Anticoagulant Factors Research Articles

Loss of function in protein Z (PROZ) is associated with increased risk of ischemic stroke in the UK Biobank

BackgroundThe vitamin K–dependent coagulation factor protein Z (PZ), encoded by the PROZ gene, is canonically considered to have anticoagulant effects through negative regulation of factor Xa. Paradoxically, higher circulating PZ concentrations have repeatedly been associated with an elevated risk of acute ischemic stroke. ObjectivesWe performed a large-scale genetic association study to examine the relationship between germline genetic variants in PROZ and the risk of ischemic stroke. MethodsUsing whole-exome sequencing and clinical data for 416 711 participants in the UK Biobank (UKB), we identified individuals with rare (minor allele frequency ≤0.1%) putatively function-altering variants in PROZ. Using Firth’s logistic regression and controlling for known stroke risk factors, we evaluated the association between variant carrier status and noncardioembolic ischemic stroke (NCEIS). Additionally, we evaluated differences in the plasma levels of 1472 proteins between PROZ variant carriers and noncarriers in a subset of 48 893 UKB participants. ResultsAfter accounting for missing data, qualifying variants in PROZ were identified in 414 UKB participants (99.0% heterozygous). Variant carriers had a significantly increased risk of NCEIS (odds ratio, 2.34; 95% CI, 1.15-4.13; P = .02) but not of venous thromboembolism, myocardial infarction, or peripheral artery disease. Plasma proteomics analysis revealed that PROZ variant carriers had significantly elevated levels of 2 proteins related to the response to cerebral ischemia, peroxiredoxins 1 and 6 (PRDX1: fold change, 1.83; P = 1.3 × 10−5; PRDX6: fold change, 1.78; P = 9.6 × 10−10). ConclusionLifelong exposure to decreased PZ levels confers a significantly increased risk of NCEIS, consistent with the role of PZ as an anticoagulant factor.

Extracellular vesicle tissue factor and tissue factor pathway inhibitor are independent discriminators of sepsis-induced coagulopathy

BackgroundSepsis-induced disseminated intravascular coagulopathy (DIC) remains a challenging clinical entity associated with significant morbidity and mortality. Endothelial injury or activation and extracellular vesicles (EV) are postulated as important determinants of DIC. However, there is limited research available which specifically tests the discriminatory ability of these characteristics in sepsis-induced coagulopathy. MethodsIn this prospective, single-centre study we collected plasma samples within 24 hours after sepsis diagnosis and followed these patients for five consecutive days. Overt DIC was determined by the ISTH-DIC score. 87 sepsis patients were recruited (35 with overt DIC) and presented with increased levels of EV, EV-associated TF activity (TF-PCA), E-selectin, TF and TFPI at admission compared to healthy subjects. ResultsOnly TFPI levels and TF-PCA discriminated between sepsis patients with or without DIC (AUC 0.76, p = 0.0002). Increased TF-PCA was not sensitive in detecting sepsis-associated DIC, however levels above 1.38 pg/mL showed a high specificity in this cohort (sensitivity 27%, specificity 95%). The hazard ratio to progress to DIC over five days was 1.14 (95% CI 0.64 – 2.07) for TF-PCA levels of 0.5 pg/mL or higher and 3.18 (95% CI 1.74 – 5.79) for TFPI levels of 22.28 ng/mL or higher at admission. ConclusionThese findings highlight the critical balance between pro- and anticoagulant factors, especially the pivotal roles of TF-PCA and TFPI in an early phase of sepsis-induced DIC. Only EV-associated and functionally active TF and not TF antigen levels showed a predictive potential regarding DIC. These novel results might support the improvement of diagnostic or even therapeutic strategies to mitigate the devastating consequences of DIC in septic patients.

Impact of Treatment with Direct Antivirals on Coagulation Parameters in Patients with Hepatitis C Virus-Related Liver Cirrhosis and Sustained Virological Response.

Background and Objectives: Sustained virologic responses (SVRs) lead to a decrease in portal hypertension, the regression of fibrosis, and the improvement in the hepatic synthesis of procoagulant and anticoagulant factors. We aimed to assess the influence of SVR on coagulation parameters in cirrhotic patients with HCV treated with DAAs. Methods: We performed a prospective study in the Institute of Gastroenterology and Hepatology Iasi, Romania, between January 2022 and February 2024. We included patients diagnosed with compensated and decompensated HCV-related liver cirrhosis, treated with direct antivirals (PrOD ± RBV or SOF/LED ± RBV) for 12/24 weeks. Blood samples for biochemical, immunological, and coagulation tests were collected at the baseline, end of treatment (EOT), and once sustained virological response had been achieved over a period of 12/24 weeks (SVR12/24). Results: We analyzed a group of 52 patients with HCV-related liver cirrhosis, predominantly female (68.0%), and the degree of severity of cirrhosis placed the patients mainly in Child-Pugh classes B (40%) and C (36%). All patients achieved SVRs. The MELD score decreased at EOT (13.48 ± 4.273; p = 0.001) and SVR (9.88 ± 2.774; p = 0.000), compared to the baseline (14.92 ± 4.707). The FibroScan values decreased at SVR (17.596 ± 3.7276; p = 0.000) compared to the baseline (26.068 ± 7.0954). For all common coagulation parameters (platelets, INR, PT, fibrinogen, aPTT), there was a trend towards improvement during treatment, including changes which were statistically significant for the majority of patients. Factor II was low at the baseline (75.40 ± 7.506) but increased at EOT (87.40 ± 9.587) and, later, at SVR (99.12 ± 11.695; p = 0.000). The FVIII values increased at the baseline (175.52 ± 16.414) and decreased at EOT (151.48 ± 13.703) and SVR (143.40 ± 13.937). The FvW values decreased during treatment (146.84 ± 9.428, at baseline; 141.32 ± 9.690, p = 0.000, at EOT; and 126.68 ± 17.960, at SVR). In regard to the anticoagulant factors (PC, PS, ATIII), a significant improvement was brought on by SVR. Advanced stages of liver disease showed the most diminished FII activity, while at the baseline and in Child-Pugh C patients we recorded the highest values of FVIII and FvW. Conclusions: Our study proved that the "reset" of coagulopathy might be due to the improvement in liver function due to viral eradication secondary to AAD therapy.

Deep Vein Thrombosis

Deep vein thrombosis (DVT) is a major preventable cause of morbidity and mortality worldwide. Venous thromboembolism (VTE), which includes DVT and pulmonary embolism (PE), affects an estimated 1 per 1,000 people and contributes to 60,000–100,000 deaths annually. Normal blood physiology hinges on a delicate balance between pro- and anti-coagulant factors. Virchow’s Triad distills the multitude of risk factors for DVT into three basic elements favoring thrombus formation: venous stasis, vascular injury, and hypercoagulability. Clinical, biochemical, and radiological tests are used to increase the sensitivity and specificity for diagnosing DVT.

Impact of thyroid function on coagulation and venous thromboembolism: a two-sample mendelian randomization study.

The association between thyroid function, coagulation and venous thromboembolism (VTE) has been reported in observational studies with conflicting findings. This study aimed to elucidate the causal effects of thyroid function on coagulation and VTE from a genetic perspective. Two sample Mendelian randomization analysis was conducted using summary statistics from genome-wide association studies in a European population. Coagulation status was associated with nine coagulation-related factors (F VIII, F IX, F XI, Fibrinogen, Antithrombin-III, Thrombomodulin, Plasminogen activator inhibitor-1, Protein C and Protein S). Inverse variance weighting with random effect method was used as the main analytic approach with MR-Egger, weighted median, simple mode and weighted mode methods serving as complements. Sensitivity analyses including heterogeneity test, horizontal pleiotropy test and leave-one-out analysis were conducted to further assess the reliability of results. No genetic causal effects of thyroid function on VTE (including pulmonary embolism and deep venous thrombosis) were found. Genetically, hyperthyroidism was suggestively related to decreased Antithrombin-III (β: -0.04 [95% CI: -0.06 to - 0.01], p = 0.010) and Protein C (β: -0.03 [95% CI: -0.06 to 0.00], p = 0.045). No notable associations were observed between other thyroid function parameters and coagulation-related factors. We provide suggestive genetic evidence supporting the causal effect of hyperthyroidism on decreased level of anticoagulant factors including Antithrombin-III and Protein C. However, whether this genetic causality could lead to clinically significant hypercoagulable state and increased risk of VTE in hyperthyroid population needs to be further addressed.

Serum Calcification Propensity T50 Is Associated with Soluble Thrombomodulin in Patients on Hemodialysis.

Background/Objectives: Levels of circulating soluble thrombomodulin (sTM), an anticoagulant factor, are associated with the severity and progression of arteriosclerotic diseases. However, the role of elevated sTM levels remains to be clarified in patients on dialysis. As the calcification propensity time T50 is a novel marker of arterial calcification, we aimed to determine the association between sTM and T50 in patients on hemodialysis (HD). Methods: This cross-sectional study included 49 adult patients on maintenance HD. Correlation analysis was performed to test the association between T50 and patient characteristics. Linear regression was used to evaluate the association between T50 and sTM. Results: Partial correlation analysis showed a strong association between T50 and glycated albumin, phosphorous, and sTM levels (partial correlation coefficient: r [partial] = -0.359, p = 0.023; r [partial] = -0.579, p < 0.001; and r [partial] = 0.346, p = 0.029, respectively). Multivariate linear regression analysis revealed that only sTM level was significantly and positively associated with T50 (β = 0.288; t = 2.27; p = 0.029; 95% confidence interval, 0.082-1.403). Conclusions: sTM is independently and positively associated with the propensity time for calcification, suggesting that sTM could be a good marker of arterial calcification progression in patients on HD.

Purification and Structural Analyses of Sulfated Polysaccharides from Low-Value Sea Cucumber Stichopus naso and Anticoagulant Activities of Its Oligosaccharides.

Three polysaccharides (SnNG, SnFS and SnFG) were purified from the body wall of Stichopus naso. The physicochemical properties, including monosaccharide composition, molecular weight, sulfate content, and optical rotation, were analyzed, confirming that SnFS and SnFG are sulfated polysaccharides commonly found in sea cucumbers. The highly regular structure {3)-L-Fuc2S-(α1,}n of SnFS was determined via a detailed NMR analysis of its oxidative degradation product. By employing β-elimination depolymerization of SnFG, tri-, penta-, octa-, hendeca-, tetradeca-, and heptadeca-saccharides were obtained from the low-molecular-weight product. Their well-defined structures confirmed that SnFG possessed the backbone of {D-GalNAc4S6S-β(1,4)-D-GlcA}, and each GlcA residue was branched with Fuc2S4S. SnFS and SnFG are both structurally the simplest version of natural fucan sulfate and fucosylated glycosaminoglycan, facilitating the application of low-value sea cucumbers S. naso. Bioactivity assays showed that SnFG and its derived oligosaccharides exhibited potent anticoagulation and intrinsic factor Xase (iXase) inhibition. Moreover, a comparative analysis with the series of oligosaccharides solely branched with Fuc3S4S showed that in oligosaccharides with lower degrees of polymerization, such as octasaccharides, Fuc2S4S led to a greater increase in APTT prolongation and iXase inhibition. As the degree of polymerization increases, the influence from the sulfation pattern diminishes, until it is overshadowed by the effects of molecular weight.

TFPI from erythroblasts drives heme production in central macrophages promoting erythropoiesis in polycythemia

Bleeding and thrombosis are known as common complications of polycythemia for a long time. However, the role of coagulation system in erythropoiesis is unclear. Here, we discover that an anticoagulant protein tissue factor pathway inhibitor (TFPI) plays an essential role in erythropoiesis via the control of heme biosynthesis in central macrophages. TFPI levels are elevated in erythroblasts of human erythroblastic islands with JAK2V617F mutation and hypoxia condition. Erythroid lineage-specific knockout TFPI results in impaired erythropoiesis through decreasing ferrochelatase expression and heme biosynthesis in central macrophages. Mechanistically, the TFPI interacts with thrombomodulin to promote the downstream ERK1/2-GATA1 signaling pathway to induce heme biosynthesis in central macrophages. Furthermore, TFPI blockade impairs human erythropoiesis in vitro, and normalizes the erythroid compartment in mice with polycythemia. These results show that erythroblast-derived TFPI plays an important role in the regulation of erythropoiesis and reveal an interplay between erythroblasts and central macrophages.

Performance of risk scores in predicting major bleeding in left ventricular assist device recipients: a comparative external validation

BackgroundImplantation of a left ventricular assist device (LVAD) is a crucial therapeutic option for selected end-stage heart failure patients. However, major bleeding (MB) complications postimplantation are a significant concern. ObjectivesWe evaluated current risk scores’ predictive accuracy for MB in LVAD recipients. MethodsWe conducted an observational, single-center study of LVAD recipients (HeartWare or HeartMate-3, November 2010-December 2022) in the Netherlands. The primary outcome was the first post-LVAD MB (according to the International Society on Thrombosis and Haemostasis [ISTH] and Interagency Registry for Mechanically Assisted Circulatory Support [INTERMACS], and INTERMACS combined with intracranial bleeding [INTERMACS+] criteria). Mortality prior to MB was considered a competing event. Discrimination (C-statistic) and calibration were evaluated for the Hypertension, Abnormal Renal/Liver Function, Stroke, Bleeding History or Predisposition, Labile INR, Elderly, Drugs/Alcohol Concomitantly score, Hepatic or Renal Disease, Ethanol Abuse, Malignancy, Older Age, Reduced Platelet Count or Function, Re-Bleeding, Hypertension, Anemia, Genetic Factors, Excessive Fall Risk and Stroke score, Anticoagulation and Risk Factors in Atrial Fibrillation score, Outpatient Bleeding Risk Index, venous thromboembolism score, atrial fibrillation score, and Utah Bleeding Risk Score (UBRS). ResultsOne hundred four patients were included (median age, 64 years; female, 20.2%; HeartWare, 90.4%; HeartMate-3, 9.6%). The cumulative MB incidence was 75.7% (95% CI 65.5%-85.9%) by ISTH and INTERMACS+ criteria and 67.0% (95% CI 56.0%-78.0%) per INTERMACS criteria over a median event-free follow-up time of 1916 days (range, 59-4521). All scores had poor discriminative ability on their intended prediction timeframe. Cumulative area under the receiving operator characteristic curve ranged from 0.49 (95% CI 0.35-0.63, venous thromboembolism-BLEED) to 0.56 (95% CI 0.47-0.65, UBRS) according to ISTH and INTERMACS+ criteria and from 0.48 (95% CI 0.40-0.56, Anticoagulation and Risk Factors in Atrial Fibrillation) to 0.56 (95% CI 0.47-0.65, UBRS) per INTERMACS criteria. All models showed poor calibration, largely underestimating MB risk. ConclusionCurrent bleeding risk scores exhibit inadequate predictive accuracy for LVAD recipients. There is a need for an accurate risk score to identify LVAD patients at high risk of MB who may benefit from patient-tailored antithrombotic therapy.

Intermediate molecular weight–fucosylated chondroitin sulfate from sea cucumber Cucumaria frondosa is a promising anticoagulant targeting intrinsic factor IXa

Thromboembolic diseases pose a serious risk to human health worldwide. Fucosylated chondroitin sulfate (FCS) is reported to have good anticoagulant activity with a low bleeding risk. Molecular weight plays a significant role in the anticoagulant activity of FCS, and FCS smaller than octasaccharide in size has no anticoagulant activity. Therefore, identifying the best candidate for developing novel anticoagulant FCS drugs is crucial. Herein, native FCS was isolated from sea cucumber Cucumaria frondosa (FCScf) and depolymerized into a series of lower molecular weights (FCScfs). A comprehensive assessment of the in vitro anticoagulant activity and in vivo bleeding risk of FCScfs with different molecule weights demonstrated that 10 kDa FCScf (FCScf-10 K) had a greater intrinsic anticoagulant activity than low molecular weight heparin (LMWH) without any bleeding risk. Using molecular modeling combined with experimental validation, we revealed that FCScf-10 K can specifically inhibit the formation of the Xase complex by binding the negatively charged sulfate group of FCScf-10 K to the positively charged side chain of arginine residues on the specific surface of factor IXa. Thus, these data demonstrate that the intermediate molecular weight FCScf-10 K is a promising candidate for the development of novel anticoagulant drugs.

Activity of protein C, protein S and antithrombin 3 in COVID-19 patients treated with different modalities of oxygen supplementation

Abstract Objectives COVID-19 in it is more severe form is characterized by a hyperinflammatory condition, hypercoagulation state and the appearance of pulmonary microembolism. In this study we wanted to correlate levels of D-Dimer, protein C, protein S and antithrombin 3 with severity of disease and clinical outcome. Methods We included 134 of patients who were divided in 3 groups regarding oxygen support (high flow oxygen therapy, mechanical ventilation and oxygen supplementation with nasal cannula or mask). Results Concentration of D-Dimer, and activity of protein C and antithrombin 3 are presented as mean±SD and differed significantly between patients on mechanical ventilation (3.26 ± 1.15 mg/L, 86 ± 22.55 %, 81.21 ± 17.61 %)/HFNO (2.35 ± 1.68 mg/L, 109.6 ± 26.96 %, 94.67 ± 17.49 %)/BNC (1.37 ± 1.17 mg/L, 116.92 ± 28.16 %, 103.29 ± 15.63 %) with p&lt;0.001 for all parameters. Mortality in oxygen group was 10.9 %, in HFNC group 40.7 % and in mechanical ventilated group 80 %. Conclusions determination of anticoagulant factors in COVID-19 patients may indicate which of them are at increased risk of developing severe disease, venous thromboembolism and fatal clinical outcome.

Unlocking the polymorphic odyssey of Rivaroxaban: a journey of pharmaceutical innovation

The field of pharmaceutical science is a dynamic landscape driven by the pursuit of enhanced drug formulations and improved therapeutic outcomes. One remarkable journey within this domain is the polymorphism odyssey of rivaroxaban, a distinguished anticoagulant inhibitor targeting blood coagulation factor Xa. Rivaroxaban plays a key role in the prevention and treatment of thromboembolic disorders, including myocardial infarction, stroke, and deep venous thromboses. Its intricate crystal structures and diverse solid-state forms, each imparting unique properties affecting solubility, bioavailability, and stability, illuminate the challenges, breakthroughs, and relentless pursuit of superior drug performance in the pharmaceutical development of rivaroxaban. This work not only reflects the scientific commitment to enhancing therapeutic efficacy but also underscores the dynamic interplay between chemical innovation and clinical application in drug development.

The Vitamin K-Dependent Anticoagulant Factor, Protein S, Regulates Vascular Permeability.

Protein S (PROS1) is a vitamin K-dependent anticoagulant factor, which also acts as an agonist for the TYRO3, AXL, and MERTK (TAM) tyrosine kinase receptors. PROS1 is produced by the endothelium which also expresses TAM receptors, but little is known about its effects on vascular function and permeability. Transwell permeability assays as well as Western blotting and immunostaining analysis were used to monitor the possible effects of PROS1 on both endothelial cell permeability and on the phosphorylation state of specific signaling proteins. We show that human PROS1, at its circulating concentrations, substantially increases both the basal and VEGFA-induced permeability of endothelial cell (EC) monolayers. PROS1 induces p38 MAPK (Mitogen Activated Protein Kinase), Rho/ROCK (Rho-associated protein kinase) pathway activation, and actin filament remodeling, as well as substantial changes in Vascular Endothelial Cadherin (VEC) distribution and its phosphorylation on Ser665 and Tyr685. It also mediates c-Src and PAK-1 (p21-activated kinase 1) phosphorylation on Tyr416 and Ser144, respectively. Exposure of EC to human PROS1 induces VEC internalization as well as its cleavage into a released fragment of 100 kDa and an intracellular fragment of 35 kDa. Using anti-TAM neutralizing antibodies, we demonstrate that PROS1-induced VEC and c-Src phosphorylation are mediated by both the MERTK and TYRO3 receptors but do not involve the AXL receptor. MERTK and TYRO3 receptors are also responsible for mediating PROS1-induced MLC (Myosin Light Chain) phosphorylation on a site targeted by the Rho/ROCK pathway. Our report provides evidence for the activation of the c-Src/VEC and Rho/ROCK/MLC pathways by PROS1 for the first time and points to a new role for PROS1 as an endogenous vascular permeabilizing factor.

Does the Use of Viscoelastic Hemostatic Assays for Periprocedural Hemostasis Management in Liver Disease Improve Clinical Outcomes?

Routine hemostasis parameters such as prothrombin time and fibrinogen are frequently abnormal in patients with chronic liver disease and have been demonstrated to be poor predictors for periprocedural bleeding. Alterations in procoagulant and anticoagulant factors in this population result in a state of rebalanced hemostasis, which is not reflected by routine hemostatic measures. Viscoelastic hemostatic assays (VHA) present a point of care measure of global hemostasis with an emerging role in guiding transfusion in the liver transplant setting. The potential role for VHA in guiding periprocedural transfusion is unknown. Here we critically appraise the available limited evidence on the use of VHA to guide prophylactic treatment in patients with cirrhosis undergoing procedures. We assess whether the impact of a VHA-guided approach improves clinical outcomes. Suggested areas for future research with a focus on clinically relevant outcomes, particularly periprocedural bleeding, are highlighted.

Oxidative Stress and Thrombophilia: Focus on Pregnancy-Related Pathophysiological Mechanisms

Abstract Thrombophilia, characterized by an increased tendency to form blood clots, presents a substantial risk during pregnancy, potentially impacting maternal and fetal outcomes. This review explores the intricate relationship between thrombophilia and oxidative stress, shedding light on their combined influence on blood clot formation. Specifically, endothelial dysfunction, driven by oxidative stress, emerges as a pivotal factor in thrombophilia, setting the stage for increased platelet activation and altered coagulation factors. Factors like Factor V Leiden mutation, Prothrombin G20210A mutation, and deficiencies in antithrombin, protein C, and protein S contribute to the pro-thrombotic state observed in thrombophilia. Furthermore, inflammation, closely intertwined with oxidative stress, exacerbates the risk of blood clot formation. Inflammatory responses lead to endothelial activation, altered endothelial function, and increased adhesion molecules expression, disrupting the delicate balance between pro- and anti-coagulant factors. Chronic inflammatory conditions, such as autoimmune disorders, potentiate a persistent state of heightened clotting risk. Additionally, impaired antioxidant defenses compound the prothrombotic state by allowing the accumulation of reactive oxygen species, thereby contributing to oxidative stress-induced endothelial dysfunction. Understanding the interplay between these factors is crucial for tailored thrombophilia management, particularly in pregnancy. Treatment strategies encompass a multifaceted approach, including anticoagulant medications, lifestyle modifications, and targeted interventions to improve endothelial health. The complex nature of thrombophilia underscores the need for a collaborative healthcare approach, involving hematologists and high-risk pregnancy specialists. Early detection, vigilant monitoring, and timely intervention are paramount in mitigating risks for both mother and baby.

Impact of tissue factor expression and administration routes on thrombosis development induced by mesenchymal stem/stromal cell infusions: re-evaluating the dogma.

Hyperactive coagulation might cause dangerous complications such as portal vein thrombosis and pulmonary embolism after mesenchymal stem/stromal cell (MSC) therapy. Tissue factor (TF), an initiator of the extrinsic coagulation pathway, has been suggested as a predictor of this process. The expression of TF and other pro- and anticoagulant genes was analyzed in xeno- and serum-free manufactured MSCs. Furthermore, culture factors affecting its expression in MSCs were investigated. Finally, coagulation tests of fibrinogen, D-dimer, aPPTs, PTs, and TTs were measured in patient serum after umbilical cord (UC)-MSC infusions to challenge a potential connection between TF expression and MSC-induced coagulant activity. RESULTS: Xeno- and serum-free cultured adipose tissue and UC-derived MSCs expressed the highest level of TF, followed by those from dental pulp, and the lowest expression was observed in MSCs of bone marrow origin. Environmental factors such as cell density, hypoxia, and inflammation impact TF expression, so in vitro analysis might fail to reflect their in vivo behaviors. MSCs also expressed heterogeneous levels of the coagulant factor COL1A1 and surface phosphatidylserine and anticoagulant factors TFPI and PTGIR. MSCs of diverse origins induced fibrin clots in healthy plasma that were partially suppressed by an anti-TF inhibitory monoclonal antibody. Furthermore, human umbilical vein endothelial cells exhibited coagulant activity in vitro despite their negative expression of TF and COL1A1. Patients receiving intravenous UC-MSC infusion exhibited a transient increase in D-dimer serum concentration, while this remained stable in the group with intrathecal infusion. There was no correlation between TF expression and D-dimer or other coagulation indicators. The study suggests that TF cannot be used as a solid biomarker to predict MSC-induced hypercoagulation. Local administration, prophylactic intervention with anticoagulation drugs, and monitoring of coagulation indicators are useful to prevent thrombogenic events in patients receiving MSCs. Trial registration NCT05292625. Registered March 23, 2022, retrospectively registered, https://www. gov/ct2/show/NCT05292625?term=NCT05292625&draw=2&rank=1 . NCT04919135. Registered June 9, 2021, https://www. gov/ct2/show/NCT04919135?term=NCT04919135&draw=2&rank=1 .

Anticoagulant effects of protein C, protein S, and antithrombin levels on the protein C pathway in young children.

The protein C (PC) pathway involves physiological anticoagulant factors (PC, protein S [PS], and factor V) and performs major anticoagulant functions in adults. Variations in overall PC pathway function due to dynamic changes in PC and PS in early childhood are poorly understood. We aimed to evaluate the contributions of PC pathway function during early childhood by measuring changes in plasma thrombin generation (TG) after administration of the PC activator protac. We evaluated correlations between anticoagulant factors and percentage of protac-induced coagulation inhibition (PiCi%). Before protac addition, TG in newborns (n = 35), infants (n = 42), young children (n = 35), and adults (n = 20) were 525 ± 74, 720 ± 96, 785 ± 53, and 802 ± 64mOD/min, and PiCi% were 42.1 ± 9.9, 69.8 ± 11.0, 82.9 ± 4.4, and 86.9 ± 3.4%, respectively. The distribution of PiCi% on the two axes of TG (with or without protac) changed continuously with age and differed from that of warfarin-treated plasma and adult PC- or PS-deficient plasma. PiCi% increased dynamically during infancy and correlated with PS levels in newborns and PC levels in young children. Addition of PC or fresh frozen plasma equivalent to approximately 25% PC to PC-deficient plasma improved PiCi%. This automatic measurement requires only a small sample volume and is useful for analysis of developmental hemostasis.

A neoteric approach to understanding thrombosis

Pathophysiology of thrombosis. Thrombosis, a leading cause of morbidity and mortality worldwide, results from an imbalance between procoagulant, anticoagulant, and fibrinolytic factors. Virchow?s triad - endothelial injury, stasis of blood flow, and hypercoagulability - has long been the cornerstone for understanding thrombosis. However, evolving knowledge has refined our interpretation of how these factors contribute to venous and arterial thrombosis. Arterial thrombosis. Historically, arterial and venous thromboses were viewed as distinct pathophysiological entities. Over the past two decades, research has highlighted the complexity of etiopathogenesis of the thrombotic process, recognizing mutual risk factors offering a more comprehensive understanding the pathophysiological mechanism behind these diseases. Venous thrombosis. Recent insights focus on thrombotic potential, defined as an individual?s susceptibility to thrombosis resulting from a combination of congenital and acquired risk factors.. It has become clear that the interaction of these factors is not merely additive but synergistic, significantly increasing the risk of thrombosis. The significant social impact of thrombosis underscores the necessity of thoroughly understanding its underlying mechanisms to develop effective preventive and therapeutic strategies.

Transcriptomic profiling and the first spatial expression analysis of candidate genes in the salivary gland of the East Asian medicinal leech, Hirudo nipponia

Hirudo nipponia, a blood-sucking leech native to East Asia, possesses a rich repertoire of active ingredients in its saliva, showcasing significant medical potential due to its anticoagulant, anti-inflammatory, and antibacterial effects against human diseases. Despite previous studies on the transcriptomic and proteomic characteristics of leech saliva, which have identified medicinal compounds, our knowledge of tissue-specific transcriptomes and their spatial expression patterns remains incomplete. In this study, we conducted an extensive transcriptomic profiling of the salivary gland tissue in H. nipponia based on de novo assemblies of tissue-specific transcriptomes from the salivary gland, teeth, and general head region. Through gene ontology (GO) analysis and hierarchical clustering, we discovered a novel set of anti-coagulant factors—i.e., Hni-Antistasin, Hni-Ghilanten, Hni-Bdellin, Hni-Hirudin—as well as a previously unrecognized immune-related gene, Hni-GLIPR1 and uncharacterized salivary gland specific transcripts. By employing in situ hybridization, we provided the first visualization of gene expression sites within the salivary gland of H. nipponia. Our findings expand on our understanding of transcripts specifically expressed in the salivary gland of blood-sucking leeches, offering valuable resources for the exploration of previously unidentified substances with medicinal applications.

ENDOTHELIAL GLYCOCALYX DAMAGE IN PATIENTS WITH SEVERE FUNCTIONAL INJURY

In modern medical science, endothelial glycocalyx, which is considered a target organ in many diseases, including severe traumatic injuries, is becoming one of the main objects of researchers' attention [1,2]. Trauma is the leading cause of death and disability worldwide, and despite the introduction of damage-controlled resuscitation, mortality remains very high. More than half of trauma patients are found to have laboratory-defined coagulopathy on admission, which further leads to increased mortality [3,4]. Laboratory-defined coagulopathy, also called trauma-induced coagulopathy, is described as either excessive activation of the protein C pathway accompanied by hyperfibrinolysis or as a manifestation of the hemorrhagic phenotype of disseminated intravascular coagulation. Common to both of these explanations is that, they are based on the measurement of concentrations of pro- and anticoagulant clotting factors, platelet counts, and fibrin degradation products [5,6]. Nowadays, evidence is accumulating for a key role of the glycocalyx as one of the first structures involved in the trauma-induced coagulopathic response and it may be one of the earliest signs of progression in the severity of patients. In our study of trauma patients using whole blood thrombelastography (TEG), we found that the hemostatic profile became increasingly hypocoagulative and hyperfibrinolytic with increasing severity of injury, Therefore, studies of the significance of glycocalyx in the development of severe complications in conditions of persistently high lethality in trauma patients [7,8], are a priority and primary task of science and practical health care. Glycocalyx is a birth of a new clinical paradigm, but the full understanding of its significance and functions is still far away and researchers are only at the beginning of the way. We study the role of the endothelial glycocalyx system and analyze the relationship between markers of glycocalyx degradation and the severity of the clinical course of the disease in severe traumatic injuries. It is expected that a deeper study of the glycocalyx, understanding the relationship between the mechanisms of its degradation and trauma is extremely important and will lead to the development of new scientific strategies for early diagnosis and the possibility of predicting disease outcomes in patients with severe traumatic injuries. The object of our scientific research were patients with severe combined trauma. The study was carried out taking into account the principles of evidence-based medicine. The obtained data were processed using standard methods of statistical analysis.