Recurrent thrombosis in antiphospholipid syndrome may be associated with cardiovascular risk factors and inflammatory response

Patients with antiphospholipid syndrome and a first venous or arterial thrombotic event: clinical characteristics, antibody profiles and estimate of the risk of recurrence

OBJECTIVES

Thrombosis in antiphospholipid syndrome (APS) involves in most cases the venous circulation. Why in some patients thrombotic APS affects the arterial circulation and in particular cerebral circulation is unknown. In previous studies, both patient characteristics and antiphospholipid antibody types and titers have been associated with arterial thrombosis. Aim of this study was to compare the clinical characteristics and laboratory findings of venous and arterial thrombotic APS from a large series of patients.

METHODS

Data were retrieved from the Start 2 antiphospholipid, a multicenter prospective register of long-term collected data from Thrombosis Centers in Italy.

RESULTS

Of 167 patients with thrombotic APS, 114 (68 %) had a venous and 53 (32 %) had an arterial event as first clinical manifestation. Several clinical characteristics and risk factors were different among groups in univariate analysis. Using logistic regression analysis, reduced creatinine clearance and hyperlipidemia were independent variable for the occurrence of arterial APS. Notably, no difference in antiphospholipid antibody profiles and aβ2-Glycoprotein I levels were found between groups. A higher adjusted global antiphospholipid syndrome score (aGAPSS) was found in arterial group indicating a possible high recurrence rate in arterial APS.

CONCLUSIONS

These data have pathophysiological and clinical implication since associated conditions might predispose patients to arterial rather than venous events and call to a close monitoring and treatment of arterial APS due to their increased tendency to recurrence.

Should we be targeting type 1 interferons in antiphospholipid syndrome?

Systemic autoimmune diseases are characterized by increased production of type I interferon (IFN-1) and upregulation of IFN-1-inducible genes, suggesting an important role of the IFN-1 pathway in their pathogenesis. Recent studies have demonstrated increased IFN-1 expression in both primary and secondary antiphospholipid syndrome (APS), along with increased toll-like receptor type 9 activity and plasmacytoid dendritic cell function. The increasing knowledge of the association between IFN-1 and APS pathology may provide a rationale for conducting clinical trials to assess the efficacy of IFN-1-targeting drugs in reducing APS-related complications. In this narrative review, we summarize the current knowledge on the role of IFN-1 in APS pathogenesis, explore its clinical implications, and examine the existing evidence regarding therapeutic options that have been investigated to date.

Prevalence, risk factors, and prognosis of central nervous system manifestations in antiphospholipid syndrome

The central nervous system (CNS) is considered as one of the most frequently affected organs in antiphospholipid syndrome (APS). This study investigated the prevalence of CNS manifestations in APS and associated risk factors and evaluated stroke recurrence. We carried out this retrospective study from 2009 to 2021 at Peking University People's Hospital, which enrolled 342 APS patients, and 174 neurologic events were suffered by 119 patients (34.8%). Patients with and without CNS involvement were compared regarding demographics and laboratory parameters. The analysis showed that older age, livedo reticularis, and dyslipidaemia were significant related factors for CNS manifestations (P = 0.047, 0.038, and 0.030 respectively). The use of anticoagulants (P = 0.004), and/or hydroxychloroquine (P = 0.016) appeared to associated with a lower incidence of CNS manifestations. During a median follow-up of 4.1 years, 10 individuals developed new episodes of stroke in APS patients with previous ischemic strokes. Livedo reticularis, smoking and male gender may predict the risk of recurrent stroke (P = 0.020, 0.006, and 0.026 respectively). Collectively, our results indicated the protective and risk factors for CNS manifestations, as well as demonstrated that APS patients appeared at high risk of stroke recurrence despite current therapy.

Direct-acting oral anticoagulants in antiphospholipid syndrome: A systematic review

The objective of the systematic review is to analyze the efficacy of direct-acting oral anticoagulants (DOAC) in the prophylaxis of thrombosis in antiphospholipid syndrome (APS). We searched for clinical trials, cohort studies and meta-analyses published from January 1, 2012 to September 30, 2022. Articles that analyzed the efficacy of DOAC in the prevention of thrombosis recurrence, with or without comparison with antivitamin K (VKA) drugs, were selected. DOACs, specifically rivaroxaban and apixaban, were significantly less effective than VKAs in preventing recurrence of thrombosis in patients with APS and prior arterial thrombosis or the concomitant presence of two or three different antiphospholipid antibodies. The proportion of patients with severe bleeding as side effect are similar in those treated with DOAC and with VKA. The results argue against the use of DOAC in the treatment of patients with thrombotic APS.

Changes in Clinical Manifestations and Course of Systemic Lupus Erythematosus and Secondary Antiphospholipid Syndrome over Three Decades

Systemic lupus erythematosus (SLE) is often associated with antiphospholipid syndrome (APS), which potentially results in a more severe disease course and reduced life expectancy. Since the therapeutic guidelines have been refined in the last 15 years, we assumed that the diseases course has become more favorable. In order to shed light on these achievements, we compared the data of SLE patients diagnosed before and since 2004. In our retrospective study, we assessed a wide spectrum of clinical and laboratory data of 554 SLE patients who received regular follow-up care and therapy at our autoimmune center. Among these patients, 247 had antiphospholipid antibodies (APAs) without clinical signs of APS, and 113 had definitive APS. In the APS group, among patients diagnosed since 2004, deep vein thrombosis (p = 0.049) and lupus anticoagulant positivity (p = 0.045) were more frequent, while acute myocardial infarction was less frequent (p = 0.021) compared with patients diagnosed before 2004. Among the APA positive patients without definitive APS, anti-cardiolipin antibody positivity (p = 0.024) and development of chronic renal failure (p = 0.005) decreased in patients diagnosed since 2004. Our study demonstrates that the disease course has changed in recent years; however, in the presence of APS, we have to expect repeated thrombotic events despite adequate anticoagulant therapy.

Ocular findings in asymptomatic patients with primary antiphospholipid syndrome

BACKGROUND

Primary antiphospholipid syndrome (PAPS) is characterized by the presence of antiphospholipid antibodies (aPL), repetitive fetal loss, and arterial/venous thrombosis and no association with other autoimmune rheumatic disease. Ocular involvement can also occur including retinal vascular thrombosis and neuro-ophthalmological manifestations, such as optic neuropathy and amaurosis fugax. Early detection of ocular changes is crucial to minimize functional loss.

PURPOSE

To perform a multimodal evaluation, including the use of Optical Coherence Angiotomography (OCTA), in patients with PAPS without ocular complaints and compare with healthy individuals.

METHODS

We performed a complete structural and functional ophthalmological evaluation using OCTA and microperimetry exam in patients with PAPS, followed at a tertiary Rheumatology outpatient clinic.

RESULTS

We included 104 eyes of 52 subjects [PAPS without ocular complaints (N = 26) and healthy individuals (N = 26)]. Among PAPS patients, 21 were female (80.8%) and 21 (80.8%) were Caucasians. PAPS manifestations were venous (65.4%), arterial thrombosis (34.6%), and obstetrical (34.6%) and all of them had lupus anticoagulant. Ophthalmologic findings were more frequent in PAPS compared to healthy individuals (19.2% vs. 0%, p = 0.05). The most common retinal change was paracentral acute middle maculopathy (PAMM) (3 patients, 5 eyes), followed by drusen (1 patient, 2 eyes) and pachychoroid pigment epitheliopathy (PPE) (1 patient, 1 eye). Hypertension and hyperlipidemia were present in 100% of the PAPS patients with PAMM, while only six patients (26.1%) with PAPS without PAMM presented these two risk factors together (p = 0.03).

CONCLUSIONS

We provide novel evidence that approximately 20% of our asymptomatic PAPS patients without ocular symptoms have ophthalmologic findings that require early identification and careful surveillance focusing on minimizing systemic and vascular risk factors.

Combined oral contraceptive-associated venous thromboembolism revealing an antiphospholipid syndrome: International retrospective study of outcomes

INTRODUCTION

Limitations in the data used to define thromboprophylaxis for patients with antiphospholipid antibodies (aPLAbs) and thrombosis include uncertainties after an initial provoked venous thromboembolic event (VTE). We aimed to study such cases associated with combined oral contraceptive (COC) intake.

METHODS

We retrospectively analysed thrombotic outcomes after a first COC-associated VTE and positive aPLAbs, with a low risk HERDOO2 score, on low-dose aspirin (LDA) secondary thromboprophylaxis, seen from 2010 to 2021 in 3 tertiary referral centres, one in France and 2 in Russia. Data from 264 patients (distal deep vein thrombosis DVT: 62.9 %), cumulating in 1327.7 patient-years of observation, were collected.

RESULTS

There were 22 cases of thrombosis: 16 distal DVTs, 3 proximal, 1 pulmonary embolism (PE) and 2 transient ischemic attacks. Recurrence rate was 1.66 per 100 patient-years (p-y; 95 % CI: 0.96-2.33). No major bleeding occurred. Risk factors affecting recurrence-free survival were the time between first COC intake and VTE (p < 0.0001; the shortest, the lower), proximal DVT (p = 0.021), active smoking (p = 0.039), an associated systemic disease (p = 0.043) and circulating monocyte counts (p = 0.001).

CONCLUSIONS

We observed a low risk of recurrence which was modulated by classical risk factors for VTE. These observational data may provide clues for future randomized controlled trials.

Risk Factors and Outcomes of Acute Myocardial Infarction in a Cohort of Antiphospholipid Syndrome

Background

Antiphospholipid syndrome (APS) is a disorder associated with thromboembolic diseases, including acute myocardial infarction (AMI). Given that AMI is a relatively common condition with poor prognostic features, identification of risk factors for AMI in APS is important.

Methods

A retrospective cohort study was performed consisting of 332 patients with APS, and 239 patients with thrombotic APS were finally included. Patients were followed up in the outpatient department for 5 years. Clinical data and laboratory parameters were analyzed to identify the risk factors for AMI in APS. The primary and secondary clinical outcomes were all-cause mortality and recurrence of thrombosis, respectively.

Results

AMI was observed in 12.1% (29/239) of patients with APS. Compared to patients without AMI, patients with AMI had multiple organ thrombosis (55.1 vs. 34.3%, p = 0.029), recurrent thrombosis (58.6 vs. 34.3%, p = 0.011), a higher incidence of atherosclerosis (62.1 vs. 23.8%, p < 0.001), higher neutrophil count (×10⁹/L) [4.68 (3.25, 8.17) vs. 3.71 (2.64, 5.80), p = 0.036], longer QT interval (ms) [438 ms (423, 454) vs. 425 ms (410, 446), p = 0.016], and fewer venous thrombosis events (27.6 vs. 63.3%, p < 0.001). Multivariate logistic regression analysis (adjusted for age and gender) identified several factors that were positively associated with AMI, including multiple organ thrombosis [odds ratio (OR) 8.862, 95% confidence interval (CI): 1.817–43.212, p = 0.007), atherosclerosis (OR 5.397, 95%CI: 1.943–14.994, p = 0.001), and elevated neutrophil count (>6.3 ×10⁹/L) (OR 3.271, 95%CI: 1.268–8.440, p = 0.014). The venous thrombosis was negatively associated with AMI (OR 0.106, 95%CI: 0.036–0.314, p < 0.001). Kaplan–Meier analysis revealed that the recurrence rates of arterial thrombosis differed significantly between patients with AMI and those without AMI [hazard ratio (HR) = 3.307, p = 0.038].

Conclusion

Atherosclerosis, multiple organ thrombosis, an increased number of neutrophils are variables positively associated with AMI in APS, and venous thrombosis had a negative association with AMI. AMI only predicts the subsequent recurrence of arterial thrombosis. These findings suggest that distinct pathophysiological mechanisms may exist and contribute to the development of venous or arterial thrombotic APS.

Association between interferon-I producing plasmacytoid dendritic cells and thrombotic antiphospholipid syndrome

Background: Thrombotic risk in antiphospholipid syndrome (APS) is conferred by the association of antiphospholipid (aPL) antibodies (first hit) with additional pro-coagulant stimulus (second hit), such as inflammation. Among inflammatory responses, the production of large amounts of interferon (IFN)-I by plasmacytoid dendritic cells (pDCs) is at the basis of the pathophysiology of systemic autoimmune disorders, which raises the hypothesis that this mechanism could also be associated with vascular manifestations of APS. Purpose: Here, we determined the association of pDCs and IFN-I production with thrombotic APS. Research design: Patients with thrombotic primary (t-PAPS) and secondary APS (t-SAPS), asymptomatic aPL carriers and individuals without thrombosis (controls) were included. Data collection and analysis: Circulating pDCs and IFN-α intracellular expression (in the presence or not of oligodeoxynucleotides (CP) stimulus) were quantified by flow cytometry. The expression of five IFN-I inducing genes: ISG15, OASL, Ly6E, MX1, and OAS1 in mononuclear cells was determined by qPCR. Between-group differences were evaluated using chi-square or Kruskal-Wallis tests. Results: A total of 50 patients with t-PAPS, 50 patients with t-SAPS, 20 aPL carriers, and 50 individuals without thrombosis (controls) were included. Intracellular expression of IFN-α was increased after CPG stimulation in both t-SAPS (1.56%; IQR 1.07-2.02) and t-PAPS (0.96%; IQR 0.55-1.24), when compared to aPL carriers (0.71%; IQR 0.42-0.93) and controls (0.48%; IQR 0.24-0.78; p < .0001). ISG15, OASL, Ly6E, MX1, and OAS1 mRNA expressions were higher in t-SAPS (but not in t-PAPS) than in aPL carriers and controls. The expression of proteins and mRNA related to IFN-I response was similar between the triple aPL-positive profile and other aPL profiles. Conclusion: Our results indicate an association of IFN-I response and t-APS. Since IFN-I expression was not increased in aPL carriers or associated with a higher-risk aPL profile, this mechanism does not appear to be related to the presence of aPL alone. IFN-I response could possibly constitute a complementary mechanism for triggering clinical manifestations in APS.

Cardiovascular risk management in antiphospholipid syndrome: trends over time and comparison with rheumatoid arthritis and diabetes mellitus

OBJECTIVE

Antiphospholipid syndrome (APS) is characterised by increased cardiovascular morbidity and mortality, related to thrombo-inflammatory and atherogenic mechanisms. We examined the achievement of traditional cardiovascular risk factor (CVRF) therapeutic goals in APS versus other high cardiovascular risk disorders such as rheumatoid arthritis (RA) and diabetes mellitus (DM), and trends over time.

METHODS

122 patients with APS (74 primary APS, female 68%, mean age 44.5±11.3) were classified according to their first visit (2011-2015 and 2016-2020 APS subgroups, 61 patients in each subgroup) and matched 1:1 for age/sex with patients with RA and DM. Cardiovascular risk was estimated by the Systemic Coronary Risk Evaluation, and the CVRF therapeutic targets were defined according to the European Society of Cardiology (ESC) guidelines. Individual and multiple CVRF control was compared between APS subgroups, and in APS versus RA and DM.

RESULTS

We found a comparable or higher prevalence of CVRFs between APS and age-matched/sex-matched patients with RA and DM but low CVRF target attainment in APS according to the ESC guidelines. Despite improving trends between 2011-2015 and 2016-2020, CVRF control in high/very high-risk patients with APS was 12%, 18%, 24% and 35% for low-density lipoprotein, waist circumference, exercise and body mass index, respectively, and 59%-65% for triglycerides, high-density lipoprotein (HDL) and blood pressure, in 2016-2020 subgroup. CVRF control was worse in APS versus RA for smoking (p=0.014), HDL (p<0.001), waist circumference (p=0.042) and five CVRFs (p=0.030), and versus DM for exercise (p=0.077). Similar results were found in the sensitivity analysis.

CONCLUSIONS

Comparable prevalence of modifiable CVRFs to RA and DM but suboptimal CVRF target achievement was observed in APS, especially in high/very high-risk patients, highlighting the need for CVRF management strategies.

Inflammatory markers in thrombosis associated with primary antiphospholipid syndrome

The role of inflammation in thrombotic complications of primary antiphospholipid syndrome (PAPS) is controversial. The aim of this study was to evaluate levels of inflammation and coagulation markers in patients with thrombotic PAPS (t-PAPS). Patients with t-PAPS and individuals with no history of thrombosis were enrolled. The association of t-PAPS with levels of tumor necrosis factor (TNF)-α, C-reactive protein (hs-CRP), interferon (IFN)-α, interleukins (IL)-6, -8, factor VIII (FVIII), von Willebrand factor (VWF) and tissue factor (TF) was evaluated by regression models. The levels of these markers were also compared between controls and subgroups of t-PAPS patients with triple positivity, recently diagnosed thrombosis, recurrent thrombosis and venous thrombosis. Patients with t-PAPS (n = 101) had a 8.6-fold increased levels of TNF-α, 90% increased levels of hs-CRP, 80% increased levels of IL-6, 30% increased levels of FVIIIAg, 50% increased levels of VWF and 66% increased levels of TF as compared to controls (n = 131), and the differences did not change after adjustments for sex, age and cardiovascular risk factors. Inflammatory markers were elevated in t-PAPS regardless of the aPL profile, number of previous thrombosis or time elapsed since diagnosis. TNF-α and IL-8 levels were higher in t-PAPS patients with venous thrombosis, in comparison with those with arterial thrombosis and controls. Patients with t-PAPS presented with increased levels of inflammatory and coagulation markers, which suggests that t-PAPS is associated not only with hypercoagulability but also with a persistent inflammatory state.

Antiplatelet and anticoagulant agents for secondary prevention of stroke and other thromboembolic events in people with antiphospholipid syndrome

BACKGROUND

Antiphospholipid syndrome (APS) is a systemic autoimmune disease characterized by arterial or venous thrombosis (or both), and/or pregnancy morbidity in association with the presence of antiphospholipid antibodies. The prevalence of APS is estimated at 40 to 50 cases per 100,000 people. The most common sites of thrombosis are cerebral arteries and deep veins of the lower limbs. People with a definite APS diagnosis have an increased lifetime risk of recurrent thrombotic events.

OBJECTIVES

To assess the effects of antiplatelet (AP) or anticoagulant agents, or both, for the secondary prevention of recurrent thrombosis, particularly ischemic stroke, in people with APS.

SEARCH METHODS

We last searched the MEDLINE, Embase, CENTRAL, Cochrane Stroke Group Trials Register, and ongoing trials registers on 22 November 2019. We checked reference lists of included studies, systematic reviews, and practice guidelines. We also contacted experts in the field.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that evaluated any anticoagulant or AP agent, or both, in the secondary prevention of thrombosis in people with APS, according to the criteria valid when the study took place. We did not include studies specifically addressing women with obstetrical APS.

DATA COLLECTION AND ANALYSIS

Pairs of review authors independently worked on each step of the review, following Cochrane methods. We summarized the evidence using the GRADE approach.

MAIN RESULTS

We identified eight studies including 811 participants that compared different AP or anticoagulant agents. NOAC (non-VKA oral anticoagulant: rivaroxaban 15 or 20 mg/d) versus standard-dose VKA (vitamin K antagonist: warfarin at moderate International Normalized Ratio [INR] - 2.5) or adjusted [INR 2.0-3.0] dose): In three studies there were no differences in any thromboembolic event (including death) and major bleeding (moderate-certainty evidence), but an increased risk of stroke (risk ratio [RR] 14.13, 95% confidence interval [CI] 1.87 to 106.8; moderate-certainty evidence). One of the studies reported a small benefit of rivaroxaban in terms of quality of life at 180 days measured as health state on Visual Analogue Scale (mean difference [MD] 7 mm, 95% CI 2.01 to 11.99; low-certainty evidence), but not measured as health utility on a scale from 0 to 1 (MD 0.04, 95% CI -0.02 to 0.10; low-certainty evidence). High-dose VKA (warfarin with a target INR of 3.1 to 4.0 [mean 3.3] or 3.5 [mean 3.2]) versus standard-dose VKA (warfarin with a target INR of 2.0 to 3.0 [mean 2.3] or 2.5 [mean 2.5]): In two studies there were no differences in the rates of thrombotic events and major bleeding (RR 2.22, 95% CI 0.79 to 6.23, low-certainty evidence), but an increased risk of minor bleeding in one study during a mean of 3.4 years (standard deviation [SD] 1.2) of follow-up (RR 2.55, 95% CI 1.07 to 6.07). In both trials there was evidence of a higher risk of any bleeding (hazard ratio [HR] 2.03 95% CI 1.12 to 3.68; low-certainty evidence) in the high-dose VKA group, and for this outcome (any bleeding) the incidence is not different, only the time to event is showing an effect. Standard-dose VKA plus a single AP agent (warfarin at a target INR of 2.0 to 3.0 plus aspirin 100 mg/d) versus standard-dose VKA (warfarin at a target INR of 2.0 to 3.0): One high-risk-of-bias study showed an increased risk of any thromboembolic event with combined treatment (RR 2.14, 95% CI 1.04 to 4.43; low-certainty evidence) and reported on major bleeding with five cases in the combined treatment group and one case in the standard-dose VKA treatment group, resulting in RR 7.42 (95% CI 0.91 to 60.7; low-certainty evidence) and no differences for secondary outcomes (very low- to low-certainty evidence). Single/dual AP agent and standard-dose VKA (pooled results): Two high-risk-of-bias studies compared a combination of AP and VKA (aspirin 100 mg/d plus warfarin or unspecified VKA at a target INR of 2.0 to 3.0 or 2.0 to 2.5) with a single AP agent (aspirin 100 mg/d), but did not provide any conclusive evidence regarding the effects of those drugs in people with APS (very low-certainty evidence). One of the above-mentioned studies was a three-armed study that compared a combination of AP and VKA (aspirin 100 mg/d plus warfarin at a target INR of 2.0 to 2.5) with dual AP therapy (aspirin 100 mg/d plus cilostazol 200 mg/d) and dual AP therapy (aspirin 100 mg/d plus cilostazol 200 mg/d) versus a single AP treatment (aspirin 100 mg/d). This study reported on stroke (very low-certainty evidence) but did not report on any thromboembolic events, major bleeding, or any secondary outcomes. We identified two ongoing studies and three studies are awaiting classification.

AUTHORS' CONCLUSIONS

The evidence identified indicates that NOACs compared with standard-dose VKAs may increase the risk of stroke and do not appear to alter the risk of other outcomes (moderate-certainty evidence). Using high-dose VKA versus standard-dose VKA did not alter the risk of any thromboembolic event or major bleeding but may increase the risk of any form of bleeding (low-certainty evidence). Standard-dose VKA combined with an AP agent compared with standard-dose VKA alone may increase the risk of any thromboembolic event and does not appear to alter the risk of major bleeding or other outcomes (low-certainty evidence). The evidence is very uncertain about the benefit or harm of using standard-dose VKA plus AP agents versus single or dual AP therapy, or dual versus single AP therapy, for the secondary prevention of recurrent thrombosis in people with APS (very low-certainty evidence).

Identification of common and divergent gene expression signatures in patients with venous and arterial thrombosis using data from public repositories

STRENGTHS AND LIMITATIONS OF THIS STUDY

Our results represent the first comparison of venous and arterial thrombosis at the transcriptomic level.Our main result was the demonstration that immunothrombosis pathways are important to the pathophysiology of these conditions, also at the transcriptomic level.A specific signature for venous and arterial thrombosis was described, and validated in independent cohorts.The limited number of public repositories with gene expression data from patients with venous thromboembolism limits the representation of these patients in our analyses.In order to gather a meaningful number of studies with gene expression data we had to include patients in different time-points since the index thrombotic event, which might have increased the heterogeneity of our population.

Principal Component Analysis on Recurrent Venous Thromboembolism

The rates of recurrent venous thromboembolism (RVTE) vary widely, and its causes still need to be elucidated. Statistical multivariate methods can be used to determine disease predictors and improve current methods for risk calculation. The objective of this study was to apply principal component analysis to a set of data containing clinical records of patients with previous venous thromboembolism and extract the main factors that predict recurrent thrombosis. Records of 39 factors including blood and lipid parameters, hereditary thrombophilia, antiphospholipid syndrome, clinical data regarding previous thrombosis and treatment, and Doppler ultrasound results were collected from 235 patients. The results showed that 13 principal components were associated with RVTE and that 18 of 39 factors are the important for the analysis. These factors include red blood cell, white blood cell, hematocrit, red cell distribution width, glucose, lipids, natural anticoagulant, creatinine, age, as well as first deep vein thrombosis data (distal/proximal, d-dimer, and time of anticoagulation). The results demonstrated that simple clinical parameters easy to be collected can be used to predict rates of recurrence and to develop new clinical decision support systems to predict the rates of RVTE.

Antiphospholipid Syndrome and the Neurologist: From Pathogenesis to Therapy

Antiphospholipid syndrome (APS) is an autoimmune antibody-mediated condition characterized by thrombotic events and/or pregnancy morbidity in association with persistent positivity to antiphospholipid antibodies (aPL). The nervous system is frequently affected, as intracranial vessels are the most frequent site of arterial pathology. Over the course of years, many other neurological conditions not included in the diagnostic criteria, have been associated with APS. The pathogenic mechanisms behind the syndrome are complex and not fully elucidated. aPL enhance thrombosis, interfering with different pathways. Nevertheless, ischemic injury is not always sufficient to explain clinical features of the syndrome and immune-mediated damage has been advocated. This may be particularly relevant in the context of neurological complications. The reason why only a subgroup of patients develop non-criteria nervous system disorders and what determines the clinical phenotype are questions that remain open. The double nature, thrombotic and immunologic, of APS is also reflected by therapeutic strategies. In this review we summarize known neurological manifestations of APS, revisiting pathogenesis and current treatment options.

Circulating levels of tissue factor and the risk of thrombosis associated with antiphospholipid syndrome

The mechanisms behind the severe hypercoagulable state in antiphospholipid syndrome (APS) have not yet been fully elucidated. Knowledge on the etiology of thrombosis in APS is needed to improve treatment. We performed a case control study to evaluate the association of the levels of circulating tissue factor (TF) with thrombotic APS and unprovoked venous thromboembolism (VTE), as compared with controls without a history of thrombosis. Study participants were selected in the same geographic area. Linear regression was used to evaluate possible determinants of TF levels among controls and logistic regression was used to evaluate the association between TF, unprovoked VTE and t-APS. TF levels were grouped into three categories based on: below 50th percentile [reference], between 50-75th percentiles [second category] and 75th percentile [third category]. Two hundred and eighty participants were included in the study; 51 patients with unprovoked VTE, 111 patients with t-APS and 118 control individuals. The levels of TF were not associated with an increased risk of unprovoked VTE, as compared with controls. The adjusted odds ratio for t-APS was 2.62 (95%CI 1.03 to 6.62) with TF levels between 50-75th percentiles and 8.62 (95%CI 3.76 to 19.80) with TF levels above the 75th percentile, as compared with the reference category (below the 50th percentile). In the subgroup analysis, higher levels of TF were associated with both arterial and venous thrombosis in APS and with both primary and secondary APS. Circulating TF is associated with thrombotic complications related to APS, but not with the risk of unprovoked VTE.

How to Identify High-Risk APS Patients: Clinical Utility and Predictive Values of Validated Scores

PURPOSE OF REVIEW

Antiphospholipid syndrome (APS) is a clinical disorder characterised by thrombosis and/or pregnancy morbidity in the persistence of antiphospholipid (aPL) antibodies that are pathogenic and have pro-coagulant activities. Thrombosis in APS tends to recur and require prophylaxis; however, the stereotypical treatment for APS patients is inadequate and stratification of the thrombotic risks is important as aPL are prevalently observed in various diseases or elderly population.

RECENT FINDINGS

It is previously known that the multiple positive aPL or high titre aPL correlate to thrombotic events. To progress the stratification of thrombotic risks in APS patients and to quantitatively analyse those risks, antiphospholipid score (aPL-S) and the Global Anti-phospholipid Syndrome Score (GAPSS) were defined. These scores were raised from the large patient cohort data and either aPL profile classified in detail (aPL-S) or simplified aPL profile with classical thrombotic risk factors (GAPSS) was put into a scoring system. Both the aPL-S and GAPSS have shown a degree of accuracy in identifying high-risk APS patients, especially those at a high risk of thrombosis. However, there are several areas requiring improvement, or at least that clinicians should be aware of, before these instruments are applied in clinical practice. One such issue is standardisation of the aPL tests, including general testing of phosphatidylserine-dependent antiprothrombin antibodies (aPS/PT). Additionally, clinicians may need to be aware of the patient's medical history, particularly with respect to the incidence of SLE, which influences the cutoff value for identifying high-risk patients.

The impact of antibody profile in thrombosis associated with primary antiphospholipid syndrome

Triple positivity (TP) for antiphospholipid antibodies(aPL) may identify aPL carriers with poorer prognosis. The clinical impact of TP in primary antiphospholipid syndrome(PAPS) remains unclear and further clinical evidences are needed to validate TP as a marker of severity. The aim of this study was to evaluate the impact of TP on the clinical course of PAPS with thrombosis(t-PAPS). We performed a retrospective analysis of a cohort of t-PAPS patients, comparing groups of patients with TP and non-TP profiles according to their demographic, clinical and laboratory features. We included 105 patients with t-PAPS, the median follow-up time of 3.7 years. Twenty-two patients(21%) had TP; the demographic distribution, the presence of cardiovascular risk factors and the site of thrombosis were similar between TP and non-TP patients. The frequency of thrombotic events did not differ between TP and non-TP patients during the study period. Pregnancy morbidities were more frequent in women with t-PAPS and TP than in those with non-TP profile (80% vs. 52.8%, P = 0.05). Patients with t-PAPS and TP presented, at diagnosis, higher dRVVT ratio (median R = 2.44 vs. 1.57, P < 0.0001), higher aCL titer (median = 50UI vs. 35 UI, P < 0.0001), lower C3 levels (median = 1.08 vs. 1.30 mg dL^-1 , P = 0.001), lower C4 levels (median = 0.22 vs. 0.25 mg dL^-1 , P = 0.05) and higher frequency of positive ANA test (50% vs. 20%, P = 0.008) than patients with t-PAPS and non-TP. Lower-than-normal levels of C3 was independently associated with TP (OR = 5.1, P = 0.02). The presence of TP in patients with t-PAPS was associated with immune derangement, with no effect on the clinical course of the disease.

Antiplatelet and anticoagulant agents for secondary prevention of stroke and other thromboembolic events in people with antiphospholipid syndrome

BACKGROUND

Antiphospholipid syndrome (APS) is a systemic autoimmune disease characterized by arterial or venous thrombosis (or both) and/or pregnancy morbidity in association with the presence of antiphospholipid antibodies. The prevalence is estimated at 40 to 50 cases per 100,000 people. The most common sites of thrombosis are cerebral arteries and deep veins of the lower limbs. People with a definite APS diagnosis have an increased lifetime risk of recurrent thrombotic events.

OBJECTIVES

To assess the effects of antiplatelet or anticoagulant agents, or both, for the secondary prevention of recurrent thrombosis, particularly ischemic stroke, in people with antiphospholipid syndrome.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (February 2017), CENTRAL (last search February 2017), MEDLINE (from 1948 to February 2017), Embase (from 1980 to February 2017), and several ongoing trials registers. We also checked the reference lists of included studies, systematic reviews, and practice guidelines, and we contacted experts in the field.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that evaluated any anticoagulant or antiplatelet agent, or both, in the secondary prevention of thrombosis in people diagnosed with APS according to the criteria valid when the study took place. We did not include studies specifically addressing women with obstetrical APS.

DATA COLLECTION AND ANALYSIS

Pairs of review authors independently selected studies for inclusion, extracted data, and assessed the risk of bias for the included studies. We resolved any discrepancies through discussion or by consulting a third review author and, in addition, one review author checked all the extracted data.

MAIN RESULTS

We included five studies involving 419 randomized participants with APS. Only one study was at low risk of bias in all domains. One study was at low risk of bias in all domains for objective outcomes but not for quality of life (measured using the EQ-5D-5L questionnaire). We judged the other three studies to be at unclear or high risk of bias in three or more domains.The duration of intervention ranged from 180 days to a mean of 3.9 years. One study compared rivaroxaban (a novel oral anticoagulant: NOAC) with standard warfarin treatment and reported no thrombotic or major bleeding events, but it was not powered to detect such differences (low-quality evidence). Investigators reported similar rates of clinically relevant non-major bleeding (risk ratio (RR) 1.45, 95% confidence interval (CI) 0.25 to 8.33; moderate-quality evidence) and minor bleeding (RR 1.21, 95% CI 0.51 to 2.83) for participants receiving rivaroxaban and the standard vitamin K antagonists (VKA). This study also reported some small benefit with rivaroxaban over the standard VKA treatment in terms of quality of life health state measured at 180 days with the EQ-5D-5L 100 mm visual analogue scale (mean difference (MD) 7 mm, 95% CI 2.01 to 11.99; low-quality evidence) but not measured as health utility (MD 0.04, 95% CI -0.02 to 0.10 [on a scale from 0 to 1]).Two studies compared high dose VKA (warfarin) with moderate/standard intensity VKA and found no differences in the rates of any thrombotic events (RR 2.22, 95% CI 0.79 to 6.23) or major bleeding (RR 0.74, 95% CI 0.24 to 2.25) between the groups (low-quality evidence). Minor bleeding analyzed using the RR and any bleeding using the hazard ratio (HR) were more frequent in participants receiving high-intensity warfarin treatment compared to the standard-intensity therapy (RR 2.55, 95% CI 1.07 to 6.07; and HR 2.03, 95% CI 1.12 to 3.68; low-quality evidence).In one study, it was not possible to estimate the RR for stroke with a combination of VKA plus antiplatelet agent compared to a single antiplatelet agent, while for major bleeding, a single event occurred in the single antiplatelet agent group. In one study, comparing combined VKA plus antiplatelet agent with dual antiplatelet therapy, the RR of the risk of stroke over three years of observation was 5.00 (95% CI 0.26 to 98.0). In a single small study, the RR for stroke during one year of observation with a dual antiplatelet therapy compared to single antiplatelet drug was 0.14 (95% CI 0.01 to 2.60).

AUTHORS' CONCLUSIONS

There is not enough evidence for or against NOACs or for high-intensity VKA compared to the standard VKA therapy in the secondary prevention of thrombosis in people with APS. There is some evidence of harm for high-intensity VKA regarding minor and any bleeding. The evidence was also not sufficient to show benefit or harm for VKA plus antiplatelet agent or dual antiplatelet therapy compared to a single antiplatelet drug. Future studies should be adequately powered, with proper adherence to treatment, in order to evaluate the effects of anticoagulants, antiplatelets, or both, for secondary thrombosis prevention in APS. We have identified five ongoing trials mainly using NOACs in APS, so increasing experimental efforts are likely to yield additional evidence of clinical relevance in the near future.

Impact of Classical Risk Factors for Arterial or Venous Thrombosis in Patients With Antiphospholipid Syndrome

There are classical risk factors associated with arterial thrombosis (AT) or venous thromboembolic disease (VTD). However, less is known about these risk factors and AT or VTD episodes in patients with antiphospholipid syndrome (APS). Our aim was to elucidate whether APS-related thrombotic episodes are associated with the same risk factors as the non-APS population. We gathered demographics, medical history, complications, and causes of death associated with the risk factors for AT or VTD in patients with APS. We analyzed 677 thrombotic events in 386 patients. Type 2 diabetes mellitus and grade 3 obesity were associated with VTD instead of AT. There were no significant differences between the groups for almost all laboratory tests analyzed, although lupus anticoagulant was significantly higher in the VTD group. We suggest that thrombosis in APS is due to the APS itself and that the risks factors for AT or VTD do not have a main role. Our findings may have an ethnical background. Therefore, it may be difficult to elaborate predictive thrombotic clinical scores applicable to patients with different ethnical background.

Double positivity of the IgG isotype of both anticardiolipin and anti-β2gpI antibodies is associated with the highest number of vascular impairment parameters in patients with primary antiphospholipid syndrome: preliminary data

Although numerous studies investigated the association between homocysteine (Hcy), tumor necrosis factor alpha (TNF-α), C-reactive protein (CRP) and apolipoproteins (apo_s) with thrombosis and/or recurrent pregnancy losses, studies that analyzed the abovementioned parameters and multiple positivity of antiphospholipid antibodies (aPL Abs) in patients with primary antiphospholipid syndrome (PAPS) are lacking. Therefore, the aim of this study was to analyze the presence of various combinations of the abovementioned parameters and their associations with clinical and/or serological features of PAPS. High-pressure liquid chromatography (HPLC) was used for determination of Hcy, while apoAI, apoB, and lipoprotein (Lp) (a) concentrations were estimated by immunonephelometry. High-sensitivity C-reactive protein (hsCRP) was measured by immunoturbidimetry. Apo (a), TNF-α, and aPL Abs were measured by ELISA. Various combinations of analyzed parameters (Hcy/CRP/TNF/apoAI/apoB/apo (a)/Lp (a)) were not associated with a single presence of either aPL Abs. Double positivity for both isotypes of anticardiolipin (aCL) Abs (IgG + IgM) was associated with the increased apoB levels. The presence of the IgG isotype of both aCL + anti-beta2 glycoprotein I (aβ2gpI) Abs was associated with the highest number of analyzed parameters (i.e., increased levels of hsCRP, Lp (a), and apo (a)). The presence of the IgG isotype of both aCL + aβ2gpI Abs was associated with the highest number of vascular impairment parameters in patients with PAPS, and this combination confers the highest risk for the recurrence of thrombotic episodes. This is the first report that analyzed the association between various combinations of vascular impairment parameters with multiple aPL Ab positivity. Our results provide a rationale for further investigations of therapeutic approaches for PAPS patients.

Clinical implications of the detection of antibodies directed against domain 1 of β2-glycoprotein 1 in thrombotic antiphospholipid syndrome

INTRODUCTION

Antibodies directed against domain 1 of β2 glycoprotein 1 (aβ2GP1-Dm1) have been involved in the immunopathogenesis of antiphospholipid syndrome (APS). However, the clinical relevance of aβ2GP1-Dm1 in thrombotic APS has not yet been fully explored.

OBJECTIVES

To determine the frequency of aβ2GP1-Dm1 in a cohort of patients with thrombotic APS, and to evaluate whether testing for aβ2GP1-Dm1 could have a clinical impact upon the risk assessment of the disease.

METHODS

Patients were tested for aβ2GP1-Dm1 antibodies by chemiluminescence (BioFlash/AcuStar®, ES). The presence of aβ2GP1-Dm1 was evaluated in different clinical presentations of the disease.

RESULTS

Eight-four patients with a history of venous or arterial thrombosis were included. Forty-five (54%) patients had aβ2GP1 antibodies and 40% of them were positive for aβ2GP1-Dm1. Levels of aβ2GP1-Dm1 were higher in patients with systemic autoimmune disease (AUC=0.665; 95% CI=0.544-0.786; P=0.01), positive antinuclear antibody (AUC=0.654; 95% CI=0.535-0.772; P=0.01), triple antiphospholipid antibody (aPL) positivity (AUC=0.680; 95% CI=0.534-0.825; P=0.02) and positive lupus anticoagulant (AUC=0.639; 95% CI=0.502-0.776; P=0.07). In this cohort, aβ2GP1-Dm1 antibodies were not associated with the site of the first thrombosis (OR=0,62, 95% CI=0.20-1.94, P=0.42), thrombosis recurrence (OR=1.0, 95% CI=0.37-2.71, P=1.0) or pregnancy morbidity (OR=1.5, 95% CI=0.33-7.34, P=0.58). In multivariate analysis, positivity for aβ2GP1-Dm1 antibodies was associated with the diagnosis of systemic autoimmune disease (OR=4.01, 95% CI=1.14-14.2; P=0.03) and triple aPL positivity (OR=3.59, 95% CI=0.87-14.85; P=0.07).

CONCLUSIONS

In the present cohort of thrombotic-APS patients, aβ2GP1-Dm1 antibodies were related to the diagnosis of systemic autoimmunity and complex serological profile of the disease, as triple aPL positivity and positive antinuclear antibody. Thus, our results suggest that testing for aβ2GP1-Dm1 antibodies may be useful for improving APS risk assessment.