Generation of neutrophil extracellular traps in patients with acute liver failure is associated with poor outcome.

BACKGROUND AND AIMS: Acute liver failure (ALF) is characterized by significant changes in the hemostatic system and by systemic inflammation. The formation of neutrophil extracellular traps (NETs), in which an activated neutrophil expels its DNA, histones, and granular enzymes, such as myeloperoxidase (MPO), has been associated with immune-mediated and thrombotic diseases. We hypothesized that formation of NETs in patients with ALF contributes to progression of disease. APPROACH AND RESULTS: A total of 676 patients with ALF (international normalized ratio [INR], ≥1.5) or severe acute liver injury (ALI; INR, ≥2.0) were recruited from the U.S. ALF Study Group Registry between 2011 and 2018, of whom 308 patients (45.6%) had acetaminophen-induced ALF. Up to 21 days after admission, 483 patients (71.5%) survived without liver transplantation (LT). Levels of cell-free DNA (cfDNA) and the specific NET marker MPO-DNA complexes were measured in plasma samples obtained on admission and compared to levels in healthy controls. In addition, liver tissue obtained at transplantation of 20 ALF patients was stained for NETs. Levels of cfDNA were 7.1-fold, and MPO-DNA complexes 2.5-fold, higher in patients with ALF compared to healthy controls. cfDNA levels were not associated with 21-day transplant-free survival, but were higher in those patients with more-severe disease on admission, as reflected by various laboratory and clinical parameters. MPO-DNA levels were 30% higher in patients with ALF who died or required urgent LT. Liver tissue of ALF patients stained positive for NETs in 12 of 18 evaluable patients. CONCLUSIONS: Here, we provide evidence for NET formation in patients with ALF. Elevated plasma levels of MPO-DNA complexes in patients with ALF were associated with poor outcome, which suggests that NET formation contributes to disease progression.

Clinical screening for menorrhagia and other bleeding symptoms in Nigerian women.

Objective: The objective of the study was to evaluate the prevalence of perceived bleeding symptoms in Nigerian women and the usefulness of a simple clinical screening tool for bleeding symptoms. Materials and Methods: A population-based cross-sectional survey of 1524 women of 16-50 years in Southeast Nigeria using a structured, prevalidated, pretested questionnaire was conducted. Results: A total of 1524 (85%) women responded with the mean age of 26 (10.6) years. Prevalence of bleeding symptoms was 24.6% and 11% of the women reported a positive family history of bleeding symptoms. There was a significant association between having a positive family history of bleeding disorder and experiencing bleeding symptoms (adjusted odds ratio: 0.12, 95% confidence interval: 0.06-0.22 P < 0.0001). Two hundred and six women experienced at least one bleeding symptom, 125 (8.2%) experienced at least two, whereas 43 (2.8%) experienced >3 bleeding symptoms. The most common perceived bleeding symptom was heavy menstrual bleeding (HMB) present in 83 women (22.2%), 141 (9.3%) reported a past history of HMB, 202 (13.3%) had heavy bleeds during most of their monthly cycle, and 351 (23%) requiring resuscitation with blood support. Conclusion: The prevalence of perceived bleeding symptoms among women is high, and HMB is the most common bleeding symptom. This clinical screening tool is easy and cost-effective in routinely identifying women with bleeding symptoms needing further hemostatic and obstetrics evaluation.

RésuméObjectif: L'objectif de l'étude était d'évaluer la prévalence des symptômes hémorragiques perçus chez les femmes nigérianes et l'utilité d'un outil de dépistage clinique simple des symptômes hémorragiques. Matériel et méthodes: enquête transversale auprès de la population auprès de 1 524 femmes de 16 à 50 ans dans le sud-est du Nigéria à l'aide d'un questionnaire structuré, prévalidé et prétesté. Résultats: Un total de 1524 (85%) les femmes ont répondu avec l'âge moyen de 26 (10,6) ans. La prévalence des symptômes hémorragiques était de 24,6% et 11% des femmes ont signalé un antécédents familiaux positifs de symptômes hémorragiques. Il y avait une association significative entre avoir des antécédents familiaux de saignement positifs trouble et présentant des symptômes hémorragiques (rapport de cotes ajusté: 0,12, intervalle de confiance à 95%: 0,06­0,22 P <0,0001). Deux cent et six femmes ont présenté au moins un symptôme de saignement, 125 (8,2%) en ont eu au moins deux, tandis que 43 (2,8%) ont eu> 3 saignements symptômes. Le symptôme de saignement perçu le plus courant était le saignement menstruel abondant (HMB) présent chez 83 femmes (22,2%), 141 (9,3%) ont signalé des antécédents de HMB, 202 (13,3%) ont eu des saignements abondants pendant la majeure partie de leur cycle mensuel et 351 (23%) ont dû être réanimés avec support sanguin. Conclusion: la prévalence des symptômes hémorragiques perçus chez les femmes est élevée et le HMB est le plus courant symptôme de saignement. Cet outil de dépistage clinique est simple et économique pour identifier systématiquement les femmes présentant des symptômes hémorragiques nécessitant évaluation hémostatique et obstétrique plus poussée.

Rationale for the Role of Heparin and Related GAG Antithrombotics in COVID-19 Infection.

The SARS-CoV-2 pandemic has focused attention on prevention, restriction and treatment methods that are acceptable worldwide. This means that they should be simple and inexpensive. This review examines the possible role of glycosaminoglycan (GAG) antithrombotics in the treatment of COVID-19. The pathophysiology of this disease reveals a complex interplay between the hemostatic and immune systems that can be readily disrupted by SARS-CoV-2. Some of the GAG antithrombotics also possess immune-modulatory actions and since they are relatively inexpensive they could play an important role in the management of COVID-19 and its complications.

Device-Induced Hemostatic Disorders in Mechanically Assisted Circulation.

Mechanically assisted circulation (MAC) sustains the blood circulation in the body of a patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) or on ventricular assistance with a ventricular assist device (VAD) or on extracorporeal membrane oxygenation (ECMO) with a pump-oxygenator system. While MAC provides short-term (days to weeks) support and long-term (months to years) for the heart and/or lungs, the blood is inevitably exposed to non-physiological shear stress (NPSS) due to mechanical pumping action and in contact with artificial surfaces. NPSS is well known to cause blood damage and functional alterations of blood cells. In this review, we discussed shear-induced platelet adhesion, platelet aggregation, platelet receptor shedding, and platelet apoptosis, shear-induced acquired von Willebrand syndrome (AVWS), shear-induced hemolysis and microparticle formation during MAC. These alterations are associated with perioperative bleeding and thrombotic events, morbidity and mortality, and quality of life in MCS patients. Understanding the mechanism of shear-induce hemostatic disorders will help us develop low-shear-stress devices and select more effective treatments for better clinical outcomes.

Correlating Fibrinogen Consumption and Profiles of Inflammatory Molecules in Human Envenomation's by Bothrops atrox in the Brazilian Amazon.

Snakebites are considered a major public health problem worldwide. In the Amazon region of Brazil, the snake Bothrops atrox (B. atrox) is responsible for 90% of the bites. These bites may cause local and systemic signs from acute inflammatory reaction and hemostatic changes, and present common hemorrhagic disorders. These alterations occur due the action of hemostatically active and immunogenic toxins which are capable of triggering a wide range of hemostatic and inflammatory events. However, the crosstalk between coagulation disorders and inflammatory reaction still has gaps in snakebites. Thus, the goal of this study was to describe the relationship between the consumption of fibrinogen and the profile of inflammatory molecules (chemokines and cytokines) in evenomations by B. atrox snakebites. A prospective study was carried out with individuals who had suffered B. atrox snakebites and presented different levels of fibrinogen consumption (normal fibrinogen [NF] and hypofibrinogenemia [HF]). Seventeen patients with NF and 55 patients with HF were eligible for the study, in addition to 50 healthy controls (CG). The molecules CXCL-8, CCL-5, CXCL-9, CCL-2, CXCL-10, IL-6, TNF, IL-2, IL-10, IFN-γ, IL-4, and IL-17A were quantified in plasma using the CBA technique at three different times (pre-antivenom therapy [T0], 24 h [T1], and 48 h [T2] after antivenom therapy). The profile of the circulating inflammatory response is different between the groups studied, with HF patients having higher concentrations of CCL-5 and lower IFN-γ. In addition, antivenom therapy seems to have a positive effect, leading to a profile of circulating inflammatory response similar in quantification of T1 and T2 on both groups. Furthermore, these results suggest that a number of interactions of CXCL-8, CXCL-9, CCL-2, IL-6, and IFN-γ in HF patients are directly affected by fibrinogen levels, which may be related to the inflammatory response and coagulation mutual relationship induced by B. atrox venom. The present study is the first report on inflammation-coagulation crosstalk involving snakebite patients and supports the better understanding of envenomation's pathophysiology mechanisms and guides in the search for novel biomarkers and prospective therapies.

Bothrops snakebites in the Amazon: recovery from hemostatic disorders after Brazilian antivenom therapy.

Introduction:Bothrops atrox snakebites are a major public health problem in the Amazon region and also cause hemostatic disorders. In this study, we assessed the recovery from hemostatic disorders in Bothrops snakebite patients after being given antivenom therapy.Methods: This is a prospective study of Bothrops snakebite patients (n = 100) treated at the Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazilian Amazon, between January 2016 and December 2017. Blood samples were taken for the measurement of venom concentrations, platelets, clotting time and factors of patients on admission, 12, 24 and 48 h after antivenom therapy, and taken again on discharge. The presence of systemic bleeding was recorded during the follow-up.Results: On admission, systemic bleeding was observed in 14% of the patients. Thrombocytopenia was noted in 10% of the patients. A total of 54% of the patients presented unclottable blood with low levels of fibrinogen and alpha 2-antiplasmin, and high levels of fibrin/fibrinogen degradation product (FDP) and D-dimers. Unclottable blood and systemic bleeding were overcome in most patients 12 h after the antivenom therapy. Three patients developed systemic bleeding 48 h after antivenom therapy. Levels of fibrinogen and alpha 2-antiplasmin, FDP and D-dimer returned to normal around 48 h after the treatment or on discharge. The frequency of thrombocytopenia with high mean platelet volume increased in the first 24 h after antivenom therapy, and decreased on discharge. Bothrops venom levels in patients decreased 12 h after antivenom therapy and were not correlated with coagulation and fibrinolytic parameters. There were no deaths.Conclusion: Laboratorial parameters of coagulopathy returned to normal values within 48 h after the antivenom therapy until discharge. A few patients still presented bleeding signs within 48 h after beginning antivenom therapy. However, the Brazilian antivenom was able to overcome the hemostatic disorders in these cases of envenomation.

The impact of shear stress on device-induced platelet hemostatic dysfunction relevant to thrombosis and bleeding in mechanically assisted circulation.

The aim of this study was to examine the impact of the nonphysiological shear stress (NPSS) on platelet hemostatic function relevant to thrombosis and bleeding in mechanically assisted circulation. Fresh human blood was circulated for four hours in in vitro circulatory flow loops with a CentriMag blood pump operated under a flow rate of 4.5 L/min against three pressure heads (70 mm Hg, 150 mm Hg, and 350 mm Hg) at 2100, 2800, and 4000 rpm, respectively. Hourly blood samples from the CentriMag pump-assisted circulation loops were collected and analyzed for glycoprotein (GP) IIb/IIIa activation and receptor shedding of GPVI and GPIbα on the platelet surface with flow cytometry. Adhesion of platelets to fibrinogen, collagen, and von Willebrand factor (VWF) of the collected blood samples was quantified with fluorescent microscopy. In parallel, mechanical shear stress fields within the CentriMag pump operated under the three conditions were assessed by computational fluid dynamics (CFD) analysis. The experimental results showed that levels of platelet GPIIb/IIIa activation and platelet receptor shedding (GPVI and GPIbα) in the blood increased with increasing the circulation time. The levels of platelet activation and loss of platelet receptors GPVI and GPIbα were consistently higher with higher pressure heads at each increasing hour in the CentriMag pump-assisted circulation. The platelet adhesion on fibrinogen increased with increasing the circulation time for all three CentriMag operating conditions and was correlated well with the level of platelet activation. In contrast, the platelet adhesion on collagen and VWF decreased with increasing the circulation time under all the three conditions and was correlated well with the loss of the receptors GPVI and GPIbα on the platelet surface, respectively. The CFD results showed that levels of shear stresses inside the CentriMag pump under all three operating conditions exceeded the maximum level of shear stress in the normal physiological circulation and were strongly dependent on the pump operating condition. The level of platelet activation and loss of key platelet adhesion receptors (GPVI and GPIbα) were correlated with the level of NPSS generated by the CentriMag pump, respectively. In summary, the level of NPSS associated with pump operating condition is a critical determinant of platelet dysfunction in mechanically assisted circulation.

Thrombocytopenia: the most frequent haemostatic disorder in the ICU.

Thrombocytopenia is the most common haemostatic disorder in patients admitted to Intensive Care Units (ICUs). The mechanisms contributing to a decrease in the platelet count in critically ill patients are multifactorial, among which sepsis and trauma are the most frequent. A differential diagnosis of profound thrombocytopenia is crucial for effective treatment. A low platelet count is a strong independent predictor of morbidity and mortality because it is associated with life-threatening bleeding or thrombosis. This article aims to outline the definition and pathophysiology of thrombocytopenia and present a three-step algorithm of the clinical management of this haemostatic disorder.

Introduction: The Complexity and Challenge of Preventing, Treating, and Managing Blood Diseases in the Developing Countries.

Managing hematologic disorders in developing countries poses problems not encountered in Western societies. The clinical features of hematologic conditions may be modified by malnutrition, chronic bacterial infection, or parasitic illness. Iron deficiency is the major factor in anemia worldwide. Anemia is more common in the wet season when malaria transmission peaks. After anemia, eosinophilia is the next most common hematologic abnormality in children in the tropics. Infection with the human immunodeficiency virus can cause hematologic abnormalities. The pattern of distribution of primary disorders of the blood varies among populations and some disorders are unique to certain parts of the world.

Hemostatic Disorders in Hormonally Active Pituitary Tumors.

Endocrinopathies encompass heterogeneous diseases that can lead to hemostasis disorders at various stages over their clinical course. Normal hemostasis requires an equilibrium between the processes of coagulation and fibrinolysis, which depend on multiple activators and inhibitors. To date, the influence of various hormonal disorders on the hemostatic system has been assessed many times. The aim of this review was to analyze hemostasis abnormalities that occur in patients with hormonally active pituitary tumors: corticotropinoma, somatotropinoma, prolactinoma, gonadotropinoma and thyrotropinoma. Authors discuss studies that examined coagulation and hemostasis parameters among patients with these tumors, as well as analyze antithrombotic prophylaxis approach for endogenous hypercortisolemia subjects in particular.

Progress towards overcoming coagulopathy and hemostatic dysfunction associated with xenotransplantation.

Dysregulation of coagulation and disordered hemostasis are frequent complications in the pig-to-nonhuman primate preclinical xenotransplantation model. The most extreme manifestations are the systemic development of a life-threatening consumptive coagulopathy, characterized by thrombocytopenia and bleeding, which is balanced at the opposite extreme by local complications of graft loss due to thrombotic microangiopathy. The contributing mechanisms include inflammation, vascular injury, heightened innate, humoral and cellular immune responses, and molecular incompatibilities affecting the regulation of coagulation. There also appear to be organ-specific factors that have been linked to vascular heterogeneity. As examples, liver xenografts rapidly induce thrombocytopenia by sequestering human/primate platelets; renal xenografts cause a broader coagulopathy, linked in some cases to reactivation of porcine CMV, whereas cardiac xenografts often succumb to microvascular thrombosis without associated systemic coagulopathy but with local perturbations in fibrinolysis. Overcoming coagulation dysfunction will require a combination of genetic and pharmacological strategies. Deletion of the xenoantigen αGal, transgenic expression of human complement regulatory proteins, and refinement of immunosuppression to blunt the antibody response have all had some impact, without providing a complete solution. More recently, the addition of approaches specifically targeted at coagulation have produced promising results. As an example, heterotopic cardiac xenografts from donors expressing human thrombomodulin have survived for more than a year in immunosuppressed baboons, with no evidence of thrombotic microangiopathy or coagulopathy.

Hemostatic abnormalities in young females with heavy menstrual bleeding.

OBJECTIVE: To study the prevalence of hemostatic abnormalities, including bleeding disorders and risk factors, in young females referred to a multidisciplinary clinic for evaluation of heavy menstrual bleeding (HMB). METHODS: Retrospective chart review was undertaken for 131 post-menarchal girls with HMB, 7 to 17 years of age, enrolled in the institutional 'Menorrhagia Data Registry' protocol. The diagnostic approach included: (1) complete blood count, prothrombin time, partial thromboplastin time, fibrinogen, von Willebrand panel (2) platelet aggregometry, specific clotting factor assay, fibrinolytic pathway analysis, and factor XIII level as needed. The prevalence of hemostatic abnormalities and the prognostic significance of clinical variables associated with hemostatic abnormalities in young girls with HMB were evaluated. RESULTS: A hemostatic abnormality was identified in 69 (53%) young girls with HMB. Of these, 27 (21%) had an underlying bleeding disorder and 42 (32%) had a risk factor for bleeding, namely low von Willebrand factor activity. A larger number of girls with underlying bleeding disorder had personal history of other bleeding symptoms (48% vs 31%) and bleeding after surgical or dental procedure (25% vs 8%) when compared to females without hemostatic abnormality. Furthermore, girls with risk factor for bleeding (low vWF activity) were more likely to have bleeding after surgical or dental procedure (15% vs 8%) and family history of bleeding (79% vs 60%) than patients without hemostatic abnormality. CONCLUSIONS: There is high prevalence of hemostatic abnormalities, including bleeding disorders and risk factors, in young girls with HMB. These findings support comprehensive and systematic hemostatic evaluation in this group of patients.

Hemostatic dysfunction with acute fatty liver of pregnancy.

OBJECTIVE: To estimate the frequency of disseminated intravascular coagulation (DIC); elucidate the genesis of hemostatic dysfunction; and characterize associated hemolysis in women with acute fatty liver of pregnancy. METHODS: Hemostatic function was measured in 51 women. Disseminated intravascular coagulation was assessed using the International Society of Thrombosis and Haemostasis DIC score. Hepatic and hemostatic function was quantified with measurement of fibrinogen, fibrin-fibrinogen split products, cholesterol, and coagulation testing. As a comparison of fibrinogen synthesis, these women were compared with 25 women with placental abruption. Hemolysis was assessed indirectly by quantification of reticulocytosis and nucleated red blood cells with determination of erythrocyte morphotypes. RESULTS: Eighty-percent of women were classified as having unequivocal DIC (mean score 5.9±1.8) at delivery, which persisted 4-5 days postpartum. Fibrinogen regeneration with placental abruption was rapid, whereas it remained depressed for 4-5 days with acute fatty liver of pregnancy; fibrin-fibrinogen split products were also cleared more rapidly after abruption than women with acute fatty liver (P<.001 for interaction for both using random effects modeling). Kaplan-Meier survival analysis of fibrinogen recovery to a set point of 280 mg/dL after delivery was also different between the two cohorts (median 1.7 compared with 4.2 days, P=.046). Continuing hepatic dysfunction with acute fatty liver of pregnancy was exemplified by diminished procoagulant production. Reticulocytosis, nucleated red blood cells, and elevated serum bilirubin levels reflected ongoing hemolysis. CONCLUSIONS: Hemostatic dysfunction with acute fatty liver of pregnancy persists 4-5 days postpartum and results from substantive ongoing DIC in concert with reduced procoagulant synthesis and clinically significant hemolysis. LEVEL OF EVIDENCE: : III.

[Haemostatic abnormalities and thyroid disorders: the prospective observational MITH study]. / Alterazioni emostatiche e patologia tiroidea: lo studio prospettico osservazionale MITH.

Haemostatic abnormalities are a common phenomenon in patients with thyroid diseases. On one hand the condition of hyperthyroidism is associated with an increased risk of thrombotic events, on the other in severe hypothyroidism can be found a haemorrhagic tendency, as opposed to the subclinical hypothyroidism seems to correlate with increased thrombotic risk. The prospective, single center, observational MITH study (Mantua Investigation on Thyroid and Haemostasis), whose results are presented, aims to evaluate coagulation parameters in patients with thyroid disease, to establish the prevalence of haemostatic abnormalities in various conditions, to analyse the implications and clinical response to therapy established.

Hemostatic abnormalities in sickle cell disease.

PURPOSE OF REVIEW: Although it has long been recognized that sickle cell disease (SCD) and other hemoglobinopathies are associated with a state of chronic hyperactivation of coagulation, the study of the epidemiology of venous thromboembolic (VTE) complications in SCD is only now beginning to evolve. In parallel, mechanistic studies of the hypercoagulable state in humans and mouse models implicate an increasingly important causative role of hemolysis. RECENT FINDINGS: The case for SCD as a thrombophilic state has been strengthened by the recent literature. In an attempt to better understand the underlying mechanism(s), global assays of coagulation (thromboelastography and thrombin generation assays) have been utilized by several groups, but thus far, the results have been inconsistent, probably because of the technical differences. However, global assays continue to support the case for an important role of peripheral blood cells and their derived microparticles in promoting coagulation activation. SUMMARY: VTE is an underappreciated and potentially morbid complication of SCD. The mechanisms underlying this hypercoagulable state are complex. A greater understanding of these pathways may lead to the rational selection of therapies that not only prevent thrombosis, but also impact on many of the other vaso-occlusive complications of SCD.

Pleiotropic effects of PPARγ agonist on hemostatic activation in type 2 diabetes mellitus.

Thiazolidinediones (TZDs) represent a class of peroxisome proliferator-activated receptor (PPAR)γ agonists widely used as insulin-sensitizers in the treatment of type 2 diabetes mellitus (T2DM). The beneficial effects of hypoglycemic drugs, including TZDs, on the hemostatic abnormalities associated to T2DM have been formerly related to improved metabolic control, rather than to direct effects. However, in recent years the pleiotropic effects of PPARγ agonists on hemostatic function have become evident. In particular, the role of platelets as a pivotal player in diabetes complications by stimulating and sustaining inflammation has been lately acknowledged. Upon activation platelets synthesize and release many bioactive substances such as thromboxane A2 (TXA2) or pro-inflammatory mediators including CD40 ligand (CD40L) that exert autocrine and paracrine activation processes in vascular inflammation leading to cardiovascular disease (CVD). Although PPARγ is a nuclear hormone receptor, anucleate platelets also highly express this receptor and treatment with synthetic PPARγ ligands dampens the release of soluble(s)CD40L and TXA2 in thrombin-activated platelets. Moreover, PPARγ through Sirtuin1 pathway has been implicated in modulating inflammatory and atherosclerotic processes in patients with T2DM. Therefore, in T2DM, where platelet activation contributes to the pathogenesis of CVD, TZDs may have an enhanced therapeutic role, despite some potentially serious adverse side effects. This review will discuss the pleiotropic effects of PPARγ treatment on the hemostatic abnormalities associated with T2DM, with particular focus on platelet activation.

Coagulopathies in the PICU: DIC and liver disease.

Bleeding in patients in pediatric intensive care units is associated with an increased risk of mortality. Fortunately, most patients with an abnormal coagulation profile do not bleed because this is generally secondary to liver disease or dietary-induced vitamin K deficiency. When the laboratory markers of coagulopathy are the result of disseminated intravascular coagulation, bleeding is common and the risk of mortality extreme. Although interventions directed toward correcting the abnormal coagulation test results are generally initiated, they are also generally either not warranted or not fully successful.