Purification, and characterization of a new pro-coagulant protein from Iranian Echis carinatus venom

This work aimed to purify the proteins that cause blood coagulation in the venom of the Iranian Echis carinatus snake species in a comprehensive manner. Gel filtration chromatography (GFC), Ion exchange chromatography (IEC), and Size Exclusion High-Performance Liquid Chromatography (SEC-HPLC) were utilized in the purification of the coagulation factors. The prothrombin clotting time (PRCT) and SDS-PAGE electrophoresis were performed to confirm the coagulative fractions. The fraction with the shortest coagulation time was selected. The components of this designated fraction were identified through matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF) following thorough purification. Circular dichroism (CD) was employed to determine the second structure of the coagulation factor. The crude venom (CV) was analyzed and had a total protein concentration of 97%. Furthermore, the PRCT of the crude venom solution at a concentration of 1 mg/ml was determined to be 24.19 ± 1.05 s. The dosage administered was found to be a factor in the venom's capacity to induce hemolysis. According to CD analysis, the protein under investigation had a helical structure of 16.7%, a beta structure of 41%, and a turn structure of 9.8%. CHNS proved that the purified coagulant protein had a Carbon content of 77.82%, 5.66% Hydrogen, 3.19% Nitrogen, and 0.49% Sulphur. In the present investigation, a particular type of snake venom metalloproteinase (SVMP) has undergone the process of purification and characterization and has been designated as EC-124. This purified fraction shows significant efficacy as a procoagulant. Our findings have shown that this compound has a function similar to factor X and most likely it can cause blood coagulation by activating factor II (FII).

Kinetics and regulation of coagulation factor X activation by intrinsic tenase on phospholipid membranes

BACKGROUND

Factor X activation by the phospholipid-bound intrinsic tenase complex is a critical membrane-dependent reaction of blood coagulation. Its regulation mechanisms are unclear, and a number of questions regarding diffusional limitation, pathways of assembly and substrate delivery remain open.

METHODS

We develop and analyze here a detailed mechanism-driven computer model of intrinsic tenase on phospholipid surfaces. Three-dimensional reaction-diffusion-advection and stochastic simulations were used where appropriate.

RESULTS

Dynamics of the system was predominantly non-stationary under physiological conditions. In order to describe experimental data, we had to assume both membrane-dependent and solution-dependent delivery of the substrate. The former pathway dominated at low cofactor concentration, while the latter became important at low phospholipid concentration. Factor VIIIa-factor X complex formation was the major pathway of the complex assembly, and the model predicted high affinity for their lipid-dependent interaction. Although the model predicted formation of the diffusion-limited layer of substrate for some conditions, the effects of this limitation on the fXa production were small. Flow accelerated fXa production in a flow reactor model by bringing in fIXa and fVIIIa rather than fX.

CONCLUSIONS

This analysis suggests a concept of intrinsic tenase that is non-stationary, employs several pathways of substrate delivery depending on the conditions, and is not particularly limited by diffusion of the substrate.

Multimaterial decomposition in dual-energy CT for characterization of clots from acute ischemic stroke patients

BACKGROUND

Nowadays, there is no method to quantitatively characterize the material composition of acute ischemic stroke thrombi prior to intervention, but dual-energy CT (DE-CT) offers imaging-based multimaterial decomposition. We retrospectively investigated the material composition of thrombi ex vivo using DE-CT with histological analysis as a reference.

METHODS

Clots of 70 patients with acute ischemic stroke were extracted by mechanical thrombectomy and scanned ex vivo in formalin-filled tubes with DE-CT. Multimaterial decomposition in the three components, i.e., red blood cells (RBC), white blood cells (WBC), and fibrin/platelets (F/P), was performed and compared to histology (hematoxylin/eosin staining) as reference. Attenuation and effective Z values were assessed, and histological composition was compared to stroke etiology according to the Trial of ORG 10172 in Acute Stroke Treatment (TOAST) criteria.

RESULTS

Histological and imaging analysis showed the following correlation coefficients for RBC (r = 0.527, p < 0.001), WBC (r = 0.305, p = 0.020), and F/P (r = 0.525, p < 0.001). RBC-rich thrombi presented higher clot attenuation in Hounsfield units than F/P-rich thrombi (51 HU versus 42 HU, p < 0.01). In histological analysis, cardioembolic clots showed less RBC (40% versus 56%, p = 0.053) and more F/P (53% versus 36%, p = 0.024), similar to cryptogenic clots containing less RBC (34% versus 56%, p = 0.006) and more F/P (58% versus 36%, p = 0.003) than non-cardioembolic strokes. No difference was assessed for the mean WBC portions in all TOAST groups.

CONCLUSIONS

DE-CT has the potential to quantitatively characterize the material composition of ischemic stroke thrombi.

RELEVANCE STATEMENT

Using DE-CT, the composition of ischemic stroke thrombi can be determined. Knowledge of histological composition prior to intervention offers the opportunity to define personalized treatment strategies for each patient to accomplish faster recanalization and better clinical outcomes.

KEY POINTS

• Acute ischemic stroke clots present different recanalization success according to histological composition. • Currently, no method can determine clot composition prior to intervention. • DE-CT allows quantitative material decomposition of thrombi ex vivo in red blood cells, white blood cells, and fibrin/platelets. • Histological clot composition differs between stroke etiology. • Insights into the histological composition in situ offer personalized treatment strategies.

Association between De Ritis ratio and intraoperative blood transfusion in patients undergoing surgical clipping of unruptured intracranial aneurysms: a single center, retrospective, propensity score-matched study

BACKGROUND

Although elective surgery for unruptured intracranial aneurysms (UIA) has increased, few studies have evaluated the risk factors for transfusion during UIA surgery. We evaluated the association between the preoperative De Ritis ratio (aspartate transaminase/alanine transaminase) and the incidence of intraoperative transfusion in patients who had undergone surgical UIA clipping.

METHODS

Patients who underwent surgical clipping of UIA were stratified into two groups according to the preoperative De Ritis ratio cutoff levels (< 1.54 and ≥ 1.54), and the propensity score (PS)-matching analysis was performed to compare the incidence of intraoperative transfusion. Logistic regression analyses were performed to determine the risk factors for intraoperative transfusion. Net reclassification improvement (NRI) and integrated discrimination improvement (IDI) analyses were performed to verify the improvement in the intraoperative transfusion predictive model upon addition of the De Ritis ratio.

RESULTS

Intraoperative transfusion incidence was 15.4% (77/502). We observed significant differences in the incidence of intraoperative transfusion (16.2% vs. 39.7%, P = 0.004) between the groups after matching. In the logistic regression analyses, the De Ritis ratio ≥ 1.54 was an independent risk factor for transfusion (odds ratio [OR]: 3.04, 95% CI [1.53, 6.03], P = 0.002). Preoperative hemoglobin (Hb) value was a risk factor for transfusion (OR: 0.33, 95% CI [0.24, 0.47], P < 0.001). NRI and IDI analyses showed that the De Ritis ratio improved the intraoperative blood transfusion predictive models (P = 0.031 and P = 0.049, respectively).

CONCLUSIONS

De Ritis ratio maybe a significant risk factor for intraoperative transfusion in UIA surgery.

Acute and subacute effects of strenuous exercise on platelet aggregation, coagulation and fibrinolysis in patients with stable coronary artery disease

INTRODUCTION

Strenuous exercise may occasionally cause coronary thrombosis with myocardial infarction and sudden cardiac death.

MATERIALS AND METHODS

Patients with stable coronary artery disease (CAD) (n = 164) and healthy individuals (n = 25) performed strenuous exercise on a bicycle ergometer. Blood was drawn at baseline, immediately after exercise and 2 h later. Platelet aggregation was measured with Multiplate® Analyzer. Thrombin generation was determined using a thrombogram and by measuring prothrombin fragment 1 + 2 (F1 + 2). A clot lysis assay was used to investigate fibrinolysis.

RESULTS

From baseline to immediately after exercise, thrombin receptor activating peptide (TRAP)-induced platelet aggregation increased in CAD patients (Δ77 AU × min, 95 % confidence interval (CI): 46;107) and in healthy individuals (Δ153 AU × min, 95%CI: 75;232). Endogenous thrombin potential (ETP) was unaffected by exercise, whilst F1 + 2 increased (Δ17%, 95%CI: 11;24) in CAD patients. Fibrin clot lysis time increased by 9 % (95%CI: 1-17) in CAD patients and by 26 % (95%CI: 8;45) in healthy individuals. When comparing baseline to 2 h post-exercise, TRAP-induced platelet aggregation remained slightly elevated in both CAD patients (Δ53 AU × min, 95%CI: 22;84) and healthy individuals (Δ140 AU × min, 95%CI: 62;219). In contrast, ETP and F1 + 2 decreased in CAD patients (Δ-6 %, 95%CI: -10;-1 and Δ-8 %, 95%CI: -14;-2). Moreover, clot lysis time decreased (Δ-19 %, 95%CI: -27;-11) in patients with CAD and returned to baseline in healthy individuals. All p-values were <0.05.

CONCLUSIONS

Platelet aggregation and F1 + 2 were substantially elevated immediately after exercise in CAD patients, indicating a pro-thrombotic state. After 2 h of recovery, they exhibited a markedly increase in fibrinolysis. Similar results were observed in healthy individuals.

Effect of ultrafiltration on whole blood coagulation profile during cardiopulmonary bypass in cardiac surgery: a retrospective analysis

BACKGROUND

Ultrafiltration (UF) would enhance coagulation profiles by concentrating coagulation elements during cardiopulmonary bypass (CPB) for cardiac surgery.

METHODS

We retrospectively reviewed electronic medical records of 75 patients who had undergone cardiac surgery with rotational thromboelastometry-based coagulation management in a university hospital and analyzed the UF-induced changes in the maximum clot firmness (MCF) of extrinsically activated test with tissue factor (EXTEM) during CPB in 30 patients.

RESULTS

The median volume of filtered-free water was 1,350 ml, and median hematocrit was significantly increased from 22.5% to 25.5%. As the primary measure, UF significantly increased the median MCF-EXTEM from 48.0 mm to 50.5 mm (P = 0.015, effect size r = 0.44). The area under the receiver operating characteristic curve pre-UF MCF-EXTEM for discrimination of any increase of MCF-EXTEM after applying UF was 0.89 (95% CI [0.77, 1.00], P < 0.001), and its cut-off value was 50.5 mm (specificity of 81.8% and sensitivity of 84.2% in Youden's J statistic). In the secondary analyses using the cut-off value, UF significantly increased the median MCF-EXTEM from 40.5 mm to 42.5 mm in 18 patients with pre-UF MCF-EXTEM ≤ 50.5 mm. However, it did not increase MCF-EXTEM in 12 patients with pre-UF MCF-EXTEM > 50.5 mm. There was a significant interaction between pre-UF MCF-EXTEM values and applying UF (P < 0.001 for the subgroup, P = 0.046 for UF, P = 0.003 for interaction).

CONCLUSIONS

Applying UF improved clot firmness, and the improvement was more pronounced when pre-UF MCF-EXTEM had been reduced during CPB.

Variability of fibrinolytic activity in pregnant patients exposed to tissue plasminogen activator: an in vitro study utilizing rotational thromboelastometry

BACKGROUND

The investigation into the variability of fibrinolysis in obstetric patients is notably limited despite its relevance to postpartum hemorrhage. We investigate an in vitro model of fibrinolysis measured by rotational thromboelastrometry (ROTEM) in maternal blood samples with lysis stimulated by tissue plasminogen activator (tPA).

METHODS

Written informed consent was obtained from 19 patients at term pregnancy during admission to the labor and delivery unit. Patients who were taking medication affecting coagulation were excluded. Tissue plasminogen activator was added to whole blood samples to a final concentration of 100 or 220 ng/mL prior to ROTEM testing.

RESULTS

The addition of tPA produced high intra-individual fibrinolytic variability for clot firmness and lysis parameters. Patients responded differently to each tPA dose ranging from clot lysis within the range of 0 ng/mL tPA group to complete clot lysis. The coefficient of variation (CV) values for the 220 ng/mL tPA group were: EXTEM MCF 0.510, EXTEM LI30 1.601, FIBTEM MCF 0.349, FIBTEM LI30 2.097. CV values for the 100 ng/mL tPA group were: EXTEM MCF 0.144, EXTEM LI30 1.038, FIBTEM MCF 0.096, FIBTEM LI30 1.238.

CONCLUSION

We demonstrate a wide range of fibrinolytic response in the obstetric population to exogeneous tPA. We found subgroups of patients that were very responsive to tPA and insensitive to tPA. This study represents a preliminary exploration into classifying the obstetric fibrinolytic phenotypes. Further research will integrate relevant coagulation factors to establish a predictive model for testing susceptibility to lysis that can be applied at the point of care.

Increased blood coagulation is associated with poor neurological outcome in aneurysmal subarachnoid hemorrhage

BACKGROUND AND PURPOSE

Patients with aneurysmal subarachnoid hemorrhage (aSAH) have demonstrated increased blood coagulation which is thought to contribute to delayed cerebral ischemia (DCI) and to a worse outcome. Therefore, we sought to determine whether this increased blood coagulation, detectable with rotational thromboelastometry (ROTEM), was associated with DCI and neurological outcome.

METHODS

We conducted a prospective observational study of 60 consecutive adult aSAH patients. ROTEM's EXTEM and FIBTEM assays and D-dimer were analyzed at admission and post-bleed days (PBDs) 2-3, 4-5, 7-8, and 11-12. ROTEM's clot formation time (CFT) represents the stabilization of the clot, and the maximum clot firmness (MCF) the maximum clot strength. Glasgow Outcome Scale extended (GOSe) at three months determined the neurological outcome.

RESULTS

DCI incidence was 41.7%. EXTEM-CFT was significantly shorter in patients with unfavorable neurological outcome (GOSe 1-4) on PBDs 4-5 and 7-8, p < 0.05, respectively. FIBTEM-MCF was significantly higher in patients with unfavorable neurological outcomes on PBD 4-5 (p < 0.05), PBD 7-8 (p < 0.05), and PBD 11-12 (p < 0.05). EXTEM-CFT decreased, and FIBTEM-MCF rose during the study period in all patients. Patients with unfavorable neurological outcome had a higher D-dimer at all studied time points, p < 0.05. No difference was found in the ROTEM parameters or D-dimer when assessing patients with and without DCI.

CONCLUSIONS

Patients were in a state of increased blood coagulation after aSAH, with those with unfavorable neurological outcome being more coagulable than those with favorable outcome. However, increased blood coagulation was not associated with DCI.

CLINICALTRIALS

gov, NCT03985176.

The characterization and analysis of the compound hemostatic cotton based on Ca2+/poly (vinyl alcohol)/soluble starch-fish skin collagen

Accidental bleeding is an unavoidable problem in daily life. To avoid the risk of excessive blood loss, it is urgent to design a functional material that can quickly stop bleeding. In this study, an efficient wound dressing for hemostasis was investigated. Based on the characteristics that Ca2+ and fish skin collagen (FSC) could activate the coagulation mechanism, hemostatic cotton was prepared by solvent replacement method using CaCl2, FSC, soluble starch (SS), and polyvinyl alcohol (PVA) as raw materials. The cytotoxicity test showed the Ca2+PVA/FSC-SS hemostatic cottons had good biocompatibility. The activated partial thromboplastin time (APTT) of Ca2+PVA/FSC-SS(4) was 35.34 s, which was 22.07 s faster than that of PVA/FSC-SS, indicating Ca2+PVA/FSC-SS mediated the endogenous coagulation system. In vitro coagulation test, Ca2+PVA/FSC-SS(4) could stop bleeding rapidly within 39.60 ± 5.16 s, and the ability of wound healing was higher than commercial product (Celox). This study developed a rapid procoagulant and hemostatic material, which had a promising application in a variety of environments.

Clinical disease activity is a major determinant of plasma D-dimer elevation in outpatients with rheumatoid arthritis: A hospital-based cross-sectional study

OBJECTIVES

To identify factors associated with plasma D-dimer levels in outpatients with rheumatoid arthritis (RA).

METHODS

We consecutively recruited 460 RA patients who visited our hospital for routine follow-ups between June and October 2021. Plasma D-dimer, RA-related characteristics, comorbidities, and cardiovascular and venous thromboembolism (VTE) risk factors were examined at enrolment. Patients with elevated D-dimer levels underwent whole-leg venous ultrasonography to diagnose deep vein thrombosis (DVT).

RESULTS

Participants had no DVT signs or symptoms. Among them, 252 (54.8%) were positive for plasma D-dimer (≥0.5 μg/ml) and 40 (8.7%) had high D-dimer levels (≥3 μg/ml). The mean was 1.07 μg/ml. After adjustments, age [odds ratio (OR) 1.88 per additional 10 years, P = .003], high and moderate clinical disease activity index (OR 8.79, P < .001), and the presence of comorbidities or cardiovascular/VTE risk factors (OR 2.94, P = .017) were identified as the factors independently associated with high D-dimer levels. Among patients with D-dimer levels ≥3 μg/ml, 10 (25%) had DVT in their lower limbs, and D-dimer levels were significantly higher in patients with DVT compared with those without it (mean 6.0  vs. 4.1 μg/ml, P < .001).

CONCLUSIONS

Clinical disease activity is a major contributor to plasma D-dimer elevation in RA outpatients.

The mechanism of blood coagulation induced by sodium dehydroacetate via the regulation of the mTOR/ERK pathway in rats

Sodium dehydroacetate (DHA-S), a potent antifungal and antibacterial agent, is widely used in food, feed and cosmetics. However, recent studies have shown that DHA-S could pose a risk for human and animal health. We had previously reported that DHA-S could cause coagulation disorders in rats and chicken. In the present study, we further confirmed that DHA-S induced blood coagulation via VKORC1 and VKORC1L1 in rats, and elucidated the role played by mTOR/ERK signaling. The in vivo studies demonstrated that PT, APTT, and DHA-S content and relative protein expressions in tissues rebounded after drug withdrawal. In BRL-3A cells, 1.0 mM DHA-S increased the expression levels of mTOR, p-mTOR and p-ERK and decreased the levels of VKORC1, VKORC1L1 and Vitamin K. Rapamycin significantly decreased the expression levels of p-mTOR and p-ERK, while FR180204 (p-ERK Inhibition) lead to a decrease in p-ERK level. Rapamycin and FR180202 attenuated the inhibitory effect of DHA-S on VKORC1, VKORC1L1 and vitamin K levels. In addition, DHA-S increased the expression levels of mTOR, p-mTOR and p-ERK in male and female rat livers and prolonged PT and APTT. In summary, this study indicated that DHA-S induced blood coagulation via the modulation of the mTOR/ERK pathway in rats.

The effect of factor XIa on thrombin and plasmin generation, clot formation, lysis and density in coagulation factors deficiencies

INTRODUCTION

Growing evidence supports the importance of factor (F) XI activation for thrombosis and hemostasis as well as inflammation and complement systems. In this study, we evaluated the effect of activated FXI (FXIa) on the detection of factor deficiencies by global hemostasis assays of thrombin generation (TG), plasmin generation (PG), and clot formation and lysis (CFL).

MATERIALS AND METHODS

An absorbance and fluorescence microplate assay was used to simultaneously observe TG, PG, and CFL in FV-, FVII-, FVIII-, and FIX-deficient plasmas supplemented with purified factors. Coagulation was initiated with tissue factor with or without FXIa in the presence of tissue plasminogen activator. Thrombin and plasmin peak heights (TPH and PPH), maximal clot density (MCD), times to clotting (CT), thrombin and plasmin peaks (TPT and PPT) and clot lysis (LyT) and a new parameter, clot lifetime (LiT), were evaluated.

RESULTS

TG/CFL were elevated by the FXIa at low FV (below 0.1 IU/mL), and at FVIII and FIX above 0.01 IU/mL. FXIa affected PG only at low FV and FVII. At high factor concentrations, FXIa reduced MCD. Thrombin and plasmin substrates had effect on CT, LyT, LiT and MCD parameters.

CONCLUSIONS

FXIa reveals new relationships between TG, PG and CFL parameters in factor deficiencies suggesting potential benefits for discrimination of bleeding phenotypes.

Immunothrombosis and its underlying biological mechanisms

The evolutionary conserved link between coagulation and innate immunity is a biological process characterized by the thrombosis formation stimulus of immune cells and specific thrombosis-related molecules. In physiological settings, the relationship between the immune system and thrombosis facilitates the recognition of pathogens and damaged cells and inhibits pathogen proliferation. However, when deregulated, the interplay between hemostasis and innate immunity becomes a pathological process named immunothrombosis, which is at the basis of several infectious and inflammation-related thrombotic disorders, including coronavirus disease 2019 (COVID-19). In advanced stages, alterations in both coagulation and immune cell function due to extreme inflammation lead to an increase in blood coagulability, with high rates of thrombosis and mortality. Therefore, understanding underlying mechanisms in immunothrombosis has become decisive for the development of more efficient therapies to treat and prevent thrombosis in COVID-19 and in other thrombotic disorders. In this review, we outline the existing knowledge on the molecular and cellular processes involved in immunothrombosis, focusing on the role of neutrophil extracellular traps (NETs), platelets and the coagulation pathway. We also describe how the deregulation of hemostasis is associated with pathological conditions and can significantly aggravate a patient's condition, using COVID-19 as a clinical model.

[Comparison of coagulation function between adrenocorticotropic hormone independent Cushing syndrome and nonfunctional adrenal adenoma and its influence factors]

OBJECTIVE

To investigate the coagulation function indicators and identify influence factors of hypercoagulability in patients with adrenocorticotropic hormone (ACTH) independent Cushing syndrome (CS).

METHODS

In our retrospective study, the electronic medical records system of Peking University First Hospital was searched for the patients diagnosed with ACTH independent CS on discharge from January 2014 to June 2019. Nonfunctional adrenal adenoma patients were chosen as control group and matched 1 ∶1 by body mass index (BMI), gender, and discharge date. Clinical features and coagulation function indicators were compared between the two groups.

RESULTS

In the study, 171 patients were included in each group. Compared with control group, activated partial thromboplastin time (APTT), and prothrombin time (PT) in ACTH independent CS group were significantly lower [(29.22±3.39) s vs. (31.86±3.63) s, P < 0.001; (29.22±3.39) s vs. (31.86±3.63) s, P < 0.001], and both D-dimer and fibrin degradation products (FDP) levels were significantly higher (P < 0.05). Percentage of APTT levels under the lower limit of reference range in the CS patients was significantly higher than that in nonfunctional group (21.6% vs. 3.5%, P < 0.001). Percentage of D-dimer levels over the upper limit of reference range in the CS patients was significantly higher than that in nonfunctional group (13.5% vs. 6.6%, P=0.041). There were three patients with deep venous thrombosis and one patient with pulmonary embolism in CS group, however none was in control group. The area under curve (AUC) of serum cortisol rhythm (8:00, 16:00 and 24:00) levels was negatively associated with the levels of PT (r=-0.315, P < 0.001) and APTT (r=-0.410, P < 0.001), and positively associated with FDP (r=0.303, P < 0.001) and D-dimer levels (r=0.258, P < 0.001). There were no differences in coagulation function indicators among different histopathologic subgroups (adrenocortical adenoma, adrenocortical hyperplasia, oncocytic adenoma, adrenocortical carcinoma). With Logistic regression analysis, the AUC of cortisol and glycosylated hemoglobin A1c (HbA1c) levels were independent risk factors for hypercoagulability in the ACTH independent CS patients (P < 0.05).

CONCLUSION

ACTH independent CS patients were more likely in hypercoagulable state compared with nonfunctional adrenal adenoma, especially in ACTH independent CS patients with higher levels of cortisol AUC and HbA1c. These patients should be paid attention to for the hypercoagulability and thrombosis risk.

Foldable low-cost point-of-care device for testing blood coagulation using smartphones

Cardiovascular diseases (CVDs) caused by thrombotic events are a significant global health concern, affecting millions of people worldwide. The international normalized ratio (INR) is the most widely used measure of coagulation status, and frequent testing is required to adjust blood-thinning drug dosage, requiring hospital visits and experts to perform the test. Here we present a low-cost and portable smartphone-based device for screening INR levels from whole blood samples at the point of care. Our device uses a 3D printed platform and light-emitting diode backlight modules to create a uniform optical environment, and its foldable design allows for easy transport. Our device also features an algorithm that allows users to acquire and process video of sample flow in a microfluidic channel on their smartphone, providing a cost-effective and convenient option for blood coagulation monitoring at the point of care. We tested the performance of our smartphone-based INR device using both commercially available control samples and clinical human blood samples, demonstrating high accuracy and reliability. Our device has the potential to improve patient outcomes by enabling more frequent monitoring and, as appropriate, dosage adjustments of blood-thinning drugs, providing an affordable and portable option for screening INR levels at the point of care.

A journey to vasculopathy in systemic sclerosis: focus on haemostasis and thrombosis

Systemic sclerosis is a multisystem connective tissue disease, characterized by endothelial autoimmune activation, along with tissue and vascular fibrosis leading to vasculopathy and to a progressive loss of angiogenesis. This condition further deranges the endothelial barrier favouring the opening of the endothelial junctions allowing the vascular leak in the surrounding tissues: this process may induce cell detachment which allows the contact between platelets and collagen present in the exposed subendothelial layer. Platelets first adhere to collagen via glycoprotein VI and then, immediately aggregate because of the release of von Willebrand factor which is a strong activator of platelet aggregation. Activated platelets exert their procoagulant activity, exposing on their membrane phospholipids and phosphatidylserine, enabling the adsorption of clotting factors ready to form thrombin which in turn drives the amplification of the coagulative cascade. An essential role in the activation of blood coagulation is the tissue factor (TF), which triggers blood coagulation. The TF is found abundantly in the subendothelial collagen and is also expressed by fibroblasts providing a haemostatic covering layer ready to activate coagulation when the endothelial injury occurs. The aim of this review is to focus the attention on the underlying mechanisms related to haemostasis and thrombosis pathophysiology which may have a relevant role in SSc as well as on a possible role of anticoagulation in this disease.

Amniotic fluid pulmonary embolism and COVID-19: Case report

Amniotic fluid embolism is a rare complication of peripartum. It is caused by the entry of fetal components into the maternal systemic circulation. There are 2 main types: typical; it presents with the triad of hemodynamic collapse, respiratory distress and disseminated intravascular coagulation type coagulopathy, while atypical; disseminated intravascular coagulation does not occur. SARS CoV-2 infection causes coagulopathy due to the alteration of Virchow's triad and coagulation factors. We present the case of a 21-year-old pregnant woman who consulted for premature rupture of membranes, with an indication for cesarean section, and during surgery presented bradycardia, hypotension, and desaturation until cardiorespiratory arrest. An angiotomography showed amniotic fluid embolism associated with pulmonary edema, ruling out differential diagnoses associated with the disease, leaving as the only cause of the infection confirmed by COVID-19, which, it was inferred, was closely related to the immunological disorder suffered by the patient.

Autoimmune Hemolytic Anemia following Septic Shock with Escherichia Coli; a Case Report

Sepsis is a severe, life-threatening illness caused when the immune system responds inappropriately to infections, causing organ deterioration and negatively affecting the systems inside the body, one of which is the coagulation system. Most hematologic changes in red blood cells (RBCs) are non-antibody-mediated hemolytic anemia (NAHA). Autoimmune hemolytic anemia (AIHA) is a rare condition, challenging in diagnosis, requiring prompt recognition and management. Warm hemolytic anemia has recently been reported in patients with septic shock. This report presents a sepsis-induced autoimmune hemolytic anemia case. A 44-year-old Vietnamese female with no chronic disease came to the emergency department because of sudden periumbilical colicky pain after consuming a fresh garden salad. The abdominal pain appeared nine hours after the meal, following vomiting. Twelve hours later, she developed diarrhea, subsequently a fever, and chills. She was admitted to the emergency department in the fifteenth hour of the first symptom. Septic shock, multiple organ failure, and warm autoimmune hemolysis were all present in the patient. Hemolytic anemia and multiorgan failure made the situation worse, leading to death. Autoimmunity hemolytic anemia in sepsis or septic shock is rare, but treating both emergency hemolytic anemia and potential infectious etiology is crucial in acute situations.

Effect of restrictive fluid resuscitation on the coagulation function and hemodynamic parameters in patients with hemorrhagic traumatic shock

OBJECTIVES

To investigate the changes in the coagulation function and hemodynamic parameters in patients with Hemorrhagic Traumatic Shock (HTS) after restrictive fluid resuscitation.

METHODS

A total of 139 patients with HTS admitted to our hospital were enrolled, among which 69 HTS patients were divided into the control group and the remaining 70 HTS patients as the observation group. Patients in the control group underwent regular fluid resuscitation, while those in the observation group underwent restrictive fluid resuscitation.

RESULTS

During treatment, 70 patients in the observation group had a lower bleeding amount, infusion amount, and blood transfusion volume than those in the control group (p < 0.05). After treatment, patients in the observation group had better hemodynamic parameters and blood coagulation than those in the control group (p < 0.05), and the incidence rate in the observation group was only 12.9%, which was significantly lower than 60.87% in the control group, while the cure rate in the observation group was 100%, which was significantly higher than that in the control group (p < 0.05).

CONCLUSIONS

Restrictive fluid resuscitation could remarkably increase the cure rate and reduce the bleeding amount during HTS treatment, thereby benefiting the recovery of the patient's blood coagulation.

2-Carba cyclic phosphatidic acid regulates blood coagulation and fibrinolysis system for repair after brain injury

Effective blood coagulation prevents inflammation and neuronal loss after brain injury. 2-Carba-cyclic phosphatidic acid (2ccPA), a biotherapeutic for brain injury, inhibits blood extravasation resulting from blood-brain barrier breakdown. However, the hemostasis mechanism of 2ccPA remains unclear. We determined the effects of 2ccPA-injection on blood coagulation and fibrinolysis using a needle-induced brain injury model. 2ccPA suppressed the expression of platelet degranulation-related genes. Immediately after brain injury, 2ccPA increased CD41+ platelet aggregation around the lesions and promoted fibrin aggregation. Additionally, 2ccPA supported fibrinolysis by upregulating plasminogen activator expression. These results suggest the acute effects of 2ccPA on brain hemostasis.

Nonacog Alfa for Prophylaxis and Treatment of Bleeding Episodes in Previously Treated Patients with Moderately Severe or Severe Hemophilia B in India

Purpose

Hemophilia B is an X-linked congenital bleeding disorder caused by a deficiency of coagulation factor IX (FIX) clotting activity. This study evaluated safety and efficacy of nonacog alfa, a recombinant human blood coagulation FIX replacement product, in males aged 12-65 years with hemophilia B (FIX activity ≤ 2%) with or without inhibitors in India.

Methods

In this multicenter, open-label, post-approval phase 4 study, participants were treated for up to 8 weeks, with up to a 4-week screening period and a subsequent post-treatment 28-day safety observation period. Intravenous nonacog alfa 40 IU/kg (range 13-78 IU/kg) was administered at intervals of 3-4 days, in accordance with the approved local product document.

Results

A total of 25 participants were enrolled and completed the study. No participants developed FIX inhibitors during the study, experienced treatment-related adverse events (AEs) or serious AEs, or developed a thrombotic event and/or hypersensitivity reaction. No participants experienced bleeding events requiring on-demand treatment with nonacog alfa. Seventeen bleeding episodes (16 spontaneous and 1 traumatic) were reported in 10 participants; all occurred post treatment, with the exception of a minor gum-bleeding event, and were managed without treatment. The mean (SD) annualized total factor consumption (TFC) per patient was 224,582 (75,527) IU; the mean (SD) annualized TFC by weight per patient was 3639 (573) IU/kg.

Conclusion

Nonacog alfa was safe and effective for the prevention of hemorrhagic episodes in Indian males with congenital, severe hemophilia B. No participants developed FIX inhibitors, and no new safety signals were reported.

Incident CHD and ischemic stroke associated with lipoprotein(a) by levels of Factor VIII and inflammation

BACKGROUND

Inflammation and coagulation may contribute to the increased risk for atherosclerotic cardiovascular disease (ASCVD) associated with high lipoprotein(a). The association of lipoprotein(a) with ASCVD is stronger in individuals with high versus low high-sensitivity C-reactive protein (hs-CRP), a marker of inflammation.

OBJECTIVES

Determine the association of lipoprotein(a) with incident ASCVD by levels of coagulation Factor VIII controlling for hs-CRP.

METHODS

We analyzed data from 6,495 men and women 45 to 84 years of age in the Multi-Ethnic Study of Atherosclerosis (MESA) without prevalent ASCVD at baseline (2000-2002). Lipoprotein(a) mass concentration, Factor VIII coagulant activity, and hs-CRP were measured at baseline and categorized as high or low (≥75th or <75th percentile of the distribution). Participants were followed for incident coronary heart disease (CHD) and ischemic stroke through 2015.

RESULTS

Over a median follow-up of 13.9 years, there were 390 CHD and 247 ischemic stroke events. The hazard ratio (95%CI) for CHD associated with high lipoprotein(a) (≥40.1 versus <40.1 mg/dL) including adjustment for hs-CRP among participants with low and high Factor VIII was 1.07 (0.80-1.44) and 2.00 (1.33-3.01), respectively (p-value for interaction 0.016). The hazard ratio (95%CI) for CHD associated with high lipoprotein(a) including adjustment for Factor VIII was 1.16 (0.87-1.54) and 2.00 (1.29-3.09) among participants with low and high hs-CRP, respectively (p-value for interaction 0.042). Lp(a) was not associated with ischemic stroke regardless of Factor VIII or hs-CRP levels.

CONCLUSION

High lipoprotein(a) is a risk factor for CHD in adults with high levels of hemostatic or inflammatory markers.

Whole-exome sequencing reveals a novel frameshift mutation in a consanguineous family with a hereditary coagulation factor XII deficiency

BACKGROUND AND AIMS

We aimed to elucidate a hereditary mutation of coagulation factor XII (FXII) in a consanguineous Chinese family.

METHODS

Mutations were investigated using Sanger and whole-exome sequencing. FXII (FXII:C) activity and FXII antigen (FXII:Ag) were assessed using clotting assays and ELISA, respectively. Gene variants were annotated and the likelihood that amino acid mutations would affect protein function was predicted using bioinformatics.

RESULTS

Activated partial thromboplastin time was prolonged to >170 s (reference range, 22.3-32.5 s), and FXII:C and FXII:Ag were decreased to 0.3% and 1%, respectively, (normal range for both, 72%-150%) in the proband. Sequencing revealed a homozygous frameshift mutation c.150delC (p.Phe51Serfs*44) site in the F12 gene exon 3. This mutation results in premature termination of the encoded protein translation and the protein is truncated. Bioinformatic findings indicated a novel pathogenic frameshift mutation.

CONCLUSION

The c.150delC frameshift mutation p.Phe51Serfs*44 in the F12 gene likely explains the low FXII level and the molecular pathogenesis of an inherited FXII deficiency in a consanguineous family.

Comparing two techniques of performing an epidural catheter-assisted epidural blood patch using a 20 ml syringe versus a 5 ml syringe and its effect on clotting time, the strength of clot retraction and haemolysis - A prospective in vitro study (EC-EBP study)

Background and Aims

Epidural blood patch (EBP) is performed by injecting autologous blood into the epidural space using a Tuohy needle. Certain clinical scenarios mandate an epidural catheter (EC)-assisted EBP. Collecting blood in a 20-ml versus 5-ml syringe appears to influence the quality of the clot. This in vitro study compared the techniques of performing the EC-assisted EBP using 20-ml versus 5-ml syringe on clotting time (CT), clot retraction (CR) and haemolysis.

Methods

This in vitro study was performed in a haematology laboratory. Five consented adult healthy male volunteers donated blood. In the 5-ml syringe technique, blood was injected through an EC, and as it flowed out of the tip, it was collected at the beginning and the end of 1 min. With the 20-ml technique, blood was collected at the beginning and end of the first, second and third minute. The samples were tested for CT, CR and haemolysis by measuring the plasma-free haemoglobin (PFHb).

Results

Five injections were made using a 5-ml syringe, and another five with a 20-ml syringe. Injection time was shorter in the 5-ml technique (80.80 ± 5.89 vs. 272 ± 28.4 s, P < 0.0001). With the 20-ml technique, CT progressively increased (>15 min), whereas, with the 5-ml syringe, the CT was normal. Both techniques caused mild, insignificant haemolysis (PFHb >0.005 g/dl), without affecting the quality of CR.

Conclusion

EC-assisted EBP using a 5-ml syringe technique shortens the injection time and deposits fresh blood quickly without affecting CT and CR.

Survival analysis of coagulation disorders: A retrospective study with a 5-year follow-up

Objective

Rare bleeding disorders (RBDs) are the diseases in which patients experience a deficiency of coagulation factors. In the management of these disorders, surveillance is a significant challenge. This study aimed to assess the survival of patients with RBDs in a five-year follow-up.

Materials and methods

This descriptive cross-sectional study was conducted on 146 patients with RBDs who had referred to Be'sat Hospital of Hamadan, Iran from July 2017 to August 2022. A computerized record search was performed to identify the patients. The surveillance time for a five-year follow-up was assessed with the Kaplan-Meier curve. A log-rank test also served to compare the survival rates according to the type of factor.

Results

Out of 146 patients, 117 (80.2%) were males and 29 (19.8%) were females. They were in the range of 2-59 years of age with a mean of 23.11 ± 14.6. The most common disorder was FVIII deficiency (65.8%), and the rarest one was FXIII deficiency (4.8%). The rate of survival for any reason was 54.42 ± 1.3 months. The survival in combined FV and FVIII deficiencies was found to be longer than in the other deficiencies (55.9 ± 5.7), but there was no significant difference (P ≥ 0.05). In contrast, the survival in FXIII deficiency was observed to be lower than the other cases (44 ± 9.6); however, no significant difference was found in this regard (P ≥ 0.05).

Conclusion

The results of this study show that patients with RBDs have different rates of survival, which suggests that identifying high-risk patients may be helpful for the improvement of their survival time through timely therapeutic interventions.

Sonorheometry versus rotational thromboelastometry in trauma: a comparison of diagnostic and prognostic performance

BACKGROUND

Rotational thromboelastometry (ROTEM) is used to rapidly identify trauma-induced coagulopathy (TIC) and direct targeted interventions in hemorrhaging trauma patients. A novel technology, Quantra® System, utilizes sonic estimation of elasticity via resonance (SEER) sonorheometry, avoids mechanical clot interference and may increase diagnostic accuracy, but there is limited data in bleeding major trauma patients.

OBJECTIVES

To compare the performance of Quantra vs ROTEM for rapid diagnosis of TIC and prediction of transfusion requirements and mortality.

METHODS

Samples were collected from adult trauma patients enrolled into a perpetual cohort study upon admission to a single Level 1 trauma center between 2020-2021. Samples were analyzed using Quantra, ROTEM, multiple electrode aggregometry and conventional coagulation assays.

RESULTS

Samples from 209 patients were analyzed. Correlations were strong between Quantra and ROTEM parameters (all p<0.001): r=0.90 for clot stiffness (CS) and EXTEM A5; r=0.85 for fibrinogen contribution to clot stiffness (FCS) and FIBTEM A5; and r=0.73 for platelet contribution to clot stiffness (PCS) and EXTEM-FIBTEM A5. While CS showed higher discrimination than EXTEM A5 in detecting TIC (INR >1.2, AUROC 0.83 vs 0.79, p=0.038), the ability of FCS to detect hypofibrinogenemia (fibrinogen <2g/L) was good, but lower than FIBTEM A5 (AUROC 0.79 vs 0.84, p=0.027). There was no difference between Quantra and ROTEM in detecting platelet count <150×10⁹/L, predicting rapid transfusion or mortality at 6hr.

CONCLUSION

Quantra and ROTEM have similar diagnostic performance in evaluating TIC and predicting clinically relevant outcomes. Larger studies are required to determine the utility of Quantra for goal-directed treatment of TIC.

A cohort study on blood coagulation in childhood cancer survivors

Cancer survivors are at an increased risk of thromboembolism compared to the general pediatric population. Anticoagulant therapy decreases the risk of thromboembolism in cancer patients. We hypothesized that pediatric cancer survivors are in a chronically hypercoagulable state compared to healthy controls. Children who survived for more than five years from cancer diagnosis at the UT Health Science Center at San Antonio Cancer Survivorship Clinic were compared to healthy controls. The exclusion criteria were recent NSAID use or a history of coagulopathy. Coagulation analysis included platelet count, thrombin-antithrombin complexes (TAT), plasminogen activator inhibitor (PAI), routine coagulation assays, and thrombin generation with and without thrombomodulin. We enrolled 47 pediatric cancer survivors and 37 healthy controls. Platelet count was significantly lower in cancer survivors at a mean of 254 × 10⁹/L (95%CI: 234-273 × 10⁹/L) compared at 307 × 10⁹/L (283-331 × 10⁹/L) in healthy controls (p < 0.001), although not outside the normal range. Routine coagulation assays showed no differences, except for a significantly lower prothrombin time (PT) in cancer survivors (p < 0.004). Cancer survivors has significantly elevated biomarkers of the procoagulant state, such as TAT and PAI, compared to healthy controls (p < 0.001). A multiple logistic regression model controlling for age, BMI, gender, and race/ethnicity documented that a low platelet count, short prothrombin clot time, and higher procoagulant biomarkers (TAT and PAI) were significantly associated with past cancer therapy. Survivors of childhood cancer have a persistent procoagulant imbalance for more than five years after diagnosis. Further studies are needed to establish whether procoagulant imbalance increases the risk of thromboembolism in childhood cancer survivors.

Perioperative coagulation activation after permanent pacemaker placement

BACKGROUND

Bradyarrhythmias are typically treated with permanent pacemakers (PM). The elimination of bradyarrhythmia by PM implantation improves the patient's quality of life and prognosis, but it can also result in a number of sequalae. It is still unclear how PM implantation affects the hemostasis system's parameters and how such parameters relate to different consequences after PM placement.

AIM

To assess the blood coagulation factor activity in PM patients throughout the perioperative period.

METHODS

Patients treated in the Department of Surgical Therapy of Cardiac Arrhythmias and Pacing at the Ryazan State "Regional Clinical Cardiology Dispensary" from April 2020 to December 2021 were included in the study. Before surgery, 7 and 30 d after PM placement, peripheral venous blood samples were withdrawn to measure the level of blood coagulation factor I (FI) and the activity of blood coagulation factors II (FII), V (FV), VII (FVII), VIII (FVIII), IX (FIX), X (FX), XI (FXI), XII (FXII). We used an automatic coagulometer Sysmex CA 660 (Sysmex Europe, Germany) and reagents from Siemens (Siemens Healthcare Diagnostics Products GmbH, Germany).

RESULTS

The study included 146 patients. The activity of factors FV [147.7 (102.1-247.55)% vs 103.85 (60-161.6)% vs 81.8 (67.15-130.65)%, P = 0.002], FVIII [80.4 (60.15-106.25)% vs 70.3 (48.5-89.1)% vs 63.7 (41.6-88.25)%, P = 0.039], FIX [86.2 (70.75-102.95)% vs 75.4 (59.2-88.3)% vs 73.9 (56.45-93.05)%, P = 0.014], FX [188.9 (99.3-308.18)% vs 158.9 (83.3-230)% vs 127.2 (95.25-209.35)%, P = 0.022], FXI [82.6 (63.9-103.6)% vs 69.75 (53.8-97.6)% vs 67.3 (54.25-98.05)%, P = 0.002], FXII [87.6 (67.15-102.3)% vs 78.9 (63.4-97.05)% vs 81.2 (62.15-97.4)%, P < 0.001] decreased at 7 and 30 d after surgery; FII activity [157.9 (109.7-245.25)% vs 130 (86.8-192.5)% vs 144.8 (103.31-185.6)%, P = 0.021] decreased at 7 d and increased at 30 d postoperatively. There were no statistically significant changes in the FVII activity within 30 d after PM placement [182.2 (85.1-344.8)% vs 157.2 (99.1-259)% vs 108.9 (74.9-219.8)%, P = 0.128]. Subgroup analysis revealed similar changes only in patients on anticoagulant therapy. FXII activity decreased in patients on antiplatelet therapy [82 (65.8-101.9)% vs 79.9 (63.3-97.1)% vs 89.7 (75.7-102.5)%, P = 0.01] 7 d after surgery, returning to baseline values at 30 d postoperatively.

CONCLUSION

PM placement and anticoagulant therapy were associated with decreased activity of clotting factors FV, FVIII, FIX, FX, FXI, FXII in the postoperative period. FVII activity did not decrease within 30 d after PM placement, which may indicate endothelial injury caused by lead placement.

Detection and quantification of perioperative heparin-like effects by rotational thromboelastometry in living-donor liver transplant recipients: A prospective observational study

Background and Aims

Heparin-like effects (HLEs) can affect hemostasis during liver transplantation. The aim of this study was to assess the perioperative incidence and severity of HLE with rotational thromboelastometry (ROTEM) and activated partial thromboplastin time (aPTT).

Material and Methods

ROTEM and aPTT were measured intraoperatively and on postoperative days (POD) 1, 3, and 7. HLE was identified if ROTEM INTEM/HEPTEM CT-ratio was >1.25 and severe forms of HLE when ratio was ≥2. Based on aPTT, HLE was defined when aPTT ratio was >1.25 (patient aPTT/control aPTT).

Results

Thirty-eight recipients were included. Variable degrees of HLE were detected by aPTT-ratio and INTEM/HEPTEM CT ratio. No significant correlation existed between both ratios. Based on INTEM/HEPTEM CT ratio, HLE was detected in 7/38 during anhepatic phase, 19/38 post-reperfusion, 10/38 on POD1, 4/38 on POD3, and 0/38 on POD7. Four cases of severe HLE were identified by INTEM/HEPTEM CT ratio only in the anhepatic phase. Postoperative infusion of unfractionated heparin led to mild-moderate HLE on POD1 and 3 as evident by both tests. Red blood cell and plasma transfusion were higher with severe HLE (1350 ± 191 ml and 3558 ± 1407 ml). Composite adverse outcome of any complication or death within 3 months for patients without HLE, mild-moderate HLE, and severe HLE as detected by ROTEM was 27.8%, 42.9%, and 66.7%, respectively.

Conclusion

INTEM/HEPTEM CT ratio was able to detect and quantify HLE as aPTT ratio. The ability of the INTEM/HEPTEM CT ratio to identify severe HLE earlier in the anhepatic phase needs to be studied in a larger population. HLE is self-limiting, but when identified in a severe form, it is associated with worse outcome.

Anesthetic management of the traumatic brain injury patients undergoing non-neurosurgery

This article describes the anesthetic management of patients with traumatic brain injury (TBI) undergoing non-neurosurgery, primarily targeting intraoperative management for multiple-trauma surgery. The aim of this review is to promote the best clinical practice for patients with TBI in order to prevent secondary brain injury. Based on the current clinical guidelines and evidence, anesthetic selection and administration; maintenance of optimal cerebral perfusion pressure, oxygenation and ventilation; coagulation monitoring; glucose control; and temperature management are addressed. Neurological recovery, which is critical for improving the patient's quality of life, is most important; therefore, future research needs to be focused on this aspect.

Interaction of polystyrene nanoplastics with human fibrinogen

Nanoplastics are an emerging environmental contaminant that can penetrate biological barriers to enter the bloodstream and risk human health. In this context, nanoplastics are likely to interact with proteins in the blood to possibly affect protein structure and function and consequently induce biological effects. Here we report that polystyrene (PS), PS-NH₂, and PS-COOH nanoplastics disrupt the structure of human fibrinogen (HF) in a dose-dependent manner, as revealed by UV-vis and fluorescence spectroscopy. All three nanoplastics interacted with HF in a similar way, with PS-NH₂ having the greatest effect on HF structure. Furthermore, fibrinogen polymerization experiments demonstrated that nanoplastics have the potential to promote blood coagulation, with PS-NH₂ again having a stronger effect. Collectively, these results provide insights into the interactions occurring between nanoplastics and HF, the likely transport and fate of nanoplastics in organisms, and their potential pathophysiological consequences.

Stimulation of platelet aggregation by affinity captured rhodocytin from the Malayan pit viper Calloselasma rhodostoma

The receptor protein CLEC-2 on platelet membranes is the target of the endogenous ligand podoplanin found on cancer cells and of rhodocytin, a snake venom component of the Malayan pit viper Calloselasma rhodostoma. Ligand binding results in platelet activation, increased blood coagulation and thrombosis. In an effort to isolate rhodocytin, we have purified CLEC-2 as bait from E. coli. Affinity captured rhodocytin interacted with mammalian CLEC-2 and stimulated platelet aggregation in a dose dependent manner.

Complement factors B, D, C3bBbP and risk of future venous thromboembolism

The complement system appears to be involved in the pathogenesis of venous thromboembolism (VTE). We investigated the association of complement factors (CF) B, D, and the alternative pathway convertase, C3bBbP, measured at inclusion, with the risk of future VTE in a nested case-control study; 380 VTE patients and 804 age- and sex-matched controls derived from the Tromsø study. Odds ratios (ORs) with 95% confidence intervals (95% CI) for VTE across tertiles of CF concentrations were estimated using logistic regression. There was no association between CFB or CFD and risk of future VTE. Higher levels of C3bBbP gave an increased risk of provoked VTE; subjects in Q4 had a 1.68-fold higher OR compared with Q1 in the age-, sex- and BMI-adjusted model (OR 1.68; 95% CI 1.08-2.64). There was no increased risk of future VTE in individuals with higher levels of complement factors B or D of the alternative pathway. Increased levels of the alternative pathway activation product, C3bBbP, showed an association with future risk of provoked VTE.

Blood Coagulation Normalization Effect of Parkia Biglobosa Seed on Potassium Bromate-induced Coagulopathy

BACKGROUND

Potassium bromate (KBrO3) has been reported to be toxic, adversely affecting many body tissues and organs. The aim of this study was to determine the blood coagulation effect of Parkia biglobosa (P. biglobosa) seed on potassium bromate induced coagulopathy.

METHODOLOGY

P. biglobosa was extracted with soxhlet extractor with ethanol as the solvent. Twenty-four adult male Wistar rats were acclimatized under laboratory conditions and were randomly grouped into A, B, C and D. Group A was given distilled water orally. Animals in groups B, C and D were administered 100 mg/kg body weight of potassium bromate, but groups C and D were also treated with 100 and 200 mg/kg body weight of P. biglobosa respectively. Both potassium bromate and P. biglobosa were freshly prepared on daily basis and administered to rats by oral gavage for 28 days. At the end of the treatment period, blood samples were collected in sodium citrate bottles and were used for analysis of Prothrombin Time (PT), Activated Partial Thromboplastin Time (APTT), Thrombin Time (TT), fibrinogen and vitamin K levels using standard methods.

RESULTS

Administration of potassium bromate increased Prothrombin Time (PT) from 11.67±2.15 seconds (in control animals) to 19.53±2.83 seconds. Treatment with 100 and 200 mg/kg body weight of P. biglobosa seed extract neutralized this effect in a dose-dependent manner. Likewise, KBrO 3 was observed to have significantly elevated Activated Partial Thromboplastin Time (APTT) from 29.67±3.93 to 41.10±4.79 seconds and Thrombin Time (TT) from 15.36±2.06 to 25.43±2.83 seconds when compared with those in the control group. The result further showed that exposure of animals to KBrO3 significantly declined the levels of fibrinogen (from 4.05±0.72 to 2.59±0.30 g/dL) and vitamin K (from 3.18±0.73 to 1.84±0.18 ng/mL) when compared with the untreated animals. The effect of KBrO 3 on PT, APTT, TT, Fibrinogen and vitamin k were attenuated by P. biglobosa in a dose-dependent manner.

CONCLUSION

The results of this investigation demonstrated that potassium bromate caused prolongation of PT, aPTT and TT and decreased levels of fibrinogen and vitamin K, but P. biglobosa treatment counteracted these effects. Thus, it is recommended that these results be investigated in clinical trials in human volunteers.

Laser hemorrhoidoplasty versus conventional hemorrhoidectomy for grade II/III hemorrhoids: a systematic review and meta-analysis

PURPOSE

This study compared the short- and long-term clinical outcomes of laser hemorrhoidoplasty (LH) vs. conventional hemorrhoidectomy (CH) in patients with grade II/III hemorrhoids.

METHODS

PubMed/Medline and the Cochrane Library were searched for randomized and nonrandomized studies comparing LH against CH in grade II/III hemorrhoids. The primary outcomes included postoperative use of analgesia, postoperative morbidity (bleeding, urinary retention, pain, thrombosis), and time of return to work/daily activities.

RESULTS

Nine studies totaling 661 patients (LH, 336 and CH, 325) were included. The LH group had shorter operative time (P<0.001) and less intraoperative blood loss (P<0.001). Postoperative pain was lower in the LH group, with lower postoperative day 1 (mean difference [MD], -2.09; 95% confidence interval [CI], -3.44 to -0.75; P=0.002) and postoperative day 7 (MD, -3.94; 95% CI, -6.36 to -1.52; P=0.001) visual analogue scores and use of analgesia (risk ratio [RR], 0.59; 95% CI, 0.42-0.81; P=0.001). The risk of postoperative bleeding was also lower in the LH group (RR, 0.18; 95% CI, 0.12- 0.28; P<0.001), with a quicker return to work or daily activities (P=0.002). The 12-month risks of bleeding (P>0.999) and prolapse (P=0.240), and the likelihood of complete resolution at 12 months, were similar (P=0.240).

CONCLUSION

LH offers more favorable short-term clinical outcomes than CH, with reduced morbidity and pain and earlier return to work or daily activities. Medium-term symptom recurrence at 12 months was similar. Our results should be verified in future well-designed trials with larger samples.

Liver protection and hemostatic effects of medicinal plant Arnebia euchroma (Royle) I.M.Johnst extract in a rat model

ETHNOPHARMACOLOGICAL RELEVANCE

Arnebia euchroma (Royle) I.M.Johnst. (AE) is a Chinese medicinal herb that is traditionally used to treat various circulatory diseases. It exhibits certain effects, such as the promotion of blood circulation and cooling, rash clearance, and detoxification.

AIM OF THE STUDY

This study was designed to explore the hepatoprotective and hemostatic effects of the ethyl acetate extract of AE in rats with carbon tetrachloride (CCl4)-induced liver injury.

MATERIALS AND METHODS

Wistar rats were treated via oral gavage with different doses of the ethyl acetate extract of AE (3.5, 7, or 14 g kg^-1·day^-1) for 14 consecutive days, following which hemostatic and liver function tests were conducted. For the hemostatic tests, the platelet count, blood platelet aggregation, blood platelet adhesion to fibrinogen, platelet factor 4 (PF-4) secretion from blood platelets, prothrombin time (PT), activated partial thromboplastin time (aPTT), thrombin time (TT), and fibrinogen levels were measured at the end of the treatment period. For the liver function tests, 0.25 mL/200 g (1.25 mL kg^-1·day^-1) of olive oil was injected into the abdominal cavity of the control rats, whereas 15% CCl₄ plus olive oil (prescription: 7.5 mL CCl₄ + 42.5 olive oil) was injected into that of the treated rats at 1 h after extract administration on day 6, 13, and 20. Additionally, food and water were withheld from all the animals. On the following day, the rats were anesthetized and their albumin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), gamma-glutamyl transpeptidase (GGT), lactate dehydrogenase (LDH), reactive oxygen species (ROS), methane dicarboxylic aldehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) levels were measured. Glutathione S-transferase (GST), glutathione reductase (GR), and glutathione peroxidase (GPx) levels among the groups were determined using a one-way analysis of variance.

RESULTS

The platelet count and blood platelet aggregation, blood platelet adhesion to fibrinogen and PF-4 secretion levels were significantly increased in the (3.5 g kg^-1 day^-1) AE group as compared to those in the control group (all p < 0.001; for the 7 and 14 g kg^-1 day^-1 AE groups, all p > 0.05, respectively). Although the PT and aPTT were not affected by the AE extract (all p > 0.05), the TT was reduced and the FIB levels were significantly increased in all AE groups (p < 0.05). Liver function tests showed that CCl₄ caused significant liver damage, thereby decreasing the albumin, SOD, CAT, GSH, GST, GR, and GPx levels, while increasing the AST, ALT, ALP, SGOT, SGPT, GGT, LDH, ROS, and MDA levels (all p < 0.001). By contrast, treatment with the different doses of AE extract reversed the CCl₄ effects on all these parameters. Compared with the levels in the CCl₄ group, the GSH and GR levels in the three AE groups (3.5, 7, and 14 g kg^-1·day^-1) were significantly higher (p < 0.05, p < 0.01, and p < 0.001, respectively), whereas the differences in the other parameters for these three groups were all at the significance levels of p < 0.05, p < 0.05, and p < 0.01, respectively.

CONCLUSIONS

AE extracts administered orally exhibited hepatoprotective activity by affecting platelet production and blood coagulation and ameliorating liver function-damaging modifications. Specifically, a dosage of 3.5 g kg^-1·day^-1 resulted in the most optimal effects.

Effects of hemodilution on coagulation function during prolonged hypotensive resuscitation in a porcine model of severe hemorrhagic shock

Background

Although hemorrhage remains the leading cause of survivable death in casualties, modern conflicts are becoming more austere limiting available resources to include resuscitation products. With limited resources also comes prolonged evacuation time, leaving suboptimal prehospital field care conditions. When blood products are limited or unavailable, crystalloid becomes the resuscitation fluid of choice. However, there is concern of continuous crystalloid infusion during a prolonged period to achieve hemodynamic stability for a patient. This study evaluates the effect of hemodilution from a 6-hour prehospital hypotensive phase on coagulation in a porcine model of severe hemorrhagic shock.

Methods

Adult male swine (n=5/group) were randomized into three experimental groups. Non-shock (NS)/normotensive did not undergo injury and were controls. NS/permissive hypotensive (PH) was bled to the PH target of systolic blood pressure (SBP) 85±5 mm Hg for 6 hours of prolonged field care (PFC) with SBP maintained via crystalloid, then recovered. Experimental group underwent controlled hemorrhage to mean arterial pressure 30 mm Hg until decompensation (Decomp/PH), followed by PH resuscitation with crystalloid for 6 hours. Hemorrhaged animals were then resuscitated with whole blood and recovered. Blood samples were collected at certain time points for analysis of complete blood counts, coagulation function, and inflammation.

Results

Throughout the 6-hour PFC, hematocrit, hemoglobin, and platelets showed significant decreases over time in the Decomp/PH group, indicating hemodilution, compared with the other groups. However, this was corrected with whole blood resuscitation. Despite the appearance of hemodilution, coagulation and perfusion parameters were not severely compromised.

Conclusions

Although significant hemodilution occurred, there was minimal impact on coagulation and endothelial function. This suggests that it is possible to maintain the SBP target to preserve perfusion of vital organs at a hemodilution threshold in resource-constrained environments. Future studies should address therapeutics that can mitigate potential hemodilutional effects such as lack of fibrinogen or platelets.

Level of evidence

Not applicable-Basic Animal Research.

Unique properties of prothrombin in the bullhead shark Heterodontus japonicus: the first report of purification and characterization of a blood coagulation factor in Chondrichthyes

Prothrombin is a serine protease precursor of the blood coagulation system. In this study, the primary structure of prothrombin of a cartilaginous fish, bullhead shark (Heterodontus japonicus), was determined using RNA-Seq and the protein was purified from the blood plasma. Bullhead shark prothrombin was found to be comprised of four domains, as in the case of reported mammalian homologues. Two arginine residues that should be cleaved by activated factor X were found in the amino acid sequence of the shark prothrombin, but only one of the two cleavage sites for thrombin or meizothrombin was conserved. The apparent molecular mass of the shark prothrombin on SDS-PAGE was 110 kDa, whereas that of its amino acid sequence was 65 kDa. Potential N-glycosylation sites were found at 79th, 108th, 121st, 179th, 199th, 507th, and 527th asparagine residues in the shark prothrombin, and treatment with N-glycosidase reduced the molecular mass to 65 kDa. This indicates that, in contrast to human prothrombin, which has only 7-kDa N-glycans, the prothrombin of the shark is highly N-glycosylated. This study is the first to report on the purification and characterization of blood coagulation factors in a cartilaginous fish.

Auto-validation of Routine Coagulation/Hemostasis Assays with Reflex Testing of Abnormal Test Results

Hemostasis laboratories play a crucial role in the diagnosis and treatment of individuals with bleeding or thrombotic disorders. Routine coagulation assays, including the prothrombin time (PT)/international normalized ratio (INR), and activated partial thromboplastin time (APTT), are used for various purposes. These include as a screen of hemostasis function/dysfunction (e.g., possible factor deficiency) and for monitoring of anticoagulant therapy, such as vitamin K antagonists (PT/INR) and unfractionated heparin (APTT). Clinical laboratories are also under increasing pressure to improve services, especially response (test turnaround) times. There is also a need for laboratories to try to reduce error rates and for laboratory networks to standardize/harmonize processes and policies. Accordingly, we describe our experience with the development and implementation of automated processes for reflex testing and validation of routine coagulation test results. This has been implemented in a large pathology network compromising 27 laboratories and is under consideration for expansion to our larger network (of 60 laboratories). These rules have been custom-built within our laboratory information system (LIS), perform reflex testing of abnormal results, and fully automate the process of routine test validation for appropriate results. These rules also permit adherence to standardized pre-analytical (sample integrity) checks, automate reflex decisions, automate verification, and provide an overall alignment of network practices in a large network of 27 laboratories. In addition, the rules enable clinically significant results to be quickly referred to hematopathologists for review. We also documented an improvement in test turnaround times, with savings in operator time and thus operating costs. Finally, the process was generally well received and determined to be beneficial for most laboratories in our network, in part identified by improved test turnaround times.

Sex-specific associations between serum lipids and hemostatic factors: the cross-sectional population-based KORA-fit study

BACKGROUND

Studies on the associations between lipid parameters and different hemostatic factors in men and women from the general population are scarce. It was therefore examined whether there are possible relationships between routinely measured serum lipids (total cholesterol, HDL-cholesterol, non-HDL-cholesterol, LDL-cholesterol, and triglycerides) and different hemostatic factors (activated partial thromboplastin time (aPTT), fibrinogen, factor VIII, antithrombin III (AT III), protein C, protein S, and D-dimer).

METHODS

The analysis was based on data from the Cooperative Health Research in the Region of Augsburg (KORA)-Fit study, which included 805 participants (378 men, 427 women) with a mean age of 63.1 years. Sex-specific associations between serum lipids and coagulation factors were investigated using multivariable linear regression models.

RESULTS

In men, total cholesterol was inversely related to aPTT but positively associated with protein C activity. HDL cholesterol was inversely related to aPTT and fibrinogen. LDL cholesterol, non-HDL cholesterol, and triglycerides showed a positive association with protein C and protein S activity. In women, LDL-cholesterol, total cholesterol, and non-HDL-cholesterol were positively related to AT III concentrations and protein C and S activity. Additionally, non-HDL-cholesterol was positively associated with factor VIII activity. HDL cholesterol was inversely related to fibrinogen. Triglycerides showed a positive relationship with protein C activity.

CONCLUSIONS

There seem to be sex differences regarding various associations between blood lipid levels and hemostatic factors. Further studies are needed to address the possible impact of these associations on cardiovascular risk and the underlying mechanisms.

Domain Evolution of Vertebrate Blood Coagulation Cascade Proteins

Vertebrate blood coagulation is controlled by a cascade containing more than 20 proteins. The cascade proteins are found in the blood in their zymogen forms and when the cascade is triggered by tissue damage, zymogens are activated and in turn activate their downstream proteins by serine protease activity. In this study, we examined proteomes of 21 chordates, of which 18 are vertebrates, to reveal the modular evolution of the blood coagulation cascade. Additionally, two Arthropoda species were used to compare domain arrangements of the proteins belonging to the hemolymph clotting and the blood coagulation cascades. Within the vertebrate coagulation protein set, almost half of the studied proteins are shared with jawless vertebrates. Domain similarity analyses revealed that there are multiple possible evolutionary trajectories for each coagulation protein. During the evolution of higher vertebrate clades, gene and genome duplications led to the formation of other coagulation cascade proteins.

A Novel Anticoagulation Method Based on Electrochemical Characteristics of Blood: An in vitro Study

This in vitro experimental investigation aimed to provide a novel method for preventing blood clotting based on the electrochemical characteristics of blood. Using this method in cases such as dialysis can minimize the risk of blood clots and also avoid hemorrhagic risk for patients. Blood samples were collected from 13 sheep (45 kg) (25 mL), and the clotting time (CT) was measured using a 20-min cutoff after they were separated into control and experimental samples. The test blood sample was put in a cell designed with two aluminum electrodes (positive pole/anode) located in a container containing 0.9% sodium chloride (as a salt bridge) and a platinum (negative pole/cathode) linked to a power supply (-3.5 V, 1 mA/cm2). Biochemical and hematological tests to check blood damage and clotting were performed. The control sample coagulated after 8 min, while the electrified blood did not, even at the end of the cutoff time. Among hematologic and biochemical tests, the average time of prothrombin time (PT) and partial thromboplastin time (PTT) was significantly different between the control and test samples (p = 0.001). Our findings on electrified blood with expanding CT, PT, and PTT times revealed that the electric current passing through the blood enhanced the CT. Furthermore, no change in biochemical or hematological factors demonstrated that this current had no detrimental effect on the blood.

Thrombelastography (TEG® 6s) early amplitudes predict maximum amplitude in severely injured trauma patients

Severely injured trauma patients are often coagulopathic and early hemostatic resuscitation is essential. Previous studies have revealed linear relationships between thrombelastography (TEG^®) five- and ten-min amplitudes (A5 and A10), and maximum amplitude (MA), using TEG^® 5000 technology. We aimed to investigate the performance of A5 and A10 in predicting low MA in severely injured trauma patients and identify optimal cut-off values for hemostatic intervention based on early amplitudes, using the cartridge-based TEG^® 6s technology. Adult trauma patients with hemorrhagic shock were included in the iTACTIC randomized controlled trial at six European Level I trauma centers between 2016 and 2018. After admission, patients were randomized to hemostatic therapy guided by conventional coagulation tests (CCT) or viscoelastic hemostatic assays (VHA). Patients with available admission-TEG^® 6s data were included in the analysis, regardless of treatment allocation. Low MA was defined as <55 mm for Kaolin TEG^® and RapidTEG^®, and <17 mm for TEG^® functional fibrinogen (FF). One hundred eighty-seven patients were included. Median time to MA was 20 (Kaolin TEG^®), 21 (RapidTEG^®) and 12 (TEG^® FF) min. For Kaolin TEG^®, the optimal Youden index (YI) was at A5 < 36 mm (100/93% sensitivity/specificity) and A10 < 47 mm (100/96% sensitivity/specificity). RapidTEG^® optimal YI was at A5 < 34 mm (98/92% sensitivity/specificity) and A10 < 45 mm (96/95% sensitivity/specificity). TEG^® FF optimal YI was at A5 < 12 mm (97/93% sensitivity/specificity) and A10 < 15 mm (97/99% sensitivity/specificity). In summary, we found that TEG^® 6s early amplitudes were sensitive and specific predictors of MA in severely injured trauma patients. Intervening on early amplitudes can save valuable time in hemostatic resuscitation.

Make it double: identification and characterization of a Tandem-Hirudin from the Asian medicinal leech Hirudinaria manillensis

Haematophagous leeches express a broad variety of secretory proteins in their salivary glands, among them are hirudins and hirudin-like factors. Here, we describe the identification, molecular and initial functional characterization of Tandem-Hirudin (TH), a novel salivary gland derived factor identified in the Asian medicinal leech, Hirudinaria manillensis. In contrast to the typical structure of hirudins, TH comprises two globular domains arranged in a tandem-like orientation and lacks the elongated C-terminal tail. Similar structures of thrombin inhibitors have so far been identified only in kissing bugs and ticks. Expression of TH was performed in both cell-based and cell-free bacterial systems. A subsequent functional characterization revealed no evidence for a thrombin-inhibitory potency of TH.

Changes in thrombosis-related parameters after AstraZeneca COVID-19 vaccination in a male volunteer: a case report

Background

We speculated that subclinical thrombosis may occur frequently through crosstalk between immune/inflammatory reactions and hemostasis after corona virus disease-2019 (COVID-19) vaccination. To test this hypothesis, we measured thrombosis-related parameters after COVID-19 vaccination in a volunteer for 21 days.

Case presentation

The following parameters were measured in a 72-year-old Korean man at 1 day before vaccination and on days 1, 3, 7, 14, and 21 post vaccination (AstraZeneca COVID-19 vaccine: ChAdOx1-S/nCoV-19, CTMAV563): complete blood count, platelet indices, thrombin receptor-activating peptide-induced platelet aggregation, prothrombin time, activated partial thromboplastin time, D-dimer, thrombin–antithrombin III complex (TAT), plasmin-α2 antiplasmin complex (PAP), von Willebrand factor (vWF) antigen and activity, plasminogen activator inhibitor-1 (PAI-1), protein C and protein S antigen and activity, lupus anticoagulant, fibrinogen degradation product, and plasminogen. We found that the TAT had significantly increased from 0.7 ng/mL (baseline) to 21.7 ng/mL (day 1). There was a transient increase in the PAI-1 level from 7.2 ng/mL (baseline) to 10.9 ng/mL (day 3), followed by a decrease in PAP level from 0.9 ng/mL (baseline) to 0.3 μg/mL (day 7), suggesting that plasmin generation is suppressed by PAI-1.

Conclusions

Increased thrombotic factors (such as decreased protein S) and decreased fibrinolytic activity due to increased PAI-1 were potential factors causing thrombogenesis after COVID-19 vaccination. Sequential measurement of platelet indices, TAT, PAP, protein C, protein S, vWF, D-dimer, and PAI-1 following COVID-19 vaccination was informative.

[Perioperative management of coagulation in otorhinolaryngologic surgery]

Considering the increasing number of patients suffering from drug-induced coagulation disorders caused by antiplatelet or anticoagulant therapy, the right balance between minimizing the risk of bleeding and the risk of a venous thrombosis or embolism during otorhinolaryngologic (ORL) surgery is becoming increasingly important. According to a recent study, the highest risk of intraoperative bleeding in ORL surgery is associated with transoral tumor surgery, tonsillectomy, thyroidectomy, and glomus tumor surgery. The risk of venous thrombosis or embolism during ORL surgery is estimated to be 1%, and increases to 6% among tumor patients. Currently, there is no general recommendation for perioperative hemostatic management because of the limited available data. In the majority of patients who continue antiplatelet therapy with acetylsalicylic acid (ASS) to prevent thromboembolic events, the perioperative bleeding risk is considered to be acceptable. For patients with dual antiplatelet therapy, surgical procedures should be only performed after adaption of the medication.

35 years of discussions with Prof. Maeda on the EPR effect and future directions

In May 2021, 35 years after first announcing the enhanced permeability and retention (EPR) effect, Dr. Maeda passed away. As a theoretical pillar of high molecular weight drug delivery systems (DDS) with high biocompatibility, the EPR effect has been proven worldwide in experimental mouse models. However, in clinical solid tumors, awareness of the EPR effect is insufficient, and more importantly, DDS has not become the mainstream cancer treatment. Both Dr. Maeda and I were acutely aware of this, and for 35 years, we discussed what to do about it and strived to make up for the inadequacies of the EPR effect by employing different strategies. Dr. Maeda came up with ways to use tumor vascular permeability more effectively and to apply oxidative stress to tumor cells. I proposed cancer stromal targeting (CAST) therapy using the anti-insoluble fibrin antibody conjugated with an anticancer agent in order to overcome the insufficiency of the EPR effect in clinical solid cancers, which possess abundant stromal tissue. Clinical cancers are surrounded by an abundant stroma and survive even under hypoxia and malnutrition due to this stromal barrier. Cancer cells become resistant to any external attack, including with anticancer drugs and radiation. While it goes without saying that EPR effects are important in clinical solid cancer strategies, DDSs that offer both accumulation and even distribution in solid cancers are also required.

[Principles of the perioperative management of direct oral anticoagulants]

Within the approved indications direct oral anticoagulants (DOAC) are increasingly gaining acceptance instead of vitamin K antagonists (VKA). In the last 12 months 5 guidelines relevant to the perioperative management of DOACs have been updated. This article summarizes the current recommendations for the perioperative management of treatment with DOACs. The available substances and their pharmacological properties as well as the possibilities for specific laboratory diagnostics of the effect of DOAC are explained. Special focus is placed on anesthesiologically important aspects of substance-specific preoperative and postoperative intermission intervals, the procedure for neuraxial regional anesthesia and antagonization with specific antidotes in cases of life-threatening bleeding.