Browsing by Subject "Coagulation"

Now showing 1 - 7 of 7
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    B cell–activating factor modulates the factor VIII immune response in hemophilia A
    (American Society for Clinical Investigation, 2021-04-15) Doshi, Bhavya S.; Rana, Jyoti; Castaman, Giancarlo; Shaheen, Mostafa A.; Kaczmarek, Radoslaw; Butterfield, John S.S.; Meeks, Shannon L.; Leissinger, Cindy; Biswas, Moanaro; Arruda, Valder R.; Pediatrics, School of Medicine
    Inhibitors of factor VIII (FVIII) remain the most challenging complication of FVIII protein replacement therapy in hemophilia A (HA). Understanding the mechanisms that guide FVIII-specific B cell development could help identify therapeutic targets. The B cell–activating factor (BAFF) cytokine family is a key regulator of B cell differentiation in normal homeostasis and immune disorders. Thus, we used patient samples and mouse models to investigate the potential role of BAFF in modulating FVIII inhibitors. BAFF levels were elevated in pediatric and adult HA inhibitor patients and decreased to levels similar to those of noninhibitor controls after successful immune tolerance induction (ITI). Moreover, elevations in BAFF levels were seen in patients who failed to achieve FVIII tolerance with anti-CD20 antibody–mediated B cell depletion. In naive HA mice, prophylactic anti-BAFF antibody therapy prior to FVIII immunization prevented inhibitor formation and this tolerance was maintained despite FVIII exposure after immune reconstitution. In preimmunized HA mice, combination therapy with anti-CD20 and anti-BAFF antibodies dramatically reduced FVIII inhibitors via inhibition of FVIII-specific plasma cells. Our data suggest that BAFF may regulate the generation and maintenance of FVIII inhibitors and/or anti-FVIII B cells. Finally, anti-CD20/anti-BAFF combination therapy may be clinically useful for ITI.
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    Evaluation of Tranexamic Acid and Calcium Chloride in Major Traumas in a Prehospital Setting: A Narrative Review
    (Wolters Kluwer, 2023) Bell, Kameron T.; Salmon, Chase M.; Purdy, Benjamin A.; Canfield, Scott G.; Anatomy, Cell Biology and Physiology, School of Medicine
    Excessive blood loss in the prehospital setting poses a significant challenge and is one of the leading causes of death in the United States. In response, emergency medical services (EMS) have increasingly adopted the use of tranexamic acid (TXA) and calcium chloride (CaCl2) as therapeutic interventions for hemorrhagic traumas. Tranexamic acid functions by inhibiting plasmin formation and restoring hemostatic balance, while calcium plays a pivotal role in the coagulation cascade, facilitating the conversion of factor X to factor Xa and prothrombin to thrombin. Despite the growing utilization of TXA and CaCl2 in both prehospital and hospital environments, a lack of literature exists regarding the comparative effectiveness of these agents in reducing hemorrhage and improving patient outcomes. Notably, Morgan County Indiana EMS recently integrated the administration of TXA with CaCl2 into their treatment protocols, offering a valuable opportunity to gather insight and formulate updated guidelines based on patient-centered outcomes. This narrative review aims to comprehensively evaluate the existing evidence concerning the administration of TXA and CaCl2 in the prehospital management of hemorrhages, while also incorporating and analyzing data derived from the co-administration of these medications within the practices of Morgan County EMS. This represents the inaugural description of the concurrent use of both TXA and CaCl2 to manage hemorrhages in the scientific literature.
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    Examining Depression as a Risk Factor for Cardiovascular Disease in People with HIV: A Systematic Review
    (Oxford University Press, 2023) Polanka, Brittanny M.; Gupta, Samir K.; So-Armah, Kaku A.; Freiberg, Matthew S.; Zapolski, Tamika C. B.; Hirsh, Adam T.; Stewart, Jesse C.; Medicine, School of Medicine
    Background: People with human immunodeficiency virus (HIV) have an increased risk of cardiovascular disease (CVD) not fully accounted for by traditional or HIV-specific risk factors. Successful management of HIV does not eliminate this excess risk. Thus, there is a need to identify novel risk factors for CVD among people with HIV (PWH). Purpose: Our objective was to systematically review the literature on one such candidate CVD risk factor in PWH-depression. Methods: A systematic literature search of PubMed, PsycINFO, EMBASE, Web of Science, and CINAHL was performed to identify published English-language studies examining associations of depression with clinical CVD, subclinical CVD, and biological mechanisms (immune activation, systemic inflammation, altered coagulation) among PWH between the earliest date and June 22, 2021. Results: Thirty-five articles were included. For clinical CVD (k = 8), findings suggests that depression is consistently associated with an increased risk of incident CVD. For subclinical CVD (k = 5), one longitudinal analysis reported a positive association, and four cross-sectional analyses reported null associations. For immune activation (k = 13), systemic inflammation (k = 17), and altered coagulation (k = 5), findings were mixed, and there was considerable heterogeneity in sample characteristics and methodological quality across studies. Conclusions: Depression may be an independent risk factor for CVD among PWH. Additional research is needed to confirm depression's association with clinical CVD and to determine whether depression is consistently and meaningfully associated with subclinical CVD and biological mechanisms of CVD in HIV. We propose a research agenda for this emerging area.
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    Exploring microplastic impact on whole blood clotting dynamics utilizing thromboelastography
    (Frontiers Media, 2023-07-13) Christodoulides, Alexei; Hall, Abigail; Alves, Nathan J.; Emergency Medicine, School of Medicine
    This study investigates the influence of microplastics on blood clotting. It addresses the lack of comprehensive research on the effects of microplastic size and surface modification on clotting dynamics in human whole blood. Thromboelastography was used to examine aminated (aPS), carboxylated (cPS), and non-functionalized (nPS) polystyrene particles with sizes of 50, 100, and 500  nm. Results show that cPS consistently activated the clotting cascade, demonstrating increased fibrin polymerization rates, and enhanced clot strength in a size and concentration-dependent manner. nPS had minimal effects on clotting dynamics except for 50  nm particles at the lowest concentration. The clotting effects of aPS (100  nm particles) resembled those of cPS but were diminished in the 500  nm aPS group. These findings emphasize the importance of microplastic surface modification, size, concentration, and surface area on in-vitro whole blood clotting dynamics.
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    Factor XIII Val34Leu polymorphism and recurrent myocardial infarction in patients with coronary artery disease
    (Springer, 2014-10) Kreutz, Rolf P.; Bitar, Abbas; Owens, Janelle; Desta, Zeruesenay; Breall, Jeffrey A.; von der Lohe, Elisabeth; Sinha, Anjan; Vatta, Matteo; Nystrom, Perry; Flockhart, David A.; Department of Medicine, IU School of Medicine
    Factor XIII (FXIII) is necessary for cross linking of fibrin strands and generation of stable fibrin clot. FXIII Val34Leu is a common genetic single nucleotide polymorphism that has been associated with accelerated fibrin stabilization and reduced rate of fibrinolysis. The contribution of Val34Leu to long term risk of recurrent myocardial infarction (MI) in patients with coronary stenting has not been conclusively established. The objective of the study was to examine the effects of Val34Leu on fibrin generation, platelet aggregation, and long term clinical outcomes in patients with coronary artery disease treated with dual antiplatelet therapy. Patients with angiographically documented coronary artery disease who were treated with aspirin and clopidogrel were enrolled (n = 211). Light transmittance aggregometry and plasma fibrin clot formation using thrombelastography (TEG) were determined. Genotyping of Val34Leu was performed using Taqman assay. Clinical events during follow up were recorded. Homozygous carriers of 34Leu variant had significantly shorter fibrin clot formation time as compared to wild type individuals (TEG K: 1.27 ± 0.3 vs. 1.68 ± 1.1 min, p = 0.011). The Val34Leu variant was associated with gene dose dependent increased risk of MI (log rank, p = 0.002) or occurrence of composite of MI and CV death (log rank, p = 0.005) with highest event rates observed in homozygous carriers of 34Leu. In summary, FXIII Val34Leu polymorphism was associated with increased rate of fibrin stabilization in homozygous carriers of the variant and may increase risk of recurrent MI and death in patients with angiographically established coronary artery disease treated with dual antiplatelet therapy.
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    Microplastic Effects on Thrombin-Fibrinogen Clotting Dynamics Measured via Turbidity and Thromboelastography
    (MDPI, 2022-12-13) Tran, Daniela Q.; Stelflug, Nathan; Hall, Abigail; Chakravarthula, Tanmaye Nallan; Alves, Nathan J.; Emergency Medicine, School of Medicine
    Micro/nanoplastics, whether manufactured or resulting from environmental degradation, can enter the body through ingestion, inhalation, or dermal pathways. Previous research has found that nanoplastics with diameters of ≤100 nm can translocate into the circulatory system in a dose-dependent manner and potentially impact thrombosis and hemostasis. To investigate the direct effects of microplastics on fibrin clot formation, a simplified ex vivo human thrombin/fibrinogen clot model was utilized. The 100 nm polystyrene particles (non-functionalized [nPS] and aminated [aPS]) were preincubated (0-200 µg/mL) with either thrombin or fibrinogen, and fibrin clot formation was characterized via turbidity and thromboelastography (TEG). When the particles were preincubated with fibrinogen, little effect was observed for aPS or nPS on turbidity or TEG up through 100 µg/mL. TEG results demonstrated a significant impact on clot formation rate and strength, in the case of nPS preincubated with thrombin exhibiting a significant dose-dependent inhibitory effect. In conclusion, the presence of microplastics can have inhibitory effects on fibrin clot formation that are dependent upon both particle surface charge and concentration. Negatively charged nPS exhibited the most significant impacts to clot strength, turbidity, and rate of fibrin formation when first incubated with thrombin, with its impact being greatly diminished when preincubated with fibrinogen in this simplified fibrin clot model.
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    Plasma and Whole Blood Clot Strength Measured by Thrombelastography in Patients Treated with Clopidogrel during Acute Coronary Syndromes
    (Elsevier, 2013) Lu, Deshun; Owens, Janelle; Kreutz, Rolf P.; Medicine, School of Medicine
    Introduction: Treatment with clopidogrel, a selective platelet P2Y12 receptor antagonist, reduces risk of recurrent ischemic events in patients with acute coronary syndrome (ACS), by limiting platelet aggregation and activation. Stable whole blood clot formation requires activation of platelets, generation of fibrin and final fibrin crosslinks. In this study we intended to compare plasma and whole blood thrombelastography (TEG) measurements in patients during ACS. Materials and methods: Whole blood and plasma samples from 32 patients with non-ST segment elevation myocardial infarction (NSTEMI) were collected after administration of clopidogrel. Whole blood and plasma fibrin clot strength (MA) were determined by TEG. Platelet aggregation was determined by light transmittance aggregometry (LTA) using adenosine 5'-diphosphate (ADP), thrombin receptor activation peptide (TRAP), or collagen as agonists. Fibrinogen and C-reactive protein (CRP) concentrations were measured by ELISA. Results: Heightened plasma fibrin clot strength was associated with increased platelet reactivity stimulated by ADP (ρ=0.536; p=0.002), TRAP (ρ=0.481; p=0.007), and collagen (ρ=0.538; p=0.01). In contrast to plasma fibrin MA, whole blood MA did not correlate with platelet aggregation. Platelet count was the primary contributor to the difference in thrombin induced whole blood MA and plasma fibrin MA. Increasing levels of CRP were associated with increased plasma fibrin clot strength and platelet reactivity. Conclusions: Our data suggest that inflammation is associated with increased plasma fibrin clot strength and lower platelet inhibition by clopidogrel during ACS. Platelet count is a main contributor to additional contractile force of whole blood TEG as compared to plasma TEG during treatment with clopidogrel.