parameters, AIx turned out to be related to organ damage measured by Systemic Lupus International collaborative Clinics (SLICC) index and age, and FMD obtained strong and significant relation with vessel diameter, and BMI, and disease duration. Regardless of the small number of study group patients, we can state that controlling for MBP and taking measures towards organ damage prevention can partially slow down the process of early atherosclerosis in SLE patients.

A controlled comparison of brachial artery flow mediated dilation (FMD) and digital pulse amplitude tonometry (PAT) in the assessment of endothelial function in systemic lupus erythematosus

The utility of flow mediated dilation (FMD) a measure of endothelial function is limited by operator dependence. Pulse amplitude tonometry (PAT) is a novel, less operator-dependent technique to assess endothelial function. This study compares PAT to FMD in SLE and controls. Thirty women with SLE and 31 controls were enrolled. Medications, cardiovascular disease and risk factors, SLE activity (SLAM-R) and damage (SLICC-DI) were recorded. FMD and PAT were performed simultaneously. Endothelium-independent function was assessed with nitroglycerin. Average age was 48.3 +/- 10.1 years, SLE duration 16.2 years, SLAM-R 8.3 and SLICC-DI 1.0. Framingham Risk Scores were < or =2% in most subjects. There were no differences between SLE cases and controls in FMD, PAT or response to nitroglycerin. This study found no association between FMD and PAT in SLE or controls. In the 17 SLE cases with a history of Raynaud's, correlation between FMD and PAT was 0.50 (P = 0.04). There was no difference in endothelial function assessed by FMD or PAT in SLE cases versus controls. FMD did not correlate with PAT except in SLE cases with a history of Raynaud's. Correlation between FMD and PAT may be stronger in populations with greater variation in endothelial function and more cardiovascular risk factors.

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.

Human endothelial impairment in sepsis

The onset of sepsis is often non-specific, and its severity is cryptic. The pathophysiological mechanism of sepsis development involves vascular alteration and, in particular, the impairment of endothelial function. Aim of the study was to evaluate the potential implications of brachial endothelial function assessment in patients affected by Gram-negative sepsis. Forty-five young patients (mean age 41+/-8 years, 18 males) with Gram-negative sepsis were included; at admission time (T0) signs and symptoms, clinical and laboratory data were collected; the Sequential Organ Failure Assessment (SOFA) score was assessed at the time of the access along with the evaluation of brachial flow-mediated vasodilation (FMV). The same parameters were repeated 3 days after hospitalization (T1). Study population at the hospitalization time was divided on the basis of a brachial FMV cut off: at the T0 subjects with FMV<7.5% had lower white blood cell count in comparison to subjects with FMV> or =7.5% (6693+/-1559 mmc versus 14,270+/-2399 mmc); subjects with FMV<7.5% had a significant increase in SOFA score at T1 (4+/-1 versus 6+/-1) and a significant reduction of brachial FMV at T1 (4.8+/-2.7% versus 3.7+/-2.6%) (all p<0.05). FMV at the admission time was predicted by white blood cells (beta=0.65; p<0.001) and brachial diameter (beta=-0.292; p<0.05); Delta changes in FMV were predicted by changes in SOFA score (beta=-0.41; p<0.05). In conclusion, the present study indicates that in the initial phase of sepsis an impairment of brachial FMV anticipated the progression in organ failures; these considerations support the potential utility of brachial FMV in clinical practice in acute pathologies as septic state.

Haematopoietic and endothelial progenitor cells are deficient in quiescent systemic lupus erythematosus

BACKGROUND

Systemic lupus erythematosus (SLE) is associated with a high prevalence of cardiovascular disease. Circulating endothelial progenitor cells (EPCs) contribute to vascular regeneration and repair, thereby protecting against atherosclerotic disease. EPCs are derived from CD34+ haematopoietic stem cells (HSCs), which have an increased propensity for apoptosis in the bone marrow of patients with SLE.

AIM

To determine whether circulating HSCs and EPCs are reduced in SLE, contributing to an increased cardiovascular risk.

METHODS

Progenitor cells were sampled from 15 female patients with SLE in prolonged clinical remission from their disease and 15 matched healthy controls. HSC and CD34+KDR+ EPCs were quantified by flow cytometry. Annexin V staining was used to identify apoptotic cells.

RESULTS

Patients with SLE had reduced levels of circulating CD34+ HSCs and CD34+KDR+ EPCs, associated with increased HSC apoptosis. Compared with controls, the fraction of HSCs that could be identified as EPCs was higher in patients with SLE, consistent with a primary defect of HSCs. EPC outgrowth from mononuclear cells, which depends mainly on CD34- cells, was unaffected.

CONCLUSIONS

Patients with SLE have lower levels of circulating HSCs and EPCs, even during clinical remission. The data suggest that increased HSC apoptosis is the underlying cause for this depletion. These observations indicate that progenitor cell-mediated endogenous vascular repair is impaired in SLE, which may contribute to the accelerated development of atherosclerosis.

Endothelial function in systemic lupus erythematosus: relationship to disease activity, cardiovascular risk factors, corticosteroid therapy, and coronary calcification

Objectives

Endothelial dysfunction is frequently present in patients with systemic lupus erythematosus and may increase their risk of premature coronary artery disease. In this pilot study we have characterized the relationship between endothelial function, measures of disease activity, and cardiovascular risk factors in patients with lupus.

Methods

Clinical characteristics and cardiovascular risk factors were evaluated in 20 patients with lupus. Flow-mediated dilation of the brachial artery was measured using high resolution ultrasound and the presence or absence of coronary calcification determined by electronbeam computed tomography. The relationship between these variables and flow-mediated dilation was determined using Spearman correlation coefficients (RHO) and Mann Whitney-Wilcoxon tests.

Results

Twenty patients (17 female) median age (interquartile range) 42.5 (32.0–47.5) years were studied. The median flow-mediated vasodilation was 3.6% (1.7%–7.7%). In patients with coronary calcification (n = 6), flow-mediated dilation was 2.1% (−0.42%–3.6%) compared with 4.0% (3.5%–8.3%) in those without (p = 0.12). There was no significant relationship between flow-mediated dilation and markers of disease activity, duration of disease, and cardiovascular risk factors. Lower flow-mediated dilation was associated with duration of corticosteroid therapy (RHO = −0.44, p = 0.05).

Conclusions

In these preliminary results, endothelial dysfunction is associated with longterm exposure to corticosteroids.

Subclinical impairment of arterial mechanics in systemic lupus erythematosus identified by arterial waveform analysis

Structural and functional changes in wall and endothelial components of arterial blood vessels underlie the accelerated vascular disease progression in systemic lupus erythematosus (SLE). Using pulse contour analysis we sought to determine if subclinical vascular abnormalities could be identified in a well-characterised cohort of patients with SLE who had no increase in traditional cardiovascular risk factors. Radial artery pressure waveforms were obtained by applanation tonometry and pressure envelopes were analysed by descriptive and model-based approaches. Waveshape morphology was quantified by a novel eigenvector approach and model-based compliance indices of the large arteries (C1, capacitative arterial compliance) and small arteries (C2, reflective arterial compliance) were derived using a third-order four-element modified Windkessel model. Data were recorded from 30 patients with SLE (mean age 44 +/- 7 years and mean SLAM-R 10 +/- 4) and 19 age-matched control subjects. Significant differences in the lower frequency sinusoidal components of the pressure waveforms were evident between groups (P < 0.05). Both C1 and C2 were significantly reduced in patients with SLE: C1 mean +/- SD 13.5 +/- 4.0 ml/mmHg x 10 versus C1 17.5 +/- 4.8 ml/mmHg x 10 (P = 0.003 in patients vs. controls, respectively) and C2 5.2 +/- 3.4 ml/mmHg x 100 versus C2 9.4 +/- 2.8 ml/mmHg x 100 (P < 0.001 in patients vs. controls, respectively). In this group of SLE patients, without an excess of traditional cardiovascular risk factors and SLAM-R scores indicating mild disease, descriptive and model-based analysis of arterial waveforms identified vascular abnormalities at a preclinical stage.

Hypertension and impaired vascular function in a female mouse model of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune inflammatory disease that predominantly affects women during their reproductive years. Although women with SLE have hypertension, the underlying mechanisms for this have not been examined. Despite the fact that inflammation is associated with altered endothelial and vascular function, the role of altered vascular function in the development of hypertension during SLE is unclear. In the present study, we tested whether a mouse model of SLE (NZBWF1) develops hypertension and examined whether increased blood pressure was associated with impaired endothelial-dependent relaxation. Female NZBWF1 mice were studied at 8, 20, and 36 wk of age. By 36 wk, urinary albumin and antinuclear antibodies were increased in SLE compared with control mice. Mean arterial pressure, measured by radiotelemetry, was significantly increased in SLE mice (124 ± 4 mmHg, n = 10) compared with control NZW/LacJ mice (111 ± 3 mmHg, n = 7) at 36 wk. Isolated carotid arteries from NZBWF1 mice, precontracted with U-46619 for assessment of endothelial-dependent relaxation, demonstrated a progressively impaired relaxation to ACh with age, although endothelial nitric oxide synthase mRNA expression was not different. Maximal tension generated by 5-hydroxytryptamine was increased in carotid arteries from NZBWF1 mice compared with controls at 8, 20, and 36 wk of age, suggesting a role for altered vascular function early on in the progression of SLE. Taken together, our data support a role for altered endothelial function as a contributing factor to the development of hypertension during SLE.

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.

Use of a flow-mediated vasodilation technique to assess endothelial function in dogs

OBJECTIVE

To develop and assess the reproducibility of a protocol to noninvasively test endothelial function in dogs on the basis of the flow-mediated vasodilation (FMD) procedure used in humans.

ANIMALS

5 healthy spayed female dogs.

PROCEDURES

Luminal arterial diameter and blood flow velocity in the brachial and femoral arteries were measured with ultrasonography. The within-dog reproducibility of these ultrasonographic measurements was tested. An occlusion period of 1, 3, or 5 minutes with an inflatable cuff was used to create the FMD response. Measurements made at 15, 30, and 60 seconds following release of the occlusion were compared with measurements made immediately prior to each occlusion to assess the FMD response.

RESULTS

Within-dog reproducibility of measurements revealed moderate to high correlations. Change from baseline in luminal arterial diameter was most substantial when measured at 30 seconds following release of occlusion, whereas blood flow velocity changes were maximal when measured at 15 seconds following release. The brachial imaging site provided a larger number of significant FMD responses than the femoral site. The 3-minute occlusion period provided equal or better responses than the 5-minute occlusion period.

CONCLUSIONS AND CLINICAL RELEVANCE

Ultrasonographic measurement of the FMD responses was a feasible and reproducible technique and significant changes from baseline were detected. The FMD responses in dogs were most substantial when performed at the brachial artery with blood flow velocity and luminal arterial diameter changes from baseline measured at 15 and 30 seconds, respectively, following release of a 3-minute occlusion period.