Search Results (338)

Objectives: This study investigated the antithrombotic properties of a fibrinolytic enzyme (CFE) purified from the culture supernatant of Coprinus comatus using a zebrafish thrombosis model. Methods: A phenylhydrazine-induced thrombosis model was employed to evaluate the in vivo thrombolytic efficacy and mechanisms of CFE. Results: CFE significantly attenuated thrombogenesis by inhibiting erythrocyte aggregation in the caudal vessels, reducing staining intensity (3.61-fold decrease) and staining area (3.89-fold decrease). Concurrently, CFE enhanced cardiac hemodynamics, increasing erythrocyte staining intensity (9.29-fold) and staining area (5.55-fold) while achieving an 85.19% thrombosis inhibition rate. Behavioral analysis confirmed improved motility, with CFE-treated zebrafish exhibiting 2.23-fold increases in total movement distance and average speed, alongside a 3.59-fold extension in active movement duration. Mechanistically, ELISA revealed the multi-pathway activity of CFE, promoting fibrinolysis through reductions in plasminogen, fibrinogen, and D-dimer; inhibiting platelet activation via downregulation of prostaglandin-endoperoxide synthase (PTGS), thromboxane A2 (TXA2), P-selectin, and von Willebrand factor (vWF); and modulating coagulation cascades through elevated protein C and tissue factor pathway inhibitor (TFPI) with concurrent suppression of coagulation factor VII (FVII). Conclusions: These results indicate that the fibrinolytic enzyme CFE, derived from Coprinus comatus, exerts potent antithrombotic effects, supporting its potential as a basis for fungal-derived natural antithrombotic functional food ingredients. Full article

Post-acute sequelae of COVID-19 have been associated with an elevated risk of thromboembolism and adverse cardiovascular events (CVEs). We aim to evaluate whether alterations in poorly studied hemostatic and endothelial proteins are associated with CVEs in patients previously admitted to the ICU and evaluated one year post-discharge. We carried out a cross-sectional study involving 63 COVID-19 patients previously admitted to the ICU one year post-discharge. Plasma levels of factor IX (coagulation factor), protein C, protein S (natural anticoagulant), and von Willebrand factor (VWF, an endothelial marker) were measured using a Luminex 200™ analyzer. Generalized linear models (GLMs) were used to assess the association of these coagulation proteins with CVEs and N-terminal pro-B-type natriuretic peptide (NT-proBNP). We found that lower levels of factor IX (p = 0.011), protein C (p = 0.028), and protein S (p = 0.008) were associated with CVEs one year after ICU discharge. Additionally, at the one-year follow-up, we found lower levels of factor IX (p = 0.002) and higher levels of VWF (p = 0.006) associated with higher levels of NT-proBNP, underscoring the involvement of both hemostatic imbalance and persistent endothelial dysfunction. Our findings revealed a gender-specific pattern of associations with NT-proBNP levels. These findings highlight the significant role of persistent hemostatic imbalance and endothelial dysfunction in the development of cardiovascular abnormalities among COVID-19 survivors discharged from the ICU. Full article

Background: The enzyme A Disintegrin and metalloprotease with thrombospondin type 1 motif, member 13 (ADAMTS13) regulates hemostasis by cleaving von Willebrand factor (VWF) multimers. ADAMTS13–VWF axis dysregulation leads to different thrombotic conditions. This study investigated changes in ADAMTS13 activity during major cardiac procedures and their relationship to VWF changes and clinical complications. Methods: A total of 628 ADAMTS13 activity and inhibitor measurements were carried out in 168 patients who underwent cardiac surgery. ADAMTS13 activity was measured after the initiation of anesthesia and daily for up to 6 days postoperatively via Technozym chromogenic ELISA. The von Willebrand factor antigen (VWF:Ag) and collagen binding (VWF:CB) were also measured. Clinical complications and correlations with liver function biomarkers were also assessed. Results: ADAMTS13 activity significantly decreased during surgery, with mean values markedly decreasing from preoperative to postoperative measurements (p = 0.01). A clear inverse relationship between ADAMTS13 activity and the VWF:CB/VWF:AG ratio was observed, indicating that increased high-molecular-weight VWF multimers are associated with decreased ADAMTS13 activity. Correlation analyses (CHE, Spearman’s rho = 0.39) indicated that the reduction in ADAMTS13 activity was not attributable to impaired liver synthesis but likely resulted from peripheral consumption, potentially influenced by surgical stress. Conclusions: Perioperative reductions in ADAMTS13 activity are associated with an accumulation of high-molecular-weight VWF multimers and a higher incidence of postoperative complications. These results demonstrate that ADAMTS13 could be a useful perioperative risk biomarker for cardiac surgery patients. Full article

As a synthetic analogue of vasopressin, desmopressin or DDAVP has well established hemostatic properties. We present a review of DDAVP and summarize the clinical and laboratory evidence for its use in hemophilia A, von Willebrand disease (VWD), platelet function disorders, uremia, liver cirrhosis, and pregnancy, followed by illustrative examples of its broad efficacy from our local practice. In brief, DDAVP acts to release von Willebrand factor (VWF) and factor VIII from endogenously stored reserves, thereby correcting plasma deficiencies present in mild to moderately affected patients with hemophilia A and VWD. Thus, DDAVP represents a non-transfusional therapy for these disorders. Typically, a trial of DDAVP is arranged to assess individual responsiveness before employing DDAVP clinically, since there is individual variation in responsiveness. Thereafter, DDAVP can be utilized in responsive patients for clinical use and provides a factor replacement sparing strategy in these patients for some clinical situations. Nevertheless, DDAVP is best applied as a factor replacement sparing strategy, especially for minor procedures or short-term use. Full article

Severe COVID-19 is often associated with coagulopathy and thrombotic complications. The underlying mechanisms are complex and multifactorial, involving platelet activation, dysregulation of the complement cascade, fibrinolytic imbalance, release of pro-inflammatory cytokines, immunothrombosis, antiphospholipid antibodies, and alterations in the von Willebrand factor (vWF)/ADAMTS13 axis. These pathways are also implicated in thrombotic microangiopathies (TMAs), characterized by endothelial injury and widespread microvascular thrombosis. In this prospective monocentric observational study, we investigated whether COVID-19-associated coagulopathy meets the criteria for TMA and evaluated the roles of complement activation and vWF/ADAMTS13 imbalance in disease severity. Forty-three hospitalized COVID-19 patients were enrolled and stratified by disease severity. Blood samples collected at admission were analyzed for hematologic, coagulation, inflammatory, and complement parameters. A 30-day follow-up recorded survival and thrombotic events. All patients showed elevated vWF and factor VIII levels; however, only vWF collagen-binding activity (vWF-CBA) significantly correlated with disease severity. ADAMTS13 activity remained above 60% in all cases, and no schistocytes were detected, arguing against a diagnosis of classical TMA. Nevertheless, the vWF-CBA/ADAMTS13 ratio was significantly higher in severe cases, particularly in unvaccinated individuals, suggesting endothelial dysregulation. Complement analysis revealed increased C5a levels and decreased C3b/iC3b ratios in severe disease, consistent with complement activation and consumption. C2 levels were also lower in these patients. Although complement activation and vWF/ADAMTS13 imbalance did not directly correlate, both pathways showed a similar trend according to disease severity. Overall, our findings indicate that COVID-19-related coagulopathy does not fulfill the criteria for classical TMA but shows features of complement-mediated endothelial injury and vWF dysregulation. The vWF-CBA may serve as a rapid, standardized tool for assessing endothelial dysfunction. Activation of the complement system, particularly via the lectin and alternative pathways, appears central to the prothrombotic state in severe COVID-19. Full article

Background: Hepatic resection is performed for liver lesions and requires careful preoperative planning to minimize bleeding. Blood type O, associated with lower von Willebrand factor (vWF) levels, may increase bleeding risk. This study investigates the relationship between the ABO blood type and perioperative bleeding in partial hepatectomy for colorectal liver metastases (CRLMs). Methods: Out of 563 patients who underwent hepatectomy, 135 cases were analyzed for CRLM at Carmel Medical Center (2013–2023). Patients were categorized into blood type O (61 patients) and non-O (74 patients) groups. Data on perioperative hemoglobin levels, blood loss, coagulation parameters, transfusion needs, and complications were assessed using χ², t-tests, and ANOVA (p < 0.05). Results: No significant differences were observed for estimated blood loss (474.3 ± 696 mL for O vs. 527.8 ± 599 mL for non-O; p = 0.29), intraoperative hemoglobin drop (p = 0.613), or transfusion rates (24.59% for O vs. 28.37% for non-O; p = 0.698). Although non-O patients had a higher postoperative INR (p = 0.035), this did not correlate with increased bleeding or transfusion needs. Conclusions: Blood type O does not significantly affect perioperative bleeding or transfusion requirements in partial hepatectomy for CRLM. Further research is needed to better understand the significance of the ABO blood type. Full article

The severe outbreak of SARS-CoV-2, the etiological agent of COVID-19, has precipitated the development of vaccines and antiviral therapeutics. However, it remains a significant public health concern. This study investigated the association between disease severity, biomarkers of coagulation, and endothelial damage, including P-selectin, thrombomodulin, PAI, von Willebrand antigen (VWF: Ag) and von Willebrand factor ristocetin cofactor (VWF: RCo). A cross-sectional, observational study was conducted in a cohort of 90 adult COVID-19 patients (≥18 years), categorized into three groups: ICU-hospitalized, non-ICU hospitalized, and asymptomatic non-hospitalized (outpatient). In these groups, biomarkers, including PAI-1, TM, and P-selectin, were assessed using enzyme-linked immunosorbent assay (ELISA), and immunological assays for VWF: Ag and VWF: RCo. Across all groups, we observed significantly elevated levels of P-selectin, VWF: Ag, and VWF: RCo. Elevated levels of PAI-1 and TM were observed in ICU patients compared to non-ICU and asymptomatic patients, indicating increased endothelial injury and activation. Furthermore, COVID-19 mutations significantly affect the P-selectin biomarker. This finding supports the hypothesis that P-selectin is a more reliable biomarker for assessing the severity of the disease than other endothelial damage and coagulation markers, especially in heterogeneous clinical presentations. Our study also highlights the requirement of comprehensive examination for its broader implications in viral strains, infection severity, and genetic variants. Full article

Efanesoctocog alfa (Altuvoct; BIVV001) is a fusion protein comprising domains of (i) factor VIII, (ii) the von Willebrand factor, and (iii) IgG1 coupled to two polypeptide linkers. The half-life of efanesoctocog alfa in plasma is about 40 h. The polypeptide linkers are released by thrombin activation, resulting in an active form of efanesoctocog alfa that results in the formation of a fibrin clot. Data from two single-arm ongoing studies were submitted: the XTEND-1 study enrolled 159 subjects aged 12–72 years, and the XTEND-kids study enrolled 74 subjects aged <12 years; all subjects had severe haemophilia A. Single-arm studies are not amenable to conventional statistical analysis of ‘effect of cause’, and so a supplementary analysis was conducted on the basis of ‘cause of effect’, making use of the scheme described by Toulmin coupled to an analysis of causal inference. Overall, the claim that Altuvoct is indicated to treat people aged ≥2 years with severe (and moderate) haemophilia A was considered to be supported by the results of the submitted studies and associated modelling exercises; the benefit–risk evaluation of Altuvoct was found to be positive in the target population. Full article

Snake venoms contain numerous toxic proteins, but low-abundance proteins often remain uncharacterized due to identification challenges. This study employs a bioinformatics approach to identify and structurally model low-abundance proteins from the venom gland transcriptomes of Bothrops asper and Bothrops jararaca. Using tools such as tblastn, Jalview, and CHIMERA, we analyzed sequences and structural features of proteins including arylsulfatase, CRISP (Cysteine-Rich Secretory Protein), von Willebrand factor type D (vWFD), and dihydroorotate dehydrogenase (DHODH), and identified potential new isoforms of SVMP-PIIIb (Ba_1) and botrocetin in B. asper. Protein models were generated with AlphaFold2, compared with crystallized structures from the Protein Data Bank (PDB), and validated using Procheck, ERRAT, and Verify3D. Conserved motifs and domains were annotated through Pfam and InterPro, revealing structural elements that suggest possible roles in venom physiology and toxicity. These findings emphasize the potential of computational biology to characterize structurally relevant but experimentally inaccessible venom proteins, and to lay the groundwork for future functional validation. Full article

The red seaweed Asparagopsis taxiformis (Bonnemaisoniaceae, Rhodophyta) produces a bioactive natural product, bromoform, which, when fed to ruminant livestock, can eradicate methane emissions. However, to cultivate enough A. taxiformis to produce a yield that would have a meaningful impact on global greenhouse gas emissions, we need to advance our current understanding of the biology of this seaweed species. Here, we used both a domesticated diploid tetrasporophyte (>1.5 years in culture) and wild samples to establish a high-quality draft nuclear genome for A. taxiformis (lineage 6 based upon phylogenetic analyses using the cox2-3 spacer). The constructed nuclear genome is 142 Mb in size (including 70.67% repeat regions) and was determined to encode for approximately 10,474 protein-coding genes, including those associated with secondary metabolism, photosynthesis, and defence. To obtain information regarding molecular differences between cultured and wild tetrasporophytes, we further explored differential gene expression relating to their different growth environments. Cultured tetrasporophytes, which contained a relatively higher level of bromoform compared to wild tetrasporophytes, demonstrated an enrichment of regulatory factors, such as protein kinases and transcription factors, whereas wild tetrasporophytes were enriched for the expression of defence and stress-related genes. Wild tetrasporophytes also expressed a relatively high level of novel secretory genes encoding proteins with von Willebrand factor A protein domains (named rhodophyte VWAs). Gene expression was further confirmed by proteomic investigation of cultured tetrasporophytes, resulting in the identification of over 400 proteins, including rhodophyte VWAs, and numerous enzymes and phycobiliproteins, which will facilitate future functional characterisation of this species. In summary, as the most comprehensive genomic resource for any Asparagopsis species, this resource for lineage 6 provides a novel avenue for seaweed researchers to interrogate genomic information, which will greatly assist in expediating production of Asparagopsis to meet demand by both aquaculture and agriculture, and to do so with economic and environmental sustainability. Full article

Acute-on-chronic liver failure (ACLF) is a complex and severe condition marked by multiple organ failure and high short-term mortality. Coagulopathy, a key component of ACLF, is characterized by rebalanced hemostasis with both hypo- and hypercoagulable features, increasing the risk of bleeding and thrombosis. Conventional coagulation tests, including prothrombin time (PT) and platelet count, fail to fully capture the complexity of coagulation dysfunction in ACLF. Advanced diagnostic tools, like viscoelastic tests (VETs), offer a more comprehensive assessment, yet they remain limited in evaluating endothelial dysfunction and fail to account for reduced levels of anticoagulant factors. Emerging therapeutic strategies targeting coagulopathies in ACLF hold promise, but their clinical efficacy remains unclear. A more nuanced approach to diagnosing and managing coagulopathy in ACLF is needed, incorporating advanced hemostatic profiling to better inform prognosis and guide treatment decisions. Full article

Background/Objectives: Endovascular aneurysm repair (EVAR) of the aorta may trigger an inflammatory response that affects coagulation. In the EVAR of para-renal and thoraco-abdominal aortic aneurysms, the implants are more complex and the duration of surgery is longer. However, the exact pathophysiological mechanisms of coagulation activation are not yet well understood. The primary aim of this study is to investigate the effects of complex EVAR of para-renal and thoraco-abdominal aortic aneurysms on the coagulation status of patients. Methods: This prospective observational study (STROBE), approved and registered by the Ethics Committee of the University Hospital of Larissa (UHL) (NCT06432387), will enroll consecutive patients undergoing elective EVAR of para-renal and thoraco-abdominal aortic aneurysms. Exclusion criteria: Refusal to participate, previous surgery within 3 months, American Society of Anesthesiologists physical status (ASA PS) > 3, known history of thrombophilia or functional platelet dysfunction. Perioperative laboratory tests will be performed according to institutional guidelines. These include a complete blood count, conventional coagulation tests, and kidney and liver function tests. In addition, the following parameters will be determined: von Willebrand factor, factors VIII and XI, D-dimers, fibrinogen, Adamts-13, anti-Xa, platelet activation (multiplate), and high-sensitivity troponin. Blood samples will be taken pre-operatively before induction of anesthesia (01), on postoperative day 1 (02), and on postoperative day 3–4 (03). During hospitalization, myocardial injury after non-cardiac surgery (MINS), major adverse cardiovascular events after non-cardiac surgery (MACE), acute kidney injury (AKI), post-implantation syndrome (PIS), and death from any cause will be recorded. In addition, our patients will be reviewed at 30 days, 3, 6, and 12 months for MACE, implant failure, or death from any cause. All enrolled patients will be treated by the same medical team at UHL according to the indications. According to our power analysis, for a cohort of patients with three consecutive measurements, 58 patients should be included in the study. To compensate for possible dropouts, the sample size was increased to 65 patients. Conclusions: The results of the present study could help physicians to better understand the effects of complex EVAR of para-renal and thoraco-abdominal aortic aneurysms on blood coagulation and platelet activation. Full article

Normal pregnancy is associated with multiple changes in the coagulation and the fibrinolytic system. In contrast to a non-pregnant state, pregnancy is a hypercoagulable state where the level of VWF increases by 200–375%, affecting coagulation activity. Moreover, in this hypercoagulable state of pregnancy, preeclampsia is exacerbated. ADAMTS13 cleaves the bond between Tyr1605 and Met1606 in the A2 domain of VWF, thereby reducing its molecular weight. A deficiency of ADAMTS13 originates from mutations in gene or autoantibodies formed against the protease, leading to defective enzyme production. Von Willebrand protein is critical for hemostasis and thrombosis, promoting thrombus formation by mediating the adhesion of platelets and aggregation at high shear stress conditions within the vessel wall. Mutations in VWF disrupts multimer assembly, secretion and/or catabolism, thereby influencing bleeding. VWF is the primary regulator of plasma ADAMTS13 levels since even minute amounts of active ADAMTS13 protease have a significant inhibitory effect on inflammation and thrombosis. VWF is released as a result of endothelial activation brought on by HIV infection. The SARS-CoV-2 infection promotes circulating proinflammatory cytokines, increasing endothelial secretion of ultra large VWF that causes an imbalance in VWF/ADAMTS13. Raised VWF levels corresponds with greater platelet adhesiveness, promoting a thrombotic tendency in stenotic vessels, leading to increased shear stress conditions. Full article

Thrombotic thrombocytopenia purpura is a serious disease that can involve complex symptomatology, prolonged hospitalization, and a high risk of mortality if treatment is delayed. This disease is rare, but it is even rarer among pediatric patients. Even though it was first described 100 years ago, the earliest documented case was a pediatric patient. The last three decades have seen the discovery of the pathological mechanisms responsible for its clinical presentation. Symptoms/signs characteristic of microangiopathic hemolytic anemia with significant thrombocytopenia characterize the vast majority of patients. Its pathology centers on the accumulation of ultra-large von Willebrand factor multimers due to an enzyme deficiency that prevents their breakdown. Currently, in pediatric patients, two forms of the disease are known: congenital due to a mutation in the enzyme’s gene and immune-mediated due to enzyme depletion or neutralization secondary to autoantibody formation. With the advent of therapeutic plasma exchanges, immunosuppression, and, more recently, a TTP-specific nanobody, there is reason for optimism that the disease does not necessarily equate to a bad outcome. Thus, the aim of this review is to contrast the congenital and immune-mediated forms of the disease in pediatric patients while presenting them in the context of their pathologic mechanisms, diagnosis, and treatment. Full article

Background and Objectives: Elevated von Willebrand factor (vWF) levels have been reported in malaria, but their relationship with disease severity remains unclear. This study aimed to compare vWF levels between Plasmodium-infected and uninfected individuals and assess changes in severe infections. Materials and Methods: The systematic review was registered in PROSPERO (CRD42024558479). A comprehensive search across six databases identified studies reporting vWF levels in malaria. A meta-analysis was conducted using a random-effects model, with standardized mean difference (SMD) as the effect measure due to varying measurement units. Heterogeneity was assessed using the I² statistic. Results: Of 1647 identified records, 26 studies met the inclusion criteria. The meta-analysis showed significantly higher vWF levels in Plasmodium-infected individuals compared to uninfected controls (p < 0.001, SMD: 2.689 [95% CI 1.362; 4.017], I²: 98.1%, 12 studies, 3109 participants). However, no significant difference was found between severe and less severe cases (p = 0.051, SMD: 3.551 [95% CI −0.007; 7.109], I²: 99.3%, 8 studies, 1453 participants). Conclusions: vWF levels are significantly elevated in individuals with Plasmodium infections, indicating a potential role in malaria pathophysiology. Although levels tend to be higher in severe cases, current evidence is insufficient to support vWF as a reliable marker for disease severity. Further prospective and well-controlled studies are needed to validate its diagnostic and prognostic value in malaria management. Full article