Potential utility of a multi-component coagulation factor panel to calculate MELD scores and assess the risk of portal vein thrombosis in chronic liver disease.

BACKGROUND: Current quantitative approaches to assess chronic liver disease (CLD) severity have limitations. Further, portal vein thrombosis (PVT) pre-liver transplant (LT) is a major contributor to morbidity in CLD; the means of detecting and/or predicting PVT are limited. We sought to explore whether plasma coagulation factor activity levels can serve as a substitute for prothrombin time/international normalized ratio (PT/INR) in the Model for End-stage Liver Disease (MELD), and/or help assess the risk of PVT. METHODS: Plasma activity levels of Factor V (FV), Factor VIII (FVIII), Protein C (PC), and Protein S (PS) and the concentrations of D-dimer, sP-selectin, and asTF were assessed in two cohorts of CLD patients (ambulatory, n = 42; LT, n = 43). RESULTS: FV and PC activity levels strongly correlated with MELD scores, which enabled the development of a novel scoring system based on multiple linear regressions of the correlations of FV and PC activity with MELD-Na that substitutes PT/INR. Six-month and 1-year follow-up revealed that our novel approach was non-inferior to MELD-Na at predicting mortality. A significant inverse correlation between FVIII activity levels and PVT was found in the LT cohort (p = 0.010); FV and PS activity levels were in-trend (p = 0.069, p = 0.064). We developed a logistic regression-based compensation score to identify patients at risk of PVT. CONCLUSIONS: We demonstrate that FV and PC activity levels may be used to replace PT/INR in MELD scoring. We also show the potential of using the combination of FV, FVIII, and PS activity levels to assess the risk of PVT in CLD.

PARP Inhibitor Inhibits the Vasculogenic Mimicry through a NF-κB-PTX3 Axis Signaling in Breast Cancer Cells.

Poly (ADP-ribose) polymerase inhibitors (PARPi) are targeted therapies that inhibit PARP proteins which are involved in a variety of cell functions. PARPi may act as modulators of angiogenesis; however, the relationship between PARPi and the vasculogenic mimicry (VM) in breast cancer remains unclear. To determine whether PARPi regulate the vascular channel formation, we assessed whether the treatment with olaparib, talazoparib and veliparib inhibits the vascular channel formation by breast cancer cell lines. Here, we found that PARPi act as potent inhibitors of the VM formation in triple negative breast cancer cells, independently of the BRCA status. Mechanistically, we find that PARPi trigger and inhibit the NF-κB signaling, leading to the inhibition of the VM. We further show that PARPi decrease the expression of the angiogenic factor PTX3. Moreover, PTX3 rescued the PARPi-inhibited VM inhibition. In conclusion, our results indicate that PARPi, by targeting the VM, may provide a new therapeutic approach for triple negative breast cancer.

Prospective Assessment of Clinical Risk Factors and Biomarkers of Hypercoagulability for the Identification of Patients with Lung Adenocarcinoma at Risk for Cancer-Associated Thrombosis: The Observational ROADMAP-CAT Study.

BACKGROUND: The aim of this prospective study was to identify the most clinically relevant hypercoagulability biomarkers in lung adenocarcinoma patients for elaboration of an improved risk assessment model (RAM) for venous thromboembolism (VTE). SUBJECTS, MATERIALS, AND METHODS: One hundred fifty ambulatory patients with lung adenocarcinoma were prospectively enrolled. Thrombin generation, procoagulant phospholipid-dependent clotting time (Procoag-PPL), tissue factor activity (TFa), factor VIIa (FVIIa), factor V (FV), antithrombin, D-Dimers, P-selectin, and heparanase levels were assessed in platelet-poor plasma at inclusion (baseline) and at the end of the third chemotherapy cycle (third chemotherapy). Cox regression analysis was used to identify independent VTE predictors. RESULTS: At baseline, patients had significantly attenuated thrombin generation, shorter Procoag-PPL, higher levels of TFa, D-Dimers, and heparanase, and lower levels of FVIIa and P-selectin, compared with controls. A significant increase in Procoag-PPL, FV, and FVIIa and a decrease of P-selectin levels were observed between baseline and third chemotherapy. Hospitalization within the last 3 months prior to assessment, time since cancer diagnosis less than 6 months, mean rate index (MRI) of thrombin generation, and Procoag-PPL were independently associated with symptomatic VTE. Accordingly, a prediction model including Procoag-PPL and MRI showed significant discriminating capacity (area under the curve: 0.84). CONCLUSION: Ambulatory patients with lung adenocarcinoma may display pronounced blood hypercoagulability due to decreased Procoag-PPL, increased endothelial cell activation, and increased degradation of fibrin. Incorporation of Procoag-PPL and MRI of thrombin generation may improve the accuracy of a VTE-RAM in the above setting. IMPLICATIONS FOR PRACTICE: The prospective ROADMAP-CAT study identified two biomarkers of hypercoagulability, the procoagulant phospholipid-dependent clotting time (Procoag-PPL) and the mean rate index (MRI) of the propagation phase of thrombin generation assessed with the Calibrated Automated Thrombinoscope, as being clinically relevant for the classification of ambulatory patients with lung adenocarcinoma receiving a maximum of one cycle of chemotherapy into high and intermediate/low risk for venous thromboembolism. Measurement of Procoag-PPL and MRI within 1 month after the administration of the first chemotherapy cycle provides significant accuracy of the assessment. Association of the Procoag-PPL and MRI with the clinical risk assessment model for cancer-associated thrombosis in ambulatory patients with solid tumors (COMPASS-CAT RAM) further improved its accuracy.

Impact of blood hypercoagulability on in vitro fertilization outcomes: a prospective longitudinal observational study.

BACKGROUND: Blood coagulation plays a crucial role in the blastocyst implantation process and its alteration may be related to in vitro fertilization (IVF) failure. We conducted a prospective observational longitudinal study in women eligible for IVF to explore the association between alterations of coagulation with the IVF outcome and to identify the biomarkers of hypercoagulability which are related with this outcome. METHODS: Thirty-eight women eligible for IVF (IVF-group) and 30 healthy, age-matched women (control group) were included. In the IVF-group, blood was collected at baseline, 5-8 days after administration of gonadotropin-releasing hormone agonist (GnRH), before and two weeks after administration of human follicular stimulating hormone (FSH). Pregnancy was monitored by measurement of ßHCG performed 15 days after embryo transfer. Thrombin generation (TG), minimal tissue factor-triggered whole blood thromboelastometry (ROTEM®), procoagulant phospholipid clotting time (Procoag-PPL®), thrombomodulin (TMa), tissue factor activity (TFa), factor VIII (FVIII), factor von Willebrand (FvW), D-Dimers and fibrinogen were assessed at each time point. RESULTS: Positive IVF occurred in 15 women (40%). At baseline, the IVF-group showed significantly increased TG, TFa and TMa and significantly shorter Procoag-PPL versus the control group. After initiation of hormone treatment TG was significantly higher in the IVF-positive as compared to the IVF-negative group. At all studied points, the Procoag-PPL was significantly shorter and the levels of TFa were significantly higher in the IVF-negative group compared to the IVF-positive one. The D-Dimers were higher in the IVF negative as compared to IVF positive group. Multivariate analysis retained the Procoag-PPL and TG as predictors for the IVF outcome. CONCLUSIONS: Diagnosis of women with hypercoagulability and their stratification to risk of IVF failure using a model based on the Procoag-PPL and TG is a feasible strategy for the optimization of IVF efficiency that needs to be validated in prospective trials.

HMGB1 and thrombin mediate the blood-brain barrier dysfunction acting as biomarkers of neuroinflammation and progression to neurodegeneration in Alzheimer's disease.

BACKGROUND: The blood-brain barrier (BBB) dysfunction represents an early feature of Alzheimer's disease (AD) that precedes the hallmarks of amyloid beta (amyloid ß) plaque deposition and neuronal neurofibrillary tangle (NFT) formation. A damaged BBB correlates directly with neuroinflammation involving microglial activation and reactive astrogliosis, which is associated with increased expression and/or release of high-mobility group box protein 1 (HMGB1) and thrombin. However, the link between the presence of these molecules, BBB damage, and progression to neurodegeneration in AD is still elusive. Therefore, we aimed to profile and validate non-invasive clinical biomarkers of BBB dysfunction and neuroinflammation to assess the progression to neurodegeneration in mild cognitive impairment (MCI) and AD patients. METHODS: We determined the serum levels of various proinflammatory damage-associated molecules in aged control subjects and patients with MCI or AD using validated ELISA kits. We then assessed the specific and direct effects of such molecules on BBB integrity in vitro using human primary brain microvascular endothelial cells or a cell line. RESULTS: We observed a significant increase in serum HMGB1 and soluble receptor for advanced glycation end products (sRAGE) that correlated well with amyloid beta levels in AD patients (vs. control subjects). Interestingly, serum HMGB1 levels were significantly elevated in MCI patients compared to controls or AD patients. In addition, as a marker of BBB damage, soluble thrombomodulin (sTM) antigen, and activity were significantly (and distinctly) increased in MCI and AD patients. Direct in vitro BBB integrity assessment further revealed a significant and concentration-dependent increase in paracellular permeability to dextrans by HMGB1 or α-thrombin, possibly through disruption of zona occludins-1 bands. Pre-treatment with anti-HMGB1 monoclonal antibody blocked HMGB1 effects and leaving BBB integrity intact. CONCLUSIONS: Our current studies indicate that thrombin and HMGB1 are causal proximate proinflammatory mediators of BBB dysfunction, while sTM levels may indicate BBB endothelial damage; HMGB1 and sRAGE might serve as clinical biomarkers for progression and/or therapeutic efficacy along the AD spectrum.

Levels of Alternatively Spliced Tissue Factor in the Plasma of Patients with Pancreatic Cancer May Help Predict Aggressive Tumor Phenotype.

BACKGROUND: Circulating ('blood-borne') tissue factor (TF) is implicated in the pathogenesis of several chronic conditions, most notably cardiovascular disease, diabetes, and cancer. Full-length TF is an integral membrane protein, while alternatively spliced TF (asTF) can be secreted and, owing to its unique C-terminus, selectively detected in bio-specimens. The predictive and/or prognostic value of asTF in the circulation is unknown. In a retrospective study, we measured levels of circulating asTF in healthy subjects and individuals with acute coronary syndrome (ACS), diabetes mellitus (DM), ongoing ACS + DM, and pancreatic ductal adenocarcinoma (PDAC). METHODS: The prototype-tailored procedure (Diagnostica Stago) was used to measure asTF in plasma from 205 subjects. RESULTS: There was no significant difference between the proportion of healthy subjects with asTF ≥200 pg/mL and those with ACS, DM, or ACS + DM. The proportion of pancreatic cancer patients (n = 43; PDAC: 42; pancreatic neuroendocrine tumor: 1) with asTF levels ≥200 pg/mL was significantly higher than in healthy subjects; asTF levels ≥200 pg/mL were detected more often in patients with unresectable disease irrespective of initial evaluation and/or preoperative carbohydrate antigen 19-9 (CA19-9) levels. CONCLUSIONS: While asTF levels ≥200 pg/mL are not observed with increased frequency in patients with ACS and/or DM, they do occur more frequently in the plasma of patients with pancreatic cancer and are associated with lower likelihood of tumor resectability, irrespective of the preoperative diagnosis. asTF may thus have utility as a novel marker of aggressive pancreatic tumor phenotype.

Prevalence of antiphospholipid antibodies in psychiatric patients users and non-users of antipsychotics.

Past reports have suggested that antiphospholipid (aPL) antibodies may emerge as a response to antipsychotics treatment, as a high prevalence of aPL antibodies in antipsychotics users has been observed. However, no control group of non-medicated psychiatric patients was included in these reports. In a cross sectional study we determined the prevalence of aPL antibodies in 333 psychiatric inpatients. We compared the proportions of positive aPL antibodytests between users and non-users of antipsychotics with adjustments for potential confounders. The proportion of antipsychotics users carrying at least one aPL antibody ranged from 10·8% to 27·0% compared with 6·8% to 27·2% in non-users (P = 0·24, P = 0·24) depending on the method of detection of lupus anticoagulant (LA). The prevalence of LA detected by dilute Russell viper venom time or partial thromboplastin time-LA was not different between antipsychotics users and non-users (8·1% vs. 5·4%, P = 0·53 and 18·4% vs. 18·2%, P = 0·22), as well as the prevalence of IgM and IgG anti-ß2-glycoprotein-I antibodies, IgM and IgG anti-cardiolipin antibodies(3·8% vs. 2·0%, P = 0·75, 0·0% vs. 0·0%, P = not applicable, 1·1 vs. 1·4%, P = 0·91, 2·7% vs. 3·4%, P = 0·71). In conclusion, aPL antibodies were frequently found in patients with psychiatric diseases and no significant increase in the prevalence of aPL antibodies was observed in antipsychotics users.

Impact of breast cancer stage, time from diagnosis and chemotherapy on plasma and cellular biomarkers of hypercoagulability.

BACKGROUND: In breast cancer patients routine thromboprophylaxis is not recommended but individualized risk assessment is encouraged. The incorporation of hypercoagulability biomarkers could increase the sensitivity of risk assessment models (RAM) to identify patients at VTE risk. To this aim we investigated the impact of cancer-related characteristics on hypercoagulability biomarkers. METHODS: Thrombin generation (TG) assessed with the Thrombogramme-Thrombinoscope®, levels of platelet derived microparticles (Pd-MP) assessed with flow cytometry, procoagulant phospholid dependent clotting time (PPL-ct) measured with a clotting assay and D-Dimers (were assessed in a cohort of 62 women with breast cancer and in 30 age matched healthy women. RESULTS: Patients showed significantly higher TG, Pd-MP, D-Dimers levels and shortened PPL-ct compared to the controls. The PPL-ct was inversely correlated with the levels of Pd-MP, which were increased in 97% of patients. TG and D-Dimers were increased in 76% and 59% of patients respectively. In any stage of the disease TG was significantly increased as compared to the controls. There was no significant difference of TG in patients with local, regional of metastatic stage. There was no significant difference in Pd-MP or Pd-MP/PS+ between the subgroups of patients with local or regional stage of cancer. Patients with metastatic disease had significantly higher levels of Pd-MP and Pd-MP/PS+ compared to those with regional stage. The D-Dimers increased in patients with metastatic stage. In patients on chemotherapy with less than 6 months since diagnosis TG was significantly higher compared to those on chemotherapy who diagnosed in interval > 6 months. Patients with metastatic disease had significantly higher levels of Pd-MP and D-Dimers compared to those with non-metastatic disease. CONCLUSION: In breast cancer patients the stage, the time elapsed since the diagnosis and the administration of chemotherapy are determinants of cellular and plasma hypercoagulability. The levels and the procoagulant activity of Pd-MP are interconnected with the biological activity and the overall burden of cancer. TG reflects the procoagulant properties of both breast cancer and chemotherapy in the initial period of cancer diagnosis. Thus the weighted incorporation of the biomarkers of cellular and plasma hypercoagulabilty in RAM for VTE might improve their predictive value.

The procoagulant signature of cancer cells drives fibrin network formation in tumor microenvironment and impacts its quality. Implications in cancer cell migration and the resistance to anticancer agents.

INTRODUCTION: Cancer cells induce hypercoagulability in the tumoral microenvironment by expressing Tissue Factor (TF). We aimed to study the impact of the procoagulant signature of cancer cells on the quality and structure of fibrin network. We also studied the impact of fibrin clot shield (FCS) on the efficiency of anticancer agents and the migration of cancer cells. MATERIALS AND METHODS: Pancreatic cancer cells BXPC3 and breast cancer cells MDA-MB231 and MCF7, were cultured in the presence of normal Platelet Poor Plasma (PPP), diluted 10 % in conditioning media. Their potential to induce thrombin generation and their fibrinolytic activity were assessed. The structure of fibrin network was analyzed with Scanning Electron Microscopy (SEM). Cancer cells' mobility with fibrin clot and their interactions with fibrin were observed. Cancer cells were treated with paclitaxel (PTX) or 4-hydroxy-tamoxifen (4OHTam) in the presence or absence of FCS. RESULTS: Cancer cells, in presence of PPP, induced fibrin network formation. High TF-expressing cancer cells (BXPC3 and MDA-MB23 cells), led to dense fibrin network with fine fibers. Low TF expressing cells MCF7 led to thick fibers. Exogenous TF enhanced the density of fibrin network formed by MCF7 cells. Cancer cells through their inherent profibrinolytic potential migrated within the fiber scaffold. The BXPC3 and MCF7 cells moved in clusters whereas the MDA-MB231 cells moved individually within the fibrin network. FCS decreased the efficiency of PTX and 4OHTam on the viability of cancer cells. CONCLUSIONS: The procoagulant signature of cancer cells is determinant for the quality and structure of fibrin network in the microenvironment. Original SEM images show the architecture of "bird's nest"-like fibrin network being in touch with the cell membranes and surrounding cancer cells. Fibrin network constructed by triggering thrombin generation by cancer cells, provides a scaffold for cell migration. Fibrin clot shields protect cancer cells against PTX and 4OHTam.

Plasma tissue factor activity in lung cancer patients predicts venous thromboembolism and poor overall survival.

Background: Biomarkers to identify lung cancer (LC) patients with high risk of venous thromboembolism (VTE) are needed. Objectives: To evaluate the usefulness of plasma tissue factor activity (TFA) and D-dimer levels for the prediction of VTE and overall survival in patients with LC. Methods: In a prospective multicenter observational cohort of consecutive LC patients, TFA and D-dimer levels were measured at diagnosis before any cancer treatment (V1) and between 8 and 12 weeks after diagnosis (V2). Results: Among 302 patients, 38 (12.6%) experienced VTE within the first year after diagnosis. V1-TFA and V1-D-dimer levels were significantly (P = .02) higher in patients who presented VTE within 3 months than in patients without VTE: V1-TFA was 2.02 (25th-75th percentiles, 0.20-4.01) vs 0.49 (0.20-3.09) ng/mL and V1-D-dimer was 1.42 (0.64-4.40) vs 0.69 (0.39-1.53) µg/mL, respectively. Cutoffs of 1.92 ng/mL for TFA and 1.26 µg/mL for D-dimer could discriminate both groups of patients. In multivariate analysis, V1-TFA > 1.92 ng/mL was the only significant predictor of VTE risk at 1 year (hazard ratio, 2.10; 95% CI, 1.06-4.16; P = .03). V2-TFA, quantified in 251 patients, decreased significantly compared with V1-TFA (0.20 vs 0.56 ng/mL, P < .05), but a V2-TFA level > 0.77 ng/mL could predict VTE in the following 3 months. Median overall survival was worse for patients with V1-TFA > 1.92 ng/mL (14.6 vs 23.8 months) and V1-D-dimer > 1.26 µg/mL (13.8 vs 24 months, P < .001). Conclusion: High plasma TFA levels are associated with the occurrence of VTE within the next 3 months after each visit (V1 or V2) and poor survival.

Tissue factor pathway-related biomarkers in liver cancer: activated factor VII-antithrombin complex and tissue factor mRNA levels are associated with mortality.

Background: Tissue factor (TF), the main initiator of the coagulation cascade, plays a role in cancer progression and prognosis. Activated factor VII-antithrombin complex (FVIIa-AT) is considered an indirect marker of TF exposure by reflecting TF-FVIIa interaction. Objectives: To assess the link between FVIIa-AT plasma levels, TF messenger RNA (mRNA) expression, and survival in cancer. Methods: TF pathway-related coagulation biomarkers were assessed in 136 patients with cancer (52 with hepatocellular carcinoma, 41 with cholangiocarcinoma, and 43 with colon cancer) undergoing surgical intervention with curative intent. TF mRNA expression analysis in neoplastic vs nonneoplastic liver tissues was evaluated in a subgroup of 91 patients with primary liver cancer. Results: FVIIa-AT levels were higher in patients with cancer than in 136 sex- and age-matched cancer-free controls. In patients with cancer, high levels of FVIIa-AT and total TF pathway inhibitor were associated with an increased mortality risk after adjustment for confounders, but only FVIIa-AT remained a predictor of mortality by including both FVIIa-AT and total TF pathway inhibitor in Cox regression (hazard ratio, 2.80; 95% CI, 1.23-6.39; the highest vs the lowest quartile). This association remained significant even after adjustment for extracellular vesicle-associated TF-dependent procoagulant activity. In the subgroup of patients with primary liver cancer, patients with high TF mRNA levels had an increased mortality risk compared with that for those with low TF mRNA levels (hazard ratio, 1.92; 95% CI, 1.03-3.57), and there was a consistent correlation among high FVIIa-AT levels, high TF mRNA levels, and increased risk of mortality. Conclusion: High FVIIa-AT levels may allow the identification of patients with cancer involving high TF expression and predict a higher mortality risk in liver cancer.

Contribution of procoagulant phospholipids, thrombomodulin activity and thrombin generation assays as prognostic factors in intensive care patients with septic and non-septic organ failure.

BACKGROUND: Multiple organ dysfunction syndrome (MODS) observed in patients with sepsis and in nonseptic patients organ failure (OF) is associated with a high mortality rate. We investigated whether new coagulation assays [quantification of procoagulant phospholipids (PPL) activity, functional assays measuring the activity of thrombomodulin (TMa) or tissue factor (TFa) and thrombin generation using calibrated automated thrombography (CAT)] could constitute new tools to better understand the physiopathology of MODS and have any prognostic value. METHODS: We measured TMa, TFa, PPL and CAT in 32 healthy controls, 24 patients with sepsis and 26 patients with non-septic OF. We compared these parameters with usual coagulation assays [prothrombin time, activated partial thromboplastin time, protein C (PC), protein S, D-Dimers (D-Di), soluble thrombomodulin (sTM)] and markers of inflammation (IL-6, CRP). Samples were collected within 24 h of the diagnosis. RESULTS: TMa, TFa, PPL, the lag time and time to thrombin peak levels were increased in both groups of patients. For both groups D-Di, IL-6, CRP and endogenous thrombin potential (ETP) were higher in non-survivors than in survivors, while PC and PPL were lower in non-survivors than in survivors. TMa increase was more marked in non-survivors patients with OF, while the ratio TMa/sTM was low in non-survivors with sepsis. Received operating characteristic (ROC) curve analysis indicated that thrombin peak and ETP were the more powerful discriminating factors in patients with sepsis or non-septic OF, respectively. CONCLUSIONS: PPL, TMa and CAT assays could represent promising tools to identify patients with increased risk of mortality in MODS and could procure insights into pathogenesis of MODS.

High Plasma Levels of Activated Factor VII-Antithrombin Complex Point to Increased Tissue Factor Expression in Patients with SARS-CoV-2 Pneumonia: A Potential Link with COVID-19 Prothrombotic Diathesis.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causal agent of coronavirus disease 2019 (COVID-19), in which coagulation abnormalities and endothelial dysfunction play a key pathogenic role. Tissue factor (TF) expression is triggered by endothelial dysfunction. Activated factor VII-antithrombin (FVIIa-AT) complex reflects indirectly FVIIa-TF interaction and has been proposed as a potential biomarker of prothrombotic diathesis. FVIIa-AT plasma concentration was measured in 40 patients (30 males and 10 females; 64.8 ± 12.3 years) admitted with SARS-CoV-2 pneumonia during the first pandemic wave in Italy. Two sex- and age-matched cohorts without COVID-19, with or without signs of systemic inflammation, were used to compare FVIIa-AT data. The FVIIa-AT plasma levels in COVID-19 patients were higher than those in non-COVID-19 subjects, either with or without inflammation, while no difference was observed among non-COVID-19 subjects. The association between COVID-19 and FVIIa-AT levels remained significant after adjustment for sex, age, C-reactive protein, renal function, fibrinogen, prothrombin time and activated partial thromboplastin time. Our results indicate that SARS-CoV-2 infection, at least during the first pandemic wave, was characterized by high FVIIa-AT levels, which may suggest an enhanced FVIIa-TF interaction in COVID-19, potentially consistent with SARS-CoV-2-induced endotheliopathy.

Endothelial dysfunction and hypercoagulability in severe sickle-cell acute chest syndrome.

RATIONALE: Acute pulmonary hypertension (PH) may develop during sickle-cell acute chest syndrome (ACS), and is associated with an increased mortality. Its mechanisms remain poorly known. We questioned whether there is endothelial dysfunction and hypercoagulability in severe ACS, with and without acute PH. METHODS: In a prospective monocentre cohort follow-up study, all sickle-cell adult patients with ACS admitted to the intensive care unit underwent transthoracic echocardiography and measurement of biomarkers of coagulation, endothelial activation and platelet and erythrocyte activation. Acute PH was defined as a high echocardiographic probability of PH. The biological profiles of sickle-cell patients were analysed at the time of ACS, contrasting with the existence of acute PH, and compared with steady-state and with non-sickle-cell controls (healthy subjects and community-acquired pneumonia). RESULTS: Most patients (36 patients with 39 ACS episodes; 23 males; median age 27 years) had thoracic pain, dyspnoea and computed tomography scan lung consolidation. Acute PH was diagnosed in seven (19%) patients. Erythrocyte- and platelet-derived microparticles and the pro-coagulant activity of microparticles were higher in ACS patients with acute PH, compared with their counterparts. Compared with healthy controls, ACS patients had higher levels of tissue factor, fibrin monomers, D-dimer, release of pro-coagulant microparticles and erythrocyte- and platelet-derived microparticles. Compared with community-acquired pneumonia patients, ACS patients had increased levels of fibrin monomers and erythrocyte- and platelet-derived microparticles. CONCLUSIONS: Severe ACS is characterised by endothelial dysfunction and hypercoagulability, with a marked pro-coagulant profile in cases of associated PH.

SARS-CoV-2 Vaccine and Thrombosis: An Expert Consensus on Vaccine-Induced Immune Thrombotic Thrombocytopenia.

Historically, the vaccination strategies developed in the second half of the 20th century have facilitated the eradication of infectious diseases. From the onset of COVID-19 pandemic to the end of April 2021, more than 150 million cases and 3 million deaths were documented worldwide with disruption of the economic and social activity, and with devastating material, physical, and psychological consequences. Reports of unusual and severe thrombotic events, including cerebral and splanchnic venous thrombosis and other autoimmune adverse reactions, such as immune thrombocytopenia or thrombotic microangiopathies in connection with some of the SARS-CoV-2 vaccines, have caused a great deal of concern within the population and the medical community. This report is intended to provide practical answers following an overview of our knowledge on these thrombotic events that are extremely rare but have serious consequences. Vaccine hesitancy threatens to reverse the progress made in controlling vaccine-preventable diseases. These adverse events must be put into perspective with an objective analysis of the facts and the issues of the vaccination strategy during this SARS-CoV-2 pandemic. Health care professionals remain the most pertinent advisors and influencers regarding vaccination decisions; they have to be supported to provide reliable and credible information on vaccines. We need to inform, reassure, and support our patients when the prescription is made. Facing these challenges and observations, a panel of experts express their insights and propose a tracking algorithm for vaccinated patients based on a 10-point guideline for decision-making on what to do and not to do.

Increased levels of tissue factor activity and procoagulant phospholipids during treatment of children with acute lymphoblastic leukaemia.

The use of L-asparaginase (L-ASP) in paediatric patients with acute lymphoblastic leukaemia (ALL) is associated with thrombotic complications. We evaluated the activities of tissue factor (TFa), thrombomodulin (TMa) and procoagulant phospholipids (PPL) in 26 consecutive children with ALL (25 B-ALL and one T-ALL) treated by the French Acute Lymphoblastic Leukemia group (FRALLE)-2000 protocol. Samples were obtained at diagnosis, after glucocorticoid (GC) therapy, during the induction phase with L-ASP, vincristine (VCR) and adriamycin (ADR), during the re-induction and within the week after treatment. Plasma levels of TFa, TMa and PPL increased gradually and significantly during the different phases of the treatment, with higher levels observed during the induction period, and decreased after treatment discontinuation. In vitro studies showed that the different drugs used for ALL treatment could induce a weak expression of TF and procoagulant activity (PCA) on normal and leukaemia blood cells, while a marked effect was observed on endothelial cells. In conclusion, these data indicate that, in addition to the well-identified increased in coagulation factors and inhibitor deficiencies, the injury of the endothelium could lead to the release of TF and PPL and could contribute to the hypercoagulability of children treated for ALL.

Prospective Assessment of Biomarkers of Hypercoagulability for the Identification of Patients With Severe Coronary Artery Disease. The ROADMAP-CAD Study.

In patients with stable coronary artery disease (CAD) blood hypercoagulability figures among factors leading to thrombosis. Tissue factor (TF) exposure at ruptured plaque initiates blood coagulation and hypercoagulability is responsible for thrombus formation. Early identification of patients eligible for angiography is a challenging issue for effective prevention of ACS. This pilot study aimed to identify biomarkers of hypercoagulability that can be prospectively used in risk assessment tools for the evaluation of CAD severity. Biomarkers of hypercoagulability could be a used for the evaluation of CAD severity. Platelet-poor plasma from 66 patients who were referred to coronary angiography was assessed for thrombin generation, phospholipid-dependent clotting time (Procoag-PPL ® ) and D-Dimers, and evaluated against atherosclerotic burden. Patients with CAD, as compared to controls, showed attenuated thrombin generation lag time: 4.7 (3.8-5.4) min versus 2.5 (2.1-2.9) min; p < 0.0001, shorter Procoag-PPL® clotting time 55.0(32-66) s versus 62.8 (42-85) s; p = 0.001), and higher D-Dimer levels 0.509 (0.27-2.58) µg/ml versus 0.309 (0.23-0.39) µg/ml; p = 0.038. Multivariate logistic regression model showed excellent discriminatory value in predicting CAD severity. The ROADMAP-CAD study showed that the Procoag-PPL® clotting time and thrombin Peak are informative for the the burden of the coronary atherosclerotic disease. The clinical relevance of this observation in the development of a new clinic-biological risk assessment model for early diagnosis of severe CAD has to be examined in a prospective study.

Extracellular vesicles derived from pancreatic cancer cells BXPC3 or breast cancer cells MCF7 induce a permanent procoagulant shift to endothelial cells.

The endothelium could be a potential target of cancer cell derived extracellular vesicles (CaCe-dEV). We investigated in vitro the effect of CaCe-dEV on the hemostatic balance of endothelial cells. Extracellular vesicles released from pancreas adenocarcinoma cells (BXPC3) or human breast cancer cells (MCF7) were isolated by differential centrifugation. Human umbilical vein endothelial cells (HUVEC) were cultured for 72 h in the presence or absence of CaCe-dEV. Subsequently, they were washed and re-cultivated over three cycles to get daughter cell generations (DG) which were not exposed to CaCe-dEV. Thrombin generation of normal platelet poor plasma (PPP) added in wells carrying HUVEC was assessed by the Calibrated Automated Thrombogram®. Tissue factor activity (TFa) and procoagulant phospholipid clotting time were assessed. Some traces of TFa were displayed by non-exposed HUVEC (0.18 ±â€¯0.03 pM) and their EVs (1.2 ±â€¯1.0 pM). Non-exposed HUVEC did not induce any detectable thrombin generation. BXPC3-dEV displayed significantly higher TFa as compared to MCF7-dEV (45 ±â€¯5 pM versus 4.6 ±â€¯2.3pM respectively; p < 0.05). HUVEC exposed to CaCe-dEV enhanced thrombin generation. BXPC3-dEV induced significantly higher thrombin generation as compared to those exposed to MCF7-dEV. The procoagulant properties of HUVEC, acquired upon exposure to CaCe-dEV were transferred to DG. In conclusion, CaCe-dEV lead to a procoagulant shift of endothelial cells which, upon exposure, display TFa and enhance thrombin generation which is transferred to DG of HUVEC. The potency of CaCe-dEV to induce procoagulant shift of HUVEC depends on the histological type of the cancer cells. The procoagulant shift of endothelial cells which is transferable to DG could be an additional mechanism - together with cancer-induced blood hypercoagulability - in the pathogenesis of cancer associated thrombosis.