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.

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.

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 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.

StarClose™ femoral arteriotomy closure device: an advance in arterial closure

Millions of femoral arterial punctures are performed annually worldwide for the diagnosis and treatment of cardiovascular disease. Traditionally, hemostasis following arterial sheath removal has employed compression techniques but more recently, a number of arteriotomy closure devices have become available, none of which have been shown to produce an outcome superior to the standard technique of compression. The authors investigated a novel device, which utilizes a nitinol clip that gathers the artery from the outside producing a purse-string-like seal, with very promising results. The authors feel that this device has great potential, may impact significantly on the closure of arteriotomy sites and may also find application in other aspects of procedural medicine.

[Association of hemostatic disorders in diabetic patients with methylenetetrahydrofolate reductase (C677T) and coagulation factors II (G20210A) and V (G1691A) gene polymorphism]

The purpose of the investigation was to study an association of hemostatic disorders in diabetic patients with methylenetetrahydrofolate reductase (MTHFR) (C677T) and coagulation factors II (G20210A) and V (G1691A) gene polymorphism. The investigators examined 90 patients with diabetic nephropathy complicating types 1 and 2 diabetes in 54 and 36 cases, respectively. A control group comprised 100 healthy individuals. A polymerase chain reaction was used to diagnose single-nucleotide substitution of C6777T in the MTHFR gene, a point mutation in the coagulation factor V (FV) gene, and a factor II (FII) G20210A gene mutation in the coagulation factor II (FII) gene. The parameters of platelet and coagulation hemostasis were analyzed. Gene mutations (C677T in the MTHFR gene, G1691A in the FV gene and G20210A in FII gene) are encountered in diabetic patients more frequently than those in healthy individuals. The mutations are associated with increased blood coagulation potential and platelet hyperactivation.

[Platelets haemostatic in patients with multiple myeloma]

Multiple myeloma (MM) is a type of disseminated cancer which derive plasma cells that are immune system cells in bone marrow and produce monoclonal protein. It represents approximately 1% of all cancers, but recent statistics indicate both increasing incidence and earlier age of onset. Haemostatic disorders are an important clinical problem in patients with MM. The most common disturbances symptoms are bleeding and deep-vein thrombosis can due to platelet dysfunction, inhibition of fibrin and increased clearance of coagulation factors connected with monoclonal protein presence. The aim of study is a presentation of disturbances haemostatic in patients with MM, which make up important clinical and diagnostic problems.

[Hyperhomocysteinemia and the disturbance of haemostasis--facts and mythes]

The elevated concentration of homocysteine--Hcys (hyperhomocysteinemia) has been correlated with different pathologists, such as cardiovascular diseases. In the article, the some pathways of homocysteine metabolism (i.e. remethylation to methionine, formation of homocysteine thiolactone, and its enzymatic hydrolysis) and the actions of homocysteine and its metabolite--cyclic thioester--homocysteine thiolactone (HTL) on complex process of haemostasis, which regulates the flowing properties of blood, are described. Possible interaction of Hcys and HTL with endothelial cells, blood platelets, plasmatic fibrinogen and other coagulation factors, as the important major components of haemostasis are also discussed. The modification of haemostatic proteins (N-homocysteinylated or S-homocysteinylated proteins) induced by Hcys or its thiolactone, seem to be the main reason of biotoxicity of homocysteine in the disturbance of haemostasis and cardiovascular diseases.

[Disturbances of primary hemostasis in patients with dilation cardiomyopathy]

We studied morphological characteristics of platelets and parameters of platelet aggregation in patients with dilation cardiomyopathy. Augmented aggregatory activity of platelets was found in 76% of patients. In blood of majority of patients we found circulating leukocyte-platelet aggregates. This evidenced for development of inflammatory process and could be related to disturbances of blood rheology. In 2 patients examined by virusological method we revealed presence of a virus inside platelets. This phenomenon might serve as one of possible pathological pathways of disease progression at the account of spread of viral infection along vascular bed during thrombus formation.

[Acquired platelet function disorders: pathogenesis, classification, frequency, diagnosis, clinical management]

Given the high consumption of pharmacological agents in western societies, it is not surprising at all that drugs represent the most common cause of acquired platelet dysfunction. While acetylsalicylic acid, clopigogrel and integrin alphaIIbbeta3 (GPIIb-IIIa) receptor antagonists are well-known as prototypes of antiplatelet drugs, other widely used agents including non-steroidal anti-inflammatory drugs, antibiotics, serotonin reuptake inhibitors, and volume expanders can also impair platelet function and cause or aggravate haemorrhages. Besides pharmacological agents, certain clinical conditions are often associated with qualitative platelet disorders and bleeding diathesis. Consequently, in contrast to inherited platelet disorders, acquired platelet function defects are much more frequent in clinical practice and deserve special attention. Their pathogenesis is widespread and heterogeneous with various, sometimes overlapping abnormalities. Moreover, acquired platelet dysfunctions can occur at any age and range in severity from mild to life-threatening haemorrhages. Due to their heterogeneity, acquired platelet function disorders will be classified and discussed according to the underlying clinical setting or disease.

Tissue factor and factor VIIa as therapeutic targets in disorders of hemostasis

For hemophilia patients with inhibitors against FVIII or FIX, the development of recombinant factor VIIa (rFVIIa) raises the possibility of a therapeutic alternative whose availability and convenience of treatment are comparable to those of FVIII or FIX. In support of this new concept for the treatment of bleeding episodes, pharmacological doses of FVIIa have been shown to induce hemostasis. Pharmacological doses of rFVIIa enhance thrombin generation on thrombin-activated platelets, thereby facilitating the formation of strong, well-structured fibrin plugs resistant to premature proteolysis. Modified rFVIIa molecules with a stronger hemostatic potential have been produced. Inhibition of the FVII-TF-dependent pathway (TFPI and rFVIIai) has been tried in attempts to prevent thrombosis, with promising results in animal models so far not confirmed in clinical trials.

[Hemostatic disorders in liver disease]

Hemorrhagic complications are common in patients with liver diseases and contribute to the morbidity and mortality associated to this condition. The liver plays a central role in the hemostatic process as here all clotting factors and their inhibitors are synthetized. Liver damage is commonly associated with variable impairment of hemostasis due to multiple causes: decreased synthesis of clotting and inhibitor factors, decreased clearance of activated factors, hyperfibrinolysis, accelerated intravascular coagulation, quantitative and qualitative platelet defects. Their clinical implications remain to be elucidated, so further studies addressing this issue are needed.

Levetiracetam and bleeding disorders

Six studies were conducted in healthy male volunteers to evaluate the effect of levetiracetam on bleeding time. In three open-label studies, a single dose of levetiracetam (250, 500, or 1000 mg, respectively) was administered 12 hours after acetylsalicylic acid (aspirin). Bleeding time increased by 3.5% to 30% relative to baseline, but the effect was not dose-related and not clinically relevant. In a fourth open-label study, levetiracetam was administered twice daily for 4 days, with aspirin administered with the penultimate dose of levetiracetam. The other two studies had a double-blind, placebo-controlled crossover design: levetiracetam or placebo was administered twice daily for 4.5 days and then aspirin was coadministered with the final dose. In the open-label multiple-dose study, the bleeding time increase was more pronounced after repeated levetiracetam doses and ingestion of aspirin than after a single 250-mg dose. However; no clinically relevant change in bleeding time or difference from placebo was observed in the double-blind, crossover studies. Except for two subjects in a crossover study, one of whom received placebo, no absolute bleeding time value was above the normal range of 4-8 minutes. These results indicate that levetiracetam does not produce clinically significant increases in bleeding time in healthy male volunteers. Further a review of clinical trials suggests that levetiracetam does not appear to cause clinically significant or relevant hematological adverse events suggestive of underlying hematological disorders.

[Hemostasis disorders in severe infections: State of the art]

The haemostatic system is greatly modified during severe infections. The early activation of coagulation is triggered by tissue factor expression and secondary fibrinolysis impaired by the upregulation of fibrinolysis inhibitors. This imbalance is a major cause of subsequent organ dysfunction. Natural anticoagulants (Tissue factor pathway inhibitor (TFPI), Antithrombin (AT), and Protein C (PC) are consumed or inhibited in this pathological process justifying a therapeutic supplementation with these inhibitors to improve sepsis-induced organ failure and mortality. No effect on the mortality rate could be documented in controlled studies using recombinant TFPI or AT concentrates but a biological interaction with heparin therapy could have biased the results. Treatment with recombinant activated PC was associated with a significant reduction in the mortality rate of severely ill patients. An increase in the rate of hemorrhagic adverse effects was observed with these compounds, justifying a strict observance of contraindications and of patient selection.

[Unusual haemostasis disorder in a seriously burned patient]

We report the case of a woman severely burned during a gas explosion with an unusual disorder of haemostasis. The prothrombin time was very elevated, essentially by a drop in factor II. This abnormality persisted for a long time after the correction of the dilutional and consumption coagulopathy which followed immediately the burn. Blood analysis found fluindione and benzodiazepine derivatives. Such a disorder during a potentially suicidal burn must evoke a toxic aetiology.

[Endotoxin aggression as a universal factor of pathogenesis of hemostatic disorders in children with urological pathology]

The role of the kidneys in development of endotoxin aggression and participation of the latter in impaired regulation of hemostasis was demonstrated basing on examination of 30 children with congenital urological pathology. In progressive decline of accumulative-excretory function of the kidneys, compensated chronic endotoxin aggression in children with urological diseases transforms into a subcompensated or uncompensated one with definite clinical manifestation: fever, aggravation of chronic pyelonephritis, marked DIC syndrome, macrohematuria.

[Endotoxin aggression in the development of hemostatic disorders in children with surgical diseases]

The role of endotoxin aggression in the development of hemostatic disorders was analyzed in 62 children who had undergone urgent and elective surgeries. It is demonstrated that indices of endotoxin-antiendotoxin system and hemostasis before surgery may be regarded as prognostic criteria for development of complications during and after surgery.

Snake envenomation in a north Indian hospital

OBJECTIVES

To study the clinical profile of snake envenomation in a tertiary referral north Indian hospital.

METHODS

Retrospective case note analysis of all cases of snakebite admitted to the medical emergency from January 1997 to December 2001.

RESULTS

Of a total of 142 cases of snakebite there were 86 elapid bites presenting with neuroparalytic symptoms and 52 viper bites having haemostatic abnormalities. Some 60.6% of the cases of snakebite occurred when the patient was asleep. Urban to rural ratio was 1:4.7 and male to female ratio was 4.25:1. Median time to arrival at our hospital after the bite was nine hours and mean duration of hospital stay was eight days. Twenty seven cases had acute renal failure and 75% of all elapid bites required assisted ventilation. Seventeen of 119 patients who received antivenom had an adverse event. The average dose of antivenom was 51.2 vials for elapid bites and 31 vials for viper bites. Overall mortality rate was 3.5%.

CONCLUSION

Snakebites are common in the rural population of developing countries. There is a need to educate the public about the hazards of snakebite, early hospital referral, and treatment.

[Hemostatic disturbances after aorto-femoral and femoro-popliteal bypasses in patients with lower limbs obliterating atherosclerosis]

Forty-seven men aged from 38 to 74 years with lower limb obliterating atherosclerosis (III-IV degree, indication for surgery) were examined. Growth of lipoperoxides level, a decrease of antioxidant potential, activation of hemostasis were revealed. These phenomena intensified after bypass surgeries and persisted till discharge. Supplement of standard therapy with antioxidant selmevit limited degree of disturbances before and after surgery, accelerated normalization of hemostasis.

Clinical studies on coronary revascularization in patients with type 2 diabetes

With the increasing prevalence, diabetes is rapidly growing into a global public health problem. Cardiovascular disease is a major consequence of this chronic condition, and a critical issue facing physicians worldwide today is choice of coronary revascularization procedures in treating these patients. Since the Bypass Angioplasty Revascularization Investigation (BARI) alert in 1995, there have been several reports on subgroup analysis of clinical trials and registries concerning revascularization among patients with diabetes. Although randomized control studies comparing percutaneous and surgical revascularization procedures in this high-risk group of patients are lacking, this article provides the background for the excess risk and reviews the findings of these investigations. Current strategies to improve outcomes in patients with diabetes undergoing coronary revascularization procedures are discussed.

Atherosclerotic and hemostatic abnormalities in patients undergoing hemodialysis

Vascular events caused by atherosclerosis are the major cause of death in patients undergoing hemodialysis (HD). The relationship between the tests of atherosclerosis and hemostasis in 84 patients with HD was examined. Abnormal test results indicting the occurrence of atherosclerosis were found in 66% by the Fontaine score, in 33% by ankle blood pressures, and in 79% by aortic calcification index (ACI). When HD was prolonged, the mean Fontaine score and ACI were further increased. Particularly, the ACI tended to correlate with HD duration. The ankle-brachial index (ABI) was decreased in patients with HD duration of more than 10 years. Before HD, the plasma levels of fibrinogen, plasmin-plasmin inhibitor complex (PIC), thrombomodulin (TM), and D-dimer were increased, while the plasma levels of protein C (PC), antithrombin (AT), thrombin-antithrombin complex (TAT), and tissue plasminogen activator (tPA)-plasminogen activator inhibitor-I (PAI-I) complex (tPA-PAI-1 complex) were decreased. With prolonged HD, the plasma levels of AT and PC were decreased, while those of D-dimer were increased. The plasma levels of TAT and TPA-PAI-1 complex were significantly increased and those of PIC, soluble fibrin (SF) and D-dimer tended to be high in patients with less than 0.7 of ABI. The plasma levels of D-dimer, TPA-PAI-1 complex, TAT, PIC, and SF tended to be high in patients with more than 0.5 in ABI. These findings suggest that patients undergoing HD have progressive atherosclerosis and that this is associated with some hemostatic abnormalities.

Aberrations in hemostasis and coagulation in untreated discordant hepatic xenotransplantation: studies in the dog-to-pig model

Discordant liver xenotransplantation is a poorly explored entity. Data from the few large animal studies of hepatic xenotransplantation suggest that severe hemorrhage is encountered. The purpose of the studies described here is to characterize the nature of the hemorrhage that accompanies liver xenotransplantation. Canine livers were transplanted into porcine recipients, and lethal hemorrhage was encountered. Analysis of recipient blood showed that factors V, IX, and X were present in adequate levels until after the hemorrhage appeared, suggesting that coagulation factor loss was the result and not the cause of hemorrhage. Platelet counts decreased dramatically in recipients within minutes of graft reperfusion. There also was no evidence of clotting activity in the blood of recipients of liver xenografts within minutes of graft reperfusion. This loss of clotting activity was specific to liver xenografts, was not seen in renal xenografts with or without venovenous bypass, and also was absent in pig-to-pig liver allografts. In brief, the hemorrhage that accompanies liver xenotransplantation occurs because of a decrease in the number and function of circulating platelets in the recipient.

Coagulopathy of acute promyelocytic leukemia

Life-threatening bleeding is frequent in acute leukemias, particularly in acute promyelocytic leukemia (APL), a distinct subtype of acute myelogenous leukemia, characterized by the balanced reciprocal translocation between chromosomes 15 and 17. Laboratory assessments show profound hemostatic imbalance compatible with the clinical picture of disseminated intravascular coagulation. Activation of the coagulation system, hyperfibrinolysis and nonspecific proteases activity can be observed in this condition. An important pathogenetic role is attributed to the leukemic cell properties for activating hemostatic mechanisms. This review will summarize what is currently known about the coagulopathy of APL, the principal pathogenetic mechanisms, and the therapeutic tools for the management of this complication. Special attention will be devoted to the new therapy with all-trans retinoic acid, which has completely changed the natural history of APL and APL-related coagulopathy.

[Pathogenesis of disturbances of the hemostatic system in neonates]

Described in the paper are chief pathogenetic mechanisms of development of disturbances in the hemostasis system in neonates born to mothers presenting with extragenital pathologies. Marked clotting changes were noted together with those in the system of the erythron. Recordable in the above infants were also vascular permeability disorders, abnormalities of metabolism. These changes were especially manifest in those children presenting with diabetic fetopathy and in babies born to mothers with neurocirculatory asthenia. The results secured permitted the development of the system of curative-and-prophylactic measures to be instituted in the above infants.

Relationship of fibrinogen levels and hemostatic abnormalities with organ damage in hypertension

Elevated plasma levels of fibrinogen and activated coagulation pathways are risk factors of cardiovascular disease in the general population. In a cross-sectional study of a case series, we investigated the relationship between fibrinogen and hemostatic markers with target-organ damage (TOD) in patients with arterial hypertension. Prothrombin time, partial thromboplastin time, fibrinogen, fibrin D-dimer, prothrombin fragment 1+2 (F1+2), and antithrombin III were measured in 352 untreated patients with mild to moderate essential hypertension and 92 normotensive controls. Staging of TOD was assessed according to W.H.O. guidelines by clinical evaluation and laboratory tests including measurements of creatinine clearance, proteinuria, ophthalmoscopy, electrocardiography, echocardiography, and ultrasound examination of major arteries. F1+2 concentrations were significantly greater in hypertensive patients than normotensive controls and were positively correlated with blood pressure. Age, blood pressure levels, duration of hypertension, smoking, HDL-cholesterol, triglycerides, and plasma fibrinogen, fibrin D-dimer, and F1+2 levels were significantly related to the presence and severity of TOD in univariate analysis. Plasma fibrinogen and D-dimer levels were related to organ damage independent of age, blood pressure, duration of hypertension, and smoking status. Separate analysis indicated significant association of fibrinogen and D-dimer levels with cardiac, cerebrovascular, peripheral vascular, and renal damage. In conclusion, elevated plasma levels of fibrinogen and a prothrombotic state are associated with the presence and severity of TOD in patients with essential hypertension and may contribute to the development of atherosclerotic disease in these patients.

Multiple hemostatic abnormalities in young adults with activated protein C resistance and cerebral ischemia

BACKGROUND

The relationship between activated protein C resistance (APCR) and arterial stroke is uncertain. It has been speculated that multiple inherited or acquired prothrombotic conditions may alter the hemostatic balance towards thrombotic events.

METHODS

Case series from a University medical center.

RESULTS

In a series of 28 Caucasian patients under age 55 with cerebral ischemic events, nine were found to have activated protein C resistance. Five of nine patients (56%) had additional hematologic abnormalities. Four patients had elevated anticardiolipin IgG antibodies. Other abnormalities identified included Type I protein S deficiency, sticky platelet syndrome, and a positive lupus anticoagulant.

CONCLUSIONS

Activated protein C resistance is relatively common in young adults with cerebral ischemic events and may be accompanied by other hematologic abnormalities. The constellation of hemostatic abnormalities may impact the type of and intensity of the antithrombotic regimen. There are also implications for family members of affected patients. Finding evidence of APCR should not preclude a complete hemostatic evaluation in the young stroke patient.