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Plasminogen activator inhibitor (PAI) purified from human placenta was compared to PAI purified from conditioned cell culture fluid of the human fibrosarcoma cell line HT-1080. The two inhibitors had a similar mobility (Mr approximately 50,000) in sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Purified placental inhibitor revealed 2 major and 1 minor Coomassie blue stainable bands, while the fibrosarcoma inhibitor appeared as one band. By immunoblotting analysis both monoclonal and polyclonal antibodies against each of the inhibitors showed reaction with the inhibitor against which they were raised, but not cross reaction with the other inhibitor. Similar results were obtained, when antibody binding was tested by ELISA with the inhibitors coated on the solid phase. HPLC fingerprint patterns of cyanogen bromide fragments of the two inhibitors were different. The inhibitory activity of the placental PAI was decreased by a factor of 3 after incubation with SDS, while that of the fibrosarcoma PAI was increased by a factor of 30. It is concluded that the two inhibitors show no detectable common antigenic determinants and most likely are products of different genes.

N-acetyl glucosamine (NAG) alone did not aggregate platelets but in low concentrations shortened the delay phase of the Staphylococcus aureus induced platelet aggregation in a concentration dependent manner, which suggests that NAG may be one of the components of the S. aureus cell wall responsible for platelet aggregation. NAG, on the other hand, inhibited collagen induced platelet aggregation and the secondary platelet aggregation induced by epinephrine and ADP. This inhibition appears to be due to impurities that occur at higher levels in some NAG lots than in others. NAG has also been shown to decrease the length of time before the release of ATP from platelets when S. aureus is the aggregating agent.

Introduction Venous thromboembolic events (VTE) occur in more than 5% of hospitalized patients with acute CMV infection. In immunocompetent patients, splanchnic vein thrombosis (SVT) and splenic infarction have been suggested to represent approximately half of the published cases of CMV-associated VTE. We performed a systematic review of the literature with the aim to describe epidemiology, clinical characteristics, treatment, and natural history of CMV-associated SVT in immunocompetent patients. Methods Studies were identified by a PubMed and Google Scholar electronic database search until January 2018. All published papers describing immunocompetent adults with SVT occurring concomitantly to an acute CMV infection were included. Results Forty-four patients with CMV-associated SVT were described in 38 papers. Twenty-three patients were male, mean age was 38.1 years (range, 17–68). Symptomatic SVT occurred in 31 patients, incidental SVT in 13 patients. In symptomatic SVT, an acute and severe onset with small bowel or splenic infarction required surgical treatment for resolution in 22.6% of cases. Anticoagulation induced both a favourable clinical outcome and a recanalization of SVT in more than 70% of the remaining cases. In incidental SVT, a favourable clinical outcome and a complete recanalization of SVT by anticoagulation were reported in more than 80% of cases. No patient with CMV-associated SVT died and no SVT recurrence was reported. Conclusions CMV-associated SVT has probably a favourable clinical course in most patients. Only future, well-designed, prospective studies with an adequate follow-up will allow to confirm the data of published cases.

Positive family history is known to be an independent risk factor for venous thromboembolic (VTE) that may or may not reflect an underlying hereditary disorder. However, there is no clear standardized definition of what constitutes a positive family history for VTE in children. We aimed to assess the current published definitions of positive family history as a risk factor for VTE in children and ascertain if any consensus exists. Methods We conducted a literature review through two major databases PUBMED and EMBASE (1969–June 2018). Three different search statements were used for each database to maximize the number of relevant results, giving rise to 1050 non-duplicated papers. Results Of the 1050 papers, 32 articles demonstrated 18 separate definitions on what constitutes a positive family history in paediatric studies. Variations in definitions were related to the closeness of kinship (first or second-degree relatives), whether thrombosis was provoked or unprovoked, the age of presentation of thrombosis in the kinship, and clinical vs. laboratory definition of positive family history. Of the definitions, 1st degree relative/s developing VTE at any age whether provoked or unprovoked was most commonly described. Conclusion: According to this literature review, the definition of a positive family history in paediatric populations is non-standardized amongst current published papers. To enable accurate comparisons across studies and improve clinical risk assessment, we therefore propose the need for a standardized definition of what constitutes a positive family history.

This paper reviews the current evidence on the pathogenesis, clinical manifestations, diagnosis and management of cancer-associated non-bacterial thrombotic endocarditis (NBTE). NBTE is an underdiagnosed condition characterized by sterile valvular vegetations composed of platelets and fibrin which are susceptible to systemic embolization. Cancer is a leading cause of NBTE and should be excluded in NBTE cases without a clear etiology. Malignancies most frequently associated with NBTE are mucin-releasing adenocarcinomas of the lung, ovary, biliary system, pancreas, breast and stomach. NBTE carries a high risk of arterial thromboembolism, while cardiac valvular dysfunction is much less frequent. NBTE appears to be an important underdiagnosed cause of cancer-associated embolic stroke of undetermined source. Characteristics associated with cancer-associated NBTE include elevated D-dimer, visceral infarcts, cerebral infarcts in multiple vascular territories, transcranial doppler microembolic signals, disseminated cancer and adenocarcinoma histology. Transesophageal echocardiography is the diagnostic test of choice, and all suspected cases should be evaluated for the presence of elevated D-dimers and disseminated intravascular coagulation. Long-term anticoagulation with low molecular weight heparin should be strongly considered, and surgical intervention is usually not needed. Underlying cancer must be diagnosed swiftly (if previously undiagnosed) and anti-cancer treatment should be initiated as soon as possible. The paucity of data regarding all aspects of NBTE, and the severe clinical consequences of untreated NBTE, are an urgent call for future research.

Objective Coagulation and inflammatory parameters are mildly altered in children with SARS-CoV-2 (COVID-19) infection, and laboratory evidence of a proinflammatory and procoagulant state has been noted in multisystem inflammatory syndrome in children (MIS-C). It is not clear whether this pediatric condition is related to thrombotic events. With this study we reviewed the literature for thrombotic complications in children with COVID-19 infection and MIS-C. Data sources We searched the Medline PubMed Advanced Search Builder, Scopus, Web Of Science, and Google Scholar electronic databases (until 1 January 2021) using the medical subject headings (MeSH) terms and text words (their combinations and truncated synonyms): (THROMBOSIS OR THROMBOPHILIA) AND (CHILD OR CHILDREN OR INFANT) AND (COVID-19 OR SARS-CoV-2). Study eligibility criteria Inclusion criteria were children with COVID-19 or SARS-COV-2 infection. The search was limited to articles published in English. Exclusion criteria were: reviews of published studies, studies published only as abstracts, letters or conference proceedings, discussion papers, animal studies, or editorials. Results After screening for duplicates, the initial search yielded 86 records: 12 were case reports involving 19 children; comorbidities were absent or mild in 73.7%. The most common site of thrombosis the lung (21%); the most often used drug was heparin (42%). Two studies were an international survey (n = 337 patients) and a large multicenter study (n = 186 patients with MIS-C). The risk of ischemic stroke in SARS-CoV-2 infection (0.82%) and deep venous thrombosis in MIS-C (4.3%) was lower in children than in adults. Conclusions Thrombodic or thromboembolic events are rare in pediatric patients with COVID-19 infection and MIS-C. Nonetheless, as in adults, a high index of suspicion should be maintained in children with COVID-19 infection or MIS-C, particularly in those with comorbidities predisposing to thrombotic events.

After acute pulmonary embolism, chronic thromboembolic pulmonary hypertension (CTEPH) is diagnosed in about 1% of patients. We performed a systematic review and meta-analysis aimed at assessing the effects of bosentan therapy in patients with CTEPH.We searched in MEDLINE and Embase using the terms 'pulmonary hypertension' AND 'bosentan'. Papers were included in this review if they reported on patients with objectively confirmed CTEPH treated with bosentan. Efficacy measures were the improvement in NYHA class, in 6 minute walking distance (6 mwd) and in hemodynamics (cardiac index, pulmonary artery pressure, pulmonary vascular resistance). Mortality and safety were also assessed.Overall, 543 papers were found. Eight single-arm cohort studies (175 patients), one randomized double-blind study, one case-control study and one case report were included in the analysis. A 35.9 meters weighted mean increase in 6 minute walking distance was observed after 3-6 months of treatment (9 studies, 208 patients) (95% CI 33.6 to 38.2; p0.001) and an additional increase of 21 meters after one year (4 studies, 80 patients). About 25% of patients had an improvement on functional NYHA class at 3-6 months. Data on hemodynamics were available in seven studies, 185 patients. The mean weighted increase in cardiac index at 3-6 months was 0.23 l/min/m2 (95% CI 0.22 to 0.25); the mean weighted decrease in pulmonary artery pressure at 3-6 months was 2.62 mmHg (95% CI 2.44 to 2.80). Three patient died within 3-6 months (1.4%) and 3 additional patients died within one year.Bosentan therapy is associated with an improvement of hemodynamics and probably exercise capacity in patients with CTEPH. Controlled data on mortality and time to clinical worsening in patients with CTEPH are needed.

Introduction The use of oral anticoagulant therapy is increasing in children. Managing anticoagulant therapy in children presents unique challenges, including poor venous access. The advent of point-of-care (POC) monitoring of anticoagulant therapy offers a potential solution to this challenge. This paper reviews the published literature relating to POC monitoring of oral anticoagulant therapy in children. Materials and methods A Medline search was conducted and identified key publications. Papers were reviewed with respect to their objectives, populations and POC device investigated. Study limitations were identified. Results Five publications and one abstract were identified, reporting studies using five different POC monitors. Three studies had a strong clinical management focus. Outcome measures assessed included target therapeutic range achievement and frequency of adverse events. Correlation between POC and laboratory-based results ranged from 0.83 to 0.96. Home monitoring and self-management using POC monitors were both reported to be preferred compared to standard laboratory testing. Conclusions POC monitoring of oral anticoagulant therapy in children offers considerable advantages. The reviewed literature would suggest such monitoring can be performed accurately and reliably. The impact of quality control issues, such as calibration of thromboplastin ISI in POC devices, has not been explored in a paediatric population. Further studies are needed to clarify such issues and confirm the safety, reliability and efficacy of POC monitoring of oral anticoagulant therapy in children, including its home monitoring and self-management programs.

In this paper, we will give an overview of the background for the possible effects of long-chain marine n-3 (synonymously called omega-3) polyunsaturated fatty acids (PUFA) in coronary heart disease (CHD) with focus on recent findings. In a forthcoming paper, we will focus on the clinical trial data, current recommendations and suggest trials to further study the role of marine n-3 PUFA in the prevention and treatment of CHD.

Background Direct oral anticoagulants (DOACs) have emerged as safe and effective alternatives to Vitamin-K antagonists for treatment and prevention of arterial and venous thrombosis. Due to their novelty, pharmacokinetic DOAC drug-drug interactions (DDIs) that result in clinical adverse events have not been well-documented. Objective This study aims to systematically review reported pharmacokinetic DDIs resulting in clinical adverse events through documented observational evidence to better inform clinicians in clinical practice. Methods A comprehensive literature review of EMBASE, MEDLINE, and Ovid HealthStar was conducted through March 10th, 2020. Two independent reviewers screened and extracted data from eligible articles according to pre-established inclusion and exclusion criteria. Articles reporting bleeding or thrombotic outcomes in non-controlled (observational) settings resulting from suggested pharmacokinetic DOAC DDIs were included. Results A total of 5567 citations were reviewed, of which 24 were included following data extraction. The majority were case reports (n = 21) documenting a single adverse event resulting from a suspected DOAC DDI, while the remaining papers were a case series (n = 1) and cohort studies (n = 2). The most commonly reported interacting drugs were amiodarone and ritonavir (bleeding), and phenobarbital, phenytoin, and carbamazepine (thrombosis). Bleeding events more often resulted from a combined mechanism (P-glycoprotein AND CYP3A4 inhibition), whereas thrombotic events resulted from either combined OR single P-glycoprotein/CYP3A4 induction. Conclusion Current literature evaluating the real-world risk of DOAC DDIs is limited to few case reports and retrospective observational analyses. Clinicians are encouraged to continue to report suspected drug interactions resulting in adverse events., Highlights • Patients on direct oral anticoagulants (DOACs) can encounter drug interactions. • Drug interactions can alter the amount of DOAC in a patient's system. • Research on DOAC interactions is currently limited and larger studies are required. • Health providers should continue to be cautious with potential DOAC interactions.

Despite a breadth of data on the management of cancer-associated thrombosis, all the studies informing clinical guidelines excluded patients receiving palliative care. Patients with advanced cancer have a higher rate of recurrent venous thromboembolism (VTE) and bleeding, making them one of the most challenging populations to treat. The dearth of population-specific research leaves clinicians with few options but to extrapolate data from clinical trials conducted on a healthier population. Recent observational studies have challenged the utility of doing this, suggesting the natural history of VTE in the advanced cancer patient may differ to our first beliefs and that a less aggressive approach to anticoagulation is warranted particularly near the end of life. This paper highlights what we know so far.

The current thesis was divided into two parts. Basic platelet research is the topic of the first section. The subsequent clinical part examines platelet reactivity in stable angina pectoris (AP) and in atrial fibrillation. Platelet heterogeneity was investigated in the first section (papers 1 and 2). The cells were separated according to density using linear Percoll™ (a density medium) gradients. The latter contained EDTA, prostaglandin E1 and theophylline to prevent platelet in vitro activity. The platelet population was then divided into density subpopulations (n = 16 - 20). Membrane attached fibrinogen was determined with a flow cytometer technique and used as a marker reflecting platelet in vivo activity. Platelet P-Selectin content was employed to estimate the quantity of platelet α-granules. Paper I examined healthy blood donors (n = 3). The second report (paper II) compared healthy volunteers (n = 2) and subjects with essential thrombocythemia (ET) (n = 2). The latter is a clonal disease being characterized by an excessive platelet production. Platelet counts were determined in all fractions. In manuscripts I and II determination of surface bound fibrinogen and intracellular P-Selectin was carried out in 12 and 16 platelet density fractions, respectively. High density platelets displayed more surface bound fibrinogen indicating in vivo activity. They also contained less P-Selectin. The latter finding implies platelet in vivo release reactions. Low density platelets circulated with more surface bound fibrinogen as well. Compared with peak density platelets, lighter cells contained more P-Selectin. ET was characterized by a similar platelet density pattern in that high and low density platelets displayed more surface bound fibrinogen. The similarity may explain why severe bleedings do not occur more frequently in ET. It is also obvious from the current thesis that the significance of platelet heterogeneity remains unclear and stimulates to further research. In particular, future work must involve more patients. The second part (papers III-VI) of the thesis was devoted to stable AP and atrial fibrillation. Determination of platelet reactivity i.e. platelet bound fibrinogen after stimulation was carried out in whole blood. A flow cytometer technique was employed (papers III-VI). Adenosine diphosphate (ADP) (1.7 and 8.5 μmol/L) and a thrombin-receptor activating peptide (TRAP-6) (57 and 74 μmol/L) were used as stimulating agents. Determination of peak platelet density (kg/L) was utilized as a further measure reflecting platelet reactivity (paper V). Surface bound and soluble P-Selectin were employed as platelet activity markers (paper VI). Gender differences with respect to platelet reactivity were investigated in paper III. Paper IV examined platelets in stable AP without significant coronary flow obstruction(s) as determined by coronary angiography. In a following study platelet reactivity was analysed in diabetes type II complicated by stable AP (paper V). Finally, long-term (more than 2 years) outcome of atrial fibrillation was related to platelet reactivity and activity (paper VI). In this study the subjects were investigated at the initial electrical cardioversion and the analysis were repeated after more than 2 years. Postmenopausal women with stable AP demonstrated more reactive platelets when stimulating with TRAP-6. They had higher platelet counts (paper III) as well. Stable AP without significant coronary flow obstruction(s) was associated with elevated platelet reactivity (paper IV). Diabetes type II was linked to higher peak platelet density and elevated platelet reactivity (paper V). Augmented platelet reactivity proved to be a feature of subjects remaining in atrial fibrillation more than 2 years after the electrical cardioversion (paper VI). In contrast, the irregular heart rhythm did not affect platelet activity. It is to assume that platelets at least partly are responsible for the sometimes atypical symptoms of females with stable AP. It is also conceivable to speculate that platelets contribute to chest pain in AP free from significant coronary flow obstruction(s). Theoretically, enhanced platelet reactivity could at least partly explain why diabetes type II affects the prognosis of coronary heart disease. The thesis further shows a possible theoretical link between atrial fibrillation, increased platelet reactivity and clot formation.

Patients with cancer have increased risks of venous and arterial thromboembolism and/or atrial fibrillation, for which anticoagulation is commonly used. For these indications, three main types of anticoagulants are recommended or used: low-molecular-weight heparin (LMWH), direct oral anticoagulants (DOACs), and vitamin K antagonists (VKAs), all have different advantages and disadvantages. Drug-drug interactions (DDIs) with anticoagulation are often cautioned against by major guidelines, but evidence remains scarce regarding the best management approach for specific drug combinations, particularly with DOACs. Significant DDIs might affect the efficacy and safety of anticoagulants and/or anticancer therapies as well as other interfering medications, and more studies are needed. This paper will review the available evidence and guidelines on DDIs with anticoagulants, focusing on the cancer population whenever possible, and propose directions for future research.

In this paper we tested a group of 66 healthy volunteers in terms of the influence of circadian rhythm on selected parameters of the coagulation system and fibrinolytic system. Blood was collected at 6-hour intervals, at 8 am, 2 pm, 8 pm and 2 am. Circadian variability was observed in the coagulation system parameters as well as in the fibrinolytic system. We observed increased platelet aggregation, APTT prolongation, along with increased levels of factors (fibrinogen, PAI-1) and PAP and TAT complexes that influence coagulation and fibrinolysis systems, in the blood samples collected in the morning (8 am). We also demonstrated a circadian rhythm in the number of circulating platelets (PLT), with a peak in the afternoon (2 pm) accompanied by increased concentrations of t-PA, D-dimers and PT prolongation. Based on the obtained results it was possible to conclude that circadian rhythm had an influence on the activation of coagulation processes in the morning, with a progressive activation of fibrinolysis up to the afternoon. Our results may be helpful in determining the transient risk of cardiovascular events, including myocardial infarction and ischemic stroke, and hence, can contribute to the effective prevention of such events. Such observations may also become a starting point of departure for further studies aimed at determining the circadian effect of secretion of parameters in the hemostasis system on the other systems and parameters in the human body.

Eponyms are honorific terms ascribed to individuals who discovered a sign, test, syndrome, technique, or instrument. Despite some contentions, eponyms continue to be widely ingrained and incorporated into the medical literature and contemporary language. Physical signs are considered unreliable methods alone for detecting deep venous thrombosis (DVT). The accuracy of the majority of these signs is unknown. For those signs that have been studied, there are a number of methodological limitations hindering the ability to draw meaningful conclusions about their accuracy and validity in clinical practice. Nevertheless, some findings when present and used in conjunction with other key signs, symptoms, and aspects of the patients history may be useful in further supporting the clinical suspicion and likelihood of DVT and/or pulmonary embolism (PE) or venothromboembolism (VTE). These signs also provide the means to better recognize the relationship between clinical findings and VTE. The acquisition of historical knowledge about these signs is important as it further enhances our understanding and appreciation of the diagnostic acumen that physicians were required to employ and to diagnose VTE prior to the advent of advanced imaging methods. Described in this paper is a brief overview of thrombosis as enumerated by Rudolf Virchow, and eponymous signs described in the late eighteenth and nineteenth centuries.

A Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) has become a pandemic disease named Coronavirus Disease-19 (COVID-19) of epochal dimension. The clinical spectrum of COVID-19 is wide, ranging from asymptomatic forms to severe pneumonia, sepsis and multiple organ dysfunction syndromes resulting in poor outcomes. Among the various consequences of severe COVID-19, cardiovascular (CV) collapse appears the most serious and potentially lethal. On the other hand, pre-existent CV comorbidities are also associated with higher mortality. The most reliable hypothetical pathogenetic mechanism for CV complications and cardiac injury in severe COVID-19 patients appears to be a sustained endothelial dysfunction, caused by the interplay of inflammation and coagulation. In this review, we survey papers addressing issues related to severe COVID-19, characterized by enhanced lung microvascular loss, hypercytokinemia, hypoxemia and thrombosis. We discuss about how the virus-induced downregulation of the angiotensin converting enzyme-2 (ACE2) receptor, used to enter the host cell, could affect the renin-angiotensin system, attempting to clarify the doubts about the use of ACE inhibitors and Angiotensin-II receptor blockers in COVID-19 patients. Finally, we point out how the delicate and physiological homeostatic function of the endothelium, which turns into a disastrous battlefield of the complex interaction between “cytokine and coagulative storms”, can be irreparably compromised and result in systemic inflammatory complications., Highlights • Cardiovascular (CV) collapse appears the most serious consequence of severe COVID-19. • Endothelial dysfunction as pathogenetic mechanism for (CV) complications in COVID-19 patients • Hyperinflammation, immune dysregulation, hypoxia may drive vascular damage in COVID-19 patients. • Hypercoagulability state characterizes patients with severe COVID-19.

Introduction Venous thromboembolism (VTE) is the leading cause of direct maternal mortality in high-income countries. We previously developed a risk prediction score for postpartum venous thromboembolism (VTE) in women without a previous VTE. In this paper, we provide further external validation and assess its performance across various groups of postpartum women from England. Materials and methods Cohort study using primary and secondary care data covering England. We used data from QResearch comprising women with pregnancies ending in live birth or stillbirth recoded in Hospital Episodes Statistics between 2004 and 2015. Outcome was VTE in the 6 weeks postpartum. Our predictor variables included sociodemographic and lifestyle characteristics, pre-existing comorbidities, and pregnancy and delivery characteristics. Results Among 535,583 women with 700,185 deliveries, 549 VTE events were recorded (absolute risk of 7.8 VTE events per 10,000 deliveries). When we compared predicted probabilities of VTE for each woman from the original model with actual VTE events, we obtained a C-statistic of 0.67 (95% CI 0.65 to 0.70). However, our model slightly over-predicted VTE risk for the higher risk women (calibration slope = 0.84; 95% CI 0.74 to 0.94). Performance was similar across groups defined by calendar time, socioeconomic status, age group and geographical area. The score performed comparably with the existing algorithm used by the UK Royal College of Obstetrician and Gynaecologists. Conclusions Our model enables flexibility in setting new treatment thresholds. Adopting it in clinical practice may help optimise use of low-molecular-weight heparin postpartum to maximise health gain by better targeting of high-risk groups.

Background The prevalence of calreticulin (CALR) mutations in splanchnic vein thrombosis (SVT) varies among studies. The role of routine screening for CALR mutations in SVT patients remains a debate. Aim To synthesize the prevalence of CALR mutations according to the different types (i.e., Budd-Chiari syndrome [BCS] and portal vein thrombosis [PVT]) and characteristics (i.e., with and without myeloproliferative neoplasms [MPNs] and JAK2V617F mutation) of SVT patients. Methods Eligible studies were searched by the PubMed and Embase databases. The study quality was assessed according to the STROBE checklist. The proportion of CALR mutations was pooled by using a random-effects model. The heterogeneity and publication bias were calculated. Results Eleven papers were included. The study quality was moderate to high. The pooled proportion of CALR mutations was 1.21%, 1.41%, and 1.59% in SVT, BCS, and PVT patients, respectively; 1.52%, 1.03%, and 1.82% in these patients without JAK2V617F mutation, respectively; 3.71%, 2.79%, and 7.87% in these patients with MPN, respectively; and 15.16%, 17.22%, and 31.44% in these patients with MPN but without JAK2V617F mutation, respectively. Only the meta-analysis examining the prevalence of CLAR mutations in BCS patients with MPN but without the JAK2V617F mutation showed statistically significant heterogeneity. Statistically significant publication bias was seen only in the meta-analysis examining the prevalence of CALR mutations in SVT patients without the JAK2V617F mutation. Conclusion Screening for CALR mutations may have a role in SVT patients with a high probability of MPN in whom the JAK2V617F mutation has been excluded.

Post-thrombotic syndrome (PTS) is the most common long-term complication after deep vein thrombosis (DVT) developing in up to 70% of the patients. PTS is diagnosed on the basis of typical symptoms and signs of the lower limb with a previous DVT, but no objective diagnostic test exists. A number of diagnostic scales have been developed primarily for research purposes. An optimal diagnostic test for PTS should be reliable and easy to use, sensitive and specific, able to grade PTS severity, and to identify changes over time. We have identified reports on seven diagnostic scales that have been used for the diagnosis of PTS; the Widmer classification, the Clinical-Etiological-Anatomical-Pathological (CEAP) classification, the Venous Clinical Severity Score (VCSS), the Brandjes scale, the Ginsberg measure, the Villalta scale, and the Patient-reported Villalta scale. The aim of this paper was to review and present the existing diagnostic scales for PTS in adults and their utility in clinical studies.

Background The value of D-dimer testing for the diagnosis of thrombosis in unusual sites is not properly established and evidence is scarce. We performed a systematic review of the literature. Methods The search was conducted in MEDLINE and Cochrane Library for papers published in the last 10 years including different presentations of thrombosis in unusual sites. Twenty-three articles were included, from January 1, 2008, to December 31, 2018, comprising 3378 patients with thrombosis in unusual sites (upper extremity deep vein thrombosis, cerebral vein thrombosis and splanchnic vein thrombosis). The Newcastle-Ottawa scale was used to assess the quality of the studies. Results Two articles were related to upper extremity thrombosis, showing a high sensitivity and negative predictive value for D-dimer testing. Twelve articles concerned cerebral vein thrombosis, concluding that the timing of D-dimer testing was important, and that patients with a shorter duration of symptoms showed higher D-dimer levels. Sensitivity and specificity in these patients ranged from 58% to 97% and from 77% to 97.5%, respectively. Nine articles were related to splanchnic vein thrombosis. One described a population of patients with mesenteric venous thrombosis, and the rest included patients with portal vein thrombosis. The D-dimer testing methods and the proposed cut-off levels were remarkably different among the included studies. Conclusion D-dimer testing should not be currently recommended for the diagnosis of thrombosis in unusual sites as a first line diagnostic tool. The development of algorithms combining biomarkers such as D-dimer and clinical decision tools could improve the diagnosis.

Introduction Identifying risk factors and strategies for the prevention of deep venous thromboembolism in major orthopedic surgery has allowed the development of Clinical Practice Guidelines (CPGs). Currently, there is a gap between clinical practice and the implementation of the recommendations of CPGs. The purpose of this paper is to report the impact of the implementation of improvement strategies on adherence to venous thromboembolism (VTE) prophylaxis guidelines. Materials and methods We defined 3 quality indicators to assess the adequate use of thromboprophylaxis according to CPGs. We obtained a baseline measurement and identified several barriers for adherence. Six improvement strategies to promote adherence to CPGs were designed and applied. A systematic monitoring of these indicators was performed in real time and a description of the data was completed for patients undergoing primary joint replacement of the hip, knee and shoulder, during February 2012 and August 2014. Results Data from 773 patients were obtained. In the first trimester, the average of adherence was: 98.3% for medical order in the post-operative note, 60.3% for opportune administration and 67% for adherence to therapy at home. In the trimester, the rates of adherence were 100%, 95.7% and 100% respectively. Conclusions Combined strategies for improvement of adherence to VTE prophylaxis is associated with higher compliance with clinical practice guidelines. © 2015 Published by Elsevier Ltd.

Introduction Von Willebrand disease (vWD) is the second least common hemostatic disorder in Malaysia, and it has a low prevalence. This study examined the underlying platelet thrombogenicity cascades in the presence of different formulations of chitosan-derivatives in vWD patients. This paper aimed to determine the significant influence of chitosan biomaterial in stimulating the platelet thrombogenicity cascades that involve the von Willebrand factor, Factor 8, Thromboxane A2, P2Y12 and Glycoprotein IIb/IIIa in vWD. Materials and methods Variable chitosan formulations of N,O-Carboxymethylchitosan (NO-CMC) and Oligo-Chitosan (O-C) were tested. Fourteen vWD subjects voluntarily participated in this study after signing informed consent forms. The patient’s demographic profiles, family history, type of vWD, clinical symptoms and laboratory profiles were recorded and analyzed. Enzyme-linked immunosorbent assay, flow cytometry and Western blot tests were used to determine the level of the chitosan-adhered-platelet-mechanisms. Results The study revealed that most patients were predominantly affected by vWD type I. The O-C group of chitosan’s scaffold pores is sufficient to allow for nutrients and cells. The O-C-stimulated-mediators are capable of initiating the platelet actions and were detected to expedite the blood coagulation processes. The oligo-group of chitosans was capable of amplifying and triggering more platelet activator’s pathways via the studied mediators. The present findings suggest that the ability of each type of chitosan to coagulate blood varies depending on its chemical composition. Conclusion The oligo group of chitosans is potentially capable of triggering platelet thrombogenicity cascades by activating platelets in vWD patients to form a platelet plug for hemostasis process.

Background Thrombophilia is reported to be a candidate etiology of recurrent pregnancy loss (RPL). No conclusive results on the association between prothrombin G20210A mutation and RPL have been reported. Methods We undertook a systematic review and meta-analysis of 37 case-control studies using a comprehensive electronic search on papers published by May 2014. We studied 5400 cases and 4640 controls to investigate the potential association between G20210A and RPL. In this review, we define RPL as more than 2 miscarriages. Results A significant association was found between G20210A and RPL, with a combined odds ratio (OR) of 1.81 (95% confidence interval [CI]: 1.26-2.60). However, the risks differed in the subgroup analyses, categorized by study sites, maternal age, and type of miscarriages. The pooled OR remained significant in European studies (OR: 1.80, 95% CI: 1.35-2.41), whereas in the Middle-Eastern studies, it was not significant (OR: 2.39, 95% CI: 0.96-5.92). The risk of RPL was significantly higher in women older than 29 years (OR: 1.91, 95% CI: 1.61-6.11), and a positive relationship was only observed between prothrombin G20210A mutation and fetal loss, but not embryonic loss. There was no evidence of publication bias in any of the analyses. The sensitivity analyses showed that the findings were quite stable. Conclusion This meta-analysis suggests that the G20210A prothrombin mutation increases the risk of RPL (fetal loss, primary RPL, or secondary RPL), particularly in Europeans and women older than 29 years. We recommend further screening in more specific groups among women.

The brain and the placenta synthesize identical peptides and proteins, such as brain-derived neurotrophic factor, oxytocin, vascular endothelial growth factor, cortisol, and matrix metalloproteinases. Given the promiscuity between neurochemistry and the mechanism of placentation, it would be expected that mental disorders occurring during pregnancy would increase the risk of adverse obstetric and neonatal outcomes. Indeed, expectant mothers with anxiety disorders, post-traumatic stress disorder, schizophrenia, or depressive disorders are at higher risk of preterm birth, low-birth-weight and small-for-gestational-age infants than controls. These mental illnesses are accompanied by a procoagulant phenotype and low activity of tissue plasminogen activator, which may contribute to placental insufficiency. Another risk factor for pregnancy complications is hyperemesis gravidarum, more common among women with eating disorders or anxiety disorders than in controls. Severe hyperemesis gravidarum is associated with dehydration, electrolyte imbalance and malnutrition, all of which may increase the risk of miscarriages, of low-birth-weight babies and preterm birth. This paper reviews some aspects of mental disorders that may influence pregnancy and neonatal outcomes.

The structure and function of the blood clot has been associated with altered risk of thrombosis. Dense fibrin structures with small pores increase the risk of thrombosis, and have major functional consequences by increasing the resistance to fibrinolysis and altering the visco-elastic properties of the clot. However, while the structural changes to the overall fibrin network have been extensively characterised, little is known regarding the intrafibrillar structure of fibrin, the way protofibrils are arranged inside the fibrin fibers and the functional consequences of this. This brief paper aims to review recent findings regarding novel mechanisms that regulate fibrin intrafibrillar structure, including the degree of protofibril packing, their functional consequences, and the effects of FXIII activation on clot structure and thrombosis. It is concluded that fibrin intrafibrillar structure represents a major novel mechanism that influences clot structure and stability. Future studies are required to investigate the role of fibrin intrafibrillar structure in the functional characteristics of the blood clot, and in diseases of bleeding and thrombosis.

Salvianolic acid B (SAB) is a hydrophilic component isolated from the Chinese herb Salviae miltiorrhizae, which has been used clinically for the treatment of ischemic cardiovascular and cerebrovascular diseases. Platelets-mediated vascular inflammatory response contributes to the initiation and progression of atherosclerosis. In this paper, we focus on the modulating effects of SAB on the inflammatory reaction of endothelial cells triggered by activated platelets. Human umbilical vein endothelial cells (EA.hy926) were pretreated with SAB followed by co-culture with ADP-activated platelets. Adhesion of platelets to endothelial cells was observed by amorphological method. The activation of nuclear factor-kappa B was evaluated by NF-κB p65 nuclear translocation and the protein phosphorylation. A determination of the pro-inflammatory mediators (ICAM-1, IL-1β, IL-6, IL-8, MCP-1) mRNA and protein were also conducted. In addition, the inhibitory effects of SAB on platelets activation were also evaluated using a platelet aggregation assay and assessing the release level of soluble P-selectin. The results showed that SAB dose-dependently inhibited ADP- or α-thrombin-induced human platelets aggregation in platelet rich plasma (PRP) samples, and significantly decreased soluble P-selectin release from both agonists stimulated washed platelets. It was also found that pre-treatment with SAB reduced adhesion of ADP-activated platelets to EA.hy926 cells and inhibited NF-κB activation. In addition, SAB significantly suppressed pro-inflammatory mediators mRNA and protein in EA.hy926 cells in a dose-dependent manner. These results indicated that, in addition to its inhibitory effects on platelets activation, SAB was able to attenuate platelets-mediated inflammatory responses in endothelial cells even if the platelets had already been activated. This anti-inflammatory effect was related to the inhibition of NF-κB activation. Our findings suggest that SAB may be a potential candidate for the treatment of various atherosclerotic diseases.

The Fontan procedure has transformed the lives of children born with single-ventricle physiology, previously deemed inoperable. Worldwide, there are an increasing number of children with Fontan circulation, with the potential for survival into adulthood. Due to the abnormal circulation, Fontan patients have an increased risk of thromboembolic (TE) events, with up to 25% of events leading to death. Despite the importance of preventing TE events in this patient population, there is currently no clinical consensus on the optimal monitoring, thromboprophylaxis therapies, and treatment of these events. This paper reviews the available literature regarding anticoagulation in the pediatric and adult Fontan population, including the mechanisms for thrombosis and current antithrombotic therapies.

Background Pediatric hospital-acquired venous thromboembolism (HA-VTE) rates have increased dramatically. To achieve generalizable knowledge in the derivation and validation of HA-VTE risk factors and risk prediction models and inform future risk-stratified prevention strategies, multi-institutional studies are needed. Objectives This paper presents an investigator-initiated, multicenter pediatric case-cohort study designed to identify risk factors for HA-VTE to create a HA-VTE risk prediction model. Methods A registry, which houses pertinent variables from HA-VTE subjects and non-HA-VTE controls, was created for the Children's Hospital-Acquired Thrombosis (CHAT) study. Specific variables from the registry associated with HA-VTE risk will be identified using multivariable regression to create a pediatric HA-VTE risk prediction model to be prospectively validated. Results Seven large pediatric institutions have entered over 600 HA-VTE subjects aged 0–21 years of age into the registry. Subjects showed a male predominance (57%), a median age of three years (IQR 0.3–13) and were most likely admitted to an intensive care unit (57%) at VTE diagnosis. Median time to HA-VTE was 10 days after admission. The most prevalent risk factors include central venous catheters (80%), surgery (43%), systemic steroids (31%), congenital heart disease (27%), infection (14%) and cancer (13%). Conclusions CHAT, with its creation of a risk prediction model with prospective validation using the CHAT registry, is a novel study design and will be the first step in identifying safe and effective strategies to decrease HA-VTE in children by helping define the highest risk population for initial, or more aggressive, thromboprophylaxis efforts.

Placenta-mediated pregnancy complications, such as pre-eclampsia, placental abruption, birth of a small-for-gestational age infant and late pregnancy loss, are common and carry significant morbidity and mortality. The etiology of placenta-mediated pregnancy complications is likely multifactorial and may include abnormal coagulation activation of the maternal-fetal interface. The use of antepartum low-molecular-weight heparin (LMWH) prophylaxis to prevent recurrent placenta-mediated pregnancy complications has become common practice despite limited and conflicting evidence to support its use. This paper reviews the evidence, including recently published data from an individual patient level meta-analysis, which challenges the role of LMWH in preventing recurrent placenta-mediated pregnancy complications. Incorporating this recent evidence, we recommend against the use of LMWH to prevent recurrent placenta-mediated pregnancy complications in women with and without inherited thrombophilia.

Antithrombin (AT) deficiency is a high-risk thrombophilia and a rare condition. Despite full anticoagulation during pregnancy and the postpartum period, women with AT deficiency may still be vulnerable to developing venous thromboembolism (VTE), including fatal events. There is limited guidance on the management of AT deficiency in pregnancy, including the role of AT concentrates. Following a comprehensive review of the state of the art with respect to recommendations and guidelines, our expert panel in maternal-fetal medicine, hematology and basic science reached consensus on key issues in the recognition and management of AT deficiency in pregnancy. This paper summarizes the state of the art and summarizes what we believe are best practices with special emphasis on a multidisciplinary approach involving obstetrics and hematology in the care of women with AT deficiency.

The relationship between cancer and thrombosis is a complex one with the haemostatic system and mechanisms of cancer growth and metastasis inextricably linked. The possibility that antithrombotics may confer a survival benefit on cancer patients has been considered for over sixty years, over which time a growing body of evidence has suggested that drugs such as low molecular weight heparins may inhibit cancer growth and metastasis through a myriad of mechanisms. Much of the trial data suggesting a survival benefit has been obtained through secondary subgroup analyses in highly heterogeneous populations. To date no sufficiently powered studies have been undertaken which support the routine use of LMWH to improve survival in cancer patients. This paper will review the current evidence around the topic to identify where we currently stand in this exciting yet challenging field.

Introduction Cerebral ischaemia is associated with altered platelet and fibrin network ultrastructure indicating increased coagulation activity and resistance to fibrinolysis; which may lead to the occlusion of blood vessels. Recently, it has been shown that the addition of red blood cells to plasma has a significant effect on the structural and mechanical properties of fibrin clots and is associated with lytic resistance of thrombi. Materials and Methods Whole blood was collected from pre-ischaemic control Sprague Dawley rats and those in which experimental cerebral ischaemia was induced by hyperglycaemic two-vessel occlusion, for the ultrastructural investigation of whole blood thrombi by scanning electron microscopy. Post-ischaemic groups were terminated at 2 h, 24 h and 48 h subsequent to reperfusion; which were time points selected for the demonstration of initial inflammation upon neural injury, maximal neural injury and onset of regeneration. Results Subsequent to ischaemic insult, red blood cells transformed from normal discoid shape to form projections which allowed them to interact both with each other and with fibrin fibres in various manners. Researches have in recent years shown that inclusion of red blood cells in experimental coagula results in delayed fibrinolysis and lytic resistance. This paper shows the morphological alterations at cellular level which may elucidate the structural and mechanical strength of these clots. Conclusions Through the extension of projections, red blood cells become intertwined within a thrombus to stabilise and strengthen its structure. The tighter these mechanical bonds, the more resistant thrombi are to lysis, an established characteristic of thrombi in cerebral ischaemia.

Background Glycoprotein (GP) Ibα contains binding sites for von Willebrand factor (VWF), α-thrombin, P-selectin, and Mac-1 at the extracellular N-terminal 282 residues. Particularly, the interaction of GPIbα with VWF exposed at the injured vessel wall initiates platelet adhesion, and simultaneously triggers intracellular signaling leading to integrin activation and platelet thrombus formation. Therefore, GPIbα ectodomain shedding, which down-regulates the surface expression of the functional receptor and results in the generation of glycocalicin (GC), a soluble N-terminal fragment of GPIbα, has important implications for thrombosis and hemostasis. Stimulations of platelet with either physiological or chemical compounds result in GPIbα ectodomain shedding in vitro and in vivo. The generation of ROS has been observed in platelets stimulated with physiological or chemical compounds, such as collagen, thrombin, and thromboxane A2 analog U46619. In this paper, we plan to clarify the relationship between physiological stimulation-induced ROS generation and GPIbα shedding and the regulatory mechanism of ADAM17-mediated GPIbα shedding. Methods Washed platelets (3×108/ml) were pre-incubated with or without N-acetylcysteine (NAC) (10 mM), dithiothreitol (DTT) (3 mM), or vehicle control (DMSO) at RT for 15 minutes, and then were incubated with A23187 (5 μM), thrombin (1 U/ml), collagen (5 ug/ml), or dibucaine (1 mM) at 37 °C (or at RT for dibucaine) for different time. Western blot and flow cytometry was used to evaluate the GPIbα ectodomain shedding. ROS levels in platelets were examined using ROS assay kit according to the manufacture’s instruction. Results and conclusions Collagen, thrombin, and calcium ionophore A23187 induced ROS generation, and simultaneously incurred GPIbα ectodomain shedding. ROS scavengers NAC and DTT abolished not only collagen, thrombin, and A23187 induced ROS production, but also GPIbα ectodomain shedding. Interestingly, a recognized calpain activator, dibucaine, induced both ROS production and GPIbα shedding, which were also obviously reduced by NAC and DTT. Furthermore, calpain inhibitors calpain inhibitor I and carbobenzoxy-valinyl-phenylalaninal (MDL), obviously reduced dibucaine-induced ROS production, and inhibited ROS generations induced by A23187 and thrombin. These data indicate that ROS, regulated by calpain, plays a key role in collagen, thrombin, and A23187 induced GPIbα ectodomain shedding. These findings will help to understand the negative-regulatory mechanisms of platelet function, and may suggest a novel strategy to design new class of anti-platelet drug. Disclosures: No relevant conflicts of interest to declare.

Whilst the term cancer associated thrombosis (CAT) offers an overarching term for all thrombotic events encountered during the cancer journey, the reality is that this is a far too simplistic reflection of a complex multifactorial process occurring within a heterogeneous population. The management of CAT needs to consider factors beyond the thrombus itself: patients must be treated as individuals within the context of their own cancer journey and their preferences for different treatment options. The breath of pathological, pharmacological and psychosocial variants means it is highly unlikely that one treatment regime will be appropriate for all patients. It is inevitable that regimes may need to be modified and anticoagulant agents changed according to clinical and patient preference needs. There is strong evidence supporting the use of low molecular weight heparin first line in the treatment of acute CAT. The evidence for warfarin and the direct acting oral anticoagulants is not as strong but, as oral agents, may be preferred by some patients. This paper shall identify the various treatment options available, factors which will influence the decision making process and when it is justifiable to treat patients differently to the established protocol.

Background The immediate administration of oral antiplatelet therapy in the form of aspirin plus a P2Y12 inhibitor is the universally recognised standard of care for patients who present with acute myocardial infarction. Despite strong recommendations for their use, there are a paucity of data describing their onset of action and clinical efficacy during the short time frames from confirmation of diagnosis to reperfusion with primary percutaneous coronary intervention. Objectives To complete a systematic review evaluating the currently available evidence regarding the pharmacokinetic and pharmacodynamic activity of orally administered clopidogrel, prasugrel and ticagrelor during the acute phase of a myocardial infarction in relation to mechanical reperfusion with primary percutaneous coronary angioplasty. Methods We searched PubMed and EMBASE databases up to January 2016 using the terms outlined in our search strategy. Results Twelve papers were included in our final analysis; seven relating to pharmacodynamic studies, one to a pharmacokinetic study and four to pharmacokinetic/pharmacodynamic studies. Conclusion Our results indicate that despite the administration of oral P2Y12 inhibitors including newer more potent agents that should allow for greater and more consistent levels of platelet inhibition, the physiological state of ST segment elevation MI (STEMI) and the co-administration of opioid based analgesia are associated with a reduction in the degree of platelet inhibition achieved following their administration.

Mechanisms involved in the relationship between hyperhomocysteinemia and hemostatic process are still unclear. In the literature there are few papers describing studies on the effects of homocysteine (Hcys) on proteins that participate in blood coagulation and fibrinolysis in human. The aim of our study was to establish and compare the influence of a reduced form of Hcys (at final doses of 0.01 – 1 mM) and the most reactive form of Hcys – its cyclic thioester, homocysteine thiolactone (HTL, 0.1 – 1 μM) on the clot formation (using whole human plasma and purified fibrinogen) and the fibrin lysis. Moreover, the aim of our study was to explain the effect of plasma protein modifications (S- and N-homocysteinylation) on selected parameters of hemostasis. We observed that HTL, like its precursor, a reduced form of Hcys stimulated polymerization of fibrinogen, but this process was not dose-dependent. In the presence of HTL (at the lowest tested concentration – 0.1 μM) the increase was about 55%. Our present results also demonstrated that Hcys in the reduced form (0.01 – 1 mM) and HTL at lower doses than Hcys (0.1 – 1 μM) reduced the fibrin lysis in whole human plasma. Our results reported that HTL, like the reduced form of Hcys (at concentrations corresponding to concentrations in plasma during hyperhomocysteinemia) induced modifications of hemostatic plasma proteins, and the consequence of these modifications may be alteration in protein structure associated with changes of hemostatic functions.

Women with bleeding disorders are disproportionately affected by reproductive tract bleeding and other related complications. Data on the management of women with bleeding disorders are hampered by a lack of randomized trials, case-control studies or even large case series. In the absence of strong evidence to direct practice, government agencies and hemophilia organizations have developed consensus guidelines. This paper summarizes existing recommendations from these guidelines.

Chronic venous insufficiency resulting in post-thrombotic syndrome occurs commonly after acute deep vein thrombosis, and is a prevalent cause of vascular disease morbidity in the community. Therefore, a better understanding of the pathophysiologic mechanisms that promote the development of chronic venous insufficiency could lead to novel approaches to interrupt the natural history and prevent post-thrombotic syndrome. In this paper, we will review the evidence that venous thrombus resolution is an inflammatory process that is dependent on chemokines and leukocytes.

In previous papers we described insoluble polystyrenes grafted with L-arginyl methyl ester (PAOM) which exhibit a high affinity for thrombin. Based on their specific interaction with the protease, the resin has been used as stationary phases for affinity chromatographic procedure of thrombin in affinity chromatography (AC) and high performance liquid affinity chromatography (HPLAC). A slight adsorption of antithrombin III (AT III) was shown in AC. In this paper we study the interaction of AT III for PAOM resin in batch procedure. The adsorption is measured using purified protein and corresponds to a monolayer adsorbed on the surface of the polymer. The affinity constant is evaluated kAT = 3.105 1.M-1. Furthermore, insoluble sulfonated polystyrenes grafted with different amino acid were shown to possess an heparin-like behaviour and catalyse the generation of thrombin-AT III complex. So, compared to one of the resin previously mentioned, it could be concluded that PAOM is not heparin-like. When thrombin is adsorbed on the surface of the polymer, AT III cannot interact with the specific seryl residue of the enzyme.

ADP plays a key role in platelet aggregation which has led to the development of antiplatelet drugs that target the P2Y12 receptor. The aim of this study was to characterize the effects of two novel P2Y12 receptor antagonists, BX 667 and its active metabolite BX 048, on platelets. BX 667 and BX 048 block the binding of 2MeSADP to platelets and antagonize ADP-induced platelet aggregation in human, dog and rat washed platelets. Both compounds were shown to be reversible inhibitors of platelet aggregation. BX 048 prevents the decrease in cAMP induced by treatment of platelets with ADP. The specificity of BX 667 and BX 048 was demonstrated against cell lines expressing P2Y1 and P2Y6 as well as against a panel of receptors and enzymes. Taken all together these data show that both BX 048 and BX 667 are potent P2Y12 antagonists with high specificity which, in the accompanying paper are demonstrated to behave predictably in vivo.

Introduction Various dysfibrinogenemias have been described worldwide. This paper describes two new cases of dysfibrinogenemia identified in the Czech Republic. Materials and methods The proposita of fibrinogen Nový Jicin, a 12-year-old girl, presented with hemorrhagic complications, low Clauss fibrinogen level (0.3 g/l) and prolonged both thrombin (70.8 s) and reptilase (> 180 s) time. Her mother and sister both presented with normal coagulation tests, normal fibrinogen level and reported no history of bleeding. The carriers of the fibrinogen Praha II were a 31-year-old man and his 11-year-old daughter. They both presented with low fibrinogen Clauss level (0.88 g/l) and prolonged thrombin and reptilase time. To identify the genetic mutation responsible for these dysfibrinogens, genomic DNA extracted from the blood was analyzed. The presence of the mutant chains in the circulation was determined by MALDI-TOF mass spectroscopy. Scanning electron micrographs of the patients' fibrin clots were obtained. Results The kinetics of fibrinopeptide release and fibrin polymerization were impaired for both fibrinogen Nový Jicin and Praha II. DNA sequencing showed heterogeneous fibrinogen Aα R16C mutation in the fibrinogen Nový Jicin case and heterogeneous fibrinogen Aα R16H in the fibrinogen Praha II case. The mutant chains were found to be expressed to the circulation by MALDI-TOF mass spectroscopy. Scanning electron micrographs of the patient's fibrin clot were found to be abnormal. Conclusions The case of dysfibrinogenemia Aα R16C-fibrinogen Nový Jicin and the case of dysfibrinogenemia Aα R16H were found by routine coagulation testing and were genetically identified.

Background Lenalidomide in combination to steroid therapy, including high-dose dexamethasone (RD), low-dose dexamethasone (Rd) or triple therapy of melphalan, prednisolone, lenalidomide (MPR), has shown to be an effective and well-tolerated treatment for patients with newly diagnosed multiple myeloma (NDMM) and relapsed refractory multiple myeloma (RRMM). Lenalidomide is associated with an increased risk of venous thromboembolism, and studies have consistently demonstrated the need for venous thromboembolism (VTE) prophylaxis in patients receiving these combinations. However, the optimal approach to thromboprophylaxis has not yet been established. Objective In this systematic review we sought to compare the efficacy of aspirin (ASA) or low molecular weight heparin (LMWH) in the prevention of VTE in patients with myeloma using lenalidomide- based therapy. Methods A systematic literature search strategy was used to identify potential studies on MEDLINE, EMBASE, and CENTRAL using an OVID interface. The methodological quality of the selected cohort studies was assessed according to Newcastle-Ottawa Quality Assessment Scale, and risk of bias of randomised controlled trials (RCTs) was assessed according to risk of bias assessment tool from the Cochrane Handbook. The primary outcome measure was the incidence rate of VTE while using ASA or LMWH. Results Out of 247 studies, 6 met our inclusion criteria with a total of 1126 participants including a total of 5 phase III RCTs, and one retrospective study. Overall, all studies show high quality: In 4 of the 5 RCTs type of randomization was clearly reported, outcome assessment was blinded, and withdrawal rates were reported, and the remaining RCT was an abstract. In 4 RCTs the intervention and comparator arms were related to anti-myeloma treatment regimens. Pooled data of studies of NDMM treated with lenalidomide based regimen with ASA prophylaxis show a VTE rate of 98 of 915 (10.7%) [95% CI: 8.86-12.88] (Table1). In NDMM and RRMM patients treated with lenalidomide, VTE rate on LMWH prophylaxis was 3 of 211 (1.4%) [95% CI: 0.48-4.09] (Table2). The relative risk (RR) of VTE in patients receiving ASA compared to LMWH was 7.5 (95% CI: 2.41-23.53, p =0.0005). Overall, the rate of VTE was 1.4 (95% CI: 1.14 - 1.69) per 100 patient-cycles of anti-myeloma treatment. A subgroup analysis on patient using ASA showed a similar risk of 1.5 (95% CI: 1.24 - 1.84).The incidence of VTE in those using ASA while on RD was 52 of 195 (26.6%) [95% CI: 20.9-33.2], while VTE rate in those receiving Rd was 27 of 262 (10.3%) [95% CI: 7.18-14.58] demonstrating a statistically significant higher risk for patients on RD [RR=2.5 (95% CI: 1.68- 3.96), p Conclusion The study showed that the most frequent thromboprophylaxis of choice for patients with myeloma on lenalidomide-based therapy is ASA. However, ASA may not confer appropriate protection against VTE, especially in patients using high dose dexamethasone. On the other hand, the risk of VTE in patients receiving MPR and ASA was low and ASA may be a safe option for these patients. More studies comparing the safety of ASA to other anticoagulants such as LMWH or direct oral anticoagulants are warranted. Table 1. Rate of VTE using ASA in NDMM with different lenalidomide based regimens. Rx: treatment; 95% CI: 95% confidence interval. Study Design Rx N VTE rate: N (%) 95% CI Zonder, 2010 Rajkumar, 2010 Phase III RCT RD 195 52 (26.6) 20.9-33.2 Larocca, 2011 Rajkumar, 2010 Phase III RCT Rd 262 27 (10.3) 7.18-14.58 Palumbo, 2012 Stewart, 2014 Phase III RCT MPR 458 19 (4.1) 2.67-6.38 Total 915 98 (10.7) 8.86-12.88 Table 2. Rate of VTE using LMWH in myeloma patients (NDMM or RRMM) on lenalidomide-based regimen. 95% CI: 95% confidence interval. Paper Design Induction Setting N VTE rate: N (%) 95% CI Klein, 2008 Retrospective cohort RD RRMM 45 1(2.2) 0.39-11.57 Larocca, 2011 Phase III RCT Rd NDMM 166 2(1.2) 0.33-4.28 Total 211 3(1.4) 0.48-4.09 Disclosures Louzada: pfizer: Consultancy, Other: advisory board and expert opinion; janssen: Consultancy, Other: advisory board and expert opinion; Celegene: Consultancy, Other: advisory board and expert opinion.

Type 1 von Willebrand disease (VWD) is transmitted mainly as a dominant trait - especially in forms involving von Willebrand factor (VWF) levels below 20 U/dL - and less frequently as a recessive trait. In the latter case, mutations at heterozygous level may be associated with type 3 carrier status, while mutations at homozygous or compound heterozygous level often coincide with type 3 VWD. Here we present a recessive, severe type 1 form as a distinct type of VWD. Eight patients with severe type 1 VWD belonging to 7 unrelated families were studied. They had VWF levels below 10 U/dL, FVIII higher than 10 U/dL, and a significantly lower than normal platelet VWF content. All patients were homozygous or compound heterozygous for the c.1534-3C>A VWF mutation, that simultaneously induces the skipping of exon 14, the activation of a cryptic splice site, and a normal VWF gene transcription. This means that one of the three different mRNA generated assures the synthesis of normal VWF. The probands' relatives who were heterozygous for the c.1534-3C>A mutation always had low platelet VWF levels, sometimes with circulating VWF levels within normal range. This finding confirms the utility of measuring platelet VWF content to identify an abnormal VWF synthesis. Because the c.1534-3C>A mutation impairs, but does not abolish normal mRNA processing, it may never cause type 3 VWD. We propose a model of severe recessive type 1 VWF defect associated with mutations that sporadically go undetected by the cells’ molecular machinery, as the c.1534-3C>A VWF mutation. Bullet Points What is known about this topic? - Type 1 VWD is transmitted mainly as a dominant trait. - Recessive type 1 mutations at homozygous or compound heterozygous level are often associated with type 3 VWD, and at heterozygous level with type 3 VWD carrier status. What does this paper add? - There are quantitative VWF mutations, such as c.1534-3C>A, that impair, but do not abolish normal mRNA processing. - The c.1534-3C>A VWF mutation simultaneously induces the skipping of exon 14, the activation of a cryptic splice site, and a normal VWF gene transcription. - The c.1534-3C>A mutation is the archetype of mutations that cause severe recessive type 1 VWD, but never type 3 VWD. - Recessive, severe type 1 appears to be a distinct form of VWD.

The presence of one acidifying Cl-/HCO3- exchange mechanism in human platelets has not been previously reported. This paper demonstrates that this mechanism does function and that it increases its activity after stimulation with thrombin. On resuspension of BCECF-loaded platelets in a chloride-free medium (gluconate replaced) that contains bicarbonate, cytosolic pH (pHi) increased and stabilized after 10 min at an alkaline value. After addition of 50 mM NaCl, pHi fell rapidly reaching steady state in the succeeding 5 min. The stilbene derivative 4-acetamido-4'-isothiocyanato stilbene-2,2' disulfonic acid (SITS) inhibited both, the alkalization in chloride-poor solution and the recovery from the alkaline load after chloride enrichment. The decline in pHi was observed whether chloride was delivered to the solution in the form of LiCl or NaCl, or when the later was applied after blockage of the Na+/H+ exchanger. The recovery in chloride-containing solution was in contrast to the effect of a similar change in osmolarity by addition of 50 mM sodium gluconate that did not produced a significant variation of pHi. Posterior addition of NaCl after 5 min in high gluconate reproduced the pHi fall of the control experiment. Alkali loads produced by 25 mM trimethylamine hydrochloride (TMA) were also counteracted by HCO(3-)-equivalent efflux via Cl-/HCO3- exchange. One of the major observations of the present study is that HCO3- equivalent efflux was twice as high when the platelets were previously stimulated with 0.1 IU of thrombin, but thrombin did not produce significant changes of the pHi recovery rate in a bicarbonate-free solution. The increase of the decline in pHi elicited by preexposure to thrombin was still observed in the presence of an inhibitor of the Na+/H+ exchange or in sodium-free solutions. It is concluded that a Na-independent Cl-/HCO3- exchange mechanism mediates the recovery of pHi from alkalosis in platelets and that thrombin activates this exchanger by a direct regulatory pathway.

Patients with antiphospholipid antibodies (APLA) are at risk of arterial thromboembolism (ATE) or venous thromboembolism (VTE). The true strength of the association between APLA and first TE is unknown as there are no prospective studies of a large, well-characterized inception cohort of matched patients with and without APLA. Thus, evidence-based treatment recommendations for primary prophylaxis of TE in such patients cannot be made. Optimal therapy of patients with recent TE and APLA remains controversial; although there is no doubt that some such patients have a malignant hypercoagulable state characterized by resistance to "usual intensity" anticoagulation; recent evidence suggests that most such patients are adequately treated with "usual therapy". After warfarin discontinuation, such patients appear to be at increased risk of recurrent TE, as demonstrated in a series of studies of discontinuation of secondary TE prophylaxis in patients with APLA and venous TE (VTE). Because of this increased risk of recurrent TE, after anticoagulants are discontinued, most "experts" recommend extended duration therapeutic dose warfarin for such patients. This paper will briefly review this evidence.

There are many well-known drawbacks associated with the currently used antithrombotic agents, warfarin, heparin, and low-molecular-weight heparins (LMWHs). Because heparins can be administered only parenterally, their application is limited. Though warfarin can be administered orally, its unpredictable anticoagulant effect means that it must be regularly monitored. Ximelagatran (Exanta, AstraZeneca) is a novel, oral direct thrombin inhibitor (oral DTI) that is rapidly converted to its active form, melagatran, upon administration. The antithrombotic effects of melagatran have been demonstrated. Following the oral administration of ximelagatran, melagatran has stable and reproducible pharmacokinetic and pharmacodynamic properties that enable ximelagatran to be administered orally, twice daily, according to a fixed-dose regimen, with no need for routine coagulation monitoring. In view of its favourable profile, a clinical trial programme has been designed to evaluate the efficacy and tolerability of ximelagatran compared with standard therapies, for the prophylaxis and treatment of venous thromboembolism (VTE), the prevention of stroke in patients with atrial fibrillation (AF), and the prevention of cardiovascular events in patients with previous acute coronary syndromes. These studies show that oral ximelagatran is well tolerated at doses of up to 60 mg, twice daily (bid), and that it is as effective as standard therapy for the prevention of thromboembolic events in patients undergoing hip or knee replacement surgery, for the treatment of clinically verified acute deep vein thrombosis (DVT), and in patients with nonvalvular AF who have a moderate to high risk of stroke. The protocols and results of some of these studies--and a study that investigates the use of ximelagatran in combination with aspirin for the management of acute coronary artery disease--are described in this paper.

Insulin lispro (Lys B28, Pro B29) is a rapid recombinant insulin analog identical to human insulin except for the inversion of the proline–lysine amino acid sequence at positions 28 and 29 in the C-terminal of the beta-chain; this reversal determines a conformational modification that reduces the ability of insulin monomers to form dimers, and therefore accounts for the physicochemical property of a weak self-association [1]. Consequently, insulin lispro is absorbed more rapidly by the subcutaneous tissue than human regular insulin, with faster, higher and shorter-lasting peak serum insulin levels [2], thus better reproducing the physiological post-prandial insulin profile [3]. Few studies have considered the non-metabolic effects of insulin analogs on isolated cells; recently, we observed that the other rapid insulin analog, insulin aspart, obtained by replacing proline position 28 of the B chain of insulin with negatively charged aspartic acid [4], anti-aggregates platelets as human regular insulin by activating the nitric oxide (NO)/cyclic nucleotide pathway, but with kinetic differences, resulting in more prolonged effects [5]. We extensively described in previous papers the platelet anti-aggregating effect exerted by insulin via a phosphati

With the availability of efficient and safe clotting factor replacement therapy, elective total joint arthroplasty is increasingly performed in subjects with haemophilia suffering from chronic haemophilic arthropathy. Little has been published addressing the prevalence and the specific risk factors of thromboembolic complications and the role of thromboembolic prophylaxis in this specific population. While the risk of thrombosis in hemophilic patients following hip or knee arthroplasty is considered to be low and probably mitigated by the clotting factor deficiency, cases have been reported of pulmonary embolism and deep vein thrombosis in hemophilic patients. Although most guidelines advocate thromboembolic prophylaxis in the general population undergoing major orthopaedic surgery, no such standard of care is in place for hemophilic patients. This paper discusses the scope of the problem of venous thromboembolism in patients with haemophilia undergoing major orthopaedic surgery and reviews the published approaches to the use of prophylactic anticoagulation in this setting.

The treatment and prevention of deep vein thrombosis (DVT) and pulmonary embolism (PE) in pregnant patients is challenging for several reasons. Coumarins can cause embryopathy and other adverse effects in the fetus. Although unfractionated heparin and low-molecular-weight heparins, the cornerstones of initial therapy, are safe for the fetus, they can have significant maternal side effects, including osteoporosis and thrombocytopenia. Because they must be given parenterally, long-term administration is inconvenient. Further, although low-molecular-weight heparins probably cause less maternal osteoporosis and thrombocytopenia than unfractionated heparin, the appropriate dosing regimens for prevention and treatment of thrombosis during pregnancy have not been established. In addition, there is a paucity of reliable information on the incidence of venous thromboembolism and the risk of recurrent thrombosis during pregnancy. This paper briefly reviews the areas of controversy and provides recommendations for the treatment and prophylaxis of acute deep vein thrombosis and pulmonary embolism in pregnant patients.