Viewpoint: Provoked thrombosis in antiphospholipid syndrome.

Unprovoked thrombosis (thrombosis occurring without an established environmental factor favouring the episode) is a classic feature of APS. In the general population, provoked venous thromboembolism (VTE) is clearly defined and has clinical and therapeutic differences compared with unprovoked VTE. Whether provoked VTE in the context of APS may lead to a limited treatment duration is not well established. Therefore, careful clinical and laboratory evaluation is needed to identify patients eligible for a limited duration of anticoagulation treatment after provoked VTE. Given the uncertainties of available data, the risks and benefits of treatment decisions should be clearly explained. Decisions should be shared by both the patient and physician. Cardiovascular risk factors are common in patients with APS with arterial thrombosis. There are insufficient data suggesting that cardiovascular risk factor control would allow the cessation of anticoagulation. In most instances, arterial thrombosis will require prolonged anticoagulants. A careful analysis of clinical characteristics and laboratory evaluation, particularly the aPL antibody profile, is needed to make decisions on a case-by-case basis.

Damage measured by Damage Index for Antiphospholipid Syndrome (DIAPS) in antiphospholipid antibody-positive patients included in the APS ACTION registry.

OBJECTIVES: Our primary objective was to quantify damage burden measured by Damage Index for Antiphospholipid Syndrome (DIAPS) in aPL-positive patients with or without a history of thrombosis in an international cohort (the APS ACTION cohort). Secondly, we aimed to identify clinical and laboratory characteristics associated with damage in aPL-positive patients. METHODS: In this cross-sectional study, we analysed the baseline damage in aPL-positive patients with or without APS classification. We excluded patients with other autoimmune diseases. We analysed the demographic, clinical and laboratory characteristics based on two subgroups: (i) thrombotic APS patients with high vs low damage; and (ii) non-thrombotic aPL-positive patients with vs without damage. RESULTS: Of the 826 aPL-positive patients included in the registry as of April 2020, 586 with no other systemic autoimmune diseases were included in the analysis (412 thrombotic and 174 non-thrombotic). In the thrombotic group, hyperlipidaemia (odds ratio [OR] 1.82; 95% CI 1.05, 3.15; adjusted P = 0.032), obesity (OR 2.14; 95% CI 1.23, 3.71; adjusted P = 0.007), aß2GPI high titres (OR 2.33; 95% CI 1.36, 4.02; adjusted P = 0.002) and corticosteroid use (ever) (OR 3.73; 95% CI 1.80, 7.75; adjusted P < 0.001) were independently associated with high damage at baseline. In the non-thrombotic group, hypertension (OR 4.55; 95% CI 1.82, 11.35; adjusted P = 0.001) and hyperlipidaemia (OR 4.32; 95% CI 1.37, 13.65; adjusted P = 0.013) were independent predictors of damage at baseline; conversely, single aPL positivity was inversely correlated with damage (OR 0.24; 95% CI 0.075, 0.77; adjusted P = 0.016). CONCLUSIONS: DIAPS indicates substantial damage in aPL-positive patients in the APS ACTION cohort. Selected traditional cardiovascular risk factors, steroids use and specific aPL profiles may help to identify patients more prone to present with a higher damage burden.

Thrombin Generation Assay in Antiphospholipid Antibodies Positive Subjects as a Personalized Thrombotic Risk Assessment: State of the Art and Perspectives.

PURPOSE OF THE REVIEW: Thrombotic risk assessment in antiphospholipid positive (aPL +) subjects is a major challenge, and the study of in vitro thrombin generation (thrombin generation assays (TGA)) could provide useful information. Activated protein C (APC) sensitivity is involved in thrombotic events in antiphospholipid syndrome patients. We summarized methods used to assess APC sensitivity with TGA and evaluated the prognostic role of APC resistance through literature search. RECENT FINDINGS: APC resistance induced by aPL is a complex pathway. Several cross-sectional studies assessed APC sensitivity to understand thrombotic event mechanisms in aPL + subjects. Only one prospective cohort had investigated the prognostic impact of APC resistance in aPL + subjects, with a positive and significant correlation between APC sensitivity and the risk of thrombosis during the follow up (hazard ratio, 6.07 [95% CI, 1.69-21.87]). APC resistance assessed with TGA could be associated with thrombotic events in aPL + subjects.

The mediating effect of fatigue in impaired quality of life in systemic lupus erythematosus: mediation analysis of the French EQUAL cohort.

OBJECTIVES: Mediation analyses were conducted to measure the extent to which musculoskeletal (MSK) flares and depression affected physical health through excessive fatigue. METHODS: Mediation analyses were performed in a large multicentre cohort of SLE patients. Domains of the LupusQoL and SLEQOL questionnaires were selected as outcomes, MSK flares according to the SELENA-SLEDAI flare index (SFI-R) score and depression defined by Center for Epidemiologic Studies-Depression scale (CES-D) scale as exposures and different fatigue domains from MFI-20 and LupusQoL questionnaires as mediators. For each model, total, direct, indirect effects and proportion of effect mediated by fatigue (i.e. proportion of change in health-related quality of life) were determined. RESULTS: Of the 336 patients, 94 (28%) had MSK flares at inclusion and 99 (29.5%) were considered with depression. The proportion of the total effect of MSK flares on physical health impairment explained by fatigue ranged from 59.6% to 78% using the LupusQOL 'Physical health' domain and from 51.1% to 73.7% using the SLEQOL 'Physical functioning' domain, depending on the fatigue domain selected. The proportion of the total effect of depression on physical health impairment explained by fatigue ranged from 68.8% to 87.6% using the LupusQOL 'Physical health' domain and from 79.3% to 103.2% using the SLEQOL 'Physical functioning' domain, depending on the fatigue domain selected. CONCLUSIONS: The effect of MSK flares and depression on physical health impairment is largely mediated by fatigue. Thus, the patient's perception of disease activity as measured by physical health is largely influenced by fatigue. In addition, fatigue has a significant negative impact on quality of lifeof SLE patients with depression. TRIAL REGISTRATION: ClinicalTrials.gov, http://clinicaltrials.gov, NCT01904812.

Health related quality of life, remission and low lupus disease activity state in patients with systemic lupus erythematosus.

OBJECTIVES: To measure the association between systemic lupus erythematosus (SLE) remission and scores of patients reported outcome measures (PRO). METHODS: We performed a prospective cohort study of SLE patients with a 2-year follow-up, recording LupusPRO, LupusQol, SLEQOL, and SF-36 questionnaires. Remission was defined as remission-off-treatment (ROFT) and remission-on-treatment (RONT) according to the DORIS consensus. Mixed models accounting for repeated measures were used to compare groups as follow: ROFT and RONT versus no remission, and Lupus Low Disease activity state (LLDAS) versus no LLDAS. RESULTS: A total of 1478 medical visits and 2547 PRO questionnaires were collected during the follow-up from the 336 recruited patients. A between-group difference in PRO scores reaching at least 5 points on a 0-100 scale was obtained in the following domains: "lupus symptoms" (LLDAS: +5 points on the 0-100 scale, RONT: +9 and ROFT: +5), "lupus medication" (LLDAS: +5, RONT: +8 and ROFT: +9), "pain vitality" (LLDAS: +6, RONT: +9 and ROFT: +6) of LupusPRO, "role emotional" (LLDAS: +5, RONT: +8), "role physical" (RONT: +7 and ROFT: +7), "bodily pain" (RONT: +6), "mental health" (RONT: +5) and "social functioning" (RONT: +6) of SF-36. In contrast, a between-group difference reaching at least 5 points was not achieved for any of the LupusQol and SLEQOL domains. CONCLUSIONS: RONT, ROFT, and LLDAS were associated with significant and clinically relevant higher quality of life in most PRO domains of LupusPRO (disease-specific) and SF-36 (generic) questionnaires, but not with LupusQol and SLEQOL disease-specific questionnaires.

Heart and systemic sclerosis-findings from a national cohort study.

OBJECTIVES: Heart involvement is one of the leading causes of death in systemic sclerosis (SSc). The prevalence of SSc-related cardiac involvement is poorly known. Our objective was to investigate the prevalence and prognosis burden of different heart diseases in a nationwide cohort of patients with SSc. METHODS: We used data from a multicentric prospective study using the French SSc national database. Focusing on SSc-related cardiac involvement, we aimed to determine its incidence and risk factors. RESULTS: Over the 3528 patients with SSc 312 (10.9%) had SSc-related cardiac involvement at baseline. They tended to have a diffuse SSc subtype more frequently, more severe clinical features, and presented more cardiovascular risk factors. From the 1646 patients available for follow-up analysis, SSc-related cardiac involvement was associated with an increased risk of death. There was no significant difference in overall survival between SSc-related cardiac involvement, ischaemic heart disease or pulmonary arterial hypertension. Regarding survival analysis, 98 patients developed SSc-related cardiac involvement at five years (5-year event rate: 11.15%). Regarding reduced LVEF < 50% and left ventricular diastolic dysfunction, the 5-year event rate was 2.49% and 5.84% respectively. Pericarditis cumulative incidence at five years was 3%. Diffuse SSc subtype was a risk factor for SSc-related cardiac involvement and pericarditis. Female sex was associated with less left ventricular diastolic dysfunction incidence. CONCLUSIONS: Our results describe the incidence and prognostic burden of SSc-related cardiac involvement at a large scale, with gender and diffuse SSc subtype as risk factors. Further analyses should assess the potential impact of treatment on these various cardiac outcomes.

A new pro-thrombotic mechanism of neutrophil extracellular traps in antiphospholipid syndrome: impact on activated protein C resistance.

OBJECTIVES: In APS, precise evaluation of thrombotic risk is a major challenge. Different players, such as activated protein C (APC) resistance or neutrophil extracellular traps (NETs) contribute to the risk of thrombosis. Nevertheless, no study has investigated the interaction between these actors. The main objective of this study was to investigate the relation between NETs and APC resistance. METHODS: We designed a cross-sectional study including APS/antiphospholipid antibodies (aPL) patients and patients with autoimmune diseases (AID). We performed thrombin generation tests without and with APC to determine APC resistance. To evaluate circulating NETs, we measured plasma levels of MPO-DNA complexes and cell-free DNA with ELISA. RESULTS: We recruited 117 patients with definite APS/aPL or AID. We found a positive correlation between NETs and APC resistance, in APS patients and specifically in patients with high thrombotic risk, displaying LA or positivity of all three aPL tests (triple+), or anti-domain I IgG (aDI+). All these patient subgroups had increased NETs concentrations and APC resistance. As the risk profile for thrombosis increased, the relationship between NETs and APC resistance was stronger. CONCLUSION: We have shown that NETs participate in the hypercoagulable state of APS patients by contributing to APC resistance, in particular in high-risk patients. In these most at-risk patients, a targeted action on NETs could reduce APC resistance and constitute a new therapeutic approach in the treatment of APS patients in addition to antithrombotic therapy.

Antiphospholipid syndrome in patients over 65 years: A comparative study of clinical and biological features and thrombotic relapses.

OBJECTIVE: The aim of the study was to describe clinical and biological characteristics and thrombotic relapses of patients diagnosed with antiphospholipid syndrome (APS) after the age of 65 years, in comparison with patients diagnosed with APS before 65. METHODS: This retrospective multicenter study was performed to 2005 from 2017 and included patients diagnosed with APS after the age of 65 years, in accordance with Sydney criteria. We compared these patients with APS patients diagnosed before the age of 65 years, and with control thrombotic patients older than 65 years. RESULTS: Fifty-eight APS patients over the age of 65 years were compared to 127 APS patients aged less than 65 and to 58 controls. In elderly APS versus younger APS, there was a male predominance (58.6% vs 36.2% p = .001); myocardial infarction and lower limb deep vein thrombosis (LLDVT) were more frequent in elderly, respectively, 12.1% versus 1.6% (p = .005), and 44.8% versus 29.9% (p = .048). Anticardiolipin antibody (aCL) IgM was more frequently found in old patients compared to younger patients (33.9% vs 18.1%, p = .02), contrary to lupus anticoagulant (LAC) (52.8% vs 66.9%, p = .02). Older patients were more often diagnosed with single positive APS (82.8% vs 59.8% p = .002). The thrombotic relapse free survival was lower in elderly APS patients (p = .044) compared to younger APS. Elderly APS patients had more recurrent arterial and venous thrombosis (p = .03) and had poorer overall survival (p = .004) than elderly controls. CONCLUSION: In this study, APS was different in patients aged more than 65 years, with a male predominance and more myocardial infarctions and LLDVT at diagnosis. Single antiphopholipid positivity and aCL IgM were more frequent in older patients. Older patient with APS had more thrombotic recurrence during follow-up. Compared to elderly controls, elderly APS patients had more thrombosis recurrences and poorer survival.

Risk of livedo with antiphospholipid antibodies in patients with systemic lupus erythematosus: A systematic review and meta-analysis.

BACKGROUND: Livedo is a well-known skin condition in patients with systemic lupus erythematosus (SLE) which correspond to small vessels involvement. The influence of antiphospholipid antibodies (aPL) on the occurrence of livedo is controversial. The aim of our study was to estimate the risk of livedo associated with aPL in patients with SLE. METHODS: We conducted a systematic review and meta-analysis of the literature from 1977 to 2021 to estimate the risk of livedo in SLE patients according to different aPL profiles. Data sources were PubMed, Embase, Cochrane Library, hand search, and reference lists of studies. Studies were selected if they included SLE patients with descriptions of the exposure to aPL and the outcome (livedo). Two independent investigators assessed study eligibility, quality, and extracted patient characteristics from each study as well as exposure (aPL) and outcome (livedo). Risk estimates were pooled using random effects models and sensitivity analyses. For all stages of the meta-analysis, we followed the PRISMA guidelines. PROSPERO registration number: CRD42015027377. RESULTS: Of the 2,355 articles identified, 27 were included with a total of 4,810 SLE patients. The frequency of livedo was 25.5% in aPL-positive patients and 13.3% in aPL-negative patients. The overall Odds Ratio (OR) for livedo in aPL-positive patients compared to aPL-negative patients was 2.91 (95% CI; 2.17-3.90). The risk of livedo was significantly increased for most of aPL subtypes, including lupus anticoagulant (LA) (OR = 4.45 [95% CI; 2.21-8.94]), IgG anticardiolipin (OR = 3.95 [95% CI; 2.34-6.65]), and IgG anti-ß2-glycoprotein 1 (OR = 3.49 [95% CI; 1.68-7.27]). CONCLUSIONS: We demonstrated in this meta-analysis an excess risk of livedo in aPL-positive SLE patients compared to aPL-negative patients. For daily practice, in patients with SLE, livedo associated with aPL could correspond to a peculiar group of patients with small vessel disease. Livedo could be a good candidate for inclusion in future classification criteria for antiphospholipid syndrome.

Immunosuppression use in primary antiphospholipid antibody-positive patients: Descriptive analysis of the AntiPhospholipid Syndrome Alliance for Clinical Trials and InternatiOnal Networking (APS ACTION) Clinical Database and Repository ("Registry").

BACKGROUND/PURPOSE: APS ACTION Registry was created to study the outcomes of patients with persistently positive antiphospholipid antibodies (aPL) with or without other systemic autoimmune disease (SAIDx). Given that immunosuppression (IS) is used for certain aPL manifestations, for example, thrombocytopenia (TP), our primary objective was to describe the indications for IS in aPL-positive patients without other SAIDx. Secondly, we report the type of IS used in patients with selected microvascular or non-thrombotic aPL manifestations. METHODS: An online database is used to collect clinical data. The inclusion criteria are positive aPL based on the laboratory section of the APS Classification Criteria, tested at least twice within one year prior to enrollment. Patients are followed every 12 ± 3 months. For this descriptive retrospective and prospective analysis, we included aPL-positive patients without other SAIDx and excluded those with new SAIDx classification during follow-up. For each patient, we retrieved clinical data at baseline and follow-up including selected aPL manifestations (diffuse alveolar hemorrhage [DAH], antiphospholipid-nephropathy [aPL-N], livedoid vasculopathy [LV]-related skin ulcers, TP, autoimmune hemolytic anemia [AIHA], cardiac valve disease [VD]), and IS medications. RESULTS: Of 899 patients enrolled, 537 were included in this analysis (mean age 45 ± 13 years, female 377 [70%], APS Classification in 438 [82%], and at least one selected microvascular or non-thrombotic aPL manifestation in 141 (26%)). Of 537 patients, 76 (14%) were reported to use IS (ever), and 41/76 (54%) received IS primarily for selected aPL manifestation. In six of 8 (75%) DAH patients, 6/19 (32%) aPL-N, 4/28 (14%) LV, 25/88 (28%) TP, 6/11 (55%) AIHA, and 1/43 (2%) VD, the IS (excluding corticosteroids/hydroxychloroquine) indication was specific for selected aPL manifestation. CONCLUSION: In our international cohort, 14% of aPL-positive patients without other SAIDx were reported to receive IS; the indication was at least one of the selected microvascular and/or non-thrombotic aPL-related manifestations in half. Thrombocytopenia was the most frequent among those selected aPL-related manifestations; however, approximately one-third received IS specifically for that indication. Diffuse alveolar hemorrhage was frequently treated with IS followed by AIHA and aPL-N. Systematic controlled studies are urgently needed to better define the role of IS in APS.

Shedding Light on Hemostasis in Patients With Inflammatory Bowel Diseases.

Patients with inflammatory bowel diseases (IBD) have an increased risk of thrombosis, possibly due to changes in blood cells and molecules involved in hemostasis. They have increased platelet counts and reactivity as well as increased platelet-derived large extracellular vesicles. Coagulation is continuously activated in patients with IBD, based on measured markers of thrombin generation, and the anticoagulant functions of endothelial cells are damaged. Furthermore, fibrinogen is increased and fibrin clots are denser. However, pathogenesis of thrombosis in patients with IBD appears to differ from that of patients without IBD. Patients with IBD also take drugs that might contribute to risk of thrombosis, complicating the picture. We review the features of homeostasis that are altered in patients with IBD and possible mechanisms of this relationship.

Ophthalmologic manifestations in patients with antiphospholipid antibodies: Beware of iatrogenic complications.

BACKGROUND: Antiphospholipid syndrome (APS) is characterized by several clinical manifestations such as venous and arterial thrombosis associated with persistent antiphospholipid antibodies (aPL). Several studies confirmed that retinal vein occlusion was the most common APS ocular manifestation. The purpose of this study was to identify ophthalmologic manifestations in a homogeneous cohort of well-defined persistently aPL-positive patients and to determine variables associated with these manifestations. METHODS: APL-positive patients were selected from two research programs. All ophthalmologic manifestations including those related to APS were recorded. RESULTS: A total of 117 patients were included and 10 of them had APS-related ophthalmologic manifestations (glaucoma, hydroxychloroquine-related maculopathy, anterior acute uveitis, anterior ischemic optic neuropathy). Systemic Lupus Erythematosus (SLE) (OR = 3.4[95%CI; 0.9-12.7), corticosteroids (OR = 9.0 [95%CI; 2.2-37.7]) and aPL-related nephropathy (OR = 7.1 [95%CI; 1.7-30.0]) were significatively associated with the risk of APS-related ophthalmologic manifestations. CONCLUSION: Most of ocular manifestations in this study were iatrogenic related to corticosteroids or hydroxychloroquine. Patients with SLE, small vessel thrombosis in general, or with aPL-related nephropathy in particular, seemed at higher risk to develop APS-related ophthalmologic manifestations thus deserving adequate monitoring.

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-ß2-glycoprotein I (aß2-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 aß2-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.

Disease-specific quality of life following a flare in systemic lupus erythematosus: an item response theory analysis of the French EQUAL cohort.

OBJECTIVE: To explore, at an item-level, the effect of disease activity (DA) on specific health-related quality of life (HRQoL) in SLE patients using an item response theory longitudinal model. METHODS: This prospective longitudinal multicentre French cohort EQUAL followed SLE patients over 2 years. Specific HRQoL according to LupusQoL and SLEQOL was collected every 3 months. DA according to SELENA-SLEDAI flare index (SFI) and revised SELENA-SLEDAI flare index (SFI-R) was evaluated every 6 months. Regarding DA according to SFI and each SFI-R type of flare, specific HRQoL of remitting patients was compared with non-flaring patients fitting a linear logistic model with relaxed assumptions for each domain of the questionnaires. RESULTS: Between December 2011 and July 2015, 336 patients were included (89.9% female). LupusQoL and SLEQOL items related to physical HRQoL (physical health, physical functioning, pain) were most affected by musculoskeletal and cutaneous flares. Cutaneous flares had significant influence on self-image. Neurological or psychiatric flares had a more severe impact on specific HRQoL. Patient HRQoL was impacted up to 18 months after a flare. CONCLUSION: Item response theory analysis is able to pinpoint items that are influenced by a given patient group in terms of a latent trait change. Item-level analysis provides a new way of interpreting HRQoL variation in SLE patients, permitting a better understanding of DA impact on HRQoL. This kind of analysis could be easily implemented for the comparison of groups in a clinical trial. TRIAL REGISTRATION: ClinicalTrials.gov, http://clinicaltrials.gov, NCT01904812.

Cluster analysis for the identification of clinical phenotypes among antiphospholipid antibody-positive patients from the APS ACTION Registry.

OBJECTIVE: This study aimed to use cluster analysis (CA) to identify different clinical phenotypes among antiphospholipid antibodies (aPL)-positive patients. METHODS: The Alliance for Clinical Trials and International Networking (APS ACTION) Registry includes persistently positive aPL of any isotype based on the Sydney antiphospholipid syndrome (APS) classification criteria. We performed CA on the baseline characteristics collected retrospectively at the time of the registry entry of the first 500 patients included in the registry. A total of 30 clinical data points were included in the primary CA to cover the broad spectrum of aPL-positive patients. RESULTS: A total of 497 patients from international centres were analysed, resulting in three main exclusive clusters: (a) female patients with no other autoimmune diseases but with venous thromboembolism (VTE) and triple-aPL positivity; (b) female patients with systemic lupus erythematosus, VTE, aPL nephropathy, thrombocytopaenia, haemolytic anaemia and a positive lupus anticoagulant test; and (c) older men with arterial thrombosis, heart valve disease, livedo, skin ulcers, neurological manifestations and cardiovascular disease (CVD) risk factors. CONCLUSIONS: Based on our hierarchical cluster analysis, we identified different clinical phenotypes of aPL-positive patients discriminated by aPL profile, lupus or CVD risk factors. Our results, while supporting the heterogeneity of aPL-positive patients, also provide a foundation to understand disease mechanisms, create new approaches for APS classification and ultimately develop new management approaches.

Health-Related Quality of Life in Antiphospholipid Syndrome: Current Knowledge and Future Perspectives.

PURPOSE OF REVIEW: Antiphospholipid syndrome (APS) is a chronic autoimmune disease that can be seen as a burden, with consequences on patients' daily life. Health has traditionally been measured using measures of morbidity or mortality. Health-related quality of life (HRQoL) is a concept that includes quality of life through physical, mental, and social domains. As in other autoimmune diseases, HRQoL has been investigated in patients with APS. Here, we provide a comprehensive review of the current knowledge of the assessment of HRQoL in APS. RECENT FINDINGS: APS patients have an impaired HRQoL compared with the general population. The presence of systemic lupus erythematosus (SLE) in APS patients is associated with a worse HRQoL than in patients without SLE. Several determinants of HRQoL impairment in APS have been identified: age, gender, history of arterial thrombosis, organ damage, lack of social support and treatments. This review highlights the negative impact of thrombosis on APS patients' HRQoL that should not be neglected. Besides, there is a need for a better strategy of communication and information, in order to improve HRQoL in APS.

New Insights into the Use of Direct Oral Anticoagulants in Non-high Risk Thrombotic APS Patients: Literature Review and Subgroup Analysis from a Meta-analysis.

PURPOSE OF REVIEW: The efficacy of direct oral anticoagulants (DOACs) in antiphospholipid syndrome (APS) is discussed. Results from randomized controlled trials are available. It has been stated that a history of arterial thrombosis and triple positivity was associated with a higher risk of thrombosis in APS patients treated with DOACs. However, their efficacy in non-high-risk APS patients with isolated venous manifestations is unsolved. Therefore, we performed a sub-group analysis of a previously published meta-analysis after the exclusion of patients with triple positivity and those with history of arterial or small vessel thrombosis. RECENT FINDINGS: We identified 290 APS patients with previous isolated venous event treated with DOACs; among them, 25 (8.6%) patients experienced a recurrent thrombosis in comparison to 16% in the original cohort. We found that the rate of recurrent thrombosis is lower in APS patients with isolated venous manifestations than in overall APS patients including high-risk patients. Research about DOAC use in non-high-risk APS patients needs to be continued.

EULAR recommendations for the management of antiphospholipid syndrome in adults.

The objective was to develop evidence-based recommendations for the management of antiphospholipid syndrome (APS) in adults. Based on evidence from a systematic literature review and expert opinion, overarching principles and recommendations were formulated and voted. High-risk antiphospholipid antibody (aPL) profile is associated with greater risk for thrombotic and obstetric APS. Risk modification includes screening for and management of cardiovascular and venous thrombosis risk factors, patient education about treatment adherence, and lifestyle counselling. Low-dose aspirin (LDA) is recommended for asymptomatic aPL carriers, patients with systemic lupus erythematosus without prior thrombotic or obstetric APS, and non-pregnant women with a history of obstetric APS only, all with high-risk aPL profiles. Patients with APS and first unprovoked venous thrombosis should receive long-term treatment with vitamin K antagonists (VKA) with a target international normalised ratio (INR) of 2-3. In patients with APS with first arterial thrombosis, treatment with VKA with INR 2-3 or INR 3-4 is recommended, considering the individual's bleeding/thrombosis risk. Rivaroxaban should not be used in patients with APS with triple aPL positivity. For patients with recurrent arterial or venous thrombosis despite adequate treatment, addition of LDA, increase of INR target to 3-4 or switch to low molecular weight heparin may be considered. In women with prior obstetric APS, combination treatment with LDA and prophylactic dosage heparin during pregnancy is recommended. In patients with recurrent pregnancy complications, increase of heparin to therapeutic dose, addition of hydroxychloroquine or addition of low-dose prednisolone in the first trimester may be considered. These recommendations aim to guide treatment in adults with APS. High-quality evidence is limited, indicating a need for more research.

Platelet aggregation impacts thrombin generation assessed by calibrated automated thrombography.

A calibrated automated thrombogram (CAT) is performed usually with human platelet-free plasma (PFP) but may be more relevant with platelet-rich plasma (PRP). In this case, platelets are not stimulated by subendothelial molecules like collagen. Our aim was to assess the consequence of strong (collagen) or weak (ADP) induction of platelet release and aggregation on thrombin generation. Platelet aggregation in PRP was triggered with 10 µg/mL collagen or 10 µM ADP using a lumi-aggregometer. Thrombin generation curves were monitored by CAT in different conditions: PRP, PRP with activated platelets (actPRP), aggregated PRP (agPRP), aggregated platelets resuspended in autologous PFP (resPRP), PFP and PFP obtained after aggregation (agPFP). We found a 3-fold shortening of the lag time and time to peak and a marked increase in velocity and thrombin peak without changes in endogenous thrombin potential (ETP) in agPRP with both agonists compared with PRP. The same holds true in agPFP but with a marked increase in ETP compared with PFP. Similar changes in the kinetics of thrombin generation were observed with actPRP-collagen and to a lesser extent in resPRP-collagen compared with PRP. By contrast, there were no modifications of the thrombin generation curves in actPRP-ADP. Alpha-2-macroglobin-thrombin complexes were unchanged in the different PRP conditions but were increased in PFP prepared from agPFP compared to control PFP. Platelet aggregation during activation by agonists other than thrombin did not increase thrombin generation but accelerated its kinetics mainly via platelet content release and platelet-derived extracellular vesicules formation. In diseases characterized by altered platelet granule content or release as well as altered platelet activation, a platelet aggregation step prior to CAT analysis may be clinically relevant to improve laboratory estimation of the bleeding/thrombotic balance.

Vascular smooth muscle cells are responsible for a prothrombotic phenotype of spontaneously hypertensive rat arteries.

OBJECTIVE: The hypothesis that hypertension induces a hypercoagulable state arises from the complications associated with hypertension: stroke and myocardial infarction. Here, we determine whether hypertension causes changes in the thrombin-generating capacity of the vascular wall. APPROACH AND RESULTS: We used spontaneously hypertensive rats (SHR) compared with Wistar rats. The addition of thoracic aortic rings of SHR to a Wistar or SHR plasma pool resulted in a greater increase in thrombin generation compared with equivalent rings from Wistar. This increase occurred in 12- but not 5-week-old rats and was prevented by an angiotensin II-converting enzyme inhibitor, indicating that established hypertension is required to induce increased thrombin generation within the vessel wall. Whereas no difference was observed for endothelial cells, thrombin formation was higher on aortic smooth muscle cells (SMCs) from SHR than on those from Wistar. Exposure of negatively charged phospholipids was higher on SHR than on Wistar rings, as well as on cultured SMCs. Tissue factor activity was higher in SHR SMCs. Twelve-week-old SHR exhibited accelerated FeCl3-induced thrombus formation in carotid arteries, and the resulting occlusive thrombi were disaggregated by blockade of glycoprotein Ibα-von Willebrand factor interactions. SHR SMCs were more sensitive to thrombin-induced proliferation than Wistar SMCs. This effect was totally abolished by a protease-activated receptor 1 inhibitor. CONCLUSIONS: The prothrombotic phenotype of the SHR vessel wall was due to the ability of SMCs to support greater thrombin generation and resulted in accelerated occlusive thrombus formation after arterial injury, which was sensitive to glycoprotein Ibα-von Willebrand factor inhibitors.