Anti-phospholipid antibody prevalence and association with subclinical atherosclerosis and atherothrombosis in the general population

Intima media thickness of the carotid artery in primary antiphospholipid syndrome: A systematic review and meta-analysis

BACKGROUND

Primary antiphospholipid syndrome (PAPS) has been associated with an increase in clinical events associated with atherosclerotic vascular disease. Intima media thickness (IMT) of carotid arteries is a surrogate marker of atherosclerotic vascular disease.

OBJECTIVES

To conduct a systematic review and meta-analysis of studies evaluating IMT and their clinical correlates in PAPS.

METHODS

Systematic search of EMBASE and PubMed databases from January 2000 to December 2023; we employed random effect meta-analyses for continuous outcomes and Peto's odds ratio for rare events.

RESULTS

The meta-analysis included 21 studies (20 case control and 1 cohort) showing that PAPS patients (n = 1103) had thicker IM than controls (n = 832) (p < 0.0001) with wide heterogeneity (I2 = 86.9 %); PAPS patients (n = 782) also had a greater pooled prevalence of carotid plaques than controls (n = 537) (13.1 % vs 2.97 %, p < 0.0001). A sensitivity analysis by meta-regression indicated that mean age, gender, disease duration, lipid profile, blood pressures, smoking and statin use all explained the heterogeneity variance; a sensitivity analysis by subgroups confirmed smoking status and statin use as explanatory variables with the addition of ethnicity.

CONCLUSION

Atherosclerosis of the carotid artery represents a clinical feature of PAPS in relation to the traditional risk factors and to statin use. Minimising the atherogenic risk with statins could reduce the late arterial atherothrombotic risks of PAPS.

Risk factors for thrombotic events in systemic lupus erythematosus patients with antiphospholipid antibodies: insights from morphometric measurements of carotid arteries

Objective

To identify the correlation between thrombosis and atherosclerosis in systemic lupus erythematosus (SLE) patients with antiphospholipid antibodies (aPLs) (SLE/aPLs) through high-resolution magnetic resonance imaging (HR-MRI) of the carotid artery.

Methods

A single-center, cross-sectional study was conducted. We collected consecutive patients with SLE/aPLs and healthy controls who underwent carotid HR-MRI examinations. The morphometric characteristics of the common carotid artery (CCA), internal carotid artery (ICA), external carotid artery (ECA), and carotid bulb (Sinus) were measured, and the differences in morphometric parameters between different groups were analyzed.

Results

A total of 144 carotid arteries were analyzed. Compared with the control group, the wall area, wall thickness (WT and WTmax), and normalized wall index of CCA, ICA, ECA, and Sinus were increased in patients with SLE/aPLs, and the total vascular area (TVA) of CCA, ICA, and Sinus, and the bifurcation angle (BIFA) of ICA-ECA were also increased. A negative lupus anticoagulant (LAC) (with or without positive anticardiolipin antibody (aCL) or anti-β2glycoprotein antibody (aβ2GPI)) contributed to illustrating lower increased TVA and thickened vessel walls of CCA and ICA in SLE/aPLs patients without thrombotic events. Logistic regression analysis showed that WTmaxSinus and WTmaxGlobal were independent risk factors for thrombotic events in SLE/aPLs patients. The receiver operator characteristic curve showed that the cut-off value of WTmaxSinus was 2.855 mm, and WTmaxGlobal was 3.370 mm.

Conclusion

HR-MRI ensures the complete and accurate measurement of carotid morphometric parameters. Compared with the control group, the carotid artery in patients with SLE/aPLs is mainly characterized by diffusely thickened vessel walls, and the patients with thrombotic events showed additional higher vascular area of CCA and ICA, and BIFA of ICA-ECA without significant change in lumen area. The carotid arteries of SLE/aPLs patients with thrombotic events exhibited significant vessel wall thickening in all segments except ECA compared to those without thrombotic events. LAC-negative and non-thrombotic events distinguish relatively early atherosclerosis in the carotid arteries in patients with SLE/aPLs. Patients with SLE/aPLs that possess circumscribed thickened carotid vessel walls (>3.370 mm), particularly thickened at the Sinus (>2.855 mm), may require management strategies for the risk of thrombotic events.

A predictive model for premature atherosclerosis in systemic lupus erythematosus based on clinical characteristics

OBJECTIVE

Systemic lupus erythematosus (SLE) is associated with a significant risk of atherosclerotic cardiovascular disease, especially in the development of premature atherosclerosis. Specific prediction models for premature atherosclerosis in SLE patients are still limited. The objective of this study was to establish a predictive model for premature atherosclerosis in SLE.

METHOD

The study collected clinical and laboratory data from 148 SLE patients under the age of 55, between January 2021 and June 2023. The least absolute shrinkage and selection operator logistic regression model was utilized to identify potentially relevant features. Subsequently, a nomogram was developed using multivariable logistic analysis. The performance of the nomogram was evaluated through a receiver-operating characteristic curve, calibration curve, and decision curve analysis (DCA).

RESULTS

A total of 148 SLE patients who fulfilled the inclusion criteria were enrolled in the study, of whom 53 patients (35.81%) met the definition of premature atherosclerosis. Hypertension, antiphospholipid syndrome, azathioprine use, duration of glucocorticoid, and age of patients were included in the multivariable regression. The nomogram, based on the non-overfitting multivariable model, was internally validated and demonstrated sufficient clinical utility for assessing the risk of premature atherosclerosis (area under curve: 0.867).

CONCLUSIONS

The comprehensive nomogram constructed in this study serves as a useful and convenient tool for evaluating the risk of premature atherosclerosis in SLE patients. It is helpful for clinicians to early identify SLE patients with premature atherosclerosis and facilitates the implementation of more effective preventive measures. Key Points • SLE patients are at a significantly higher risk of developing premature atherosclerosis compared to the general population, and this risk persists even in cases with low disease activity. Traditional models used to evaluate and predict premature atherosclerosis in SLE patients often underestimate the risk. • This study establishes a comprehensive and visually orientated predictive model of premature atherosclerosis in SLE patients, based on clinical characteristics. • The scoring system allows for convenient and effective prediction of individual incidence of premature atherosclerosis, and could provide valuable information for identification and making further intervention decision.

The interaction of persistent antiphospholipid antibodies positivity and cigarette smoking is associated with an increased risk of cardiovascular events: Cross-sectional and longitudinal analysis

BACKGROUND

The antiphospholipid antibody (aPL)-positivity was suggested as a nontraditional risk of coronary artery disease (CAD) and it was associated with cigarette smoking. The co-occurrence of them was usually reported in individuals with cardiovascular diseases. This study was to demonstrate their interaction on the increasing risk of cardiovascular events.

METHODS AND RESULTS

A total of 826 consecutive male individuals who underwent coronary angiography (CAG) /percutaneous coronary intervention (PCI) were prospectively followed and classified into three groups based on different smoking statuses. The current smoking subjects had the highest occurrence of aPL-positivity, including aCL IgM (20.1%) and aβ2GP1 IgM (15.5%). IgM isotype positivity was an independent risk factor of CAD in the multivariate model, OR: 2.70 (1.52-4.80) for aCL IgM and OR:2.50 (1.35-4.63) for aβ2GP1 IgM.The interaction of current smoking and IgM isotype positivity was significantly associated with increased risk of CAD, OR: 8.75(4.59-16.66) for aCL IgM and OR: 8.78(4.28-17.98) for aβ2GP1 IgM. During about 3 years of follow-up, the smoking patients carrying persistent aPL positivity had the highest cumulative incidence of recurrent myocardial infarction and in-stent restenosis after CAD.

CONCLUSION

The interaction of current smoking and IgM isotype positivity was significantly associated with the increased risk of CAD, including positive aCL IgM and aβ2GP1 IgM. Cigarette smoking elevated the risk of subsequent cardiovascular events in the presence of IgM isotype positivity, including recurrent myocardial infarction and in-stent restenosis.

Risk of Subclinical Atherosclerosis in Patients with Antiphospholipid Syndrome and Subjects With Antiphospholipid Antibody Positivity: A Systematic Review and Meta-analysis

Currently, the guidelines for the prevention of atherosclerosis in patients with antiphospholipid syndrome (APS) do not differ substantially from those in the general population. We aimed to assess the risk of subclinical atherosclerosis in patients with APS and subjects with antiphospholipid antibody (aPL) positivity. Systematic literature search was conducted through Medline and Scopus until January 2023. Random effects meta-analyses were performed to examine the differences in markers of subclinical atherosclerosis between APS patients, subjects positive for aPLs and healthy controls. Patients with APS had significantly higher values of common carotid artery (CCA) intima-media thickness (IMT) (MD = 0.07 mm; P < 0.0001), internal carotid artery IMT (MD = 0.06 mm; P < 0.01), carotid bifurcation IMT (MD = 0.14 mm; P < 0.01) and were more frequently diagnosed with atherosclerotic plaques compared to controls (OR = 3.73; P < 0.01). Similarly, APS patients showed a decreased flow and nitrate-mediated dilation (MD = -4.52 %; <0.01, MD = -1.25 %; P < 0.05, respectively). Interestingly, comparable were the results for subjects with aPL positivity, who had higher CCA-IMT (MD = 0.06 mm; P < 0.01) and higher prevalence of atherosclerotic plaques (OR = 2.59; P = 0.08) compared to controls. Sensitivity analysis conducted on primary APS patients revealed that the risk of atherosclerosis is associated with APS per se and is not exclusively driven by other underlying conditions. Patients with APS and subjects with aPLs have an increased risk of subclinical atherosclerosis and require early and disease-specific prevention of atherosclerosis.

Antiphospholipid antibodies in patients with calcific aortic valve stenosis

OBJECTIVES

The antiphospholipid syndrome is defined by antiphospholipid antibodies (aPL) together with arterial and/or venous thromboembolism and/or obstetric morbidities. aPL are overrepresented in SLE and acute myocardial infarction, but it is unknown whether aPL are associated with calcific aortic valve stenosis (CAVS) in the general population. The prevalence of aPL and other SLE-associated autoantibodies and their impact on aortic valve transcriptomics were therefore determined.

METHODS

A total of 233 tricuspid CAVS cases (median age 74, 69% male) and an age- and sex-matched control population were included. aPL were measured as anti-cardiolipin and anti-β2Glycoprotein-I of IgG/M/A isotypes. Resilient, thickened and calcified aortic valve (AV) tissue derived from five aPL positive and five matched aPL negative CAVS patients undergoing surgical aortic valve replacement were analysed by microarrays.

RESULTS

The prevalence of positivity for any aPL (IgG/M/A) in patients with CAVS was 6.4% (95% CI 3.6% - 10.4%: n = 233). aPL IgG was significantly more prevalent in CAVS cases vs controls (4.6% vs 0.6%, P = 0.04). AV tissue from aPL IgG/IgM-positive patients was negatively enriched in pathways related to interferon signalling. One hundred differentially expressed genes could predict local AV CAVS progression with supervised machine learning algorithms.

CONCLUSIONS

aPL IgG was more common in CAVS patients compared with matched controls and aPL positivity was associated with altered AV transcriptomics related to local disease progression and interferon pathways. Further studies should aim to establish aPL as a possible risk marker and/or causal factor for CAVS and could offer new precision therapeutic targets.

Cardiovascular disease risk in antiphospholipid syndrome: Thrombo-inflammation and atherothrombosis

Antiphospholipid syndrome (APS) is an autoimmune disorder characterized by the presence of antiphospholipid antibodies (aPL) (lupus anticoagulant, anticardiolipin antibodies and anti-beta2glycoprotein I (anti-β2GPI) antibodies) and a plethora of macro- and micro-vascular manifestations, affecting predominantly young adults. Cardiovascular events are the leading causes of morbidity and mortality in APS. APL-mediated thrombo-inflammation and atherothrombosis are emerging pathogenetic mechanisms of cardiovascular disease (CVD) in APS, involving endothelial cell and monocyte activation, cytokines and adhesion molecules expression, complement and neutrophils activation, neutrophil extracellular traps formation, platelet cell activation and aggregation, and subsequent thrombin generation, in parallel with an oxidized low-density lipoprotein (oxLDL)-β2GPI complex induced macrophage differentiation to foam cells. High risk aPL profile, especially the presence of lupus anticoagulant and triple aPL positivity (all three aPL subtypes), co-existence with Systemic Lupus Erythematosus (SLE), as well as traditional risk factors such as smoking, hypertension, hyperlipemia and obesity are associated with both subclinical atherosclerosis and cardiovascular events in APS. Increased awareness of CVD risk by the physicians and patients, regular assessment and strict control of traditional risk factors, and lifestyle modifications are recommended. Use of low-dose aspirin should be considered for cardiovascular prevention in asymptomatic aPL carriers or SLE patients with high-risk aPL profile. The role of older agents such as hydroxychloroquine and statins or new potential targeted treatments against immuno- and athero-thrombosis has been demonstrated by experimental and some clinical studies and needs to be further evaluated by randomized controlled studies. This review summarizes the available evidence about the pathogenetic mechanisms and prevalence of cardiovascular events and subclinical atherosclerosis, the interrelationship between traditional and disease-related CVD risk factors, and the cardiovascular risk assessment and management in APS.

Antiphospholipid antibodies in patients with myocardial infarction with and without obstructive coronary arteries

BACKGROUND

Recent studies demonstrate that prothrombotic antiphospholipid antibodies (aPL) are overrepresented in patients with myocardial infarction (MI) due to coronary artery disease (MICAD). However, it is not known whether aPL differ between the two subsets of MI: MICAD and MI with nonobstructive coronary arteries (MINOCA).

OBJECTIVES

To determine whether aPL are associated with MINOCA or MICAD, or with hypercoagulability as assessed by activated protein C-protein C inhibitor (APC-PCI) complex.

METHODS

Well-characterized patients with MINOCA (n = 98), age- and gender-matched patients with MICAD (n = 99), and healthy controls (n = 100) were included in a cross-sectional case-control study. Autoantibodies (IgA/G/M) targeting cardiolipin and β₂ glycoprotein-I and specific nuclear antigens were analyzed by multiplexed bead technology. The concentration of APC-PCI was determined as a measure of hypercoagulability by an immunofluorometric sandwich assay.

RESULTS

Both prevalence and titers of aPL of the IgG isotype (anti-cardiolipin and/or anti-β₂ glycoprotein-I) were higher in patients with MINOCA and MICAD than in controls. aPL IgG positivity was twice as frequent among patients with MICAD than MINOCA (11% vs. 6%, nonsignificant). We observed no group differences regarding aPL IgA/M or antibodies targeting specific nuclear antigens. Levels of APC-PCI were elevated in aPL IgG-positive compared to aPL IgG-negative MICAD patients.

CONCLUSIONS

aPL IgG, but not IgA/M, are enriched particularly in patients with MICAD but also in patients with MINOCA, as compared to controls. Interestingly, signs of hypercoagulability-measured by increased levels of the APC-PCI complex-were present in aPL IgG-positive MICAD patients, indicating an association with functional disturbances of the coagulation system.

Antimitochondrial Antibodies: from Bench to Bedside

Anti-mitochondrial antibodies (AMA) are directed against the E2 subunits of the 2-oxo acid dehydrogenase complexes (PDC-E2) and are the typical biomarkers of primary biliary cholangitis (PBC), being present in 90-95% of patients, with increasing sensitivity at increasing titers. Albeit being highly specific for PBC diagnosis, AMA can be detected in less than 1% of healthy subjects, and thus the management subjects with no sign or symptom of liver disease is still a challenge and data concerning clinical risk of developing PBC in this subgroup of patients are controversial. Moreover, AMA can also be detected in patients affected by overlap syndrome, as well as hepatic diseases (i.e., NASH and viral hepatitis), while the association with autoimmune diseases, in particular Sjögren's syndrome, systemic sclerosis, and systemic lupus erythematosus, is well established. Furthermore, new associations are being identified with inflammatory myositis and heart disease. AMA are directed towards the pyruvate dehydrogenase multi enzyme complex (PDC-E2) subunit, which represents an epithelial specific autoantigen for PBC. This review focuses on the main characteristics of AMA, their association with autoimmune diseases and liver diseases.

Persistent IgG anticardiolipin autoantibodies are associated with post-COVID syndrome

Persistence of various symptoms in patients who have recovered from coronavirus disease 2019 (COVID-19) was recently defined as ‘long COVID’ or ‘post-COVID syndrome’ (PCS). This article reports a case of a 58-year-old woman who, although recovering from COVID-19, had novel and persistent symptoms including neurological complications that could not be explained by any cause other than PCS. In addition to a low inflammatory response, persistence of immunoglobulin G anticardiolipin autoantibody positivity and eosinopenia were found 1 year after acute COVID-19 infection, both of which have been defined previously as independent factors associated with the severity of COVID-19. The pathophysiological mechanism of PCS is unknown, but the possibility of persistence of the virus, especially in the nervous system, could be suggested with a post-infectious inflammatory or autoimmune reaction.

Risk Factors for the Development of the Disease in Antiphospholipid Antibodies Carriers: A Long-term Follow-up Study

The natural history of antiphospholipid antibodies (aPL) carriers is not well-established. The objectives of the present study were (a) to study the probability of developing clinical criteria of antiphospholipid syndrome (APS), (b) to identify potential risk factors for developing thrombosis and/or obstetric complications, (c) to study the association between the antibody profile and development of APS, and (d) to determine the efficacy of primary prophylaxis. We retrospectively analyzed 138 subjects with positive aPL who did not fulfill clinical criteria for APS. The mean follow-up time was 138 ± 63.0 months. Thirteen patients (9.4%) developed thrombosis after an average period of 73.0 ± 48.0 months. Independent risk factors for thrombosis were smoking, hypertension, thrombocytopenia, and triple aPL positivity. Low-dose acetyl salicylic acid did not prevent thrombotic events. A total of 28 obstetric complications were detected in 92 pregnancies. During the follow-up, only two women developed obstetric APS. Prophylactic treatment in pregnant women was associated with a better outcome in the prevention of early abortions. The thrombosis rate in patients with positive aPL who do not meet diagnostic criteria for APS is 0.82/100 patients-year. Smoking, hypertension, thrombocytopenia, and the aPL profile are independent risk factors for the development of thrombosis in aPL carriers. Although the incidence of obstetric complications in this population is high (31.6%), only a few of them meet APS criteria. In these women, prophylactic treatment might be effective in preventing early abortions.

Systematic Review of Antiphospholipid Antibodies in COVID-19 Patients: Culprits or Bystanders?

PURPOSE OF REVIEW

COVID-19 patients have a procoagulant state with a high prevalence of thrombotic events. The hypothesis of an involvement of antiphospholipid antibodies (aPL) has been suggested by several reports. Here, we reviewed 48 studies investigating aPL in COVID-19 patients.

RECENT FINDINGS

Prevalence of Lupus Anticoagulant (LA) ranged from 35% to 92% in ICU patients. Anti-cardiolipin (aCL) IgG and IgM were found in up to 52% and up to 40% of patients respectively. Anti-β2-glycoprotein I (aβ2-GPI) IgG and IgM were found in up to 39% and up to 34% of patients respectively. Between 1% and 12% of patients had a triple positive aPL profile. There was a high prevalence of aβ2-GPI and aCL IgA isotype. Two cohort studies found few persistent LA but more persistent solid phase assay aPL over time. aPL determination and their potential role is a real challenge for the treatment of this disease.

Location of recurrent cardiovascular events and anticardiolipin antibodies

BACKGROUND

The relationship between anticardiolipin (aCL) antibodies and cardiovascular events is uncertain and may vary according to arterial location.

MATERIALS AND METHODS

FRENA is an ongoing registry of stable outpatients with symptomatic coronary artery disease (CAD), cerebrovascular disease (CVD) or peripheral artery disease (PAD). The rate of subsequent ischaemic events was cross-referenced with the presence of aCL antibodies (any isotype, IgG or IgM).

RESULTS

As of June 2017, 1387 stable outpatients were recruited. Of these, 120 (8.7%) showed positive levels of aCL antibodies. Over an average follow-up of 18 months, 250 patients developed subsequent events: 101 myocardial infarction, 57 ischaemic stroke and 92 critical leg events. Patients with positive aCL antibodies had a higher risk of distal artery events (a composite of ischaemic stroke or critical leg events) than patients with undetectable or low levels (rate ratio: 1.66; 95% CI: 1.07-2.60). However, an association with central coronary events was not found. The multivariate Cox analysis after adjustment for relevant clinical covariates showed that positivity of aCL antibodies is an independent risk factor for distal events (hazard ratio: 1.60; 95% CI: 1.01-2.55; P < .05).

CONCLUSIONS

Positivity of aCL antibodies is associated with an increased risk of subsequent distal artery ischaemic events (cerebral or leg arteries) but not coronary artery events. Anticardiolipin antibodies appear to have a different relationship on the localisation of ischaemic events in patients with symptomatic artery disease.

CA.ME.LI.A. An epidemiological study on the prevalence of CArdiovascular, MEtabolic, LIver and Autoimmune diseases in Northern Italy

BACKGROUND AND AIMS

CA.ME.LI.A (CArdiovascular risks, MEtabolic syndrome, LIver and Autoimmune disease) is a cross-sectional, epidemiological study performed between 2009-2011 in Abbiategrasso (Milan, Italy) to estimate the prevalence of cardiovascular risk factors, metabolic syndrome, liver and autoimmune diseases in the general adult population. This report focuses on the description and presentation of baseline characteristics of the population.

METHODS AND RESULTS

Citizens were randomly selected from the city electoral registers (n = 30903), yielding a sample of 2554 subjects (M = 1257, F = 1297; age, 47 ± 15 yrs; range 18-77 yrs). Men had higher prevalence of overweight or obesity (60.8% vs 41.6%; p < 0.0001) and greater thickness of visceral adipose tissue (40 ± 19 vs 27 ± 17 mm; p < 0.0001); no gender difference was found in subcutaneous adipose tissue thickness. Men also showed higher levels of serum triglycerides, γ-GT, fasting blood glucose, insulin and Homa-IR Index, while HDL, CRP, and prevalence of elevated (>5.0 mg/L) CRP were lower. Compared to normal weight men, risk-ratio (RR) of CRP elevation was 1.32 (ns) in overweight and 2.68 (p < 0.0001) in obese subjects. The corresponding figures in females were 2.68 (p < 0.0001) and 5.18 (p < 0.0001). Metabolic syndrome was more frequent in men (32.7% vs 14.5%; RR: 2.24, p < 0.0001). Interadventitia common carotid artery diameter was higher in men and increased with age and BMI.

CONCLUSIONS

The present study reports on the overall characteristics of a large population from Northern Italy. It aims to identify the associations among cardiovascular risk factors to prevent their development and progression, improve healthy lifestyle and identify subjects liable to pharmacological interventions.

The JANUS of chronic inflammatory and autoimmune diseases onset during COVID-19 - A systematic review of the literature

The diverse clinical manifestations of COVID-19 is emerging as a hallmark of the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection. While the initial target of SARS-CoV-2 is the respiratory tract, it is becoming increasingly clear that there is a complex interaction between the virus and the immune system ranging from mild to controlling responses to exuberant and dysfunctional multi-tissue directed autoimmune responses. The immune system plays a dual role in COVID-19, being implicated in both the anti-viral response and in the acute progression of the disease, with a dysregulated response represented by the marked cytokine release syndrome, macrophage activation, and systemic hyperinflammation. It has been speculated that these immunological changes may induce the loss of tolerance and/or trigger chronic inflammation. In particular, molecular mimicry, bystander activation and epitope spreading are well-established proposed mechanisms to explain this correlation with the likely contribution of HLA alleles. We performed a systematic literature review to evaluate the COVID-19-related autoimmune/rheumatic disorders reported between January and September 2020. In particular, we investigated the cases of incident hematological autoimmune manifestations, connective tissue diseases, antiphospholipid syndrome/antibodies, vasculitis, Kawasaki-like syndromes, acute arthritis, autoimmune-like skin lesions, and neurologic autoimmune conditions such as Guillain-Barré syndrome. We screened 6263 articles and report herein the findings of 382 select reports which allow us to conclude that there are 2 faces of the immune response against SARS-CoV-2, that include a benign virus controlling immune response and a many faceted range of dysregulated multi-tissue and organ directed autoimmune responses that provides a major challenge in the management of this viral disease. The number of cases for each disease varied significantly while there were no reported cases of adult onset Still disease, systemic sclerosis, or inflammatory myositis.

Mitochondrial DAMPs and altered mitochondrial dynamics in OxLDL burden in atherosclerosis

Atherosclerosis results in life-threatening cardiovascular pathologies, including ischemic heart disease, stroke, myocardial infarction, and peripheral arterial disease. The role of increased serum low-density lipoprotein (LDL) and resultant accumulation of oxidized-LDL (oxLDL) in atheroma formation is well established. Recent findings elucidate the significance of mitochondrial damage-associated molecular patterns (mtDAMPs) in triggering sterile inflammation in concert with oxLDL. The mtDAMPs including mitochondrial DNA (mtDNA), cytochrome C, cardiolipin, heat shock protein 60 (HSP60), mitochondrial transcription factor A (TFAM), and N-formyl peptides, are expected to possess proatherogenic roles. However, limited data are available in the literature. The mtDAMPs initiate sterile inflammation in atherosclerotic lesions via numerous signaling pathways, most of which converge to the NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome. Priming the activation of the NLRP3 inflammasome, mtDAMPs promote secretion of proinflammatory cytokines, including interleukin-1β (IL-1β), implicated in atherosclerotic lesions through vascular smooth muscle and fibroblast proliferation, arterial wall thickening, and plaque formation. In this article we critically reviewed and discussed the central role of the NLRP3 inflammasome in mtDAMP-induced sterile inflammation in atherosclerosis with specific components including caspase-1, pregnane X receptor (PXR), adenosine monophosphate activated protein kinase (AMPK), protein phosphatase 2A (PP2A), thioredoxin-interacting protein (TXNIP), and downstream cytokines including IL-1β and IL-18 as potential mediators of atherosclerosis. Better understanding of the proinflammatory effects of mtDAMPs and its pathological association with oxLDL possess immense translational significance for novel therapeutic intervention.

The Weight of IgA Anti-β2glycoprotein I in the Antiphospholipid Syndrome Pathogenesis: Closing the Gap of Seronegative Antiphospholipid Syndrome

The specific value of IgA Anti-β2glycoprotein I antibodies (aB2GP1) in the diagnosis and management of antiphospholipid syndrome (APS) is still controversial and a matter of active debate. The relevance of the IgA aB2GP1 isotype in the pathophysiology of APS has been increasingly studied in the last years. There is well know that subjects with multiple positive APS tests are at increased risk of thrombosis and/or miscarriage. However, these antibodies are not included in the 2006 APS classification criteria. Since 2010 the task force of the Galveston International Congress on APS recommends testing IgA aB2GP1 isotype in patients with APS clinical criteria in the absence of criteria antibodies. In this review, we summarize the molecular and clinical “state of the art” of the IgA aB2GP in the context of APS. We also discuss some of the characteristics that may help to evaluate the real value of the IgA aB2GP1 determination in basic research and clinical practice. The scientific community should be aware of the importance of clarifying the role of IgA aB2GP1 in the APS diagnosis.

Antiphospholipid antibodies and lower extremity peripheral artery disease: A systematic review and meta-analysis

AIM

To evaluate the clinical relevance of antiphospholipid antibodies (aPL) in patients with lower extremity peripheral artery disease (PAD).

DATA SOURCES

EMBASE and MEDLINE databases were searched from inception to March 2020 for clinical studies reporting on the association between of aPL [IgG/IgM anticardiolipin (aCL) and lupus anticoagulant (LA)] and PAD.

METHODS

We determined the pooled prevalence (PP) of patients positive for aPL in PAD or the PP of PAD in patients positive for aPL; we employed Peto's odds ratio with random effect for the meta-analysis.

RESULTS

Twenty-one studies comprising 6,057 patients were evaluated: in patients with PAD, the PP of IgG aCL was 12% vs 4.1% in those without, IgM aCL was 13.2% vs 2.1%, and LA 13.3% vs 3.3%, respectively. The PP of patients with LA was greater in critical limb ischemia than in the control group (19.3% vs 4.2%). Also, the PP of patients with LA was greater in the failed than in the successful revascularisation group (35.8% vs 15.8%). The PP of post-procedural revascularisation failures was similar in the groups given or not given oral anticoagulation (59.2% vs 61.9%).

CONCLUSION

All the aPL related to PAD regardless of diagnostic definition used, whereas LA related also to critical limb ischaemia and failed revascularisation. Data expressed as percentage of participants positive for aPL limit the interpretation of these relationships.