Targeting thromboinflammation in antiphospholipid syndrome

NETosis: A key player in autoimmunity, COVID-19, and long COVID

NETosis, the process through which neutrophils release neutrophil extracellular traps (NETs), has emerged as a crucial mechanism in host defense and the pathogenesis of autoimmune responses. During the SARS-CoV-2 pandemic, this process received significant attention due to the central role of neutrophil recruitment and activation in infection control. However, elevated neutrophil levels and dysregulated NET formation have been linked to coagulopathy and endothelial damage, correlating with disease severity and poor prognosis in COVID-19. Moreover, it is known that SARS-CoV-2 can induce persistent low-grade systemic inflammation, known as long COVID, although the underlying causes remain unclear. It has been increasingly acknowledged that excessive NETosis and NET generation contribute to further pathophysiological abnormalities following SARS-CoV-2 infection. This review provides an updated overview of the role of NETosis in autoimmune diseases, but also the relationship between COVID-19 and long COVID with autoimmunity (e.g., latent and overt autoimmunity, molecular mimicry, epitope spreading) and NETosis (e.g., immune responses, NET markers). Finally, we discuss potential therapeutic strategies targeting dysregulated NETosis to mitigate the severe complications of COVID-19 and long COVID.

Towards precision medicine in antiphospholipid syndrome

Antiphospholipid syndrome is a rare systemic autoimmune disorder with complex pathophysiology and high heterogeneity in clinical presentation and treatment responses. The core idea of precision medicine is that the varying treatment responses among patients with the same clinical diagnosis are due to differences in their underlying pathogenetic mechanisms and genetic makeup. A better understanding of the pathophysiology and multiple clinical subtypes of antiphospholipid syndrome has led to better classification and subphenotyping of the syndrome. Advances in microarray analysis, cytometry, and omic technologies have helped to identify genes, epigenetic variations, and pathway-informed biomarkers and identified new factors in disease development. By stratifying patients with antiphospholipid syndrome based on clinical or laboratory phenotypes and cellular and molecular profiles in the blood and affected tissues, treatments can be more effectively tailored, improving efficacy and reducing toxicity. This Review explores the current evidence on clinical, genetic, and biomolecular stratification in antiphospholipid syndrome and how artificial intelligence algorithms from clinical and molecular profiles can guide precision medicine in antiphospholipid syndrome.

Platelet lipidomics indicates enhanced thrombocyte activation in patients with antiphospholipid syndrome in vivo

BACKGROUND

Antiphospholipid syndrome (APS) is an autoimmune disorder characterized by the presence of antiphospholipid antibodies in patients with thromboembolic/thromboinflammatory events and/or obstetric complications.

OBJECTIVES

The aim of this study was to examine whether there are alterations in the platelet lipidome of APS patients in comparison with patients affected by thromboembolism without APS (control) and healthy volunteers.

METHODS

We applied quantitative mass spectrometry-based lipidomics to investigate the platelet lipidome of isolated resting and thrombin-stimulated platelets as well as platelet release in patients with APS, controls, and healthy volunteers.

RESULTS

Lipidomic data revealed an increase in lysophospholipids (LPLs) in platelets from APS patients, specifically in lysophosphatidylcholine and lysophosphatidylethanolamine species. As LPLs are cleavage products generated by phospholipase A (PLA) from the corresponding phospholipid precursor, LPL/phospholipid ratios may be employed as surrogates for PLA1 and PLA2 activities. The surrogate ratios for PLA2, which participates in the release of arachidonic acid during platelet activation, were significantly increased in APS in both resting platelets and upon thrombin-induced activation for phosphatidylcholine and phosphatidylethanolamine. The phosphatidylcholine-PLA2 surrogate ratio was found to correlate with serum levels of anti-β2-glycoprotein I and anticardiolipin immunoglobulin G. Finally, receiver operator characteristic analysis demonstrated excellent discrimination of patients with APS from controls and healthy volunteers.

CONCLUSION

These findings provide substantial evidence that platelet activation is enhanced in APS in vivo, involving the activation of PLA2.

S-hydroxychloroquine prevents the antiphospholipid thrombogenic complexes for antiphospholipid syndrome treatment

Clinically used in systemic lupus erythematosus (SLE), Hydroxychloroquine (HCQ) exerts antithrombotic effects by inhibiting anti-β2-glycoprotein I (anti-β2GPI) antibody binding to phospholipid bilayers. However, HCQ is a racemic mixture, with only one enantiomer offering therapeutic benefits, while the other may contribute to toxicity. The current study evaluated the thromboprophylactic efficacy of R-enantiomer Hydroxychloroquine (R-HCQ), S-enantiomer Hydroxychloroquine (S-HCQ), and racemic HCQ (Rac-HCQ), with a focus on their impact on APS-associated markers. Both in vitro and in vivo models were employed, with human umbilical vein endothelial cells (HUVECs) and mice immunized with human β2-glycoprotein I antibodies used to evaluate the formation of antiphospholipid thrombotic complexes and their modulation by HCQ enantiomers. S-HCQ significantly reduced β2GPI complex binding and restored the AnxA5 anticoagulant shield in vitro, demonstrating superior efficacy over R-HCQ in disrupting β2GPI/anti-β2GPI interactions and preventing endothelial dysfunction in APS models. Pretreatment of HUVECs with S-HCQ significantly attenuated the expression of proinflammatory cytokines (tumor necrosis factor-alpha, interleukin-6, interleukin-1 beta, and C-C motif ligand 2) and endothelial activation markers (intercellular adhesion molecule 1, vascular cell adhesion molecule 1, and E-selectin). S-HCQ alleviates endothelial dysfunction by reducing proinflammatory cytokines, endothelial activation markers, and NO production while downregulating iNOS expression, highlighting its potential to mitigate oxidative stress and thrombogenic activity in APS-related endothelial damage. In vivo, S-HCQ effectively reduced clot formation in the femoral veins of APS mouse models. Among the HCQ enantiomers tested, S-HCQ demonstrated superior efficacy in modulating inflammatory and angiogenic pathways, influencing the formation of antiphospholipid thrombotic complexes and mitigating thrombosis. These findings underscore the potential of S-HCQ as a therapeutic alternative for APS management.

P-Selectin, Vascular Endothelial Cadherin, and Vascular Cell Adhesion Molecule-1 as Novel Biomarkers for ABO Hemolytic Disease of the Fetus and Newborn

Objective: This study aims to assess the potential of vascular endothelial injury markers, namely, P-selectin (PS), vascular endothelial cadherin (VE-Cad), and vascular cell adhesion molecule-1 (VCAM-1), as diagnostic and prognostic biomarkers for ABO hemolytic disease of the fetus and newborn (HDFN). Methods: A total of 218 pregnant women with ABO blood group incompatibility were recruited from the Third People's Hospital of Bengbu Affiliated to Bengbu Medical University. The serum levels of PS, VCAM-1, and VE-Cad were measured, and the participants were followed up until postpartum. The women were divided into an HDFN group and a control group based on the occurrence of ABO-HDFN. The correlations between the three vascular endothelial injury markers, pregnant anti-A/B antibody titers, and the occurrence and severity of HDFN were analyzed. Results: Compared to the control group, the levels of PS, VCAM-1, and VE-Cad were significantly elevated in the HDFN group. Additionally, these markers increased with higher IgG anti-A/B titers. For diagnosing HDFN, the area under the curve (AUC) for PS, VCAM-1, and VE-Cad were 0.826, 0.765, and 0.799, respectively. Moreover, the combined AUC of the three markers with IgG anti-A/B titers was 0.9. The levels of the three biomarkers were significantly negatively correlated with neonatal hemoglobin (Hb) and significantly positively correlated with reticulocyte percentage (Ret%), indirect bilirubin (IBIL), and lactate dehydrogenase (LDH). Univariate logistic regression indicated that increased levels of PS, VCAM-1, and VE-Cad were associated with a higher probability of ABO-HDFN. Multivariate logistic regression revealed that PS is an independent positive factor for HDFN. Conclusion: PS, VCAM-1, and VE-Cad provide experimental evidence for prenatal screening, diagnosis, early prevention and treatment of ABO-HDFN.

Neutrophil extracellular traps aggravate placental injury in OAPS by facilitating activation of BNIP3 mediated mitophagy

Obstetric antiphospholipid syndrome (OAPS) is an autoimmune disease mediated by antiphospholipid antibodies (aPL), characterized by miscarriage, pre-mature birth caused by pre-eclampsia, intrauterine growth restriction, and other pregnancy complications. Neutrophil extracellular traps (NETs) consist of chromatin scaffolds coated with histones, proteases, granules, and cytosolic proteins. Here, we have observed increased levels of NETs in both human OAPS placental tissues and animal models, accompanied by apoptosis increases. In vitro, NETs induce a decrease in trophoblasts proliferation and an increase in apoptosis. In addition, NETs induce oxidative stress and mitochondrial reactive oxygen species (mtROS) production, upregulation of fission-associated mitochondrial proteins coupled with reduced fusion-associated protein levels. It also led to a rise in BNIP3 and autophagy-related protein expressions, along with an increase in autophagosomal numbers. Moreover, mtROS scavenging or knockdown strategies targeting BNIP3 effectively attenuated mitophagic activation alongside trophoblast apoptosis induction. Furthermore, upregulation of BNIP3 expression was evident in placentas from both APS murine models and human OAPS cases. These results suggest that aPL-induced NETs trigger BNIP3-mediated mitophagy, elevate ROS production, induce apoptosis in trophoblasts, and thereby exacerbate placental damage, with implications for our understanding of the pathogenesis of OAPS and devising novel treatment strategies.

Remnant cholesterol predicts risk of recurrent thrombosis beyond LDL-cholesterol in patients with antiphospholipid syndrome

BACKGROUND

Antiphospholipid syndrome (APS) is notably linked to thrombotic events, particularly cardiovascular disease (CVD). The role of remnant cholesterol (RC) in predicting CVD risk is established, yet its relationship with thrombotic risk in APS patients remains to be elucidated. This study aims to assess the association between RC and recurrent thrombotic risk in patients with APS.

METHODS

A prospective analysis was conducted based on a cohort of APS patients who met the 2006 Sydney revised classification criteria. Thrombotic risks associated with varying levels of RC were evaluated using Kaplan-Meier survival analysis and Cox proportional hazards regression models. Mendelian randomization (MR) was applied to examine the causal link between RC and different types of thrombotic events.

RESULTS

A total of 325 patients with APS were enrolled in this study. Over a median follow-up of 35 months, 51 patients experienced thrombotic events, including 24 venous, 19 arterial, and 16 microvascular incidents. Patients with RC levels above 0.60 mmol/L exhibited significantly higher risks, with multivariable-adjusted hazard ratio (and 95% confidence interval) for all-cause, venous, arterial thrombosis, and microvascular disease being 5.05 (2.23-11.41), 6.34 (1.71-23.54), 3.79 (1.00-14.32), and 4.36 (1.08-17.58), respectively. Notably, elevated RC remained a significant thrombotic risk factor even in patients with normal conventional lipid profiles. MR analysis revealed a significant causal association between RC and arterial thrombosis, but not venous thrombosis.

CONCLUSIONS

Elevated RC is linked to a substantial increase in the risk of thrombotic events in APS patients. These findings suggest that RC could be a valuable marker for thrombotic risk in this population and a potential target for therapeutic intervention.

Mechanism of antiphospholipid antibody-mediated thrombosis in antiphospholipid syndrome

Antiphospholipid syndrome (APS) is an autoimmune disease characterized by the occurrence of thrombotic or obstetrical events in patients with persistent antiphospholipid antibodies (aPL). Thrombotic events, the primary pathological hallmarks and clinical manifestations, are among the leading causes of mortality in APS. Our understanding of the mechanism underlying APS-related thrombosis has significantly advanced in recent years. The presence of aPL, particularly anti-β2-glycoprotein I (anti-β2GPI) antibodies, is a major driver of thrombosis. The proposed pathophysiological mechanisms of aPL-mediated pro-thrombotic events can be broadly categorized into three types: disruption of anticoagulant reactions and fibrinolysis, interference with coagulation cascade cells, and complement activation. A triggering 'second hit' is typically necessary to initiate thrombosis. The development of animal models of APS has further refined our understanding of the role of aPL in thrombosis. In this review, we focused on the role of β2GPI-dependent aPL in thrombosis of thrombotic APS.

Macrophage metabolic reprogramming: A trigger for cardiac damage in autoimmune diseases

Macrophage metabolic reprogramming has a central role in the progression of autoimmune and auto-inflammatory diseases. The heart is a major target organ in many autoimmune conditions and can sustain functional and structural impairments, potentially leading to irreversible cardiac damage. There is mounting clinical evidence pointing to a link between autoimmune disease and cardiac damage. However, this association remains poorly understood, and numerous patients do not receive appropriate preventive measures, which poses serious cardiovascular risks and significantly impacts their quality of life. This review discusses the relationship between macrophage metabolic reprogramming and cardiac damage in patients with autoimmune diseases and the role of adaptive immunity in macrophage reprogramming. It also provides an overview of the immunosuppressive therapies used at present. Exploiting the properties of macrophage reprogramming could lead to development of novel treatments for patients with autoimmune-related cardiac damage.

Unresolved issues in the diagnosis and management of thrombotic antiphospholipid syndrome

Antiphospholipid syndrome (APS) is a highly prothrombotic autoimmune disease characterized by the persistent presence of antiphospholipid autoantibodies (aPL) in association with thrombotic or nonthrombotic macro- and microvascular manifestations and/or pregnancy complications. This review is restricted to thrombotic APS. Since the publication of the American College of Rheumatology/European Alliance of Associations for Rheumatology classification criteria for APS, several authors have emphasized the difference between "classification" and "diagnosis" as a potential pitfall for clinicians. In addition to challenges associated with the diagnosis of APS, there are many unresolved areas in understanding pathogenesis and in the management of both thrombotic and obstetric APS. Although APS is an antibody-mediated autoimmune disease, secondary thrombosis prevention is achieved by anticoagulation, mainly with vitamin K antagonists, such as warfarin, rather than immunomodulation. Evidence is convincing for the use of vitamin K antagonists in triple-positive APS with venous thromboembolism. However, the best anticoagulant approach in the management of venous thromboembolism patients with single or dual positive aPL is not clear. Management of patients with stroke or arterial thrombosis with aPL remains a major unresolved issue, although some guidelines recommend the use of warfarin rather than antiplatelet therapy as the first-line treatment of stroke in APS. Recurrent thrombosis, despite therapeutic anticoagulation, remains a frequent problem and may be explained by the contribution of thrombo-inflammation in patients with thrombotic APS. In this narrative review, we discuss some of the unresolved issues in the diagnosis and management of thrombotic APS.

Circulating, Extracellular Vesicle-Associated Tissue Factor in Cancer Patients with and without Venous Thromboembolism

Cancer is characterized by chronic inflammation and hypercoagulability, with an excess of venous thromboembolism (VTE). Tissue factor, the initiator of blood coagulation, circulates associated with extracellular vesicles (EV-TF). Studies investigating EV-TF between cancer-associated and non-cancer-associated VTE are lacking. We therefore compared EV-TF in unprovoked VTE (U-VTE), cancer-associated VTE (C-VTE), and cancer without VTE (C-w/o VTE). We also investigated interleukin-6 (IL-6) levels between the same groups. The final population included 68 patients (U-VTE: n = 15; C-VTE: n = 24; C-w/o VTE: n = 29). All patients with VTE were enrolled within 48 h of diagnosis; non-VTE patients were recruited in the oncologic outpatient services. EV were isolated by differential centrifugation from 4 mL of peripheral blood; the final EV pellet (16,000× g for 45 min) was resuspended in 100 μL saline and tested for TF using a one-step clotting assay. There was a statistically significant difference for higher EV-TF in C-VTE and C-w/o VTE compared to U-VTE (p = 0.024; Kruskal-Wallis test). There was no significant difference between C-VTE and C-w/o VTE. Moreover, we did not find any difference in IL-6 levels. These preliminary data suggest that cancer represents, per se, a strong driver of EV-TF generation.

Epigenetic Biomarkers in Thrombophilia-Related Pregnancy Complications: Mechanisms, Diagnostic Potential, and Therapeutic Implications: A Narrative Review

Pregnancy complications associated with thrombophilia represent significant risks for maternal and fetal health, leading to adverse outcomes such as pre-eclampsia, recurrent pregnancy loss, and intra-uterine growth restriction (IUGR). They are caused by disruptions in key physiological processes, including the coagulation cascade, trophoblast invasion, angiogenesis, and immune control. Recent advancements in epigenetics have revealed that non-coding RNAs, especially microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and extracellular vesicles (EVs) carrying these RNAs, play crucial roles in the regulation of these biological processes. This review aims to identify the epigenetic biomarkers that are the best candidates for evaluating thrombophilia-related pregnancy complications and for assessing the efficacy of anticoagulant and antiaggregant therapies. We emphasize their potential integration into personalized treatment plans, aiming to improve the risk assessment and therapy strategies for thrombophilic pregnancies. Future research should focus on validating these epigenetic biomarkers and establishing standardized protocols to enable their integration into clinical practice, paving the way for a precision medicine approach in obstetric care.

5-oxoETE promote thrombosis in antiphospholipid syndrome by triggering NETs formation through PLC/PKC/ERK pathway

BACKGROUND

One mechanism by which antiphospholipid syndrome (APS) IgG contribute to thrombotic events in patients with APS is through the potentiation of neutrophil extracellular traps (NETs) release. However, the exact mechanism by which APS IgG induces NETs formation and thrombosis has not been fully elucidated.

METHODS

We conducted untargeted metabolomics on serum samples from thrombotic APS patients to identify metabolic changes. The effect of 5-oxoETE on NETs formation and oxidative stress was evaluated in vitro by treating neutrophils with various concentrations of 5-oxoETE. The involvement of the PLC/PKC/ERK signaling pathway in 5-oxoETE-induced NETs formation was examined using pharmacological inhibitors. In vivo, we assessed the effects of inhibiting 5-oxoETE synthesis or blocking its receptor (OXE-R) on NETs formation and thrombosis in APS mouse models.

RESULTS

Serum metabolomics revealed significantly elevated levels of 5-oxoETE in APS patients. In vitro experiments demonstrated that 5-oxoETE, via OXE-R activation of the PLC/PKC/ERK signaling pathway, increased NETs formation and oxidative stress in a dose-dependent manner. In vivo, inhibiting 5-oxoETE synthesis or OXE-R reduced NETs formation and attenuated venous thrombosis in APS mice models.

CONCLUSION

This study identifies 5-oxoETE as a critical mediator of NET formation and thrombosis in APS. Targeting 5-oxoETE or OXE-R may offer a promising therapeutic approach for thrombotic APS and other NET-associated autoimmune diseases.

Simvastatin ameliorates adverse pregnancy by inhibiting glycolysis-related NETs in obstetrical antiphospholipid syndrome

AIMS

Some patients with Obstetric Antiphospholipid Syndrome (OAPS) still experience miscarriage and placental dysfunction after routine treatment, which is related to an abnormal increase in neutrophil extracellular traps (NETs). The labeling of statins has been revised to remove the contraindication for use during pregnancy. Our aim is to investigate the effect of Simvastatin on pregnancy outcomes in OAPS and its correlation mechanisms with NETs.

MAIN METHODS

The effect of Simvastatin on pregnancy outcomes was observed. The effect of simvastatin on the function and apoptosis of neutrophils has evaluated. The effect of Simvastatin to NETs and the changes in oxidative stress levels were observed. Different groups of NETs were extracted to intervene the HTR8-Svneo.RNA-seq analysis of the mechanism of which Simvastatin reduces NETs. Seahorse experiment detected the effect of Simvastatin on neutrophil glycolysis levels. Fluorescence co-localization and flow cytometry and Co-IP were used to verify relevant mechanisms.

KEY FINDINGS

In the OAPS mice, Simvastatin can reduce embryo absorption rate, reshape placental blood flow perfusion. Simultaneously reducing the production of NETs both in vivo and vitro, remolding oxidative stress. Simvastatin can improve neutrophil dysfunction caused by aPL-IgG. The reduction of NETs improved HTR8-Svneo's dysfunction. The intervention of Simvastatin on neutrophils under the stimulation of aPL-IgG showed a signature in glycolytic. The key rate limiting enzyme PKM2 in glycolysis interacts with Cit-H2b and PI3K/AKT signaling pathway.

SIGNIFICANCE

Our study providing basic theoretical support for the treatment of OAPS with Simvastatin.

Systemic risk factors of retinopathy in patients with systemic lupus erythematosus

OBJECTIVE

To investigate the risk factors of lupus retinopathy (LR) in patients with systemic lupus erythematosus (SLE).

METHODS

This is a retrospective, cross-sectional study. LR patients admitted at Peking Union Medical College Hospital from June 2013 to April 2023 were reviewed. Age- and gender-matched SLE patients without retinopathy were selected as controls. Medical records including clinical manifestations, laboratory data and ophthalmic examination were collected. Univariate and multivariate logistic regression analyses were conducted.

RESULTS

One hundred and twelve LR patients (198 eyes) were included, with 12 cases (14 eyes) presenting with retinal macrovascular obstruction, and 100 cases (184 eyes) only exhibiting microvasculopathy. Multivariate analysis indicated the presence of haemolytic anaemia, decreased haemoglobin (HGB) and higher relative percentage of neutrophils were independent risk factors for LR (p < 0.05). The first two were also risk factors for retinal microvasculopathy, whereas secondary antiphospholipid syndrome (APS) was for macrovascular obstruction. In male group, LR had significant associations with decreased HGB, no matter which types of retinopathy (p < 0.05). In female group, LR was significantly associated with haemolytic anaemia, presence of antiphospholipid antibodies, decreased white blood cells and relative high percentage of neutrophils. Specifically, haemolytic anaemia (p = 0.002) was significantly associated with retinal microvasculopathy, and APS (p = 0.003) was significantly associated with macrovasculature obstruction.

CONCLUSION

LR was related to haemolytic anaemia, decreased HGB levels and higher percentage of neutrophils. Retinal microvasculopathy accounted for most cases and macrovasculature obstructions were rare. Male and female patients have distinct risk factors. Early ophthalmic screening is recommended especially for those with risk factors of LR.

Advances in nanomaterial-targeted treatment of acute lung injury after burns

Acute lung injury (ALI) is a common complication in patients with severe burns and has a complex pathogenesis and high morbidity and mortality rates. A variety of drugs have been identified in the clinic for the treatment of ALI, but they have toxic side effects caused by easy degradation in the body and distribution throughout the body. In recent years, as the understanding of the mechanism underlying ALI has improved, scholars have developed a variety of new nanomaterials that can be safely and effectively targeted for the treatment of ALI. Most of these methods involve nanomaterials such as lipids, organic polymers, peptides, extracellular vesicles or cell membranes, inorganic nanoparticles and other nanomaterials, which are targeted to reach lung tissues to perform their functions through active targeting or passive targeting, a process that involves a variety of cells or organelles. In this review, first, the mechanisms and pathophysiological features of ALI occurrence after burn injury are reviewed, potential therapeutic targets for ALI are summarized, existing nanomaterials for the targeted treatment of ALI are classified, and possible problems and challenges of nanomaterials in the targeted treatment of ALI are discussed to provide a reference for the development of nanomaterials for the targeted treatment of ALI.

Antiphospholipid antibody carriers and patients with quiescent antiphospholipid syndrome show persistent subclinical complement activation

OBJECTIVES

Complement activation has been advocated as one mechanism by which aPLs can induce thrombosis. In patients with catastrophic APS or re-thrombosis, enhanced complement activation has been shown, even in the quiescent phase of the disease. We aimed to assess complement activation and to investigate its association with clinical variables in aPL-positive patients with a favourable disease course.

METHODS

Subjects with at least two consecutive positive aPL results obtained ≥12 weeks apart were enrolled. They were subjects without a history of thrombosis or pregnancy morbidity (aPL carriers), patients with pregnancy morbidity alone, i.e. obstetric APS patients (OAPS patients), and/or patients with arterial, venous, or small-vessel thrombotic APS (TAPS patients); for enrolment, all patients were required to have been free of symptoms for ≥2 years. Patients affected with systemic autoimmune diseases were excluded. Healthy age- and sex-matched subjects were included as controls. Plasma C5a and C5b-9 levels were assessed by commercially available ELISA assays. The non-parametric Mann-Whitney test and Spearman's correlation were applied.

RESULTS

Thirty-seven OAPS patients, 38 TAPS patients, 42 aPL carriers and 30 healthy subjects were enrolled. The median C5a and C5b-9 levels were significantly higher in quiescent aPL-positive patients (OAPS, TAPS, aPL carriers) compared with controls: C5a ng/ml 10.61 [interquartile range (IQR) 6.87-15.46] vs 4.06 (2.66-7.35), P < 0.001; C5b-9 ng/ml 283.95 (175.8-439.40) vs 165.90 (124.23-236.8), P < 0.001. Similar C5a and C5b-9 levels were observed in OAPS and TAPS patients and aPL carriers. A positive correlation between the median C5b-9 levels and the number of aPL-positive tests was found (P = 0.002).

CONCLUSION

The persistence of aPL antibodies is associated with a persistent subclinical activation of the complement cascade.

Obstetric antiphospholipid syndrome carries an increased lifetime risk for obstetric and thrombotic complications-a population-based study

Background

Antiphospholipid syndrome (APS) can present with either a thromboembolic event (thrombotic APS, TAPS) or an obstetric complication (obstetric APS, OAPS). Data on long-term complications in the different APS phenotypes are limited.

Objectives

We aimed to compare obstetric history, antiphospholipid antibody profiles, obstetric and thromboembolic complications, and pregnancy outcomes between TAPS and OAPS.

Methods

This retrospective cohort study included women who delivered singleton pregnancies between 1998 and 2020. One hundred sixteen thousand four hundred nine women were included, resulting in 320,455 deliveries. Among the included patients, 71 were diagnosed with APS, 49 were classified as OAPS, and 22 as TAPS. The demographics, obstetric, neonatal, and thrombotic outcomes were compared among TAPS, OAPS, and the general obstetric population.

Results

OAPS patients had an increased risk of thrombotic events compared with the general obstetric population (odds ratio [OR] 18.0; 95% CI, 8.7-37.2). In pregnancies following the diagnosis of APS, despite standard antithrombotic treatment, OAPS patients exhibited an elevated risk of placenta-related and neonatal complications compared with the general obstetric population (late fetal loss [adjusted OR {aOR}, 15.3; 95% CI, 0.5-27.5], stillbirth [aOR, 5.9; 95% CI, 2.2-15.4], placental abruption [aOR, 4.8; 95% CI, 1.5-15.3], preeclampsia [aOR, 4.4; 95% CI, 2.5-7.7], fetal growth restriction [aOR, 4.3; 95% CI, 8.5-27.5], small for gestational age neonate [aOR, 4.0; 95% CI, 2.4-6.6], and low Apgar scores [Apgar'1: aOR, 2.6; 95% CI, 1.3-10.4; Apgar'5: aOR, 3.7; 95% CI, 1.3-10.4]). TAPS patients exhibited increased risk of preeclampsia (aOR, 3.1; 95% CI, 1.2-8).

Conclusion

OAPS patients exhibit a heightened risk of thrombotic events compared with the general obstetric population. Despite treatment, OAPS and TAPS still presented obstetric complications. These findings, after confirmation in prospective studies, need to be taken into consideration when planning the treatment approach for these patients.

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.

Risk factors for damage accrual in primary antiphospholipid syndrome: A retrospective single-center cohort study

BACKGROUND

Despite anticoagulant therapy, a antiphospholipid syndrome (APS) has a higher rate of recurrent events, which can lead to damage accrual and a negative impact on life quality.

OBJECTIVES

To evaluate the risk factors and APS subsets associated with damage accrual.

PATIENTS/METHODS

We conducted a retrospective single-center study. We reviewed the medical records of 282 APS patients, with a median age of 36 (IQR 30-46) years and a median of 195 (IQR 137-272) months. The primary endpoint was damage accrual during follow-up, defined as organ/tissue impairment present for at least six months or causing permanent loss. The secondary endpoints were early organ damage within six months of disease onset and death.

RESULTS

Eighty (28.4%) patients presented damage accrual; 52.5% developed damage within six months of APS onset, and 41.3% had more than one organ involved. Neuropsychiatric involvement, affecting 38.8% of the patients, was the most frequent, followed by peripheral vasculopathy and renal involvement, 35% either. Death happened in 7 (2.5 %) patients; damage accrual was associated with a 6-fold risk of death [OR 6.7 (95% CI 1.3-35.1), p = 0.03]. Microangiopathy and non-criteria manifestations were independent risk factors for damage accrual with 5-fold and 4-fold higher risk, respectively [(OR 4.9 (95% CI 2.1-11.7), p < 0.0001 and (OR 3.8 (95% CI 1.5-10.1), p = 0.007]. The cumulative incidence of damage accrual increased by 5.7-fold and 3.6-fold in patients with microangiopathy and non-criteria manifestations.

CONCLUSIONS

APS patients had a higher frequency of damage accrual. Microangiopathy and non-criteria manifestations were independent risk factors for damage accrual.

Antiphospholipid antibodies as potential predictors of disease severity and poor prognosis in systemic lupus erythematosus-associated thrombocytopenia: results from a real-world CSTAR cohort study

BACKGROUND

To investigate the role of antiphospholipid antibodies (aPLs) in the disease severity and prognosis of SLE-related thrombocytopenia (SLE-TP).

METHODS

This multicenter prospective study was conducted based on data from the CSTAR registry. TP was defined as a platelet count<100 × 109/L. Demographic characteristics, platelet count, clinical manifestations, disease activity, and autoantibody profiles were collected at baseline. Relapse was defined as the loss of remission. Bone marrow aspirate reports were also collected.

RESULTS

A total of 350 SLE-TP patients with complete follow-up data, 194 (55.4%) were aPLs positive. At baseline, SLE-TP patients with aPLs had lower baseline platelet counts (61.0 × 109/L vs. 76.5 × 109/L, P<0.001), and a higher proportion of moderate to severe cases (24.2% vs. 14.1% ; 18.0% vs. 8.3%, P<0.001). SLE-TP patients with aPLs also had lower platelet counts at their lowest point (37.0 × 109/L vs. 51.0 × 109/L, P = 0.002). In addition, thean increasing number of aPLs types was associated with a decrease in the baseline and minimum values of platelets ( P<0.001, P = 0.001). During follow-up, SLE-TP carrying aPLs had a higher relapse rate (58.2% vs. 44.2%, P = 0.009) and a lower complete response (CR) rate. As the types of aPLs increased, the relapse rate increased, and the CR rate decreased. Furthermore, there was no significant difference in the ratio of granulocytes to red blood cells (G/E), the total number of megakaryocyte and categories.

CONCLUSION

SLE-TP patients with positive aPLs had more severe disease a lower remission rate but a higher relapse rate.

New advances in genomics and epigenetics in antiphospholipid syndrome

APS patients exhibit a wide clinical heterogeneity in terms of the disease's origin and progression. This diversity can be attributed to consistent aPL profiles and other genetic and acquired risk factors. Therefore, understanding the pathophysiology of APS requires the identification of specific molecular signatures that can explain the pro-atherosclerotic, pro-thrombotic and inflammatory states observed in this autoimmune disorder. In recent years, significant progress has been made in uncovering gene profiles and understanding the intricate epigenetic mechanisms and microRNA changes that regulate their expression. These advancements have highlighted the crucial role played by these regulators in influencing various clinical aspects of APS. This review delves into the recent advancements in genomic and epigenetic approaches used to uncover the mechanisms contributing to vascular and obstetric involvement in APS. Furthermore, we discuss the implementation of novel bioinformatics tools that facilitate the investigation of these mechanisms and pave the way for personalized medicine in APS.

Anticoagulant and non-anticoagulant therapy in thrombotic antiphospholipid syndrome: old drugs and new treatment targets

In this review, we discuss the current evidence on classic and newer oral anticoagulant therapy, older drugs such as HCQ and statins, and new potential treatment targets in APS. Vitamin K antagonists (VKAs) remain the cornerstone treatment for thrombotic events in APS. In patients fulfilling criteria for definite APS presenting with a first venous thrombosis, treatment with VKAs with a target international normalized ratio (INR) 2.0-3.0 is recommended. In patients with arterial thrombosis, treatment with VKA with target INR 2.0-3.0 or 3.0-4.0 is recommended by recent guidelines, considering the individual's bleeding and thrombosis recurrence risk. A combination of VKAs and low-dose aspirin (75-100 mg/daily) may also be considered. According to available evidence direct oral anticoagulants should be avoided in patients with arterial thrombosis and/or those with triple aPL positivity. Adjunctive treatment with HCQ and/or statins can be considered, especially in anticoagulation treatment-refractory APS. Potential targeted treatments in APS include B-cell targeting, complement inhibition, mammalian target of rapamycin inhibition, IFN targeting, adenosine receptors agonists, CD38 targeting or chimeric antigen receptor T-cell therapy. The safety and efficacy of these treatment targets needs to be examined in well-designed randomized controlled trials.

Monocyte Tissue Factor Expression: Lipopolysaccharide Induction and Roles in Pathological Activation of Coagulation

The coagulation system is a part of the mammalian host defense system. Pathogens and pathogen components, such as bacterial lipopolysaccharide (LPS), induce tissue factor (TF) expression in circulating monocytes that then activates the coagulation protease cascade. Formation of a clot limits dissemination of pathogens, enhances the recruitment of immune cells, and facilitates killing of pathogens. However, excessive activation of coagulation can lead to thrombosis. Here, we review studies on the mechanism of LPS induction of TF expression in monocytes and its contribution to thrombosis and disseminated intravascular coagulation. Binding of LPS to Toll-like receptor 4 on monocytes induces a transient expression of TF that involves activation of intracellular signaling pathways and binding of various transcription factors, such as c-rel/p65 and c-Fos/c-Jun, to the TF promoter. Inhibition of TF in endotoxemia and sepsis models reduces activation of coagulation and improves survival. Studies with endotoxemic mice showed that hematopoietic cells and myeloid cells play major roles in the activation of coagulation. Monocyte TF expression is also increased after surgery. Activated monocytes release TF-positive extracellular vesicles (EVs) and levels of circulating TF-positive EVs are increased in endotoxemic mice and in patients with sepsis. More recently, it was shown that inflammasomes contribute to the induction of TF expression and activation of coagulation in endotoxemic mice. Taken together, these studies indicate that monocyte TF plays a major role in activation of coagulation. Selective inhibition of monocyte TF expression may reduce pathologic activation of coagulation in sepsis and other diseases without affecting hemostasis.

The Role of Neutrophil Extracellular Traps (NETs) in the Pathogenesis of Systemic Lupus Erythematosus and Antiphospholipid Syndrome

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease of unknown aetiology [...].