Thrombin-antithrombin Complex Research Articles

Protein disulfide isomerase uses thrombin-antithrombin complex as a template to bind its target protein and alter the blood coagulation rates.

During inflammation and situations of cellular stress protein disulfide isomerase (PDI) is released in the blood plasma from the platelet and endothelial cells to influence thrombosis. The addition of exogenous PDI makes the environment pro-thrombotic by inducing disulfide bond formation in specific plasma protein targets like vitronectin, factor V, and factor XI. However, the mechanistic details of PDI interaction with its target remain largely unknown. A decrease in the coagulation time was detected in activated partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT) on addition of the purified recombinant PDI (175 nM). The coagulation time can be controlled using an activator (quercetin penta sulfate, QPS) or an inhibitor (quercetin 3-rutinoside, Q3R) of PDI activity. Likewise, the PDI variants that increase the PDI activity (H399R) decrease, and the variant with low activity (C53A) increases the blood coagulation time. An SDS-PAGE and Western blot analysis showed that the PDI does not form a stable complex with either thrombin or antithrombin (ATIII) but it uses the ATIII-thrombin complex as a template to bind and maintain its activity. A complete inhibition of thrombin activity on the formation of ATIII-thrombin-PDI complex, and the complex-bound PDI-catalyzed disulfide bond formation of the target proteins may control the pro- and anti-thrombotic role of PDI.

Are Gamers Prone to eThrombosis during Long Gaming Sessions?

During the last two decades, several cases of venous thrombosis (VTE) after a prolonged period at a computer have been described, denominated as "eThrombosis". Video gaming on a computer has become very popular and can be a social activity where several players gather to play against each other or in a virtual environment for several days ("LAN (i.e., Local Area Network) parties") where the participants are sedentary and consuming calorie-rich food items. The aim of this study was to investigate potential coagulation activation during a 42 h LAN party. Nine male gamers volunteered for the LAN party. Citrated blood was sampled before and every 6 h, and plasma was analyzed for thrombin generation, thrombin-antithrombin complexes (TAT), prothrombin fragment 1 + 2 (F1 + 2), and D-dimer. Thrombin generation increased slightly but not significantly during the LAN party, whereas the coagulation activation markers were unchanged. These results do not indicate that the coagulation system is activated significantly during 42 h of gaming with minimal physical activity. Although increased activity cannot be excluded, it does not directly indicate a risk of VTE in general.

Current Clinical Practice of Laboratory Testing of the Hemostasis and Coagulation System in Patients with Sepsis: A Nationwide Observational Study in Japan.

The clinical benefit of hemostasis molecular indicators such as thrombin-antithrombin complex (TAT), soluble fibrin (SF), and prothrombin fragment 1 + 2 (F1+2) for the diagnosis of disseminated intravascular coagulation (DIC) is reported. Recently, novel DIC diagnostic criteria that adopt them were proposed in Japan. Despite the theoretical understanding of their function, the practical use of these markers remains unclear. The present study aimed to provide a descriptive overview of current clinical practice regarding the measurement of hemostasis markers in sepsis management in Japan. This retrospective observational analysis used the Japanese Diagnosis Procedure Combination inpatient database containing data from more than 1500 acute-care hospitals in Japan. We identified adult patients hospitalized for sepsis between April 2018 and March 2021. Descriptive statistics for measuring several hemostasis laboratory markers were summarized using patient disease characteristics, hospital characteristic, and geographical location. This study included 153,474 adult sepsis patients. Crude in-hospital mortality was 30.0%. Frequency of measurement of fibrinogen, fibrin degradation products (FDP), and D-dimer in sepsis patients on admission was 43.2%, 36.1%, and 46.4%, respectively. Novel and specific hemostasis molecular markers such as TAT, SF, and F1+2 were seldom measured (1.9%, 1.7%, and 0.02%, respectively). Hemostasis molecular markers were more frequently measured with progression of thrombocytopenia. Measurement of these clinically favorite hemostasis markers was influenced not only by disease characteristics but also hospital characteristic or geographical location. Hemostasis molecular markers such as TAT, SF, and F1+2 were rarely measured in clinical settings. Although adopted by several DIC scoring systems, neither fibrinogen, FDP, nor D-dimer was routinely measured.

Coagulation activity and thrombotic risk following high-volume endurance exercise in recreationally active cyclists.

Despite the prognostic effect of physical activity, acute bouts of high-volume endurance exercise can induce cardiac stress and postexercise hypercoagulation associated with increased thrombotic risk. The aim of this study was to explore the effect of high-volume endurance exercise on coagulation and thrombotic activity in recreational cyclists. Thirty-four recreational cyclists completed 4.8 ± 0.3 h of cycling at 45 ± 5% of maximal power output on a bicycle ergometer. Intravenous blood samples were collected preexercise, immediately postexercise, 24 and 48 h postexercise, and analyzed for brain natriuretic peptide (BNP), cardiac troponin (cTn), C-reactive protein (CRP), D-dimer, thrombin-antithrombin (TAT) complex, tissue factor (TF), tissue factor pathway inhibitor (TFPI), and TF-to-TFPI ratio (TF:TFPI). An increase in cTn was observed postexercise (P < 0.001). CRP concentrations were increased at 24 and 48 h postexercise compared with preexercise concentrations (P ≤ 0.001). TF was elevated at 24 h postexercise (P < 0.031) and TFPI was higher immediately postexercise (P < 0.044) compared with all other time points. TF:TFPI was increased at 24 and 48 h postexercise compared with preexercise (P < 0.025). TAT complex was reduced at 48 h postexercise compared with preexercise (P = 0.015), D-dimer was higher immediately postexercise compared with all other time points (P ≤ 0.013). No significant differences were observed in BNP (P > 0.05). High-volume endurance cycling induced markers of cardiac stress among recreational cyclists. However, plasma coagulation and fibrinolytic activity suggest no increase in thrombotic risk after high-volume endurance exercise.NEW & NOTEWORTHY In this study, a high-volume endurance exercise protocol induced markers of cardiac stress and altered plasma coagulation and fibrinolytic activity for up to 48 h in recreationally active cyclists. However, analysis of coagulation biomarkers indicates no increase in thrombotic risk when appropriate hydration and rest protocols are implemented.

Abstract 7652: Plasma markers of hemostasis, fibrinolysis, and angiogenesis prior to androgen deprivation therapy (ADT) in progressive prostate cancer (PC) and associations with long-term thrombotic events and survival

Abstract Background: PC is the third most common malignancy associated with thrombosis, procoagulants may play a role in tumorigenesis and progression, and patients (pts) with PC may have activation of the hemostatic system evident in plasma. The prognostic significance of these markers and their relationship to thrombotic events and overall survival (OS) are under-explored. Methods: Patients &amp;gt;18 years were included if they had progressive PC planned to start ADT, were &amp;gt;6 months from surgery or RT, with no history of prior VTE, unexplained bleeding, current or planned anticoagulation, or an additional active malignancy. Plasma samples were obtained via peripheral venipuncture in tubes containing 3.2% sodium citrate and immediately placed on ice. Samples were analyzed for D-dimer, thrombin-antithrombin complex (TAT), IL-6, IL-8, VEGF, and tissue factor (TF) levels by ELISA. Patients had markers drawn at baseline (prior to initiation of ADT), 1 month, and 6 months after initiation. Results: 40 patients were accrued with a median age of 68 years. At baseline, 29 (73%) had presence of metastases. Baseline median PSA was 15 and median PSA doubling time was 0.32. Baseline median hemoglobin was 13.85, platelets were 218, D-dimer was 322 ng/dL, IL-6 was 0 pg/mL, IL-8 was 0 pg/mL, TAT was 3 ug/L, VEGF was 21 pg/mL, and TF was 26 pg/mL. Median follow-up was 78 months. During follow up, 35 (87.5%) had metastases. 10 (25%) had thrombotic events (6 [15%] venous, 4 [10%] arterial) at median 37 months follow up. Median baseline age of pts with subsequent thrombotic events was 74, vs 67 in those without a thrombotic event. While there was no significant difference in baseline PSA between groups with and without clotting events, pretreatment PSA doubling time was significantly lower in pts with subsequent thrombosis (0.27 vs 0.35, p=0.047). Median baseline D-dimer and TF were higher in patients with subsequent thrombosis (D-dimer: 516 vs 282, p=0.10; TF: 36 vs 24, p=0.12). In univariate analysis, baseline IL-6 and VEGF were associated with OS (IL-6: HR=1.05, 95% CI [1.01,1.09], p=0.025; VEGF: HR=1.02, 95% CI [1.00,1.03], p=0.028). When controlling for presence of metastasis, baseline TAT was associated with OS (HR=1.05, 95% CI [1.00,1.11], p=0.055). Conclusions: Plasma markers of hemostatic activation, fibrinolysis, and angiogenesis prior to initiation of ADT are associated with subsequent thrombotic events and overall survival years later. Further analysis will examine how these markers change over time with hormonal therapy. Citation Format: Jessica S. Palmer, Charlene Thomas, Nicole Jacobs, David Nanus, Scott T. Tagawa. Plasma markers of hemostasis, fibrinolysis, and angiogenesis prior to androgen deprivation therapy (ADT) in progressive prostate cancer (PC) and associations with long-term thrombotic events and survival [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7652.

Clinical value of TAT, PIC and t-PAIC as predictive markers for severe sepsis in pediatric patients.

Sepsis in pediatric patients can progress to severe sepsis, and identifying biomarkers of this progression may permit timely intervention to prevent it. This study aimed to investigate the ability of thrombin-antithrombin complex (TAT), α2-plasmininhibitor-plasmin complex (PIC) and tissue-type plasminogen activator-inhibitor complex (t-PAIC) to predict severe sepsis in pediatrics early. 148 eligible pediatric sepsis patients were enrolled in this study, and were then divided into those who progressed to severe sepsis (n = 50) or not (n = 98). Serum levels of TAT, PIC, and t-PAIC were analysed, and simplified pediatric critical illness score (PCIS) and DIC score were calculated on the day of pediatric sepsis diagnosis. Compared with sepsis patients, severe sepsis patients had higher levels of TAT, PIC and t-PAIC. Correlation analysis revealed that TAT, PIC and t-PAIC were significantly correlated with simplified PCIS and DIC score. ROC curve analysis suggested that TAT, PIC and t-PAIC could serve as biomarkers for predicting severe sepsis with the AUC up to 0.862, 0.759 and 0.851, respectively. Stratified analysis demonstrated that the patients with increased levels of TAT, PIC and t-PAIC had worse illness severity and clinical outcome. Univariate logistic regression analysis revealed that TAT, PIC and t-PAIC were all risk factors for severe sepsis, yet only TAT and t-PAIC were independent risk factors in multivariate model. TAT, PIC and t-PAIC could serve as biomarkers for predicting severe sepsis, and correlated with illness severity in pediatrics, what's more, serum levels of TAT and t-PAIC may be independent risk factors for pediatric severe sepsis.

Perioperative Treatment with Rivaroxaban and Dabigatran on Changes of Coagulation and Platelet Activation Biomarkers following Left Atrial Appendage Closure.

Insufficient data exist regarding the investigation of the impact of novel oral anticoagulants (NOACs) on coagulation activation biomarkers in the context of left atrial appendage closure (LAAC) and device-related thrombosis (DRT). The study was designed to investigate the changes and presence of coagulation activation biomarkers between different antithrombotic strategies following LAAC. A total of 120 nonvalvular atrial fibrillation patients intolerant of long-term anticoagulants, who underwent successful WATCHMAN closure implantation, were enrolled (rivaroxaban, n = 82; dabigatran, n = 38). Blood samples were obtained from left atrium (LA) and left atrial appendage (LAA) during the operation and fasting blood samples on the same day of LAAC and 45 days after discharge. The biochemical indicators, thrombin-antithrombin complex (TAT), soluble P-selectin (sP-selectin), von Willebrand factor (vWF), and CD40 ligand (CD40L), were measured by enzyme-linked immunosorbent assay. The primary endpoints of this study were the efficacy and safety characteristics of different antithrombotic strategies, including DRT incidence, stroke or transient ischemic attack, systemic embolism, and clinical major and nonmajor bleeding complications during the follow-up of 180 days. The results revealed that TAT, vWF, sP-selectin, and CD40L levels in vein were significantly reduced by 2.4% (p = 0.043), 5.0% (p < 0.001), 8.7% (p < 0.001), and 2.5% (p = 0.043) from their baseline levels after rivaroxaban treatment. Conversely, no significant changes were detected in the dabigatran group. Furthermore, the plasma levels of platelet activation biomarkers (CD40L and sP-selectin) in both LA and LAA groups were significantly lower after anticoagulation with rivaroxaban, as compared to dabigatran treatment (CD40L: 554.62 ± 155.54 vs. 445.02 ± 130.04 for LA p = 0.0013, 578.51 ± 156.28 vs. 480.13 ± 164.37 for LAA p = 0.0052; sP-selectin: 2849.07 ± 846.69 vs. 2225.54 ± 799.96 for LA p = 0.0105, 2915.52 ± 1402.40 vs. 2203.41 ± 1061.67 for LAA p = 0.0022). Notably, the present study suggests that rivaroxaban may be more effective in the prevention of DRT for patients undergoing LAAC.

Impact of age on the host response to sepsis in a murine model of fecal-induced peritonitis

IntroductionDespite older adults being more vulnerable to sepsis, most preclinical research on sepsis has been conducted using young animals. This results in decreased scientific validity since age is an independent predictor of poor outcome. In this study, we explored the impact of aging on the host response to sepsis using the fecal-induced peritonitis (FIP) model developed by the National Preclinical Sepsis Platform (NPSP).MethodsC57BL/6 mice (3 or 12 months old) were injected intraperitoneally with rat fecal slurry (0.75 mg/g) or a control vehicle. To investigate the early stage of sepsis, mice were culled at 4 h, 8 h, or 12 h to investigate disease severity, immunothrombosis biomarkers, and organ injury. Mice received buprenorphine at 4 h post-FIP. A separate cohort of FIP mice were studied for 72 h (with buprenorphine given at 4 h, 12 h, and then every 12 h post-FIP and antibiotics/fluids starting at 12 h post-FIP). Organs were harvested, plasma levels of Interleukin (IL)-6, IL-10, monocyte chemoattract protein (MCP-1)/CCL2, thrombin-antithrombin (TAT) complexes, cell-free DNA (CFDNA), and ADAMTS13 activity were quantified, and bacterial loads were measured.ResultsIn the 12 h time course study, aged FIP mice demonstrated increased inflammation and injury to the lungs compared to young FIP mice. In the 72 h study, aged FIP mice exhibited a higher mortality rate (89%) compared to young FIP mice (42%) (p < 0.001). Aged FIP non-survivors also exhibited a trend towards elevated IL-6, TAT, CFDNA, CCL2, and decreased IL-10, and impaired bacterial clearance compared to young FIP non-survivors.ConclusionTo our knowledge, this is the first study to investigate the impact of age on survival using the FIP model of sepsis. Our model includes clinically-relevant supportive therapies and inclusion of both sexes. The higher mortality rate in aged mice may reflect increased inflammation and worsened organ injury in the early stage of sepsis. We also observed trends in impaired bacterial clearance, increase in IL-6, TAT, CFDNA, CCL2, and decreased IL-10 and ADAMTS13 activity in aged septic non-survivors compared to young septic non-survivors. Our aging model may help to increase the scientific validity of preclinical research and may be useful for identifying mechanisms of age-related susceptibility to sepsis as well as age-specific treatment strategies.

Role of microbiota-derived corisin in coagulation activation during SARS-CoV-2 infection

BackgroundCoagulopathy is a major cause of morbidity and mortality in COVID-19 patients. Hypercoagulability in COVID-19 results in deep vein thrombosis, thromboembolic complications, and diffuse intravascular coagulation. Microbiome dysbiosis influences the clinical course of COVID-19. However, the role of dysbiosis in COVID-19-associated coagulopathy is not fully understood. ObjectivesThe present study tested the hypothesis that the microbiota-derived proapoptotic corisin is involved in the coagulation system activation during SARS-CoV-2 infection. MethodsThis cross-sectional study included 47 consecutive patients who consulted for symptoms of COVID-19. A mouse acute lung injury model was used to recapitulate the clinical findings. A549 alveolar epithelial, THP-1, and human umbilical vein endothelial cells were used to evaluate procoagulant and anticoagulant activity of corisin. ResultsCOVID-19 patients showed significantly high circulating levels of corisin, thrombin-antithrombin complex, D-dimer, soluble thrombomodulin, tumor necrosis factor-α, and monocyte-chemoattractant protein-1 with reduced levels of free protein S compared with healthy subjects. The levels of thrombin-antithrombin complex, D-dimer, and corisin were significantly correlated. A monoclonal anticorisin-neutralizing antibody significantly inhibited the inflammatory response and coagulation system activation in a SARS-CoV-2 spike protein-associated acute lung injury mouse model, and the levels of corisin and thrombin-antithrombin complex were significantly correlated. In an in vitro experiment, corisin increased the tissue factor activity and decreased the anticoagulant activity of thrombomodulin in epithelial, endothelial, and monocytic cells. ConclusionThe microbiota-derived corisin is significantly increased and correlated with activation of the coagulation system during SARS-CoV-2 infection, and corisin may directly increase the procoagulant activity in epithelial, endothelial, and monocytic cells.

Impact of Early Microparticle Release during Isolated Severe Traumatic Brain Injury: Correlation with Coagulopathy and Mortality.

Microparticles (MPs) have been implicated in thrombosis and endothelial dysfunction. Their involvement in early coagulopathy and in worsening of outcomes in isolated severe traumatic brain injury (sTBI) patients remains ill defined. We sought to quantify the circulatory MP subtypes derived from platelets (PMPs; CD42), endothelial cells (EMPs; CD62E), and those bearing tissue factor (TFMP; CD142) and analyze their correlation with early coagulopathy, thrombin generation, and in-hospital mortality. Prospective screening of sTBI patients was done. Blood samples were collected before blood and fluid transfusion. MP enumeration and characterization were performed using flow cytometry, and thrombin-antithrombin complex (TAT) levels were determined using enzyme-linked immunosorbent assay (ELISA). Circulating levels of procoagulant MPs were compared between isolated sTBI patients and age- and gender-matched healthy controls (HC). Patients were stratified according to their PMP, EMP, and TFMP levels, respectively (high ≥HC median and low < HC median). Isolated sTBI resulted in an increased generation of PMPs (456.6 [228-919] vs. 249.1 [198.9-404.5]; P = 0.01) and EMPs (301.5 [118.8-586.7] vs. 140.9 [124.9-286]; P = 0.09) compared to HCs. Also, 5.3% of MPs expressed TF (380 [301-710]) in HCs, compared to 6.6% MPs (484 [159-484]; P = 0.87) in isolated sTBI patients. Early TBI-associated coagulopathy (TBI-AC) was seen in 50 (41.6%) patients. PMP (380 [139-779] vs. 523.9 [334-927]; P = 0.19) and EMP (242 [86-483] vs. 344 [168-605]; P = 0.81) counts were low in patients with TBI-AC, compared to patients without TBI-AC. Our results suggest that enhanced cellular activation and procoagulant MP generation are predominant after isolated sTBI. TBI-AC was associated with low plasma PMPs count compared to the count in patients without TBI-AC. Low PMPs may be involved with the development of TBI-AC.

Low-level ambient ozone exposure associated with neutrophil extracellular traps and pro-atherothrombotic biomarkers in healthy adults

Background and aimsUncertainty of the causality determinations for ambient ozone (O3) on cardiovascular events is heightened by the limited understanding of the mechanisms involved in humans. We aimed to examine the pro-atherothrombotic impacts of O3 exposure and to explore the potential mediating roles of dysfunctional neutrophils, focusing on neutrophil extracellular traps (NETs). MethodsA longitudinal panel study of 152 healthy adults was conducted in the cool to cold months with relatively low levels of O3 between September 2019 and January 2020 in Beijing, China. Four repeated measurements of indicators reflecting atherothrombotic balance and NETs were performed for each participant. ResultsDaily average exposure levels of ambient O3 were 16.6 μg/m3 throughout the study period. Per interquartile range increase in average concentrations of O3 exposure at prior up to 7 days, we observed elevations of 200.1–276.3% in D-dimer, 27.2–36.8% in thrombin-antithrombin complex, 10.8–60.3% in plasminogen activator inhibitor 1, 13.9–21.8% in soluble P-selectin, 16.5–45.1% in matrix metalloproteinase-8, and 2.4–12.4% in lipoprotein-associated phospholipase A2. These pro-atherothrombotic changes were accompanied by endothelial activation, lung injury, and immune inflammation. O3 exposure was also positively associated with circulating NETs indicators, including citrullinated histone H3, neutrophil elastase, myeloperoxidase, and double-stranded DNA. Mediation analyses indicated that NETs could mediate O3-associated pro-atherothrombotic responses. The observational associations remained significant and robust after controlling for other pollutants, and were generally greater in participants with low levels of physical activity. ConclusionsAmbient O3 exposure was associated with significant increases in NETs and pro-atherothrombotic potential, even at exposure levels well below current air quality guidelines of the World Health Organization.

Vascular protein disulfide isomerase A1 mediates endothelial dysfunction induced by angiotensin II in mice.

Protein disulfide isomerases (PDIs) are involved in platelet aggregation and intravascular thrombosis, but their role in regulating endothelial function is unclear. Here, we characterized the involvement of vascular PDIA1 in angiotensin II (Ang II)-induced endothelial dysfunction in mice. Endothelial dysfunction was induced in C57BL/6JCmd male mice via Ang II subcutaneous infusion, and PDIA1 was inhibited with bepristat. Endothelial function was assessed invivo with magnetic resonance imaging and exvivo with a myography, while arterial stiffness was measured as pulse wave velocity. Nitric oxide (NO) bioavailability was measured in the aorta (spin-trapping electron paramagnetic resonance) and plasma (NO2 - and NO3 - levels). Oxidative stress, eNOS uncoupling (DHE-based aorta staining), and thrombin activity (thrombin-antithrombin complex; calibrated automated thrombography) were evaluated. The inhibition of PDIA1 by bepristat in Ang II-treated mice prevented the impairment of NO-dependent vasodilation in the aorta as evidenced by the response to acetylcholine invivo, increased systemic NO bioavailability and the aortic NO production, and decreased vascular stiffness. Bepristat's effect on NO-dependent function was recapitulated exvivo in Ang II-induced endothelial dysfunction in isolated aorta. Furthermore, bepristat diminished the Ang II-induced eNOS uncoupling and overproduction of ROS without affecting thrombin activity. In Ang II-treated mice, the inhibition of PDIA1 normalized the NO-ROS balance, prevented endothelial eNOS uncoupling, and, thereby, improved vascular function. These results indicate the importance of vascular PDIA1 in regulating endothelial function, but further studies are needed to elucidate the details of the mechanisms involved.

Abstract TP268: Markers of Coagulation and Hemostatic Activation in Ischemic Stroke Patients With Reduced Ejection Fraction on Antiplatelet Therapy

Introduction: Heart failure with reduced ejection fraction (HFrEF) is a risk factor for ischemic stroke. However, antithrombotic choice in a patient with HFrEF remains challenging. We set out to evaluate serum markers of coagulation and hemostatic activation (MOCHA) among ischemic stroke patients with HFrEF. Methods: We performed a retrospective analysis of ischemic stroke patients with HFrEF (&lt;40%) from July 28, 2017-June 13, 2023 seen at the Emory Stroke Clinic who underwent a MOCHA profile (serum D-dimer, prothrombin fragment 1.2, thrombin-antithrombin complex, and fibrin monomer) ≥2 weeks after the index stroke; abnormal MOCHA profile was defined as ≥2 elevated markers. We excluded patients who were on anticoagulation therapy at the initial visit. Results: Overall, 40 patients (mean age 60 +/- 13.1, 53% female, 85% nonwhite) met criteria; median EF was 25% (IQR 15%-30%). Frequency of abnormal MOCHA profile was 43% in EF ≥25% and 58% in EF &lt;25% (p = 0.52). No MOCHA components were associated with reduced EF in multivariate linear regression analysis (R2 = 0.03, p = 0.28). Over mean follow-up of 2.3 years, recurrent stroke occurred in 5.3 / 100 patient-years and major adverse cardiac events (MACE) occurred at 7.4 / 100 patient-years. Compared to patients with EF &lt;25%, patients with EF ≥25% had higher recurrent stroke rates (6.46 vs 3.07 per 100 patient-years) and MACE (9.69 and 3.07 per 100 patient-years) Patients on antiplatelet regimens and anticoagulant regimens experienced MACE events at a rate of 4.25 and 10.62 per 100 patient-years, respectively. Patients with abnormal MOCHA profiles (n=20) had no recurrent strokes, but experienced other MACE events at a rate of 3.86 per 100 patient years, while patients with normal MOCHA profiles (n=20) experienced 11.73 MACE events per 100 patient-years, all of which were recurrent strokes. Conclusion: In HFrEF patients with an ischemic stroke, the MOCHA profile was not associated with ejection fraction. No difference in recurrent stroke and MACE events was seen among patients with normal vs abnormal MOCHA profile.

Prognostic value of coagulation markers in patients with colorectal caner: A prospective study.

The occurrence, growth, and metastasis of colorectal cancer (CRC) are connected to the hypercoagulable state of blood (CRC). This study aimed to identify significant coagulation factors to predict metastasis and prognosis of CRC. Thrombomodulin (TM), thrombin-antithrombin complex (TAT), α2-plasmininhibitor-plasmin complex (PIC), and tissue plasminogen activator-inhibitor complex (t-PAIC) were detected by chemiluminescence immunoassay using Sysmex HISCL5000 automated analyzers. The Sysmex CS 5100 automatic blood coagulation analyzer was used to detect d-dimer (DD), fibrin degradation product (FDP), prothrombin time (PT), thrombin time (TT), international normalized ratio (INR), fibrinogen (Fbg), and activated partial thromboplastin time (APTT). Area under the curve (AUC) and the receiver operating characteristic curve (ROC) were used to assess the diagnostic efficacy of markers. Kaplan-Meier analysis was used to calculate survival probabilities. Independent prognostic factors and the nomogram were developed using single-factor and multifactor cox regression analysis model. The following indicators (TM, TAT, PIC, t-PAIC, DD, FDP, PT, INR, APTT, and Fbg) were markedly higher in CRC patients than in healthy controls, and they were higher in the metastasis (M) group than in the nonmetastasis (NM) group. The combination "TAT + PIC + DD + FDP + Fbg" can distinguish M from NM with exceptional sensitivity and specificity. Patients with CRC who had high levels of TAT, PIC, DD, FDP, Fbg, TM, tPAIC, PT, and INR had significantly shorter survival. The prognosis of CRC patients can be predicted by coagulation indicators. The independent predictive variables for overall survival were found to be TM and DD. To forecast CRC patient survival, a nomogram was created.

Alterations of Hemostatic Molecular Markers During Acute Large Vessel Occlusion Stroke.

This study aimed to investigate regional levels of TAT (thrombin-antithrombin complex), PIC (plasmin-α2 plasmin inhibitor complex), t-PAIC (tissue plasminogen activator-plasminogen activator inhibitor complex), sTM (soluble thrombomodulin), and D-dimer, along with their associations with clinical and procedural characteristics in patients with acute ischemic stroke undergoing endovascular thrombectomy. We retrospectively analyzed 166 consecutive patients with acute ischemic stroke (62±11.54 years of age, 34.3% women) using prospectively maintained clinical databases and blood samples from local ischemic (proximal to thrombus) and systemic (femoral artery, self-control) arterial compartments. Levels of TAT, PIC, t-PAIC, and D-dimer were significantly elevated, whereas sTM was significantly reduced, in local ischemic regions compared with their systemic levels. Each 1-unit increase in ischemic TAT (adjusted odds ratio [aOR], 1.086 [95% CI, 1.03-1.145]; P=0.002; area under the curve [AUC], 0.833) and PIC (aOR, 1.337 [95% CI, 1.087-1.644]; P=0.006; AUC, 0.771) correlated significantly with higher symptomatic intracranial hemorrhage risk. Additionally, each 1-unit increase in ischemic TAT (aOR, 1.076 [95% CI, 1.016-1.139]; P=0.013; AUC, 0.797), PIC (aOR, 1.554 [95% CI, 1.194-2.022]; P=0.001; AUC, 0.798), and sTM (aOR, 0.769 [95% CI, 0.615-0.961]; P=0.021; AUC, 0.756) was significantly associated with an increased risk of an unfavorable 90-day outcome (modified Rankin scale of 3-6). These hemostatic molecules, individually or combined, significantly improved the predictive power of conventional risk factors, as evidenced by significant increases in net reclassification improvement and integrated discrimination improvement (all P<0.01). We observed a hyperactive state of the coagulation-fibrinolysis system within the local ischemic region during hyperacute stroke. Rapid automated measurement of hemostatic molecular markers, particularly TAT, PIC, and sTM, during intra-arterial procedures may provide additional information for stroke risk stratification and therapeutic decision-making, and warrants further investigation.

Comparison of the hemocompatibility of neurovascular flow diverters with anti-thrombogenic coatings

Despite the continual progress in technology, thromboembolic complications still occur following endovascular treatment of cerebral aneurysms and remain the primary contributor to morbidity and mortality. Thus, coating the surfaces of blood-contacting flow diverters may reduce thrombus-related complications in clinical use. In this study, the hemocompatibility of different commercially available flow diverters Pipeline Flex Embolization Device with Shield Technology (Medtronic), the p64 MW HPC (Phenox), and the DERIVO 2heal (Acandis) was investigated using an in vitro blood circulation model. The DERIVO 2 flow diverter was included in this study as an uncoated device. The markers of coagulation (thrombin-antithrombin complex (TAT)), thrombocytes (β-thromboglobulin (β-TG)), inflammation (PMN elastase), and complement system (SC5b-9, C3a, and C5a) activation were detected by enzyme-linked immunosorbent assay (ELISA). In addition to blood cell counts and hemolysis, thrombogenicity was determined using scanning electron microscopy. Flow diverters with anti-thrombogenic coatings resulted in significantly lower activation of coagulation (TAT) and platelets (β-TG) and lower adhesion of platelets compared with the uncoated DERIVO 2 flow diverter. There were no significant differences between the coated flow diverters in terms of TAT and β-TG levels, as well as platelet adhesion. However, significantly lower activation of the complement system (SC5b-9 and C5a) was observed for the DERIVO 2heal flow diverter in comparison with the Pipeline Flex Shield and the p64 MW HPC flow diverters emphasizing the improved hemocompatibility of the fibrin/heparin-coated DERIVO 2heal flow diverter.

Coagulopathy and adverse outcomes in hospitalized patients with COVID-19: results from the NOR-Solidarity trial

BackgroundSeveral studies have examined parameters of increased thrombogenicity in COVID-19, but studies examining their association with long-term outcome and potential effects of antiviral agents in hospitalized patients with COVID-19 are scarce. ObjectivesTo evaluate plasma levels of hemostatic proteins during hospitalization in relation to disease severity, treatment modalities, and persistent pulmonary pathology after 3 months. MethodsIn 165 patients with COVID-19 recruited into the NOR-Solidarity trial (NCT04321616) and randomized to treatment with hydroxychloroquine, remdesivir, or standard of care, we analyzed plasma levels of hemostatic proteins during the first 10 days of hospitalization (n = 160) and at 3 months of follow-up (n = 100) by enzyme immunoassay. ResultsOur main findings were as follows: (i) tissue plasminogen activator (tPA) and tissue factor pathway inhibitor (TFPI) were increased in patients with severe disease (ie, the combined endpoint of respiratory failure [Po2-to-FiO2 ratio, <26.6 kPa] or need for treatment at an intensive care unit) during hospitalization. Compared to patients without severe disease, tPA levels were a median of 42% (P < .001), 29% (P = .002), and 36% (P = .015) higher at baseline, 3 to 5 days, and 7 to 10 days, respectively. For TFPI, median levels were 37% (P = .003), 25% (P < .001), and 10% (P = .13) higher in patients with severe disease at these time points, respectively. No changes in thrombin-antithrombin complex; alpha 2-antiplasmin; a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13; or antithrombin were observed in relation to severe disease. (ii) Patients treated with remdesivir had lower levels of TFPI than those in patients treated with standard of care alone. (iii) TFPI levels during hospitalization, but not at 3 months of follow-up, were higher in those with persistent pathology on chest computed tomography imaging 3 months after hospital admission than in those without such pathology. No consistent changes in thrombin-antithrombin complex, alpha 2-antiplasmin, ADAMTS-13, tPA, or antithrombin were observed in relation to pulmonary pathology at 3 months of follow-up. ConclusionTFPI and tPA are associated with severe disease in hospitalized patients with COVID-19. For TFPI, high levels measured during the first 10 days of hospitalization were also associated with persistent pulmonary pathology even 3 months after hospital admittance.

Value of novel thrombotic markers for predicting occurrence of the malignant cerebral artery infarction: a prospective clinical study

ObjectiveThis study investigated the diagnostic performance of thrombin–antithrombin complex (TAT), plasmin–α2 plasmin inhibitor complex (PIC), tissue plasminogen activator–plasminogen activator inhibitor complex (t-PAIC), and thrombomodulin (TM) in predicting the progression of massive cerebral infarction to the malignant cerebral artery infarction.MethodA total of 71 patients with massive cerebral infarction confirmed by imaging examination were divided into malignant cerebral artery infarction group (MCAI) and non-malignant cerebral artery infarction group (NMCAI) based on whether they progressed to MCAI after admission. TAT, PIC, t-PAIC, and TM were measured immediately after admission. The predictive performance was analyzed by the receiver characteristic operating curve (ROC).ResultThe median plasma concentrations of TM, PIC, TAT, and t-PAIC in the MCAI patients at admission were 10.65 IU/mL, 1.17 μg/mL, 12.25 ng/mL, and 13.85 ng/mL, respectively, which were higher than those in the NMCAI patients (9.00 IU/mL, 1.07 μg/mL, 4.60 ng/mL, and 8.70 ng/mL), and the difference was statistically significant (p = 0.045, p = 0.035, p = 0.004, and p = 0.003). Elevated plasma t-PAIC concentration was shown to be an independent risk factor for progression of massive cerebral infarction to MCAI (OR = 1.131) by multivariate logistic regression analysis. ROC curve analysis showed that t-PAIC was the best predictor of MCAI (AUC = 74.7%), with a sensitivity of 75.0% and specificity of 75.9% when t-PAIC concentration was ≥12.4 ng/mL; TAT had the highest specificity in predicting MCAI, with a specificity of 90.7% when the TAT concentration was ≥13.5 ng/mL.ConclusionThe detection of PIC, TAT, t-PAIC, and TM is a comprehensive assessment of vascular endothelial damage and activation of the coagulation and fibrinolytic systems and has predictive value for poor prognosis in patients with MCAI. The widespread use of these tests will likely greatly improve the early diagnosis rate of MCAI.

Immune Checkpoint Blockade Promotes Thrombosis Via T-Cell and Neutrophil Activation, and Tumor-Cell Associated Tissue Factor (TF) in a Murine Model of Colorectal Cancer

Background: Immune checkpoint blockade (ICB) is a paradigm shift in cancer therapy. Despite clinical benefit, various adverse events are associated with ICB using immune checkpoint inhibitors (ICI). Venous thrombosis is an emerging clinical problem in cancer patients receiving ICI. Little is known about how ICI promotes thrombosis in cancer. To define the underlying mechanisms of ICI-associated thrombosis (IAT), we assessed the ICI impact on blood hypercoagulability and tumor TF expression using a mouse thrombosis model of colorectal cancer. Methods: We developed a CT26 mouse thrombosis model with ICI (aPD-1+aCTLA4) administration. Systemic hypercoagulability was assessed by measurement of circulating nucleosomes (Nu.Q H3.1 Immunoassay), neutrophil extracellular traps (NETs) (CitH3 immunofluorescence), circulating neutrophil-platelet aggregates (immunophenotyping), and levels of thrombin-antithrombin (TAT) complexes in ICI-treated mice. Tumor-associated TF and TF activity in circulating extracellular vesicles (EV) were assessed by western blotting and Factor Xa generation assays. To gain mechanistic insights into TF induction by ICI, tumor cytokines were also profiled (proteome profiler array). The role of cancer cell-derived TF in IAT was determined using mice implanted with CRISPR/Cas9-mediated TF knockout (TFKO) CT26 tumor cells. Results: ICI treated tumor-bearing mice developed larger thrombi than control mice and demonstrated elevated levels of circulating nucleosomes (114 vs 82 ng/ml), NET (15.8 vs 6.8%), platelet-neutrophil aggregates (44.8 vs 22.3%), and TAT complexes (12.6 vs 7.9 ng/ml) compared to IgG-treated mice. Tumor TF expression was increased in tumor extracts. Cytokine profiling suggested enhanced production of IFNɣ (2-fold) and TNFα (5-fold), as well as CXCL11 (6.8-fold), an effector T cell-recruiting chemokine. IFNɣ-increased TF expression in cultured CT26 cells, suggesting that T-cell derived IFNɣ may play a role in enhancing tumor TF expression in vivo. Circulating EV TF antigen and procoagulant activity were increased by ICI. CRISPR/Cas9-mediated TF KO in CT26 cells resulted in complete loss of TF expression, and mice bearing these cells showed reduced tumor and EV-associated TF (Fig. A), associated with a significant decrease in thrombus formation after ICI treatment (24.2 vs 20.5 mg, Fig. B). There was no significant difference in growth of wild-type and TF KO CT26 tumors. Conclusions: Our findings provide insights into cellular and molecular mechanisms associated with ICI-induced thrombosis, and suggest a role for neutrophil and granulocyte activation, and tumor-associated TF. Additional studies are ongoing to further define these pathways in the murine model and in patients.

Association between Hereditary Angioedema and Venous Thromboembolism in a Large Population-Based Case-Control Study

Introduction: Hereditary Angioedema (HAE) is a rare congenital disorder primarily caused by mutations in the SERPING1 gene that results in C1 inhibitor (C1INH) deficiency or dysfunction. C1INH is a multifunctional serine protease inhibitor that functions as a major endogenous negative regulator of the kallikrein-kinin, contact pathway of coagulation and complement systems. HAE typically presents with episodes of unpredictable subcutaneous and submucosal swelling. However, HAE patients also have evidence of systemic activation of coagulation including elevated plasma prothrombin fragments, thrombin antithrombin complexes and D-dimers. Further, patients with HAE have recently been reported to have an increased risk of venous thromboembolism (VTE). Methods: To evaluate the risk of VTE in patients with HAE we conducted a large population-based case-control study leveraging data from the United Kingdom Clinical Practice Research Datalink (CPRD). The CPRD Aurum dataset used here maintains anonymized electronic medical records of over 40 million individuals from over 1600 primary care practices in the United Kingdom. SNOMED CT medical codes were used to identify a cohort of 2,198 patients diagnosed with HAE between 1992 and 2022 in the CPRD Aurum dataset with a matched (age, gender, family practice, and index date for HAE) cohort of 4,376 controls selected. VTE events including deep vein thrombosis (DVT) and pulmonary embolism in the HAE case and control cohorts were identified using SNOMED CT medical codes. The Cox proportional hazards model was used to determine hazard ratios (HR) for VTE events in HAE cases versus controls adjusting for covariates age, sex, body mass index, blood pressure, smoking status and a number of co-morbidities specifically; neoplasm, type 2 diabetes, ischemic heart disease, chronic obstructive pulmonary disease, chronic kidney disease, autoimmune disorders and depression. Results: A greater proportion of the HAE cases were female (62%) with a mean age at HAE diagnosis of 37 years. The median follow-up period for both cases and controls was 17 years (interquartile range (IQR):8-28 years). The overall incidence of VTE in HAE cases was 1.1/1000 patient years versus 0.6/1000 patient years in the control cohort. In unadjusted analyses HAE was associated with a significantly increased risk of VTE (HR 1.70, 95% CI 1.37-2.22, P&amp;lt;0.0001). Importantly, in adjusted analyses HAE remained significantly associated with an increased risk of VTE (HR 1.44, 95% CI 1.12-1.83, P=0.004, Figure 1). Of note, this association is similar in magnitude to that previously reported for heterozygous carriers of FV Leiden, the prothrombin gene mutation and high confidence loss of function mutations in Protein C and Protein S in comparable population-based case-control studies. In adjusted sub-analyses HAE was associated with a significantly increased risk of DVT (HR: 1.42, 95% CI 1.09-1.87, P=0.01) with a trend towards an increased risk of PE (HR 1.37, 95% CI 0.84-2.27, P=0.2). Conclusions: The results of this population-based case-control study, roughly an order of magnitude larger in size than prior reports, demonstrate that HAE is associated with a significantly increased risk of VTE similar to that reported for common hereditary thrombophilias. These findings reinforce the important role of endogenous C1INH as a negative regulator of prothrombotic processes involved in VTE in the setting of HAE.