Systemic Antiphospholipid Syndrome and Atherosclerosis

The Etiology of the Thrombotic Phenomena Involved in the Process of Coronary Artery Disease-What Is the Role of Thrombophilic Genes in the Development of This Pathology?

Cardiovascular diseases, among which includes coronary artery disease, represent one of the most important causes of mortality and morbidity worldwide. Research aimed at determining the risk factors involved recognizes a group of "traditional" risk factors, but also more recent studies identified over 100 "novel" ones which may have a role in the disease. Among the latter is the thrombophilia profile of a patient, a pathology well-established for its involvement in venous thromboembolism, but with less studied implications in arterial thrombosis. This paper reviews the literature, explaining the pathophysiology of the thrombophilia causes associated most with coronary thrombosis events. Results of several studies on the subject, including a meta-analysis with over 60,000 subjects, determined the significant involvement of factor V Leiden, prothrombin G20210A mutation, plasminogen activator inhibitor-1 and antiphospholipid syndrome in the development of coronary artery disease. The mechanisms involved are currently at different stages of research, with some already established and used as therapeutic targets.

Effects of β2/aβ2 on oxLDL-induced CD36 activation in THP-1 macrophages

AIMS

β2-glycoprotein I/anti-β2-glycoprotein I antibody complex (β2/aβ2) could promote oxLDL-induced endothelial inflammation through Toll-like receptor 4 (TLR4), therefore accelerates atherosclerosis in patients with anti-phospholipid syndrome (APS). However, effects of β2/aβ2 and TLR4 on oxLDL-induced CD36 activation in macrophages remain to be elucidated and are currently under investigation.

MATERIALS AND METHODS

THP-1 macrophages with or without the pre-treatment of TAK-242, a TLR4 inhibitor, were treated with RPMI 1640, oxLDL, oxLDL+β2/aβ2 or oxLDL + LPS.CD36 expression and subsequent intracellular lipid accumulation, cholesterol-transportation-related proteins (ACAT1, ABCG1 and ABCA1) expression, inflammatory cytokines (IL-1β, TNF-α and IL-6) secretion, focal adhesion kinases (FAK) activation and matrix metalloproteinases (MMP-2 and MMP-9) expression by these THP-1 macrophages were evaluated. Moreover, effects of TLR4 on oxLDL+β2/aβ2-induced peroxisome proliferators-activated receptor-γ (PPAR-γ) expression and CD36 translocation have also been observed.

KEY FINDINGS

Compared with oxLDL-treated ones, CD36 expression, intracellular lipid accumulation and FAK activation were inhibited, whereas the levels of inflammatory cytokines and MMPs were upregulated in THP-1 macrophages treated with oxLDL+β2/aβ2 (p < 0.05). Moreover, observed differences between oxLDL-treated and oxLDL+β2/aβ2-treated THP-1 macrophages could be reversed by TAK-242 pre-treatment (p < 0.05). Furthermore, oxLDL+β2/aβ2 promoted PPAR-γ expression and CD36 cytoplasmic translocation in THP-1 macrophages, these effects could also be attenuated by TAK-242 (p < 0.05).

SIGNIFICANCE

Through a TLR4 dependent manner, β2/aβ2 inhibited oxLDL-induced CD36 expression, lipid accumulation and FAK activation, while promoted inflammatory cytokines and MMPs expression in THP-1 macrophages, indicating the novel dual roles played by β2/aβ2 in APS-related atherosclerosis.

Subclinical atherosclerosis in asymptomatic carriers of persistent antiphospholipid antibodies positivity: A cross-sectional study

BACKGROUND

Whereas the relationship between subclinical atherosclerosis and antiphospholipid syndrome (APS) has been widely investigated, little is known about subclinical atherosclerosis in asymptomatic carriers with isolated antiphospholipid antibodies positivity (APP).

METHODS

Consecutive APP carriers, APS subjects and matched controls were enrolled. Intima-media thickness of the common carotid artery (CCA-IMT) and of the Bulb (Bulb-IMT) and the prevalence of carotid plaques were assessed in all enrolled subjects.

RESULTS

A total of 104 APP carriers, 221 APS subjects, and 325 matched controls were recruited. As compared with controls, APP carriers and APS subjects showed a higher CCA-IMT (0.90 ± 0.24 vs 0.82 ± 0.12, p = 0.014 and 0.93 ± 0.42 vs 0.82 ± 0.12, p < 0.001, respectively), Bulb-IMT (1.10 ± 0.44 vs 0.95 ± 0.18, p = 0.006 and 1.22 ± 0.68 vs 0.95 ± 0.18, p < 0.001, respectively) and an increased prevalence of carotid plaques (33.7% vs 10.2%, p < 0.001 and 38.5% vs 10.2%, p < 0.001, respectively). These results were confirmed stratifying for antibody isotype, after excluding subjects with systemic lupus erythematosus or other autoimmune diseases and after adjusting for major clinical and demographic variables. CCA-IMT, Bulb-IMT and the prevalence of carotid plaques were higher in subjects with high-titer antibodies and progressively increased for an increasing number of positive antibodies.

CONCLUSIONS

Similar to APS subjects, APP carriers have enhanced subclinical atherosclerosis, a more severe disease being observed in the presence of high-titer antibodies and multiple antibodies positivity. These data argue for a strict monitoring of subclinical signs of atherosclerosis and of cardiovascular risk factors in asymptomatic APP carriers.

Elevated Levels of Serum β2-Glycoprotein I/Oxidized Low-Density Lipoprotein Complexes Are Associated with Cerebral Infarction in Patients with Type 2 Diabetes Mellitus

Background

To determine whether the levels of β2-glycoprotein I (β2-GPI)/oxidized low-density lipoprotein (oxLDL) complexes are correlated with cerebral infarction in patients with type 2 diabetes mellitus (T2DM).

Material/Methods

The levels of β2-GPI/oxLDL complexes, oxLDL, routine lipid/lipoprotein parameters, oxidative stress molecules, and inflammatory factors were measured in 78 healthy controls, 82 diabetics without cerebral infarction, and 79 diabetics with cerebral infarction. Correlation, multiple linear regression, and logistic regression analyses were performed.

Results

Serum β2-GPI/oxLDL complexes and oxLDL levels were significantly elevated in cerebral infarction in patients with T2DM (β2-GPI/oxLDL: 1.09±0.16 U/mL; oxLDL: 47.83±8.17 mmol/L) compared with T2DM without cerebral infarction (β2-GPI/oxLDL: 0.95±0.13 U/mL; oxLDL: 41.24±7.12 mmol/L) and healthy controls (β2-GPI/oxLDL: 0.81±0.12 U/mL; oxLDL: 27.97±4.57 mmol/L). The levels of β2-GPI/oxLDL complex in lacunar infarction (1.16±0.15 U/ml) were significantly higher than atherothrombotic infarction (1.07±0.19 U/ml) and cardioembolic infarction (1.00±0.23 U/ml). In all patients with T2DM, the β2-GPI/oxLDL levels were positively correlated with total cholesterol (r=0.474, p=0.001) and triglycerides (r=0.431, p=0.003). oxLDL levels were positively correlated with total cholesterol (r=0.445, p=0.002). The logistic regression analysis indicated that elevated β2-GPI/oxLDL and oxLDL levels were independently associated with diabetic cerebral infarction.

Conclusions

Elevated levels of serum β2-GPI/oxLDL complexes are associated with cerebral infarction in patients with T2DM, especially in those with lacunar infarction.

Atherosclerotic vascular disease in the autoimmune rheumatologic patient

Autoimmune diseases, such as rheumatoid arthritis and systemic lupus erythematosus, have a strong association with an increased risk of atherosclerotic cardiovascular diseases (ASCVD), particularly ischemic heart disease (IHD). A majority of the autoimmune conditions occur predominantly in women, and as women continue to experience a higher cardiovascular mortality compared to men, this potential added risk factor must be recognized. Inflammation and immune mechanisms have been shown to be an underlying mechanism for the development of atherosclerosis, thus sharing a common mechanism with rheumatologic conditions. There is an under recognition, in both patient and physician, of the increased cardiovascular (CV) risk within the autoimmune population, with present CV risk profile algorithms performing poorly in these patients. Traditional risk factors play a role in the development of IHD in the autoimmune patient, but their overall significance is unclear and does not fully explain the elevated CV risk. The role of inflammation and risk factors in autoimmune conditions, and their link to the elevated CV risk will be explored within this article.

Immunotherapy in antiphospholipid syndrome

Antiphospholipid syndrome (APS) is a disorder characterized by the association of arterial or venous thrombosis and/or pregnancy morbidity with the presence of antiphospholipid antibodies (anticardiolipin antibodies, lupus anticoagulant antibodies, and/or anti-β2-glycoprotein I antibodies). Thrombosis is the major manifestation in patients with aPLs, but the spectrum of symptoms and signs associated with aPLs has broadened considerably, and other manifestations, such as thrombocytopenia, non-thrombotic neurological syndromes, psychiatric manifestations, livedo reticularis, skin ulcers, hemolytic anemia, pulmonary hypertension, cardiac valve abnormality, and atherosclerosis, have also been related to the presence of those antibodies. Several studies have contributed to uncovering the basis of antiphospholipid antibody pathogenicity, including the targeted cellular components, affected systems, involved receptors, intracellular pathways used, and the effector molecules that are altered in the process. Therapy for thrombosis traditionally has been based on long-term oral anticoagulation; however, bleeding complications and recurrence despite high-intensity anticoagulation can occur. The currently accepted first-line treatment for obstetric APS (OAPS) is low-dose aspirin plus prophylactic unfractionated or low-molecular-weight heparin (LMWH). However, in approximately 20% of OAPS cases, the final endpoint, i.e. a live birth, cannot be achieved. Based on all the data obtained in different research studies, new potential therapeutic approaches have been proposed, including the use of new oral anticoagulants, statins, hydroxychloroquine, coenzyme Q10, B-cell depletion, platelet and TF inhibitors, peptide therapy or complement inhibition among others. Current best practice in use of these treatments is discussed.

Cardiorheumatology: cardiac involvement in systemic rheumatic disease

Autoimmune rheumatic diseases can affect the cardiac vasculature, valves, myocardium, pericardium, and conduction system, leading to a plethora of cardiovascular manifestations that can remain clinically silent or lead to substantial cardiovascular morbidity and mortality. Although the high risk of cardiovascular pathology in patients with autoimmune inflammatory rheumatological diseases is not owing to atherosclerosis alone, this particular condition contributes substantially to cardiovascular morbidity and mortality-the degree of coronary atherosclerosis observed in patients with rheumatic diseases can be as accelerated, diffuse, and extensive as in patients with diabetes mellitus. The high risk of atherosclerosis is not solely attributable to traditional cardiovascular risk factors: dysfunctional immune responses, a hallmark of patients with rheumatic disorders, are thought to cause chronic tissue-destructive inflammation. Prompt recognition of cardiovascular abnormalities is needed for timely and appropriate management, and aggressive control of traditional risk factors remains imperative in patients with rheumatic diseases. Moreover, therapies directed towards inflammatory process are crucial to reduce cardiovascular disease morbidity and mortality. In this Review, we examine the multiple cardiovascular manifestations in patients with rheumatological disorders, their underlying pathophysiology, and available management strategies, with particular emphasis on the vascular aspects of the emerging field of 'cardiorheumatology'.

Markers of cardiovascular risk in patients with antiphospholipid syndrome: a meta-analysis of literature studies

Several studies reported on the association between antiphospholipid syndrome (APS) and venous thrombosis. In contrast, little is known about cardiovascular (CV) risk in APS. We performed a meta-analysis on the impact of APS on major markers of CV risk. Studies on the relationship between APS and common carotid artery intima-media thickness (CCA-IMT), internal carotid artery IMT (ICA-IMT), carotid bifurcation IMT (BIF-IMT), prevalence of carotid plaques, flow-mediated dilation (FMD), nitrate-mediated dilation (NMD), and ankle-brachial index (ABI) were systematically searched in PubMed, Web of Science, Scopus, and EMBASE databases. Twenty case-control studies (668 cases, 678 controls) were included. Compared to controls, APS patients showed a higher CCA-IMT (mean difference [MD] 0.11 mm; 95% CI 0.07, 0.14), ICA-IMT (MD 0.08 mm; 95% CI 0.05, 0.11), BIF-IMT (MD 0.09 mm; 95% CI 0.06, 0.12) and a higher frequency of carotid plaques (OR 3.87; 95% CI 1.61, 9.31). Moreover, a lower FMD was found in APS subjects than in controls (MD -4.49%; 95% CI -6.20, -2.78), with no differences in NMD (MD -1.80%; 95% CI -4.01, 0.42). Finally, an increased prevalence of pathological ABI was found in APS patients compared to controls (OR 7.26; 95% CI 1.77, 29.71). Despite heterogeneity among studies, APS appears significantly associated with markers of subclinical atherosclerosis and CV risk. These findings can be useful to plan adequate prevention strategies and therapeutic approaches.

Cardiovascular involvement in autoimmune diseases

Autoimmune diseases (AD) represent a broad spectrum of chronic conditions that may afflict specific target organs or multiple systems with a significant burden on quality of life. These conditions have common mechanisms including genetic and epigenetics factors, gender disparity, environmental triggers, pathophysiological abnormalities, and certain subphenotypes. Atherosclerosis (AT) was once considered to be a degenerative disease that was an inevitable consequence of aging. However, research in the last three decades has shown that AT is not degenerative or inevitable. It is an autoimmune-inflammatory disease associated with infectious and inflammatory factors characterized by lipoprotein metabolism alteration that leads to immune system activation with the consequent proliferation of smooth muscle cells, narrowing arteries, and atheroma formation. Both humoral and cellular immune mechanisms have been proposed to participate in the onset and progression of AT. Several risk factors, known as classic risk factors, have been described. Interestingly, the excessive cardiovascular events observed in patients with ADs are not fully explained by these factors. Several novel risk factors contribute to the development of premature vascular damage. In this review, we discuss our current understanding of how traditional and nontraditional risk factors contribute to pathogenesis of CVD in AD.

Cardiovascular risk factors in the antiphospholipid syndrome

A major cause of morbidity and mortality in the context of the antiphospholipid syndrome (APS) is the occurrence of thrombotic events. Besides the pathogenic roles of antiphospholipid antibodies (aPL), other risk factors and medical conditions, which are conditions for traditional risk of an individual without the APS, can coexist in this patient, raising their risk of developing thrombosis. Therefore, the clinical and laboratory investigation of comorbidities known to increase cardiovascular risk in patients with antiphospholipid antibody syndrome is crucial for the adoption of a more complete and effective treatment. Experimental models and clinical studies show evidence of association between APS and premature formation of atherosclerotic plaques. Atherosclerosis has major traditional risk factors: hypertension, diabetes mellitus, obesity, dyslipidemia, smoking, and sedentary lifestyle that may be implicated in vascular involvement in patients with APS. The influence of nontraditional risk factors as hyperhomocysteinemia, increased lipoprotein a, and anti-oxLDL in the development of thromboembolic events in APS patients has been studied in scientific literature. Metabolic syndrome with all its components also has been recently studied in antiphospholipid syndrome and is associated with arterial events.

Basilar artery thrombosis in the setting of antiphospholipid syndrome

Antiphospholipid syndrome is an autoimmune disorder characterized by arterial or venous thrombosis, recurrent first-trimester pregnancy loss, and multiple additional clinical manifestations. We describe a man with severe atherosclerotic basilar artery stenosis and superimposed in situ thrombus who was found to have antiphospholipid syndrome.

Increased concentrations of soluble CD40 ligand platelet in patients with primary antiphospholipidic syndrome

OBJECTIVE

To determine the concentrations of sCD40L in patients with PAPS, and establish its association with the number of thrombosis.

PATIENTS AND METHODS

We included patients with PAPS and healthy controls of the same age and sex. For analysis, patients with PAPS were divided into 2 groups: 1) patients with 1 thrombosis, and 2) patients with >1 thrombosis. Soluble CD40L concentrations were determined by ELISA method.

RESULTS

sCD40L concentrations were significantly higher in patients with PAPS compared with the controls (9.72 ng ± 11.23 ng/ml vs. 4.69 ± 4.04 ng/ml) (P=.04) There was no association between serum levels of sCD40L and the number of thrombosis (1 thrombosis: 9.81 ± 9.87 ng/ml vs 9.63 ± 12.75 ng/ml in ≥ 1thrombosis (P=.13). In women with pregnancy and abortions, (13 patients) concentrations of sCD40L were higher than in those patients without a history of abortion (26 patients) but without statically significant difference (12.11 ± 16.46 ng/ml vs. 8.80 ± 8.61 ng/ml) (P=.33). There was no correlation between levels of sCD40L and the total number of thrombosis.

CONCLUSIONS

Patients with PAPS have higher concentrations of sCD40L compared with healthy subjects, although this is not associated with a greater number of thrombosis. Among patients with PAPS, there is a tendency to higher concentrations of sCD40L in women with pregnancy and history of abortion. Since the platelet is the main cellular source of sCD40L, is possible that this pathway plays a pathogenic role in patients with PAPS.

Dendritic cells: an important link between antiphospholipid antibodies, endothelial dysfunction, and atherosclerosis in autoimmune and non-autoimmune diseases

The presence of dendritic cells, antigen-presenting cells that link innate and adaptive immunity, is necessary to generate and maintain the production of antiphospholipid antibodies in response to exposed intracellular phospholipids on the outer surface of apoptotic cells. In turn, antiphospholipid antibodies enhance dendritic cell-induced inflammatory and proatherogenic responses in a number of conditions that are associated with accelerated atherosclerosis, including diabetes, chronic kidney disease, periodontal infections, and aging. While altering dendritic cells by modifying the ubiquitin-proteasome system enhances antiphospholipid antibody production and leads to development of accelerated atherosclerosis and autoimmune features, inducing tolerance by dendritic cell manipulation leads to decreased atherosclerosis and thrombosis. Therefore, further translational studies are needed to understand the interplay between dendritic cells and antiphospholipid antibodies, and to develop potential new therapies for antiphospholipid syndrome and atherosclerosis. Here we review current experimental and translational studies that have examined the role of dendritic cells in antiphospholipid antibody formation and in antiphospholipid-associated atherosclerosis and thrombosis.

Long-term outcome of patients with antiphospholipid syndrome who undergo percutaneous coronary intervention

OBJECTIVES

Patients with antiphospholipid antibody syndrome (APS) have an increased risk of atherothrombotic complications. There are limited data regarding the outcome of patients with APS who undergo percutaneous coronary intervention (PCI). Accordingly, we aimed to assess the long-term outcomes of these patients.

METHODS

Nineteen APS patients who underwent PCI between the years 2003 and 2008 were compared to 380 patients who had undergone PCI during the same period (PCI group) and were matched by age (±5 years), gender, diabetes and hypertension. In addition, APS patients were compared to 1,458 patients with ST segment elevation myocardial infarction (MI) who were treated with PCI during the same period. Six-month to 4-year clinical outcomes were evaluated.

RESULTS

The indication for PCI in the APS group was acute coronary syndrome in 52.6% of patients. After 1 year of follow-up, patients with APS had higher rates of target vessel revascularization than the other two groups, which translated to higher rates of major adverse cardiac events. There were no differences in MI or mortality rates between the groups.

CONCLUSIONS

Patients with APS who undergo PCI have worse long-term clinical outcomes, driven by higher rates of revascularization, than other patients undergoing PCI. Further study is warranted to examine the mechanisms underlying these findings.

Patients' experiences of a diagnosis of Hughes' syndrome

The objectives of the study were to describe the experience of patients immediately prior to a diagnosis of Hughes syndrome (HS) or antiphospholipid syndrome and post-diagnosis. A questionnaire survey was carried out set in the Hughes Syndrome Foundation, St. Thomas' Hospital, London, 2006. Participants were all patients who are members of the Hughes Syndrome Foundation. The main outcome measures were responses to a questionnaire relating to the experiences of people with a diagnosis of HS, such as number of hospitalisations, number of consultants seen, number of miscarriages, etc. A total of 157 patients completed the questionnaire, giving a response rate of 60.4%. Most (85%) were women and mean age was 46 years (SD 12). The median time to diagnosis was 3 years. The median number of consultants seen was 2 (max 19) with a median time in hospital pre-diagnosis of 10 days. The most common initial diagnoses were migraines, multiple sclerosis and systemic lupus erythematosus. Among women, 46% had had a miscarriage. Two thirds of respondents thought a blood test would have led to an earlier diagnosis. Comments from patients indicated a lack of awareness among specialists and general practitioners. The survey demonstrated a long time lag for diagnosis of Hughes syndrome, with increased costs to the NHS and emotional and financial cost to the patient. Greater awareness of this condition would benefit patients and the NHS.