Antiphospholipid Syndrome: Role of Vascular Endothelial Cells and Implications for Risk Stratification and Targeted Therapeutics. J Am Coll Cardiol. 2017;69:2317-2330. [PMID: 28473138 DOI: 10.1016/j.jacc.2017.02.058]

Exosome-Contained APOH Associated With Antiphospholipid Syndrome

Background

Antiphospholipid syndrome (APS) is a systemic autoimmune disease that can lead to thrombosis and/or pregnancy complications. Exosomes, membrane-encapsulated vesicles that are released into the extracellular environment by many types of cells, can carry signals to recipient cells to affect angiogenesis, apoptosis, and inflammation. There is increasing evidence suggesting that exosomes play critical roles in pregnancy. However, the contribution of exosomes to APS is still unknown.

Methods

Peripheral plasma was collected from healthy early pregnancy patients (NC-exos) and early pregnancy patients with APS (APS-exos) for exosome extraction and characterization. The effect of exosomes from different sources on pregnancy outcomes was determined by establishing a mouse pregnancy model. Following the coincubation of exosomes and human umbilical vein endothelial cells (HUVECs), functional tests examined the features of APS-exos. The APS-exos and NC-exos were analyzed by quantitative proteomics of whole protein tandem mass tag (TMT) markers to explore the different compositions and identify key proteins. After incubation with HUVECs, functional tests investigated the characteristics of key exosomal proteins. Western blot analysis was used to identify the key pathways.

Results

In the mouse model, APS-exos caused an APS-like birth outcome. In vitro experiments showed that APS-exos inhibited the migration and tube formation of HUVECs. Quantitative proteomics analysis identified 27 upregulated proteins and 9 downregulated proteins in APS-exos versus NC-exos. We hypothesized that apolipoprotein H (APOH) may be a core protein, and the analysis of clinical samples was consistent with finding from the proteomic TMT analysis. APOH-exos led to APS-like birth outcomes. APOH-exos directly enter HUVECs and may play a role through the phospho-extracellular signal-regulated kinase pathway.

Conclusions

Our study suggests that both APS-exos and APOH-exos impair vascular development and lead to pregnancy complications. APOH-exos may be key actors in the pathogenesis of APS. This study provides new insights into the pathogenesis of APS and potential new targets for therapeutic intervention.

Presence of Extra-Criteria Antiphospholipid Antibodies Is an Independent Risk Factor for Ischemic Stroke

Background: Ischemic stroke is the most common and severe arterial thrombotic event in Antiphospholipid syndrome (APS). APS is an autoimmune disease characterized by the presence of thrombosis and antiphospholipid antibodies (aPL), which provide a pro-coagulant state. The aPL included in the classification criteria are lupus anticoagulant, anti-cardiolipin (aCL) and anti-β2-glycoprotein-I antibodies (aB2GPI) of IgG and IgM isotypes. Extra-criteria aPL, especially IgA aB2GPI and IgG/IgM anti-phosphatidylserine/prothrombin antibodies (aPS/PT), have been strongly associated with thrombosis. However, their role in the general population suffering from stroke is unknown. We aim (1) to evaluate the aPL prevalence in ischemic stroke patients, (2) to determine the role of aPL as a risk factor for stroke, and (3) to create an easy-to-use tool to stratify the risk of ischemic stroke occurrence considering the presence of aPL and other risk factors.

Materials and Methods: A cohort of 245 consecutive ischemic stroke patients was evaluated in the first 24 h after the acute event for the presence of classic aPL, extra-criteria aPL (IgA aB2GPI, IgG, and IgM aPS/PT) and conventional cardiovascular risk factors. These patients were followed-up for 2-years. A group of 121 healthy volunteers of the same age range and representative of the general population was used as reference population. The study was approved by the Ethics Committee for Clinical Research (Reference numbers CEIC-14/354 and CEIC-18/182).

Results: The overall aPL prevalence in stroke patients was 28% and IgA aB2GPI were the most prevalent (20%). In the multivariant analysis, the presence of IgA aB2GPI (OR 2.40, 95% CI: 1.03–5.53), dyslipidemia (OR 1.70, 95% CI: 1.01–2.84), arterial hypertension (OR 1.82, 95% CI: 1.03–3.22), atrial fibrillation (OR 4.31, 95% CI: 1.90–9.78), and active smoking (OR 3.47, 95% CI: 1.72–6.99) were identified as independent risk factors for ischemic stroke. A risk stratification tool for stroke was created based on these factors (AUC: 0.75).

Conclusions: IgA aB2GPI are an important independent risk factor for ischemic stroke. Evaluation of aPL (including extra-criteria) in cardiovascular risk factor assessment for stroke can potentially increase the identification of patients at risk of thrombotic event, facilitating a decision on preventive treatments.

Clinical value of amyloid-beta1-40 as a marker of thrombo-inflammation in antiphospholipid syndrome

OBJECTIVE

Amyloid-beta1-40 (Aβ40) is a pro-inflammatory peptide under investigation as a novel biomarker of vascular inflammation, endothelial dysfunction and atherothrombosis in the general population. Herein we tested the hypothesis that Aβ40 is deregulated in APS, a systemic autoimmune disease characterized by a thrombo-inflammatory state.

METHODS

Between January 2016 and July 2017, we consecutively recruited 80 regularly followed thrombotic APS patients (44 primary, 36 SLE/APS) and 80 age- and sex-matched controls. Plasma Aβ40 levels were measured using ELISA and APS-related clinical and laboratory characteristics were recorded. The adjusted Global Anti-Phospholipid Syndrome Score (aGAPSS), a validated risk score in APS, was calculated as a comparator to Aβ40 performance to detect arterial thrombotic APS-related events.

RESULTS

Higher Aβ40 levels were significantly associated with the presence of APS [odds ratio (OR) 1.024 per 1 pg/ml (95% CI 1.007, 1.041)] after adjustment for cardiovascular risk factors (CVRFs), including smoking, arterial hypertension, dyslipidaemia and BMI, and for estimated glomerular filtration rate (eGFR). Among APS patients, increased high-sensitivity CRP (hs-CRP) serum levels was the only independent determinant of Aβ40 levels. Importantly, Aβ40 levels above the optimal receiver operating characteristics (ROC)-derived cut-off value were independently associated with recurrent arterial events [OR 4.93 (95% CI 1.31, 18.51)] after adjustment for age, sex, CVRFs, hs-CRP and high anti-β2 glycoprotein I IgG titres. Finally, by ROC curve analysis, Aβ40 provided incremental additive value over the aGAPSS by significantly improving its discrimination ability for recurrent arterial thromboses.

CONCLUSION

In APS, Aβ40 plasma levels are elevated and associated with an adverse thrombo-inflammatory profile. The pathophysiological and prognostic role of Aβ40 in APS merits further investigation.

Gastrointestinal symptoms as the first manifestation of antiphospholipid syndrome

Background

Antiphospholipid syndrome (APS) is an acquired pre-thrombotic autoimmune condition, which produces autoantibodies called antiphospholipid antibodies (APL) against phospholipid-binding plasma proteins. The diagnosis of APS requires at least one of Sapporo standard clinical manifestations and one laboratory criteria (persistently medium/high titer anticardiolipin antibodies, and/or medium/high titer anti-β2-glycoprotein I antibodies, and/or a positive lupus anticoagulant test). Gastrointestinal lesions are rarely reported in APS patients. APS cases with recurrent abdominal pain as the first clinical manifestation are even rarer.

Case presentation

This report describes an APS case with recurrent abdominal pain as the first clinical manifestation of antiphospholipid syndrome. The patient has a history of two miscarriages. Computed tomography of the abdomen confirmed mesenteric thrombosis and intestinal obstruction while laboratory tests for serum antiphospholipid and anti-β2-glycoprotein I antibodies were positive. This led to the diagnosis of APS.

Conclusions

This paper provides useful information on gastrointestinal manifestations and APS, also including a brief literature review about possible gastrointestinal symptoms of APS.

Growth Differentiation Factor 15 (GDF-15) as potential cardiovascular risk biomarker in Antiphospholipid Syndrome

OBJECTIVE

An interplay between thrombo-inflammatory and atherogenic mechanisms is recognized in cardiovascular disease pathogenesis (CVD) in antiphospholipid syndrome (APS). Herein, we examine associations of growth differentiation factor-15 (GDF-15), a pro-inflammatory cytokine identified as potent CVD risk biomarker in the general population, with subclinical atherosclerosis in APS.

METHODS

We measured plasma GDF-15 levels by an electrochemiluminescence immunoassay (cut-off 1200 pg/mL) and examined carotid intima-media thickness (IMT) and the presence of carotid and femoral plaques using vascular ultrasound in 80 patients with APS (44 primary, 36 systemic lupus erythematosus (SLE)/APS) and 40 healthy controls. We calculated the aGAPSSCVD, a revised adjusted Global APS Score (aGAPSS) to predict CVD, including lupus anticoagulant, anticardiolipin and anti-beta2glycoprotein-I antibodies, and hypertension, dyslipidemia, obesity, diabetes and smoking.

RESULTS

GDF-15 levels were higher in APS patients vs. controls adjusting for age and gender (absolute difference: 281 (95% CI: 141-421) pg/mL, p < 0.001). GDF-15 levels ≥1200 pg/mL were associated with higher mean IMT of right and left carotid (beta coefficient 0.068 (95% CI: 0.020, 0.116), p = 0.006) compared with GDF-15 levels <1200 pg/mL. GDF-15 was independently associated with mean IMT adjusting for gender and aGAPSSCVD (beta coefficient 0.059 (95% CI: 0.008-0.110, p = 0.024), and additionally for statin (p = 0.025) and hydroxychloroquine use (p = 0.011). GDF-15 levels ≥1200 pg/mL were associated with 2.4 higher odds for atherosclerotic plaques (OR = 2.438 (95% CI: 0.906, 6.556), p = 0.078), while this effect reduced adding more covariates in the model.

CONCLUSION

GDF-15 is independently associated with subclinical atherosclerosis in APS patients suggesting its potential role in CVD risk stratification in APS.

Thrombocytopathy and endotheliopathy: crucial contributors to COVID-19 thromboinflammation

The core pathology of coronavirus disease 2019 (COVID-19) is infection of airway cells by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that results in excessive inflammation and respiratory disease, with cytokine storm and acute respiratory distress syndrome implicated in the most severe cases. Thrombotic complications are a major cause of morbidity and mortality in patients with COVID-19. Patients with pre-existing cardiovascular disease and/or traditional cardiovascular risk factors, including obesity, diabetes mellitus, hypertension and advanced age, are at the highest risk of death from COVID-19. In this Review, we summarize new lines of evidence that point to both platelet and endothelial dysfunction as essential components of COVID-19 pathology and describe the mechanisms that might account for the contribution of cardiovascular risk factors to the most severe outcomes in COVID-19. We highlight the distinct contributions of coagulopathy, thrombocytopathy and endotheliopathy to the pathogenesis of COVID-19 and discuss potential therapeutic strategies in the management of patients with COVD-19. Harnessing the expertise of the biomedical and clinical communities is imperative to expand the available therapeutics beyond anticoagulants and to target both thrombocytopathy and endotheliopathy. Only with such collaborative efforts can we better prepare for further waves and for future coronavirus-related pandemics.

Comparable or higher prevalence of comorbidities in antiphospholipid syndrome vs rheumatoid arthritis: a multicenter, case-control study

OBJECTIVES

Evidence on comorbidity prevalence in antiphospholipid syndrome (APS) and its difference from high comorbidity burden rheumatic diseases is limited. Herein, we compare multiple comorbidities between APS and RA.

METHODS

A total of 326 patients from the Greek APS registry [237 women, mean age 48.7 (13.4) years, 161 primary APS (PAPS), 165 SLE-APS] were age/sex matched (1:2 ratio) with 652 patients from a Greek multicentre RA cohort of 3115 patients. Prevalence of cardiovascular (CV) risk factors, stroke, coronary artery disease (CAD), osteoporosis, diabetes mellitus (DM), chronic obstructive pulmonary disease (COPD), depression and neoplasms were compared between APS and RA patients using multivariate regression analysis.

RESULTS

Ηyperlipidemia and obesity (ΒΜΙ ≥ 30 kg/m2) were comparable while hypertension, smoking, stroke and CAD were more prevalent in APS compared with RA patients. Osteoporosis and depression were more frequent in APS, while DM, COPD and neoplasms did not differ between the two groups. Comparison of APS subgroups to 1:2 matched RA patients revealed that smoking and stroke were more prevalent in both PAPS and SLE-APS vs RA. Hypertension, CAD and osteoporosis were more frequent only in SLE-APS vs RA, whereas DM was less prevalent in PAPS vs RA. Hyperlipidaemia was independently associated with CV events (combined stroke and CAD) in PAPS and SLE-APS, while CS duration was associated with osteoporosis in SLE-APS.

CONCLUSION

Comorbidity burden in APS (PAPS and SLE-APS) is comparable or higher than that in RA, entailing a high level of diligence for CV risk prevention, awareness for depression and CS exposure minimization.

Rare pulmonary embolism caused by the combination of bilateral popliteal venous aneurysms and antiphospholipid syndrome

Popliteal venous aneurysm (PVA) and antiphospholipid syndrome (APS) are under-recognised as potential causes of pulmonary embolism (PE). A 66-year-old woman presented with progressive shortness of breath. A contrast-enhanced CT revealed bilateral PE, a small renal infarction and bilateral PVAs. Direct oral anticoagulant (DOAC) therapy was initiated immediately for venous thrombosis. Given the positivity for serum antiphospholipid antibody (aPL) in an initial blood test, low-dose aspirin was included to prevent further arterial thrombosis. Her symptoms resolved and she was discharged 1 week later. Twelve weeks later, she was diagnosed with APS because of persistent aPL. Surgical resection of the right PVA was performed 1 year later from her hospitalisation. To the best of our knowledge, this is the first case of PE caused by the combination of bilateral PVAs and APS. This report emphasises the importance of careful screening to identify PE causes, and its optimal management.

Thrombin generation in subjects with lupus anticoagulant without prior thrombosis or gestational morbidities

BACKGROUND

Lupus anticoagulant (LA) can be a cause of thrombosis and/or pregnancy morbidities, producing antiphospholipid syndrome (APS). An increase in thrombin generation (TG) is correlated with prothrombotic status. Several changes in TG-derived parameters have been reported in APS patients.

OBJECTIVES

Evaluate whether the TG phenotype of APS can also be described in LA subjects without clinical manifestations of APS, and to investigate the possible influence of both LA potency and antiphospholipid (aPL) profile on it.

RESULTS

TG was analyzed in 153 cases of LA and 41 healthy controls. We have observed prolongation of both lag time (3.7 min vs 2.32 min, p < 0.001) and time to peak (6.48 min vs 5.27 min, p < 0.001), increased peak height (221.7 nM vs 182.7 nM, p < 0.001), slightly higher ETP (221.7 nM·min vs 182.7 nM·min, p = 0.041), and higher velocity index (100.7 nM/min vs 74.53 nM/min, p = 0.001) in LA subjects compared to controls. After adding thrombomodulin (TM), ETP%inh was significantly lower in LA group (37.90% vs 59.90%, p < 0.001) showing resistance to TM/activated protein C (APC). Significant differences were found in lag time, time to peak and ETP%inh according to the potency and aPL profile.

CONCLUSIONS

Previously described differences in TG-derived parameters in APS patients have been confirmed in incidental LA subjects: prolonged lag time and time to peak, slightly higher ETP, higher peak height, and less sensitivity to TM/APC. High LA potency and triple-positive aPL profile enhance differences in lag time, time to peak and, especially, increase APC resistance, but no effect in ETP was observed.

COVID-19: A Great Mime or a Trigger Event of Autoimmune Manifestations?

Viruses can induce autoimmune diseases, in addition to genetic predisposition and environmental factors. Particularly, coronaviruses are mentioned among the viruses implicated in autoimmunity. Today, the world's greatest threat derives from the pandemic of a new human coronavirus, called "severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the responsible agent of coronavirus disease 2019 (COVID-19). First case of COVID-19 was identified in Wuhan, the capital of Hubei, China, in December 2019 and quickly spread around the world. This review focuses on autoimmune manifestations described during COVID-19, including pro-thrombotic state associated with antiphospholipid antibodies (aPL), acute interstitial pneumonia, macrophage activation syndrome, lymphocytopenia, systemic vasculitis, and autoimmune skin lesions. This offers the opportunity to highlight the pathogenetic mechanisms common to COVID-19 and several autoimmune diseases in order to identify new therapeutic targets. In a supposed preliminary pathogenetic model, SARS-CoV-2 plays a direct role in triggering widespread microthrombosis and microvascular inflammation, because it is able to induce transient aPL, endothelial damage and complement activation at the same time. Hence, endothelium might represent the common pathway in which autoimmunity and infection converge. In addition, autoimmune phenomena in COVID-19 can be explained by regulatory T cells impairment and cytokines cascade.

Cardiovascular Disease in Antiphospholipid Syndrome

:

Antiphospholipid syndrome (APS) is a systemic autoimmune disease characterized by venous, arterial or microvascular thrombosis or obstetric events in the presence of persistently positive antiphospholipid antibodies and constitutes a major cause of cardiovascular events in young people. Τhis review highlights the pathophysiology of cardiovascular complications in patients with APS and possible treatment options.

:

Patients with APS have endothelial dysfunction, accelerated endothelial proliferation and intimal hyperplasia, atherogenesis, platelet activation, inflammatory products secretion and coagulation-fibrinolytic dysregulation. Cardiovascular complications include accelerated atherosclerosis, acute coronary syndrome, Libman-Sacks endocarditis, cardiomyopathy and venous, arterial or intracardiac thrombi. Moreover, pulmonary hypertension and peripheral microvascular dysfunction are common findings.

:

Management of these patients is not well documented. The role of primary thrombosis prevention remains controversial in individuals with positive antiphospholipid antibodies. Treatment of traditional cardiovascular risk factors according to current guidelines for the prevention of cardiovascular disease in the general population is recommended for primary prevention of APS. Anticoagulation therapy with unfractionated or low-molecular-weight heparin overlapped with a vitamin K antagonist remains the mainstay of the treatment for APS patients with venous thrombosis, whereas direct oral anticoagulants are not yet recommended. Data are scarce regarding the secondary arterial thrombosis prevention and it is not clear whether dual or triple antithrombotic therapy is necessary. To date, it is recommended to follow current guidelines for the management of acute coronary syndrome in the general population. New treatment targets are promising options for patients with catastrophic APS.

Acute Q Fever Endocarditis: A Paradigm Shift Following the Systematic Use of Transthoracic Echocardiography During Acute Q Fever

BACKGROUND

As Q fever, caused by Coxiella burnetii, is a major health challenge due to its cardiovascular complications, we aimed to detect acute Q fever valvular injury to improve therapeutic management.

METHODS

In the French national reference center for Q fever, we prospectively collected data from patients with acute Q fever and valvular injury. We identified a new clinical entity, acute Q fever endocarditis, defined as valvular lesion potentially caused by C. burnetii: vegetation, valvular nodular thickening, rupture of chorda tendinae, and valve or chorda tendinae thickness. To determine whether or not the disease was superimposed on an underlying valvulopathy, patients' physicians were contacted. Aortic bicuspidy, valvular stenosis, and insufficiency were considered as underlying valvulopathies.

RESULTS

Of the 2434 patients treated in our center, 1797 had acute Q fever and 48 had acute Q fever endocarditis. In 35 cases (72%), transthoracic echocardiography (TTE) identified a valvular lesion of acute Q fever endocarditis without underlying valvulopathy. Positive anticardiolipin antibodies (>22 immunoglobulin G-type phospholipid units [GPLU]) were independently associated with acute Q fever endocarditis (odds ratio [OR], 2.7 [95% confidence interval {CI}, 1.3-5.5]; P = .004). Acute Q fever endocarditis (OR, 5.2 [95% CI, 2.6-10.5]; P < .001) and age (OR, 1.7 [95% CI, 1.1-1.9]; P = .02) were independent predictors of progression toward persistent C. burnetii endocarditis.

CONCLUSIONS

Systematic TTE in acute Q fever patients offers a unique opportunity for early diagnosis of acute Q fever endocarditis and for the prevention of persistent endocarditis. Transesophageal echocardiography should be proposed in men, aged >40 years, with anticardiolipin antibodies >60 GPLU when TTE is inconclusive or negative.

Sudden Cardiac Arrest as the First Manifestation in a Patient with Catastrophic Antiphospholipid Syndrome

We herein report a 26-year-old woman with sudden cardiac arrest who had no remarkable medical history. While resuscitation was successfully performed with adrenalin administration and extracorporeal membrane oxygenation, the cause of cardiac arrest could not be determined for over two weeks. Given the presence of autoimmune disease along with the findings of refractory renal insufficiency and thrombocytopenia, a kidney biopsy and blood examinations, including lupus anticoagulant testing, were performed, which proved the presence of antiphospholipid syndrome. The patient was successfully treated with steroid pulse therapy. This drastic case scenario highlighted the fact that autoimmune disease can be the cause of sudden cardiac arrest.

Antiphospholipid syndrome and its role in pediatric cerebrovascular diseases: A literature review

Antiphospholipid syndrome (APS) or Hughes syndrome is an acquired thromboinflammatory disorder. Clinical criteria of APS diagnosis are large- and small-vessel thrombosis as well as obstetric problems; laboratory criteria are the presence of antiphospholipid antibodies (lupus anticoagulant, anticardiolipin antibodies and anti-β2-glycoprotein-1). The presence of at least 1 clinical and 1 laboratory criterion allows definitive diagnosis of APS. Primary APS is diagnosed in patients without features of connective tissue disease; secondary APS is diagnosed in patients with clinical signs of autoimmune disease. A high frequency of catastrophic APS as well as a high tendency to evolve from primary APS to secondary syndrome during the course of lupus and lupus-like disease is a feature of pediatric APS. The most characteristic clinical presentation of APS in the pediatric population is venous thrombosis, mainly in the lower limbs, and arterial thrombosis causing ischemic brain stroke. Currently, no diagnostic criteria for pediatric APS exist, which probably results in an underestimation of the problem. Similarly, no therapeutic procedures for APS specific for children have yet been established. In the present literature review, we discussed data concerning APS in children and its role in cerebrovascular diseases, including pediatric arterial ischemic stroke, migraine and cerebral venous thrombosis.

Hyperoside Protects Human Umbilical Vein Endothelial Cells Against Anticardiolipin Antibody-Induced Injury by Activating Autophagy

Anticardiolipin antibody (aCL), an important characterization of antiphospholipid syndrome, shows an intense association with vascular endothelial injury. Hyperoside is a flavonoid extracted from medicinal plants traditionally used in Chinese medicines, displaying anti-inflammatory, anti-cancer, and anti-oxidative properties in various diseases. Recent studies have shifted the focus on the protective effects of hyperoside on vascular endothelial injury. However, little is known about the mechanisms involved. In the present study, we investigated the effect of hyperoside on aCL-induced injury of human umbilical vein endothelial cells (HUVECs) in vitro. Our data illustrated that aCL induced HUVEC injury via inhibiting autophagy. Hyperoside reduced aCL-induced secretion of proinflammatory cytokines IL-1β and IL-8 and endothelial adhesion cytokines TF, ICAM1, and VCAM1 in HUVECs. Additionally, hyperoside activated autophagy and suppressed the mTOR/S6K and TLR4/Myd88/NF-κB signaling transduction pathways in aCL-induced HUVECs. To the best of our knowledge, this is the first study to investigate the effect of hyperoside on aCL-induced injury, as well as offer insights into the involved mechanisms, which is of great significance for the treatment of antiphospholipid syndrome.

The Issue of the Antiphospholipid Antibody Syndrome

Antiphospholipid antibody syndrome (APS) is a state of hypercoagulability secondary to an autoimmune disorder. It is associated with thrombotic events in venous and arterial vessels, obstetric complications characterized by recurrent fetal losses, and increased perinatal morbidity. APS is classified as primary, when not associated with other pathologies; or secondary, when associated with an underlying autoimmune disease with, solid tumor, or hematological disorder. Clinical findings include livedo reticularis, thrombocytopenia or hemolytic anemia, maternal morbidity, and recurrent thrombotic episodes and others. Laboratory tests show circulating antiphospholipid antibodies (aPLs); however, even in the presence of these antibodies, patients can be asymptomatic. Estimates predict that about 5% of the populations have circulating aPLs, but the incidence of APS is only five cases per 100,000 people, as diagnosis of this syndrome requires clinical and laboratory findings to be simultaneously present. In cases of secondary APS, or in acute cases with imminent risk of death (as in catastrophic APS), it may be necessary to reduce aPL serum levels using immunomodulators, immunosuppressants, or plasmapheresis, in order to treat the associated pathologies. In other situations, the use of immunotherapy is not indicated. In other patients heparin, aspirin or anticoagulants either alone or associated should be administered depending on each specific case.

Increased Adhesive Potential of Antiphospholipid Syndrome Neutrophils Mediated by β2 Integrin Mac-1

OBJECTIVE

While the role of antiphospholipid antibodies in activating endothelial cells has been extensively studied, the impact of these antibodies on the adhesive potential of leukocytes has received less attention. This study was undertaken to investigate the extent to which antiphospholipid syndrome (APS) neutrophils adhere to resting endothelial cells under physiologic flow conditions and the surface molecules required for that adhesion.

METHODS

Patients with primary APS (n = 43), patients with a history of venous thrombosis but negative test results for antiphospholipid antibodies (n = 11), and healthy controls (n = 38) were studied. Cells were introduced into a flow chamber and perfused across resting human umbilical vein endothelial cells (HUVECs). Surface adhesion molecules were quantified by flow cytometry. Neutrophil extracellular trap release (NETosis) was assessed in neutrophil-HUVEC cocultures.

RESULTS

Upon perfusion of anticoagulated blood through the flow chamber, APS neutrophils demonstrated increased adhesion as compared to control neutrophils under conditions representative of either venous (n = 8; P < 0.05) or arterial (n = 15; P < 0.0001) flow. At the same time, APS neutrophils were characterized by up-regulation of CD64, CEACAM1, β2 -glycoprotein I, and activated Mac-1 on their surface (n = 12-18; P < 0.05 for all markers). Exposing control neutrophils to APS plasma or APS IgG resulted in increased neutrophil adhesion (n = 10-11; P < 0.0001) and surface marker up-regulation as compared to controls. A monoclonal antibody specific for activated Mac-1 reduced the adhesion of APS neutrophils in the flow-chamber assay (P < 0.01). The same monoclonal antibody reduced NETosis in neutrophil-HUVEC cocultures (P < 0.01).

CONCLUSION

APS neutrophils demonstrate increased adhesive potential, which is dependent upon the activated form of Mac-1. In patients, this could lower the threshold for neutrophil-endothelium interactions, NETosis, and possibly thrombotic events.

Hydroxychloroquine may be beneficial in preeclampsia and recurrent miscarriage

Recurrent miscarriage (RM) and vasculoplacental disorders, such as preeclampsia (PE), affect women of childbearing age worldwide. Vascular endothelial dysfunction and immunological impairment are associated with both RM and PE. To date, there is no effective or optimal therapeutic approach for these conditions. Notably, aspirin use is only partially effective in the prevention of PE. Hydroxychloroquine (HCQ) has demonstrated beneficial effects on disease flares, pregnancy outcomes and cardiovascular impairment in systemic erythaematosus lupus (SLE) through its immunomodulatory, vasculoprotective and antithrombotic properties. Here, in the context of the underlying physiological dysregulation associated with PE and RM, the beneficial properties and potential therapeutic efficacy of HCQ are reviewed in anticipation of the results of current and future trials. Two related trials addressing RM in the absence of maternal autoimmune disease are ongoing. Other trials addressing pregnancy outcomes in the presence of maternal autoimmune disease are forthcoming. In this review, we hypothesise that the immunological and endothelial effects of HCQ may be beneficial in the context of PE and RM, regardless of the maternal autoimmune status.

Endothelium structure and function in kidney health and disease

The kidney harbours different types of endothelia, each with specific structural and functional characteristics. The glomerular endothelium, which is highly fenestrated and covered by a rich glycocalyx, participates in the sieving properties of the glomerular filtration barrier and in the maintenance of podocyte structure. The microvascular endothelium in peritubular capillaries, which is also fenestrated, transports reabsorbed components and participates in epithelial cell function. The endothelium of large and small vessels supports the renal vasculature. These renal endothelia are protected by regulators of thrombosis, inflammation and complement, but endothelial injury (for example, induced by toxins, antibodies, immune cells or inflammatory cytokines) or defects in factors that provide endothelial protection (for example, regulators of complement or angiogenesis) can lead to acute or chronic renal injury. Moreover, renal endothelial cells can transition towards a mesenchymal phenotype, favouring renal fibrosis and the development of chronic kidney disease. Thus, the renal endothelium is both a target and a driver of kidney and systemic cardiovascular complications. Emerging therapeutic strategies that target the renal endothelium may lead to improved outcomes for both rare and common renal diseases.

Biomarkers associating endothelial Dysregulation in pediatric-onset systemic lupus erythematous

BACKGROUND/PURPOSE

Endothelium is a key element in the regulation of vascular homeostasis and its alteration can lead to the development of vascular diseases. Systemic lupus erythematosus (SLE) is a systemic autoimmune disease with potential extensive vascular lesions, involving skin vessels, renal glomeruli, cardiovascular system, brain, lung alveoli, gastrointestinal tract vessels and more. We aimed to assess endothelial dysregulation related biomarkers in pediatric-onset SLE (pSLE) patient serum and elucidate its correlation with their clinical features, laboratory parameters, and the overall disease activity.

METHODS

Disease activities were evaluated by SLE disease activity index (SLEDAI). Patient characteristics were obtained by retrospective chart review. Six biomarkers associated with endothelial dysregulation, including Angiopoietin-1 (Ang-1), Angiopoietin-2 (Ang-2), Tie2, Vascular endothelial growth factor (VEGF), thrombomodulin, and a disintegrin-like and metalloprotease with thrombospondin type 1 motif (ADAMTS13) were tested through enzyme-linked immunosorbent assay (ELISA) measurement.

RESULTS

This study comprised 118 pSLE patients. Data from 40 age-matched healthy controls were also obtained. The mean diagnostic age was 13 ± 4.12 years-old and 90.7% are females. Serum levels of VEGF, Tie2, thrombomodulin were significantly higher while serum ADAMTS13 was lower in active pSLE patients when compared to those with inactive diseases (all p < 0.05). In organ specific association, serum thrombomodulin level was higher in pSLE patient with renal involvement, and serum ADAMTS13 levels was negatively associated with neurological involvement (p < 0.05). A cutoff of thrombomodulin at 3333.6 pg/ml best correlated renal involvement. (AUC = 0.752, p < 0.01).

CONCLUSION

Endothelial dysregulation associating proteins seems to be potent biomarkers for pSLE activity as well as organ involvement in pSLE patients. These biomarkers may be beneficial in understanding of the vascular pathogenesis and disease monitoring.

Endothelial cell modulation of cardiomyocyte gene expression

The anatomic arrangement of microvascular endothelial cells and cardiomyocytes in vivo enables close interactions among these cells. In our in vitro co-culture system, ANP and BNP expression in the mouse atrial cardiomyocyte cell line HL-1 and subsequent ANP release were significantly upregulated when co-cultured with mouse cardiac microvascular endothelial cells or exposed to endothelial cell-conditioned medium. Endothelin-1 (ET-1) activation of endothelial cells remarkably enhanced their paracrine effect on cardiomyocyte gene expression, suggesting that ET-1 stimulation of endothelial cells affects expression of fetal genes such as ANP and BNP in adult cardiomyocytes through paracrine signalling. Exposure of HL-1 cells and murine induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) to authentic angiopoietin-2 (Ang2) caused a concentration-dependent decrease in ANP expression while ET-1-induced ANP expression was augmented by low but inhibited by high concentrations of Ang2. FK506-mediated inhibition of the calcineurin-NFAT pathway in the HL-1 cells selectively inhibited the stimulatory effect of the conditioned medium derived from ET-1-pre-stimulated endothelial cells on cardiomyocyte fetal gene expression. Combined with previous results indicating a crucial role for ANP and BNP in cardiac homeostasis, our findings provide further evidence that paracrine signalling by cardiac microvascular endothelial cells modulates cardiomyocyte function.

The Epidemiology of Antiphospholipid Syndrome: A Population-Based Study

OBJECTIVE

To estimate the annual incidence and prevalence of and frequency of mortality associated with antiphospholipid syndrome (APS).

METHODS

An inception cohort of patients with incident APS in 2000-2015 from a geographically well-defined population was identified based on comprehensive individual medical records review. All cases met the 2006 Sydney criteria for APS (primary definition) or had a diagnosis of APS confirmed by physician consensus (secondary definition). Levels of lupus anticoagulant, IgM and IgG anticardiolipin antibodies, and anti-β2-glycoprotein I antibodies were tested in a centralized laboratory. Incidence rates were age- and sex-adjusted to the 2010 US white population. Prevalence estimates were obtained from the incidence rates, assuming that there was no increased mortality associated with APS and that migration in or out of the area was independent of disease status.

RESULTS

Among this cohort in 2000-2015, 33 cases of incident APS, as defined by the Sydney criteria, were identified (mean age of patients 54.2 years; 55% female, 97% white). The annual incidence of APS in adults ages ≥18 years was 2.1 (95% confidence interval [95% CI] 1.4-2.8) per 100,000 population. Incidence rates were similar in both sexes. The estimated prevalence of APS was 50 (95% CI 42-58) per 100,000 population, and was similar in both sexes. Six patients (18%) had a concurrent diagnosis of systemic lupus erythematosus. The most frequent clinical manifestation was deep vein thrombosis. The overall frequency of mortality among patients with APS was not significantly different from that in the general population (standardized mortality ratio 1.61, 95% CI 0.74-3.05).

CONCLUSION

APS occurred in ~2 persons per 100,000 population per year. The estimated prevalence was 50 per 100,000 population. Overall mortality was not notably different from that observed in the general population.

Acute myocardial infarction in a patient positive for lupus anticoagulant: a case report

Background

Autoimmune diseases, such as systemic lupus erythematosus (SLE), are associated with thrombosis and atherosclerosis. Presence of lupus anticoagulant is an independent risk factor for atherosclerotic diseases.

Case presentation

A 56-year-old man with past history of hypertension, and cerebral infarction was admitted to our hospital owing to acute chest pain. He was diagnosed with acute myocardial infarction based on his symptoms and electrocardiogram results, which demonstrated ST elevation in the precordial leads. Coronary angiography images revealed total occlusion at the proximal site of the left anterior descending artery. A drug-eluting stent was deployed, which successfully recovered coronary blood flow. The patient had fever of unknown cause when he was 30 years old; on admission, he presented with a low-grade fever and reddish exanthema affecting both cheeks. Based on his physical signs as well as elevated antinuclear antibodies (anti-double-stranded DNA), decreased lymphocytes, and a positive direct Coombs test, he was diagnosed with SLE. Owing to a positive lupus anticoagulant test, he was also suspected to have antiphospholipid syndrome (APS). Triple antithrombotic therapy, including dual antiplatelet therapy with aspirin and clopidogrel during coronary stenting and single anticoagulation therapy with warfarin, was initiated.

Conclusions

Careful diagnosis of autoimmune diseases should be performed in patients with thrombosis and atherosclerosis. Moreover, risk factors for coronary artery disease should be strictly controlled in patients with APS.

Four-year follow-up of two patients on maintenance therapy with fondaparinux and mycophenolate mofetil for microthrombotic antiphospholipid syndrome

Objectives

We discuss two patients with antiphospholipid syndrome (APS) who presented with critical ischemia of both lower extremities due to arterial microthrombi. They received multimodality therapy emergently: anticoagulation, immunosuppression, and therapeutic plasma exchange (TPE). Then they were maintained on anticoagulation with fondaparinux and immunosuppression with mycophenolate mofetil (MMF), and were followed for 4 years.

Methods

Two patients with APS with ischemia and necrosis of their distal lower extremities were treated emergently with anticoagulation (intravenous heparin), immunosuppression (prednisone), and TPE. They were maintained on anticoagulation with fondaparinux and immunosuppression with MMF.

Results

Neither patient had recurrent microthrombotic disease during a 4-year follow-up.

Conclusions

As described in our small cohort, patients with APS who suffer from microthrombotic arterial disease may benefit from maintenance therapy of anticoagulation with fondaparinux and immunosuppression with MMF, an approach which may be worthy of further trial. Fondaparinux does not require attention to diet, monitoring, and cumbersome bridging that is typical of warfarin therapy. MMF provides immunosuppression while sparing the side effects of steroid treatment.

A Coronary Conundrum: Papillary Muscle Rupture and Ischemic Mitral Regurgitation Secondary to Coronary Thromboembolism in Antiphospholipid Syndrome

Antiphospholipid syndrome (APS) is an autoimmune disorder that has a strong propensity for a hypercoagulable state and is known to be associated with venous and arterial thromboembolism. We describe an uncommon case of APS in the setting of non-Hodgkin's lymphoma, with thromboembolism, and a rare complication after an uncommon etiology of myocardial infarction. This case highlights the importance of early and appropriate type of anticoagulation to reduce the morbidity and mortality in patients with APS.

Transcranial Doppler findings in antiphospholipid syndrome

INTRODUCTION

Transcranial Doppler is a method that enables the assessment of different cerebral hemodynamic parameters. It also allows for the evaluation of the presence of right-to-left circulation shunts (RLS) and for the detection of microembolic signals (MESs), which might be associated with an increased risk of cerebrovascular events. For instance, the presence of MESs on transcranial Doppler in patients with systemic lupus erythematous (SLE) and antiphospholipid syndrome (APS) is associated with an increased risk of stroke. Therefore, transcranial Doppler could be a useful tool for stroke risk stratification in these patients.

OBJECTIVE

Our objective was to evaluate transcranial Doppler cerebral mean blood flow velocities as well as the presence of MESs and RLS in patients with antiphospholipid syndrome and SLE.

PATIENTS AND METHODS

Twenty-two patients with primary APS (PAPS), 24 patients with secondary APS (SAPS), 27 patients with SLE without APS and 21 healthy controls were evaluated. Clinical and epidemiological data were compiled from medical charts, and all subjects underwent transcranial Doppler examination with breath-holding index calculation. Both middle cerebral arteries were monitored for 60 min for the detection of MESs. RLS was investigated with agitated saline injected as a bolus.

RESULTS

There were no significant differences in mean blood flow velocities among the groups. MESs were more frequently found in patients with SLE when compared with controls and patients with APS (SLE: 17.4%, SAPS: 4.3%, PAPS: 0%, controls: 0%, p = 0.03). Anticoagulant therapy was more frequently used in the APS group (PAPS: 81.8%, SAPS: 75.2%, SLE: 1.7%, p < 0.001). Patients with APS had a higher frequency of RLS when compared with volunteers (63.6% versus 38.1%, p = 0.05). Breath-holding index values tended to be lower in patients with SAPS than in control subjects and patients with PAPS and SLE ( p = 0.06).

CONCLUSIONS

Patients with APS had a higher frequency of RLS than healthy controls. This finding alerts to the importance of cardiac investigation in patients with stroke and APS, because further therapies such as RLS occlusion might eventually add protection. The higher frequency of MES in patients with SLE could suggest an effect of anticoagulant therapy on MES prevention, more frequently used in patients with APS.

[ST elevation myocardial infarction in young adults: Is there an interest for thrombophilia screening?]

BACKGROUND

Coronary lesions characteristics as well as patient thrombogenicity can explain coronary events manifestation. In young patient, local conditions are usually less important and thrombogenicity could play a significant role. Assessing thrombophilia could be justified in young patients and may induce an adapted therapeutic management.

PURPOSE

We aimed to assess the prevalence of thrombophilia and therapeutic modification in young adults aged≤55 years admitted in our department for ST elevation myocardial infarction (STEMI).

METHODS

From January 2013 to January 2017, data on all patients aged≤55 years with STEMI admitted in emergency were retrospectively retrieved from our database. Thrombophilia investigation was made regarding clinical (with or without cardiovascular risk factors [CVRF]), biological and/or angiographic evaluation.

RESULTS

A total of 133 patients aged≤55 years with STEMI were included. Cardiac arrest occurred in 15 patients (11%). One or less CVRF were found in 47 patients (35%). Smoking was reported in 93 patients (70%) and drug addiction (cannabis, cocaine) in 19 patients (14%). A subset of 51 patients (38%) were screened for thrombophilia. Patients with thrombophilia assessment were younger, less active smokers and presented less CVRF than patients without investigation (P<0.001). Single vessel diseased was found in 88 patients (66%). No differences regarding coronary procedural characteristic were found between the two groups. The most frequently encountered aetiology, found in 122 patients (92%), was de novo intra-arterial thrombosis related to atherosclerosis. In patients with thrombophilia assessment (n=51), one or more abnormal biological results was found in 22 patients (43%) and a therapeutic adjustment was made in 6 patients (12%).

CONCLUSION

Thrombophilia screening in young STEMI adults showed an abnormality in 43% of cases. Antithrombotic treatment can be modified after its demonstration.

Antiphospholipid syndrome – an update

Abstract. Antiphospholipid syndrome (APS) is an autoantibody-mediated acquired thrombophilia. It is characterized by the presence of antiphospholipid antibodies (APL) that are directed against phospholipid-binding plasma proteins, such as beta-2-glycoprotein I (b2GPI). Its main manifestations are recurrent vascular thromboses (so-called “thrombotic APS”) and pregnancy complications (“obstetric APS”). According to the current consensus criteria, a persistently positive functional lupus anticoagulant (LA) assay and/or the presence of anti-b2GPI and/or anti-cardiolipin antibodies, together with clinical symptoms, is mandatory for the diagnosis of APS. Other clinical features, such as thrombocytopenia, Coombs-positive haemolytic anaemia, heart valve disease, renal microangiopathy and neurologic disorders are also common in APL-positive patients. APS can be associated with other autoimmune disorders, such as systemic lupus erythematosus. In rare cases, catastrophic APS (CAPS) occurs, with the development of excessive thrombosis at multiple sites, usually affecting small vessels and leading to multi-organ dysfunction and organ failure. Treatment usually comprises antithrombotic therapy using antiplatelet and anticoagulant agents. However, there is no consensus concerning the intensity or duration of therapy. Despite apparently adequate anticoagulation, the risk of recurrent thrombosis remains high. For patients with CAPS, a combined therapeutic approach that includes anticoagulation, glucocorticoids, plasma exchange and/or intravenous immunoglobulin seems to be the best treatment option.

Keywords: Antiphospholipid syndrome, lupus anticoagulants, anti-cardiolipin, anti-beta-2-glycoprotein I, vascular thrombosis, pregnancy complication

Oxidative post-translational modification of βeta 2-glycoprotein I in the pathophysiology of the anti-phospholipid syndrome

The anti-phospholipid syndrome (APS) is a prothrombotic autoimmune disorder characterized by either thrombosis or pregnancy complications in the setting of persistent anti-phospholipid antibodies (aPL). βeta 2-glycoprotein I (β2-GPI) is the major autoantigen in APS that binds anionic phospholipids as well as specific receptors on platelets and endothelial cells resulting in activation of prothrombotic pathways. β2-GPI consists of 5 Domains that exist in a circular or linear form, with the latter occurring after binding to anionic phospholipids. β2-GPI also undergoes dynamic posttranslational modification between oxidized and free thiol forms. The relationship between posttranslational modification and structural conformation is yet to be definitively clarified. Compared with controls, patients with the APS have higher levels of total β2-GPI and lower levels of free thiol β2-GPI. This raises the possibility of using quantification of β2-GPI posttranslational modification as a redox biomarker in the management and diagnosis of the APS.

Neurologic manifestations of antiphospholipid syndrome

Neurological involvement in antiphospholipid antibody syndrome (APS) is common, and its occurrence increases morbidity and mortality. Patients may present variable neurological involvement, such as cerebrovascular disease, cognitive dysfunction, headache, seizures, movement disorders, multiple sclerosis-like syndrome, transverse myelitis and ocular symptoms. Most neurological manifestations are associated with thrombosis of the microcirculation or of large vessels; nonetheless, there is compelling evidence suggesting that, in some cases, symptoms are secondary to an immune-mediated pathogenesis, with direct binding of aPL on neurons and glia. Herein we describe clinical characteristics and management of neurological APS manifestations.

Coronary Artery Thromboses, Stent Thrombosis and Antiphospholipid Antibody Syndrome: Case Report

The antiphospholipid antibody syndrome (APS) is defined by a state of hypercoagulability secondary to an autoimmune disorder. There are evidences that approximately 2.8-5.5% of cases of acute myocardial infarction (AMI) in young individuals are secondary to APS. In this case report, three coronary artery thromboses occurring within a short period are described. Initially, there was an ST-segment elevation (STEMI) in the presence of coronary artery disease (CAD), with the vessel being treated with stent implantation. Thereafter, a subacute stent thrombosis occurred (high thrombotic load in almost all coronary arteries), which was treated with implantation of two stents. Subsequently, there was a new infarction owing to a new thrombosis in the native coronary artery. The treatment of APS in patients who developed thrombotic events is full anticoagulation from the initial stages maintained throughout life. The standard anticoagulant therapy is administration of vitamin K antagonists, such as warfarin.

Omega-3 Fatty Acid Supplementation Improves Endothelial Function in Primary Antiphospholipid Syndrome: A Small-Scale Randomized Double-Blind Placebo-Controlled Trial

Endothelial cells are thought to play a central role in the pathogenesis of antiphospholipid syndrome (APS). Omega-3 polyunsaturated fatty acid (n-3 PUFA) supplementation has been shown to improve endothelial function in a number of diseases; thus, it could be of high clinical relevance in APS. The aim of this study was to evaluate the efficacy of n-3 PUFA supplementation on endothelial function (primary outcome) of patients with primary APS (PAPS). A 16-week randomized clinical trial was conducted with 22 adult women with PAPS. Patients were randomly assigned (1:1) to receive placebo (PL, n = 11) or n-3 PUFA (ω-3, n = 11) supplementation. Before (pre) and after (post) 16 weeks of the intervention, patients were assessed for endothelial function (peripheral artery tonometry) (primary outcome). Patients were also assessed for systemic markers of endothelial cell activation, inflammatory markers, dietary intake, international normalized ratio (INR), and adverse effects. At post, ω-3 group presented significant increases in endothelial function estimates reactive hyperemia index (RHI) and logarithmic transformation of RHI (LnRHI) when compared with PL (+13 vs. -12%, p = 0.06, ES = 0.9; and +23 vs. -22%, p = 0.02, ES = 1.0). No changes were observed for e-selectin, vascular adhesion molecule-1, and fibrinogen levels (p > 0.05). In addition, ω-3 group showed decreased circulating levels of interleukin-10 (-4 vs. +45%, p = 0.04, ES = -0.9) and tumor necrosis factor (-13 vs. +0.3%, p = 0.04, ES = -0.95) and a tendency toward a lower intercellular adhesion molecule-1 response (+3 vs. +48%, p = 0.1, ES = -0.7) at post when compared with PL. No changes in dietary intake, INR, or self-reported adverse effects were observed. In conclusion, 16 weeks of n-3 PUFA supplementation improved endothelial function in patients with well-controlled PAPS. These results support a role of n-3 PUFA supplementation as an adjuvant therapy in APS. Registered at http://ClinicalTrials.gov as NCT01956188.

Concentrated Ambient PM2.5-Induced Inflammation and Endothelial Dysfunction in a Murine Model of Neural IKK2 Deficiency

BACKGROUND

Exposure to ambient fine particulate matter (PM_2.5) is associated with cardiovascular mortality, but underlying pathophysiologic mechanisms are not fully understood. Hypothalamic inflammation, characterized by the activation of Inhibitor kappaB kinase 2/Nuclear factor kappaB (IKK2/NF-κB) signaling pathway, may play an important role in the pathogenesis of cardiovascular diseases. We recently demonstrated that hypothalamic inflammation is increased in mice exposed to concentrated ambient PM_2.5 (CAP).

OBJECTIVES

In the present study, we used a neuron-specific IKK2 knockout mouse model to examine the role of neural IKK2 expression and hypothalamic inflammation in the pathophysiologic effects of PM_2.5.

METHODS

We assessed inflammatory and vascular responses in Nestin-creIKK2^flox/flox (IKK2^Neu-KO) and littermate Nestin-creIKK2^flox/+ (control) mice after 4 mo of exposure to filtered air (FA) or CAP.

RESULTS

CAP exposure was associated with significantly higher tumor necrosis factor-α (TNFα) and interleukin (IL)-6 mRNA in the hypothalamus of control mice, but not IKK2^Neu-KO mice. In addition, CAP exposure-induced increases in bronchoalveolar lavage fluid (BALF) leukocytes, pulmonary macrophage infiltration and IL-6 expression, plasma TNFα and IL-1β levels, adipose macrophage infiltration and IL-1β expression, and endothelial dysfunction were reduced or absent in IKK2^Neu-KO mice compared with controls.

CONCLUSIONS

Our findings support a role of neural IKK2 in CAP exposure-induced local and systemic pro-inflammatory cytokine expression, pulmonary and adipose inflammation, and endothelial dysfunction, thus providing insight into pathophysiologic mechanisms that may mediate effects of PM_2.5 exposure. https://doi.org/10.1289/EHP2311.