Short activated partial thromboplastin times are related to increased thrombin generation and an increased risk for thromboembolism

Evaluation of coagulation profile in dogs with ACTH-dependent hyperadrenocorticism compared to healthy dogs by rotational thromboelastometry (ROTEM)

Despite their low morbidity, thromboembolic events in hyperadrenocorticism are associated with high mortality. Identifying the main hemostatic abnormalities will improve the prophylactic approach of these canine patients. The aim of this study was to evaluate hemostatic alterations related with ACTH-dependent HAC and its association with hypercoagulable state. For this purpose, 25 dogs diagnosed with ACTH-dependent HAC were compared with 28 healthy dogs as a control group. The hemostatic variables included platelet count, antithrombin, fibrinogen, D-dimer, PT, aPTT, rotational thromboelastometry (ROTEM) and platelet aggregation. Results showed a hypercoagulable state in 32% (8/25) dogs by ROTEM, which had at least 2 of the next features: decreased coagulation time (CT) or clot formation time (CFT) on INTEM (5/25) or EXTEM (4/25); increased maximum clot firmness (MCF) on INTEM (9/25), EXTEM (6/25) and FIBTEM (9/25). These same variables had a significant difference (P≤ 0.05) compared with the control group, as well as the parameters of α-angle and CT. Median fibrinogen levels (310 vs.178 mg/dL), mean platelet aggregation (11.1 vs. 7.9 Ohms), median platelet count (360 vs. 225 ×103/µL) and mean antithrombin activity (140 vs. 119%) were increased in ACTH-dependent HAC dogs compared to control group. PT (7.1 vs. 8.0 seconds) and aPTT (11.6 vs. 15.2 seconds) were also shortened in ACTH-dependent HAC dogs. Our findings confirm the presence of a hypercoagulable tendency in dogs with HAC. Although multifactorial, fibrinogen concentration and MCF FIBTEM showed the relevance of this protein for hypercoagulability in HAC.

CA125-Associated Activated Partial Thromboplastin Time and Thrombin Time Decrease in Patients with Adenomyosis

Objective

Adenomyosis patients are in a hypercoagulable state, and studies have shown that carbohydrate antigen125 (CA125) may relate to the hypercoagulability and thrombosis of patients with adenomyosis, but there is still a lack of clarity regarding the changes in CA125-related coagulation indicators. This study was to explore the changes and influencing factors of CA125-related coagulation parameters in patients with adenomyosis.

Methods

Retrospective observational study conducted on 200 patients with adenomyosis (AM group), 240 patients with uterine leiomyoma (LM group) and 81 patients with cervical intraepithelial neoplasia (CIN)-III (control group), of which the coagulation parameters were detected by clinical blood sample collection and statistical method analysis and informed consent was obtained.

Results

The level of CA125 in the AM group was significantly higher than that in the LM group and control group. However, thrombin time (TT) shortened in the AM group when compared with the LM and control group. Activated partial thromboplastin time (APTT) in the AM group was shorter than in the control group. Multivariate logistic regression analysis found that adenomyosis was associated with CA125 level (OR=323.860, 95% CI 90.424-1159.924, P<0.001), APTT (OR=1.295, 95% CI 1.050-1.598, P=0.016), TT (OR=0.642, 95% CI 0.439-0.938, P=0.022), menorrhagia (OR=7.363, 95% CI 2.544-21.315, P<0.001), dysmenorrhea (OR=22.590, 95% CI 8.185-62.347, P<0.001). Correlation analysis revealed that APTT (r= -0.207) and TT (r = -0.174) were negatively correlated with the level of CA125.

Conclusion

The shortening of CA125-related APTT and TT indicates that it is meaningful to detect coagulation parameters of patients with elevated CA125 levels early, dysmenorrhea and menorrhagia, and maybe further discover the hypercoagulability and prevent the occurrence of thrombus in adenomyosis.

The Role of Platelets in the Pathogenesis and Pathophysiology of Adenomyosis

Widely viewed as an enigmatic disease, adenomyosis is a common gynecological disease with bewildering pathogenesis and pathophysiology. One defining hallmark of adenomyotic lesions is cyclic bleeding as in eutopic endometrium, yet bleeding is a quintessential trademark of tissue injury, which is invariably followed by tissue repair. Consequently, adenomyotic lesions resemble wounds. Following each bleeding episode, adenomyotic lesions undergo tissue repair, and, as such, platelets are the first responder that heralds the subsequent tissue repair. This repeated tissue injury and repair (ReTIAR) would elicit several key molecular events crucial for lesional progression, eventually leading to lesional fibrosis. Platelets interact with adenomyotic cells and actively participate in these events, promoting the lesional progression and fibrogenesis. Lesional fibrosis may also be propagated into their neighboring endometrial-myometrial interface and then to eutopic endometrium, impairing endometrial repair and causing heavy menstrual bleeding. Moreover, lesional progression may result in hyperinnervation and an enlarged uterus. In this review, the role of platelets in the pathogenesis, progression, and pathophysiology is reviewed, along with the therapeutic implication. In addition, I shall demonstrate how the notion of ReTIAR provides a much needed framework to tether to and piece together many seemingly unrelated findings and how it helps to make useful predictions.

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.

An examination of causal associations and shared risk factors for diabetes and cardiovascular diseases in the East Asian population: A Mendelian randomization study

BACKGROUND

One of the major contributors to disability and mortality among diabetics is cardiovascular disease (CVD), with coronary artery disease (CAD) as the most prevalent type. However, previous studies have provided controversial evidence linking diabetes to other types of CVDs, such as atrial fibrillation (AF). In addition, the risk factors that predispose people to the risk of diabetes and its complications differ across ethnicities, but the disease risk profiles in the East Asian population have been less investigated.

METHODS

The causal association between type 2 diabetes (T2D) and two types of CVDs (i.e., AF and CAD) in the East Asian population was first studied using Mendelian randomization (MR) analyses. Next, we examined the causal effect of 49 traits on T2D and CAD to identify their separate and shared risk factors in East Asians. A causal mediation analysis was performed to examine the role of T2D in mediating the relationship between the identified shared risk factors and CAD.

RESULTS

T2D was causally associated with CAD, but not AF, in East Asians. A screening of the risk factors indicated that six and 11 traits were causally associated with T2D and CAD, respectively, with suggestive levels of evidence. Alkaline phosphatase (ALP) was the only trait associated with both T2D and CAD, as revealed by the univariable MR analyses. Moreover, the causal association between ALP and CAD no longer existed after adjusting T2D as a covariable in the causal mediation study.

CONCLUSION

Our study highlights the risk profiles in the East Asian population, which is important in formulating targeted therapies for T2D and CVDs in East Asians.

PEG-Like Brush Polymer Conjugate of RNA Aptamer That Shows Reversible Anticoagulant Activity and Minimal Immune Response

Ribonucleic acid (RNA) therapeutics are an emerging class of drugs. RNA aptamers are of significant therapeutic and clinical interest because their activity can be easily reversed in vivo-a useful feature that is difficult to achieve using other therapeutic modalities. Despite their therapeutic promise, RNA aptamers are limited by their poor blood circulation. The attachment of polyethylene glycol (PEG) to RNA aptamers addresses this limitation. However, an RNA aptamer-PEG conjugate that is a reversible anticoagulant fails in a clinical trial due to the reactivity of the conjugate with pre-existing PEG antibodies and has cast a pall over PEGylation of aptamers and other biologics, despite its long history of utility in drug delivery. Here, PEG antibody-reactivity of this RNA aptamer is eliminated by conjugating it to a next-generation PEG-like brush polymer-poly[(oligoethylene glycol) methyl ether methacrylate)] (POEGMA). The conjugate retained the drug's therapeutic action and the ability to be easily reversed. Importantly, this conjugate does not bind pre-existing PEG antibodies that are prevalent in humans and does not induce a humoral immune response against the polymer itself in mice. These findings suggest a path to rescuing the PEGylation of RNA therapeutics and vaccines from the deleterious side-effects of PEG.

SARS-CoV-2 triggered oxidative stress and abnormal energy metabolism in gut microbiota

Specific roles of gut microbes in COVID-19 progression are critical. However, the circumstantial mechanism remains elusive. In this study, shotgun metagenomic or metatranscriptomic sequencing was performed on fecal samples collected from 13 COVID-19 patients and controls. We analyzed the structure of gut microbiota, identified the characteristic bacteria, and selected biomarkers. Further, gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) annotations were employed to correlate the taxon alterations and corresponding functions. The gut microbiota of COVID-19 patients was characterized by the enrichment of opportunistic pathogens and depletion of commensals. The abundance of Bacteroides spp. displayed an inverse relationship with COVID-19 severity, whereas Actinomyces oris, Escherichia coli, and Streptococcus parasanguini were positively correlated with disease severity. The genes encoding oxidoreductase were significantly enriched in gut microbiome of COVID-19 group. KEGG annotation indicated that the expression of ABC transporter was upregulated, while the synthesis pathway of butyrate was aberrantly reduced. Furthermore, increased metabolism of lipopolysaccharide, polyketide sugar, sphingolipids, and neutral amino acids were found. These results suggested the gut microbiome of COVID-19 patients was in a state of oxidative stress. Healthy gut microbiota may enhance antiviral defenses via butyrate metabolism, whereas the accumulation of opportunistic and inflammatory bacteria may exacerbate COVID-19 progression.

Efficacy of using thromboelastography to detect coagulation function and platelet function in patients with acute cerebral infarction

Thromboelastography (TEG) is commonly used to predict coagulation state in patients with active bleeding. However, the correlation between TEG parameters and conventional tests in patients with cerebrovascular disease (CVD) remains unexplored. Here, we assessed the TEG values and their correlation with conventional tests in patients with acute cerebral infarction. Eighty-eight patients with acute cerebral infarction were enrolled from the Department of Neurology of Suzhou Medical School. Thirty healthy controls were enrolled from the preventive care department in the same hospital who were taking a physical examination. TEG 5000 thromboelastogram system was used to obtain TEG parameters. The automatic blood coagulation analyzer was used to measure the activated partial thromboplastin time (APTT), prothrombin time (PT), D-Dimer (DD) and fibrinogen (FIB) and platelet function. Among five TEG parameters, the R and K value decreased while MA value, alpha angle and CI value increased in patient group when compared with the healthy controls. The correlation between TEG parameters and conventional tests including DD, FIB, and platelet function are consistent with the high coagulation state in the patient group. Our results demonstrate that TEG parameters are sensitive indicators of high coagulation state in patients with acute cerebral infarction.

Thrombin Generation Assay and Hemostatic Profile for Elucidating Hypercoagulability in Endogenous Canine Hyperadrenocorticism

Canine hyperadrenocorticism is a common endocrine disorder caused by chronic secretion of glucocorticoid, often associated with hypercoagulability and secondary thrombosis. The thrombin generation assay (TGA) evaluates hemostasis globally by measuring endogenous thrombin potential. We aimed to determine whether TGA is suitable for assessing hypercoagulability in dogs with endogenous hyperadrenocorticism (HAC), and to correlate TGA with coagulation markers including fibrinogen, antithrombin (AT), D-dimer, prothrombin time (PT) and activated partial thromboplastin time (aPTT), and with routine laboratory tests for elucidating prothrombotic mechanisms and evaluating their utility as hypercoagulability screening tests. Thrombin generation performed with high activator concentration showed significantly higher endogenous thrombin potential (ETP) (P = .0239) and peak thrombin (P = .0281) in Cushing patients. Fibrinogen (P = <.0001) and AT (P = .0444) activities were significantly higher in the HAC group, while those of PT (P = .0046) and aPTT (P = .0002) were lower. Basal cortisol levels correlated positively with fibrinogen (r = 0.4503; P = .0355) and negatively with AT activity (r = -0.4580; P = .0280). Fibrinogen and hematocrit values were inversely correlated (r = -0.4853; P = .0076). Our study confirmed the presence of higher thrombin generation in dogs with HAC. However, TGA performed with lower activator concentrations was unsuitable for detecting hypercoagulability. Higher AT and fibrinogen levels and lower aPTT activity were identified in dogs with HAC relative to controls suggesting a potential role for the combined use of these assays when assessing hypercoagulability in canine hyperadrenocorticism.

Evaluation of Blood Coagulation Parameters and ADMA, NO, IL-6, and IL-18 Serum Levels in Patients with Neovascular AMD before, during, and after the Initial Loading Phase of Intravitreal Aflibercept

We evaluated the effect of intravitreal injections of aflibercept (IVA) on blood coagulation parameters including prothrombin time (PT), activated partial thromboplastin time (APTT), and thrombin time (TT), as well as asymmetric dimethylarginine (ADMA), nitric oxide (NO), interleukin 6 (IL-6), and interleukin 18 (IL-18) serum levels in patients with neovascular AMD (nAMD). Twenty-two eyes of 22 patients with nAMD were included. Parameters were evaluated before and 2–3 days after the first IVA injection, and then immediately before and 2–3 days after the third IVA injection. We revealed prolongation of the TT after the initial loading phase of IVA (p = 0.041) and a significant increase in IL-18 serum concentration immediately before the third IVA administration compared to baseline (p = 0.037). There were no statistically significant differences of other parameters and PT, APTT, ADMA, NO, and IL-6 values remained within the normal range at each of the time points of the study. Our results suggest that repeated IVA administration may affect the common blood coagulation pathway, which manifests as a prolongation of the TT value. Furthermore, we showed a significant increase in serum concentration of the pro-inflammatory cytokineIL-18during the initial loading phase of IVA.

Nusinersen treatment in adult patients with spinal muscular atrophy: a safety analysis of laboratory parameters

Background

Nusinersen is an intrathecally administered antisense oligonucleotide (ASO) that improves motor function in patients with spinal muscular atrophy (SMA). In addition to efficacy, the safety of a therapy is the decisive factor for the success of the treatment. For some ASOs, various organ toxicities have been described, such as thrombocytopenia, renal and liver impairment, or coagulation abnormalities. However, systematic data on laboratory parameters under treatment with nusinersen are mainly available from studies in infants and children. Therefore, our aim was to assess the safety of nusinersen therapy in adult SMA patients.

Methods

Laboratory data from 404 nusinersen injections performed in 50 adult patients with SMA type 2 and type 3 were retrospectively analyzed.

Results

The total observation period was 76.9 patient-years, and patients received up to 12 injections. Our data provides no new safety concerns. In cerebrospinal fluid (CSF), the mean white blood cell count and lactate remained stable over time. Total CSF protein increased by 2.9 mg/dL. No change in mean platelet count was observed under therapy. Only one patient showed sporadic mild thrombocytopenia. Coagulation parameters and inflammatory markers were stable. The mean creatinine level decreased by 0.09 mg/dL. Analysis of mean liver enzyme levels revealed no relevant changes during treatment.

Conclusion

Our data demonstrate a favorable safety profile of nusinersen therapy in adult SMA patients under longer-term “real-world” conditions. In particular, we found no evidence of clinically relevant platelet declines, coagulopathies, or renal or hepatic organ toxicities, which are common concerns with the use of ASOs.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00415-021-10569-8.

Identification of two different coagulation phenotypes in people living with HIV with undetectable viral replication

Altered coagulation has been reported in people living with HIV (PLWH) with ongoing viral replication and may predispose to cardiovascular diseases. However, less is known about coagulation in PLWH with undetectable viral replication. In a cross-sectional observational study, we investigated whether HIV infection with undetectable viral replication is independently associated with activated partial thromboplastin time (APTT) and coagulation factor II-VII-X concentrations out of reference. Logistic regression analyses were used to assess the association of HIV infection with APTT and coagulation factor II-VII-X, after adjusting for age, sex, smoking status, alcohol consumption, BMI, diabetes and hsCRP. 936 PLWH with undetectable viral replication from the Copenhagen Co-morbidity in HIV infection study (COCOMO-study) and 2955 uninfected controls were included. Higher prevalence of short APTT was found in PLWH compared to controls (13.5% vs. 7.6%, P < 0.001). Furthermore, higher prevalence of low coagulation factor II-VII-X was found in PLWH than in controls (9.6% vs. 7.4%, P = 0.022). HIV was independently associated with short APTT (adjusted odds ratio (aOR) 2.3 (95% CI 1.7-2.9), P < 0.001) and low coagulation factor II-VII-X (aOR 1.4 (95% CI 1.0-1.9), P = 0.046). Few participants among PLWH and controls had both short APTT and low coagulation factor II-VII-X, 2.1% vs. 0.8%, respectively. We found evidence of both procoagulant (short APTT) and anticoagulant (low coagulation factor II-VII-X) alterations in PLWH with undetectable viral replication, and our findings suggest that two different coagulation phenotypes exist in participants with treated HIV infection.

Oxidized LDL induces procoagulant profiles by increasing lysophosphatidylcholine levels, lysophosphatidylethanolamine levels, and Lp-PLA2 activity in borderline hypercholesterolemia

BACKGROUND AND AIMS

The increased risk of cardiovascular disease under hypercholesterolemia is due to associations between oxidized low-density lipoprotein (ox-LDL) and lipoprotein-associated phospholipase A₂ (Lp-PLA₂) and between ox-LDL and coagulant profiles. We investigated the impact of different ox-LDL levels on coagulation time and plasma metabolomes in subjects with borderline hypercholesterolemia.

METHODS AND RESULTS

One hundred thirty-one subjects with borderline hypercholesterolemia (serum cholesterol ≥200 mg/dL) were divided into low ox-LDL (n = 66) and high ox-LDL (n = 65) groups. After adjusting for confounding factors, the high ox-LDL group exhibited a significantly decreased activated partial thromboplastin time (aPTT) and prothrombin time (PT) and increased Lp-PLA₂ activity. Compared to the low ox-LDL group, the high ox-LDL group exhibited significantly increased intensities of 17 lysophosphatidylcholines (lysoPCs) and 7 lysophosphatidylethanolamines (lysoPEs). Ox-LDL was inversely correlated with aPTT and PT and positively correlated with Lp-PLA₂ activity. Positive correlations were also found among ox-LDL, Lp-PLA₂ activity, lysoPCs, and lysoPEs. LysoPCs and lysoPEs were inversely correlated with PT and aPTT. The identified plasma metabolites, including amino acids, fatty acid amides, acylcarnitines, and lysophospholipids, were significantly upregulated in the high ox-LDL group.

CONCLUSION

High ox-LDL levels may be involved in the development of a procoagulant state in subjects with borderline hypercholesterolemia by increasing Lp-PLA₂ activity and lysoPC and lysoPE levels.

Coagulation parameters in hyperthyroid cats before and after radioiodine treatment compared with healthy controls

OBJECTIVES

The aim of the study was to describe the coagulatory state of hyperthyroid cats before and after successful radioiodine therapy (RIT) compared with healthy age-matched controls, using classical coagulation parameters and thromboelastogram (TEG) as a global assessment method. The differences in coagulation activity after RIT, depending on the thyroid hormone (normal vs low total thyroxine [T4]) state, were also evaluated.

METHODS

Fifteen hyperthyroid cats and 10 healthy age-matched controls were recruited. Hyperthyroid cats that remained hyperthyroid 14 days after RIT were excluded. Haematology, biochemistry, T4, prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen and TEG were assessed in control cats and hyperthyroid cats before and 7 and 14 days after RIT. Two weeks after successful RIT, further comparisons were made between cats with normal T4 vs those with low T4.

RESULTS

Fourteen days after successful RIT, 7/15 cats had normal T4 and 8/15 had low T4. Thrombocytosis was noted in 6/15 cats after treatment. Fibrinogen was significantly higher (P <0.001) and PT shorter (P <0.01) in the hyperthyroid cats compared with the healthy controls and these changes persisted after RIT. Persistent increases in fibrinogen, PT, TEG maximal amplitude and TEG clot rigidity, reflecting clot stability, after RIT primarily occurred in the cats with normal T4. TEG-K (time until preset amplitude of 20 mm is reached) and alpha (α) angle reflected impaired fibrin cross-linking ability prior to RIT, which significantly increased after therapy (P <0.05).

CONCLUSIONS AND RELEVANCE

Based on some of the coagulation parameters, cats with hyperthyroidism showed hypercoagulable tendencies, which were mildly increased after RIT, possibly due to transient radiation-induced thyroiditis.

Clinical utility and impact of the use of the chromogenic vs one-stage factor activity assays in haemophilia A and B

Treatment of haemophilia A/B patients comprises factor VIII (FVIII) or factor IX (FIX) concentrate replacement therapy, respectively. FVIII and FIX activity levels can be measured in clinical laboratories using one‐stage activated partial thromboplastin time (aPTT)‐based clotting or two‐stage chromogenic factor activity assays. We discuss strengths and limitations of these assays, providing examples of clinical scenarios to highlight some of the challenges associated with their current use for diagnostic and monitoring purposes. Substantial inter‐laboratory variability has been reported for one‐stage assays when measuring the activity of factor replacement products due to the wide range of currently available aPTT reagents, calibration standards, factor‐deficient plasmas, assay conditions and instruments. Chromogenic activity assays may avoid some limitations associated with one‐stage assays, but their regulatory status, perceived higher cost, and lack of laboratory expertise may influence their use. Haemophilia management guidelines recommend the differential application of one or both assays for initial diagnosis and disease severity characterisation, post‐infusion monitoring and replacement factor potency labelling. Efficient communication between clinical and laboratory staff is crucial to ensure application of the most appropriate assay to each clinical situation, correct interpretation of assay results and, ultimately, accurate diagnosis and optimal and safe treatment of haemophilia A or B patients.

The relationship of airway structural changes to blood and bronchoalveolar lavage biomarkers, and lung function abnormalities in asthma

BACKGROUND

Airway structural changes are important in asthma pathology and require further investigations.

OBJECTIVE

We sought to evaluate which computed tomography (CT) indices, bronchial histological traits, or blood and bronchoalveolar lavage (BAL) biomarkers correlate best with lung function abnormalities in asthma.

METHODS

In 105 white adult asthmatics (53 with a component of fixed airflow obstruction), we determined airway cross-sectional geometry of two proximal (the right upper lobe apical segmental and the left apicoposterior) and two distal (the right and the left basal posterior) bronchi, quantified the low-attenuation lung area (LAA%), and analysed clusters based on airway CT-metrics. We also performed bronchofiberoscopy with BAL and endobronchial biopsy, assessed blood and BAL biomarkers, including interleukin (IL)-4, IL-5, IL-6, IL-10, IL-12p70, IL-17A, IL-23, interferon (INF)γ and periostin, together with circulating a disintegrin and metalloproteinase domain-containing protein (ADAM)33, and investigated interplays between analysed variables.

RESULTS

Patients with fixed airflow limitation were characterized by lower lumen area and increased wall area and wall thickness ratios in distal airways, accompanied by raised LAA%. They had also higher blood neutrophilia, blood and BAL eosinophilia, increased circulating fibrinogen, periostin, and ADAM33. Blood neutrophilia, serum high density lipoproteins, thyroid-stimulating hormone, and shortened activated partial thromboplastin time were determinants of thicker reticular basement membrane (RBM). BAL eosinophilia was the only positive predictor of collagen I accumulation. Surprisingly, we observed a negative correlation between RBM thickening and collagen I deposit. Cluster analysis based on CT-metrics of the right lower lobe basal posterior bronchus revealed three well-separated clusters similar in age, asthma duration, and BMI, but different in RBM thickness, collagen I accumulation, and inflammatory markers.

CONCLUSIONS AND CLINICAL RELEVANCE

Airway remodelling traits are mainly related to the Th₂ profile, higher circulating ADAM33, and blood neutrophilia. Lung function abnormalities and RBM thickening correlate better with CT-metrics of distal than proximal airways.

Elevated activated partial thromboplastin time-based clot waveform analysis markers have strong positive association with acute venous thromboembolism

Introduction

A hypercoagulable state is a predisposition for venous thromboembolism (VTE). The activated partial thromboplastin time (aPTT)-based clot waveform analysis (CWA) is a global haemostatic measure but its role in assessment of hypercoagulability and thrombotic disorders is uncertain. We aimed to study the changes of CWA parameters in acute VTE. We hypothesized that patients with acute VTE would demonstrate higher CWA values than control patients without VTE and having elevated CWA parameters is associated with acute VTE.

Materials and methods

Clot waveform analysis data from patients (N = 45) with objectively proven acute VTE who had an aPTT performed prior to initiation of anticoagulation were compared with controls (N = 111). The CWA parameters measured were min1, min2, max2 and delta change.

Results

While the mean aPTT between VTE patients and controls did not differ (P = 0.830), the mean CWA parameters were significantly higher among VTE patients than controls (min1, P < 0.001; min2, P = 0.001; max2, P = 0.002; delta change, P < 0.001). There were significantly more cases within the VTE group exhibiting CWA values above their reference intervals than the control group (all P < 0.001), with the odds ratios for VTE of 8.0, 5.2, 4.8 and 18.6 for min1, min2, max2 and delta change, respectively (all P < 0.001).

Conclusions

Patients with acute VTE had elevated aPTT-based CWA parameters than controls. Higher CWA parameters were significantly associated with acute VTE.

Evaluation of the Activity of Heparin Injected into the Fully Implantable Catheter for Chemotherapy (Portocath) between Two Moments of Use

BACKGROUND

The aim of this study is to analyze whether heparin, used as a lock in fully implantable catheter for chemotherapy (portocath), maintains its activity even if it remains in the catheter for a long period of time.

METHODS

According to the institutional protocol, all catheters routinely use the lock solution with 3 mL of heparinized solution after chemotherapy and the time interval between each change as lock in the catheters studied ranged from 7 to 30 days. A total of 25 blood samples from 22 patients with 6 types of neoplasia on chemotherapy or not were collected according to routine, and the 10 mL of liquid contained in the first aspirated reservoir/catheter (corresponding to the lock of the last section), were sent for laboratory analysis for prospectively studied with the following tests: anti-Xa, partially activated thromboplastin time (APTT), thrombin time (TT), reptilase, and thromboelastogram.

RESULTS

Heparin activity was found in 96% of the anti-Xa and APTT tests. In relation to TT, 92% presented activity. The reptilase test was performed on 24 samples with significant time reduction in all of them. In the INTEM stage, the thromboelastometry test showed activity in 92% of samples and in the HEPTEM phase there was reduction in time in all samples. In all samples, the heparin activity was found to be independent of the time of use.

CONCLUSIONS

We can conclude that lock of heparinized solution used in our service in fully implantable central venous catheters for chemotherapy was maintained with active heparin even after a long period of time (up to 30 days), demonstrating that the half-life of the substance within the catheter is greater than its plasma half-life.

Searching for a Common Thrombo-Inflammatory Basis in Patients With Deep Vein Thrombosis or Peripheral Artery Disease

Background: Inflammation and hypercoagulability play a pivotal role in venous thromboembolism and atherothrombosis. Since venous thrombosis increases the risk of atherothrombotic events and vice versa, common mechanisms may be involved.

Objectives: To elucidate the role of neutrophils and coagulation in the occurrence of atherothrombotic events in patients with a history of deep vein thrombosis (DVT or peripheral artery disease (PAD).

Materials and Methods: We studied 115 patients from two cohorts (75 DVT, 40 PAD). From those with PAD, 20 patients had progressive disease; from those with DVT, 25 patients had a recurrent DVT and 25 suffered from post thrombotic syndrome (PTS); patients were age and sex matched to DVT and PAD patients without events. Markers of neutrophil recruitment (p-selectin) and activation [nucleosomes, human neutrophil elastase- α1anti-trypsin (HNE-AT)], an anti-inflammatory marker (Lipoxin A4) and a clotting activity marker (d-dimer), were measured with ELISA. Coagulation potential was analyzed by thrombin generation (CAT method).

Results: Higher nucleosome levels were found in DVT patients [11.3 U/mL (7.4–17.7)] compared to PAD patients [7.1 U/mL (5.1–13.8)], lower HNE-AT levels were found in DVT patients [33.4 ng/mL (23.5–40.5)] in comparison to PAD patients [158 ng/mL (88.1–283)]. No difference in nucleosome levels was found between DVT patients with cardiovascular (CV) events [12.6 U/mL (8.2–16.1)], and PAD patients with CV events [6.9 U/mL (4.9–11.2)]. Lipoxin A4 levels appeared to be significantly lower in DVT [2.4 ng/mL (1.7–4.8)] vs. PAD [35.6 ng/mL (16.6–80.1)], with similar results in DVT patients with CV events vs. PAD patients with CV events. Thrombin generation showed higher ETP [160.4% (141.1–215.4)], and peak height [292.1% (177.9–330)] values in DVT patients. D-dimer levels were significantly lower in the DVT cohort [330 ng/mL (220–550)] compared to the PAD cohort [550 ng/mL (369–959)].

Conclusion: In DVT patients, neutrophil activity does not appear to be an important driver of CV events. Although neutrophil activity is more pronounced in PAD, its effect is partly dampened by Lipoxin A4. Moreover, no associations were found between NET products and coagulation activity, suggesting that neutrophil activation does not play a pivotal role in the risk of thrombosis in either DVT or PAD.

Is VTE Prophylaxis Necessary on Discharge for Patients Undergoing Adrenalectomy for Cushing Syndrome?

Background

Patients with Cushing syndrome (CS) have an increased risk for venous thromboembolism (VTE). However, it is unclear whether patients undergoing adrenalectomy for CS are at increased risk for postoperative VTE. The aim of this study was to determine the rate of postoperative VTE in patients undergoing adrenalectomy for CS.

Methods

A retrospective analysis of patients in the American College of Surgeons National Surgical Quality Improvement Program database who underwent adrenalectomy from 2005 to 2016 was performed. We compared the clinical characteristics and 30-day postoperative VTE occurrence in patients with and without CS.

Results

A total of 4217 patients were analyzed; 2607 (61.8%) were female and 310 (7.4%) had CS. The overall prevalence of postoperative VTE was 1.0% (n = 45). The rates of VTE were higher in patients with CS (2.6% vs 0.9%; P = 0.007). In the two groups, CS was associated with younger age, increased body mass index, and diabetes mellitus (P < 0.001). CS was also associated with longer length of operation and longer hospital length of stay (P < 0.001). In the subgroup of patients who had diagnosed VTE, CS was associated with longer length of operation (P < 0.001). Rates of laparoscopic vs open surgery were equivalent between patients with and without CS, and VTE events did not differ. The median time to VTE event was 14.5 days (range, 1 to 23 days) in the CS group and 4 days (range, 2 to 25 days) in the group without CS.

Conclusions

The prevalence of postoperative VTE was increased in patients undergoing adrenalectomy for CS. In patients with CS undergoing adrenalectomy, VTE prophylaxis for 28 days should be considered upon discharge.

Utility of Clot Waveform Analysis in Russell's Viper Bite Victims with Hematotoxicity

Introduction:

In Russell's viper bites, due to the lack of a better alternative, whole blood clotting test (WBCT) remains the standard test even though its reliability and sensitivity has been shown to be low. Activated partial thromboplastin time (aPTT)-based clot waveform analysis (CWA) is an optic absorbance assay that can be used as a global clotting test. In this study, the objective was to assess the changes in CWA and to compare CWA to WBCT and aPTT in patients with Russell's viper envenomation.

Methods:

The datum was collected prospectively over 2 months as a pilot observational study in a tertiary care center. All proven cases of Russell's viper-envenomated individuals with preliminary CWA data and WBCT were included in the study. The clot wave (CW) of the five individuals, which met all the stringent inclusion criteria, was analyzed and interpreted.

Results:

CW absorbance sigmoid waveform was deranged in all 5 cases, of which 4 showed a change in CWA even before an abnormal aPTT. Three of the 5 had a normal WBCT but showed early changes in CWA. Atypical biphasic waveform reported in disseminated intravascular coagulation in other prior studies is seen in venom-induced consumptive coagulopathy also. In all patients where a second derivative was plotted, the second (lower) phase of the second derivative showed a slow rise to baseline.

Conclusion:

CWA showed changes which provided information earlier than the conventional coagulation studies in the snakebite victims studied. While aPTT or WBCT reflects clotting time, CWA conveys the dynamic process of clot formation and stabilization. CWA may reveal disorders of clotting in snakebite victims before the conventional tests become abnormal. Future research should assess the speed and accuracy of the test in diagnosing hemotoxic envenomation and its potential role in guiding antivenom therapy.

Association of Admission Glucose Level and Improvement in Pulmonary Artery Pressure in Patients with Submassive-type Acute Pulmonary Embolism

Objective The admission glucose level is a predictor of mortality even in patients with acute pulmonary embolism (APE). However, whether or not the admission glucose level is associated with the severity of APE itself or the underlying disease of APE is unclear. Methods This study was a retrospective observational study. A pulmonary artery (PA) catheter was used to accurately evaluate the severity of APE. The percentage changes in the mean PA pressure (PAPm) upon placement and removal of the inferior vena cava filter (IVCF) were evaluated. We hypothesized that the admission glucose level was associated with the improvement in the PA pressure in patients with APE. Patients A total of consecutive 22 patients with submassive APE who underwent temporary or retrievable IVCF insertion on admission and repetitive PA catheter measurements upon placement and removal of IVCFs were enrolled. Results There was a significant positive correlation between the admission glucose levels and the percentage changes in the PAPm (r=0.543, p=0.009). A univariate linear regression analysis showed that the admission glucose level was the predictor of the percentage change in PAPm (β coefficient=0.169 per 1 mg/dL; 95% confidence interval, 0.047-0.291; p=0.009). A multivariate linear regression analysis with the forced inclusion model showed that the admission glucose level was the predictor of the percentage change in PAPm independent of diabetes mellitus, PAPm on admission, troponin positivity, and brain natriuretic peptide level (all p<0.05). Conclusion The admission glucose level was associated with the improvement in the PAPm in patients with submassive-type APE.

Clinical factors that influence the outcome of selective devascularization in the treatment of portal hypertension

There is a high incidence of death due to variceal hemorrhage in patients with portal hypertension. Factors to consider when choosing selective devascularization in the treatment of variceal hemorrhage remain a controversy. This study aims to generate the prevalent clinical risk factors that affect the outcomes of selective devascularization procedures. Elucidating these features may guide future treatment of esophageal varices in patients with portal hypertension. We retrospectively analyzed medical records of 455 patients who underwent selective devascularization procedures in our center. Patients were subject to splenectomy, selective devascularization with or without esophageal transection. The mode of surgery recurred in comparable rates in both the group with major complications postoperatively (high-risk group which consisted of 63 patients) or the group without major postoperative complications (low-risk group, 392). Risk factors that negatively influenced outcomes of surgery include severe symptoms (89% in high risk group and 71% in low risk group), large volume of blood loss in the hemorrhage before surgery (81% in high risk group and 16% in low risk group), sever liver cirrhosis (83% in high risk group and 67% in low risk group), previous endotherapy, prolonged prothrombin time, and poor liver function. Selective devascularization is a feasible option to treat variceal hemorrhage in patients with portal hypertension.

Development of an electrospun biomimetic polyurea scaffold suitable for vascular grafting

The optimization of biomechanical and biochemical properties of a vascular graft to render properties relevant to physiological environments is a major challenge today. These critical properties of a vascular graft not only regulate its stability and integrity, but also control invasion of cells for scaffold remodeling permitting its integration with native tissue. In this work, we have synthesized a biomimetic scaffold by electrospinning a blend of a polyurea, poly(serinol hexamethylene urea) (PSHU), and, a polyester, poly-ε-caprolactone (PCL). Mechanical properties of the scaffold were varied by varying polymer blending ratio and electrospinning flow rate. Mechanical characterization revealed that scaffolds with lower PSHU content relative to PCL content resulted in elasticity close to native mammalian arteries. We also found that increasing electrospinning flow rates also increased the elasticity of the matrix. Optimization of elasticity generated scaffolds that enabled vascular smooth muscle cells (SMCs) to adhere, grow and maintain a SMC phenotype. The 30/70 scaffold also underwent slower degradation than scaffolds with higher PSHU content, thereby, providing the best option for in vivo remodeling. Further, Gly-Arg-Gly-Asp-Ser (RGD) covalently conjugated to the polyurea backbone in 30/70 scaffold resulted in significantly increased clotting times. Reducing surface thrombogenicity by the conjugation of RGD is critical to avoiding intimal hyperplasia. Hence, biomechanical and biochemical properties of a vascular graft can be balanced by optimizing synthesis parameters and constituent components. For these reasons, the optimized RGD-conjugated 30/70 scaffold electrospun at 2.5 or 5 mL/h has great potential as a suitable material for vascular grafting applications. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 278-290, 2018.

Blood coagulation parameters after intravitreal injection of aflibercept in patients with neovascular age-related macular degeneration

PURPOSE

The aim of this study was to evaluate the effect of intravitreal injection of aflibercept (IVA) on blood coagulation tests in neovascular age-related macular degeneration (AMD) patients.

METHODS

Thirty-four patients with neovascular AMD (study group) and 32 healthy individuals (control group) were enrolled. Prothrombin time (PT) and activated partial thromboplastin time (aPTT) were measured at different times in patients with neovascular AMD.

RESULTS

The levels of PT and aPTT after IVA were decreased at 1 month after the first injection and 1 month after the second injection compared to the baseline measurement in the study group.

CONCLUSIONS

IVA may cause a decrease in the levels of PT and aPTT at 1 month after the first injection and 1 month after the second injection although these results are not statistically significant in our study.

The use of dielectric blood coagulometry in the evaluation of coagulability in patients with peripheral arterial disease

Background

Platelets and coagulation proteins contribute to the development of peripheral arterial disease, especially atherosclerotic disease. Several experimental studies have proven a significant correlation between hypercoagulability and atherosclerosis. We used dielectric blood coagulometry, which was initially designed to evaluate the coagulable status, to examine the coagulability of peripheral arterial disease patients, and investigated the factors that were significantly correlated with the results.

Methods

We performed dielectric blood coagulometry in 49 peripheral arterial disease patients. In addition, we recorded the patients’ demographic information, including the presence of comorbidities, hemodynamic status, and laboratory findings. To investigate coagulability, we calculated the T_max value, which indicates the time from recalcification to maximum normalized permittivity.

Results

The T_max values of diabetes mellitus patients were significantly lower than those of non-diabetic patients (1 MHz, P = 0.010; 10 MHz, 0.011). Furthermore, the T_max value was statistically correlated with the activated partial thromboplastin time (1 MHz, ρ = 0.286, P = 0.048; 10 MHz, ρ = 0.301, P = 0.037).

Conclusions

Dielectric blood coagulometry detected the hypercoagulable status in diabetes mellitus patients, and reflected their level of coagulability, which was also evaluated by the activated partial thromboplastin time.

Procoagulatory changes induced by head-up tilt test in patients with syncope: observational study

Background

Orthostatic hypercoagulability is proposed as a mechanism promoting cardiovascular and thromboembolic events after awakening and during prolonged orthostasis.

We evaluated early changes in coagulation biomarkers induced by tilt testing among patients investigated for suspected syncope, aiming to test the hypothesis that orthostatic challenge evokes procoagulatory changes to a different degree according to diagnosis.

Methods

One-hundred-and-seventy-eight consecutive patients (age, 51 ± 21 years; 46% men) were analysed. Blood samples were collected during supine rest and after 3 min of 70° head-up tilt test (HUT) for determination of fibrinogen, von Willebrand factor antigen (VWF:Ag) and activity (VWF:GP1bA), factor VIII (FVIII:C), lupus anticoagulant (LA1), functional APC-resistance, and activated prothrombin time (APTT) with and without activated protein C (C+/−). Analyses were stratified according to age, sex and diagnosis.

Results

After 3 min in the upright position, VWF:Ag (1.28 ± 0.55 vs. 1.22 ± 0.54; p < 0.001) and fibrinogen (2.84 ± 0.60 vs. 2.75 ± 0.60, p < 0.001) increased, whereas APTT/C+/− (75.1 ± 18.8 vs. 84.3 ± 19.6 s; p < 0.001, and 30.8 ± 3.7 vs. 32.1 ± 3.8 s; p < 0.001, respectively) and APC-resistance (2.42 ± 0.43 vs. 2.60 ± 0.41, p < 0.001) decreased compared with supine values. Significant changes in fibrinogen were restricted to women (p < 0.001) who also had lower LA1 during HUT (p = 0.007), indicating increased coagulability. Diagnosis vasovagal syncope was associated with less increase in VWF:Ag during HUT compared to other diagnoses (0.01 ± 0.16 vs. 0.09 ± 0.17; p = 0.004).

Conclusions

Procoagulatory changes in haemostatic plasma components are observed early during orthostasis in patients with history of syncope, irrespective of syncope aetiology. These findings may contribute to the understanding of orthostatic hypercoagulability and chronobiology of cardiovascular disease.

Physiological and biological predictors of length of stay and recovery in adults with acute asthma: An observational cohort study

INTRODUCTION

Asthma is a prevalent, chronic disease associated with significant risk to patients and cost to healthcare systems. Accurate estimates of length of stay and recovery are important for patient information, physician prognostication, and management of inpatient beds.

OBJECTIVES

To assess factors affecting length of stay and time to recovery in adults with acute asthma.

METHODS

We prospectively recruited adult asthmatic non-smokers admitted with an asthma exacerbation. Participants were assessed for demographics, symptoms, medications, bloods including blood count, clotting status, and cytokines. Results were analyzed for correlation and subsequently in a regression model.

RESULTS

One hundred twenty-six participants were recruited of which 75.4% were female. Mean age was 40.0 and mean length of stay was 3.98 days. Length of stay was associated with lower APTT ratio (<P = 0.001), oxygen requirement (P = 0.02), increased AST (P = 0.005), increasing age (P = 0.02), and lower %predicted FEV1 (P = 0.02). Longer time to recovery was associated with plasma IL-12 >1 pg/mL (P = 0.04).

CONCLUSION

Older participants with lower FEV1 and supplemental oxygen requirements are likely to remain in hospital longer. Activation of the "intrinsic" clotting pathway correlates with an increased length of stay as does a raised serum AST. Detectable IL-12 in plasma correlates with slower recovery and this may be due to poor response to corticosteroids.

Retrospective evaluation of shortened prothrombin time or activated partial thromboplastin time for the diagnosis of hypercoagulability in dogs: 25 cases (2006-2011)

OBJECTIVE

To evaluate the relationship between shortened prothrombin time (PT) or activated partial thromboplastin time (aPTT) values, clinical findings associated with hypercoagulability, suspicion of pulmonary thromboembolism (PTE), D-dimer concentrations, and thromboelastogram (TEG) indices.

DESIGN

Retrospective observational study from 2006 to 2011.

SETTING

University veterinary teaching hospital.

ANIMALS

Twenty-three dogs with TEG tracings and shortened PT or aPTT values and 23 control dogs with TEG tracings and normal PT and aPTT values.

MEASUREMENTS AND MAIN RESULTS

Parameters evaluated included signalment, coagulation testing results (PT, aPTT, D-dimer concentration), TEG measurements (R, K, α, maximal amplitude) and calculated clotting index, findings of clinical hypercoagulability (thrombosis of intravenous/intra-arterial catheters, vessel thrombosis, and suspected PTE). Dogs with shortened PT or aPTT had significantly more thrombus formation (P = 0.038), suspicion of PTE (P < 0.001), and increased D-dimer concentration (P < 0.001) compared to dogs with normal PT and aPTT values. There were no significant findings when compared to TEG values.

CONCLUSIONS

A shortened PT or aPTT in dogs may be indicative of a hypercoagulable state as evidenced by an increased incidence of thrombosis, frequency of suspected PTE, and increased circulating D-dimers. A prospective study is warranted to further evaluate the use of PT and aPTT to diagnose hypercoagulable states.

Anticoagulant effect and safety assessment of an aqueous extract of Pseudocedrela kotschyi (Schweinf.) harms and Adenia cissampeloides (Planch. Ex Hook.) harms

BACKGROUND

Currently available therapeutic options for thromboembolic disorders are often very expensive and are associated with unfavorable side effects.

AIM

To establish the anticoagulant effect and safety profile of an extract made from of the root bark of Pseudocedrela kotschyi (Schweinf.) Harms and the aerial part of Adenia cissampeloides (Planch. ex Hook.) Harms (PAE).

MATERIALS AND METHODS

PAE (0.5-2.0 g/L) effect on prothrombin time (PT) and activated partial thromboplastin time (aPTT) were evaluated on whole blood drawn from the marginal ear vein of New Zealand White rabbits. Effect of PAE (250-2000 mg/kg) on bleeding time (BT) and clotting time (CT) in Sprague-Dawley rats were also assessed. Histopathological, hematological, and liver function studies were also carried out to assess the safety for use of PAE (250-2000 mg/kg).

RESULTS

PAE had no significant effect (P > 0.05) on PT, but resulted in a significant increase (P ≤ 0.05-0.0001) in aPTT. The PAE treatment resulted in a significant increase (P ≤ 0.05-0.0001) in BT and CT in vivo compared with control. Safety studies indicated no deaths with PAE treatment with hematological and liver function tests being normal. Histological studies revealed pathological changes in the liver at a PAE treatment dose of 2000 mg/kg but all doses had no detrimental effect on kidney and stomach tissue. The no-observed-adverse-effect-level was <2000 mg/kg when given orally.

CONCLUSION

PAE has anticoagulant effect in vitro and is safe to use at oral doses <2000 mg/kg.

Assessment of blood changes post-challenge with Corynebacterium pseudotuberculosis and its exotoxin (phospholipase D): A comprehensive study in goat

Aim:

There is very little information regarding blood changes during the challenge of phospholipase D (PLD) in goats. Therefore, this experiment was conducted to study the changes in blood after the challenge with Corynebacterium pseudotuberculosis and its exotoxin, PLD to fill in the gap of caseous lymphadenitis (CLA) research.

Materials and Methods:

Twenty-six crossbred Boer goats aged 12-14 months were divided into 3 groups; the first group n=6 was inoculated with 1 ml phosphate buffered solution s.c. as the control. The second group n=10 was inoculated with C. pseudotuberculosis 1 × 10⁹ cfu s.c. The third group n=10 was intravenous injected with PLD 1 ml/20 kg body weight. Serial blood collections were done at 1 h, 3 h, 5 h, 8 h, and 12 h then every 24 h post-inoculation for the first 30 days of the experiment. Subsequently, the blood collection continued twice a week till the end of the experiment (90 days post-challenge).

Results:

Both C. pseudotuberculosis and PLD treated groups showed significant changes (p<0.05) in red blood cell count, hemoglobin (Hb), packed cell volume, mean corpuscular volume, mean corpuscular Hb concentration, white blood cell count, neutrophils, lymphocytes, monocytes, eosinophils, basophils, globulin, and total plasma proteins. Similarly, both treated groups showed significant changes (p<0.05) in alanine transaminase, alkaline phosphatase, aspartate transaminase, total bilirubin, calcium concentration, creatine phosphokinase, creatinine, gamma-glutamyl transpeptidase, urea concentration, lactate dehydrogenase, prothrombin time, and activated partial thromboplastin time.

Conclusion:

It concluded that C. pseudotuberculosis and PLD have a negative impact on the goat’s health in general reflected by all those changes recorded in the hemogram, leukogram, and the blood chemistry.

Shortened Activated Partial Thromboplastin Time Is Associated With Acute Ischemic Stroke, Stroke Severity, and Neurological Worsening

BACKGROUND

The role played by hemostasis in the pathogenesis of ischemic strokes is still controversial. The activated partial thromboplastin time (APTT) measures the time necessary to generate fibrin from initiation of the intrinsic pathway. In the present study, we looked for a possible association of ischemic strokes with the shortened APTT.

METHODS

The study population consisted of 154 patients with acute ischemic strokes who had been admitted from December 2013 to December 2014 to the Department of Neurology, Chiayi Chang Gung Memorial Hospital, and 71 control subjects with no history of stroke.

RESULTS

In a univariate risk analysis, shortened APTT was associated with an odds ratio (OR) for acute ischemic strokes of up to 1.86 (95% confidence interval [CI], 1.06-3.29, P = .031). In a multivariate analysis using a logistic regression model including age, sex, hypertension, diabetes mellitus, and shortened APTT, shortened APTT was still found to significantly add to the risk of ischemic stroke (OR = 2.12 with 95% CI, 1.13-3.98, P = .020). Shortened APTT was also associated significantly with neurological worsening (OR = 3.72 with 95% CI 1.03-13.5, P = .046). As for stroke severity, shortened APTT was associated with an OR for moderate/severe stroke of up to 3.42 (95% CI, 1.53-7.61, P = .003).

CONCLUSION

Shortened APTT is a prevalent and independent risk factor for ischemic stroke, stroke severity, and neurological worsening after acute stroke.

Ethanol Extract of Persimmon Tree Leaves Improves Blood Circulation and Lipid Metabolism in Rats Fed a High-Fat Diet

The leaves of the persimmon tree (PL) are known to have beneficial effects on hyperglycemia, dyslipidemia, and nonalcoholic fatty liver disease. We recently demonstrated that PL had antithrombotic properties in vitro. However, little is known about the antiplatelet and anticoagulant properties of PL in vivo. Omega-3 fatty acid (n-3 FA)-containing fish oil has been widely prescribed to improve blood circulation. This study compared the effects of dietary supplementation with an ethanol extract of PL or n-3 FA on blood coagulation, platelet activation, and lipid levels in vivo. Sprague-Dawley rats were fed a high-fat diet with either PL ethanol extract (0.5% w/w) or n-3 FA (2.5% w/w) for 9 weeks. Coagulation was examined by monitoring the activated partial thromboplastin time (aPTT) and prothrombin time. We examined plasma thromboxane B2 (TXB2), serotonin, and soluble P-selectin (sP-selectin) levels. The aPTT was significantly prolonged in the PL and n-3 FA supplement groups. PL also attenuated the TXB2 level and lowered arterial serotonin transporter mRNA expression, although it did not alter plasma serotonin or sP-selectin levels. C-reactive protein and leptin levels were significantly reduced by PL and n-3 FA supplementation. In addition, PL decreased plasma total- and low-density lipoprotein-cholesterol levels, as did n-3 FA treatment. These results indicated that the PL ethanol extract may have the potential to improve circulation by inhibiting blood coagulation and platelet activation and by reducing plasma cholesterol levels.

Improved Stability of Proline-Derived Direct Thrombin Inhibitors through Hydroxyl to Heterocycle Replacement

Modification of the previously disclosed (S)-N-(2-(aminomethyl)-5-chlorobenzyl)-1-((R)-2-hydroxy-3,3-dimethylbutanoyl)pyrrolidine-2-carboxamide 2 by optimization of the P3 group afforded novel, low molecular weight thrombin inhibitors. Heterocycle replacement of the hydroxyl functional group helped maintain thrombin in vitro potency while improving the chemical stability and pharmacokinetic profile. These modifications led to the identification of compound 10, which showed excellent selectivity over related serine proteases as well as in vivo efficacy in the rat arteriovenous shunt. Compound 10 exhibited significantly improved chemical stability and pharmacokinetic properties over 2 and may be utilized as a structurally differentiated preclinical tool comparator to dabigatran etexilate (Pro-1) to interrogate the on- and off-target effects of oral direct thrombin inhibitors.

Changes in Clotting Time, Plasma Fibrinogen Levels, and Blood Viscosity After Administration of Ranibizumab for Treatment of Choroidal Neovascularization

PURPOSE

To observe changes in clotting time, plasma fibrinogen levels, and blood viscosity after intravitreal ranibizumab (IVR) injection in patients with macular choroidal neovascularization (CNV).

METHODS

A total of 77 patients were enrolled in the study. Patients were divided into a study group (n = 42 CNV patients) and a control group (n = 35 age- and gender-matched healthy subjects). Study group patients received IVR injections; control group patients received none. Clotting times, plasma fibrinogen levels and blood viscosity were evaluated before, and 1 week and 1 month after the first IVR injection, and again 1 month after the second injection in the study group, but only once in the control group. A paired-sample t-test was used to analyze data at four time points in the study group. Study group patients were further categorized as those with neovascular age-related macular degeneration (AMD subgroup) or CNV secondary to pathological myopia (PM subgroup). Indicators were also analyzed for each subgroup.

RESULTS

There were no significant differences between study and control group patients in baseline values. Results showed that 1 week after the first IVR injection, the mean activated partial thromboplastin time (APTT) of study group patients was significantly reduced compared with baseline values (27.88 ± 4.00 versus 30.70 ± 5.56 s), respectively. Low-, median- and high-shear viscosity rates were increased significantly compared with baseline values. No statistically significant changes in tested indicators were found at other time points. In AMD subgroup patients, changes in all indicators were similar to those found overall. In contrast, only changes in median- and high-shear viscosity rates were statistically significant in PM subgroup patients.

CONCLUSION

IVR injection may cause short-term fluctuations in APTT and blood viscosity in AMD patients. Further studies are needed to establish the long-term safety of IVR treatment.

Association of activated partial thromboplastin time and fibrinogen level in patients with type II diabetes mellitus

Background

Patients with diabetes mellitus have a high risk of atherothrombotic events. Diabetes contributes for initiation and progression of microvascular and macrovascular complications. Shortened activated partial thromboplastin time (aPTT) values may reflect hypercoaguable state, which is associated with increased thrombotic risk and adverse cardiovascular events. Increased level of fibrinogen is common in type II diabetes. The present study was conducted to study the aPTT and fibrinogen levels in diabetics in a tertiary care Teaching Hospital of Nepal.

Methods

Observational study was performed at out-patients visiting Pathology Department at Tribhuvan University Teaching Hospital from August 5 to September 7, 2012. Research protocol was approved by Institutional Review Board at Tribhuvan University Institute of Medicine. Altogether 90 people who came to the hospital during study period and who met inclusion criteria were selected, out of which 72 were diabetics and 18 were normal controls. Diabetic cases were identified via verbal interview with patients themselves and review of laboratory findings and diagnosis performed by their physicians. Diabetics with a diabetic history of more than one year and stabilized with antidiabetic medicines such as insulin, metformin, glibenclamide, and gliclazide and diabetics with controlled diabetes as revealed by HbA_1c in the range 6.2-7% were taken for the study purpose. Data were analyzed with chi square test and Fischer’s exact test (when each cell frequency was less than 5) using Statistical Package for Social Sciences 17.

Results

Maximum (53; 73.6%) diabetics and all non-diabetics had aPTT in the range 26–40 seconds. Maximum (51; 70.8%) patients had fibrinogen beyond 351 whereas all non-diabetics had fibrinogen in the range 151–350. Mean aPTT values of the diabetic patients and non-diabetic persons were 29.88 ± 4.89 seconds and 32.44 ± 2.25 seconds respectively. Mean fibrinogen values of the diabetic patients and non-diabetic persons were 388.57 ± 60.90 mg/dL and 320.89 ± 10.20 mg/dL respectively. Test data identified in results were statistically significant for aPTT (p value 0.000) and fibrinogen (p value 0.000) between the diabetics and non-diabetics.

Conclusions

Diabetics have an increased level of fibrinogen and relatively shortened aPTT as compared to the non-diabetic patients.

Effect of quercetin-rich onion peel extracts on arterial thrombosis in rats

The aim of this study was to examine whether oral supplementation of quercetin-rich onion peel extract (OPE) influences blood coagulation and arterial thrombosis in Sprague-Dawley (SD) rats. 24 male rats, 5 weeks old, were divided into three groups with different diets (C: control, 2mg OPE: chow diet with 2mg OPE supplementation, 10mg OPE: chow diet with 10mg OPE supplementation) for 6 weeks. Blood coagulation parameters including prothrombin time (PT), activated partial thromboplastin time (aPTT) and platelet aggregation were examined. The OPE did not affect blood cholesterol levels but significantly decreased blood triglyceride and glucose levels. PT, aPTT and platelet aggregation were not significantly different among all tested groups. However, in vivo arterial thrombosis was significantly delayed in groups that were fed 2mg and 10mg OPE diets compared to the control group. In addition, the OPE greatly diminished thrombin-induced expression of tissue factor in human umbilical vein endothelial cells (HUVECs), a coagulation initiator. In addition, extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) signaling pathways activated by thrombin treatment were prevented by the OPE pre-treatment. These results indicate that OPE may have anti-thrombotic effects through restricting the induced expression of tissue factor via down-regulating mitogen-activated protein kinase (MAPK) activation upon coagulation stimulus, leading to the prolongation of time for arterial thrombosis.

A gene-centric analysis of activated partial thromboplastin time and activated protein C resistance using the HumanCVD focused genotyping array

Activated partial thromboplastin time (aPTT) is an important routine measure of intrinsic blood coagulation. Addition of activated protein C (APC) to the aPTT test to produce a ratio, provides one measure of APC resistance. The associations of some genetic mutations (eg, factor V Leiden) with these measures are established, but associations of other genetic variations remain to be established. The objective of this work was to test for association between genetic variants and blood coagulation using a high-density genotyping array. Genetic association with aPTT and APC resistance was analysed using a focused genotyping array that tests approximately 50 000 single-nucleotide polymorphisms (SNPs) in nearly 2000 cardiovascular candidate genes, including coagulation pathway genes. Analyses were conducted on 2544 European origin women from the British Women's Heart and Health Study. We confirm associations with aPTT at the coagulation factor XII (F12)/G protein-coupled receptor kinase 6 (GRK6) and kininogen 1 (KNG1)/histidine-rich glycoprotein (HRG) loci, and identify novel SNPs at the ABO locus and novel locus kallikrein B (KLKB1)/F11. In addition, we confirm association between APC resistance and factor V Leiden mutation, and identify novel SNP associations with APC resistance in the HRG and F5/solute carrier family 19 member 2 (SLC19A2) regions. In conclusion, variation at several genetic loci influences intrinsic blood coagulation as measured by both aPTT and APC resistance.

[Risk factor for residual deep vein thrombosis after fondaparinux administration in patients with postoperative replacement arthroplasty]

Deep venous thrombosis (DVT) is a life-threatening postoperative complication and occurs frequently after total-knee-replacement arthroplasty (TKA) and total-hip-replacement arthroplasty (THA). Fondaparinux (FPX) has been used to treat and prevent DVT, however interindividual difference of the drug efficacy exists. Therefore, this chart review was retrospectively conducted to research risk factors for a residual DVT after FPX treatment. Total of 112 patients undergone TKA or THA were treated with 2.5 mg FPX once a day between postoperative day (POD) 1 and 14 from July 2007 through December 2008. Among these patients, 30 patients who were detected DVT on POD 4 were enrolled in this study. Thirty patients were divided into two groups according to the presence (n=11) or absence (n=19) of DVT on POD14. The DVT (-) group had a significantly longer activated partial thromboplastin time (APTT, median 31.4 s) on POD 1 than the DVT (+) group (28.5 s) (p<0.02). Multivariate logistic regression analysis revealed that APTT lower than 28.5 seconds on POD1 was considered to be independent risk factor significantly contributing to residual DVT (odds ratio 17.5, 95% confidential interval 2.0-295.4, p=0.02). These findings should provide useful information for understanding the interindividual difference of the efficacy of FPX after TKA or THA.

Dynamic APTT parameters: applications in thrombophilia

BACKGROUND

Patients with a history of venous thrombosis occasionally have shortened APTTs when compared with those of healthy references, but the clinical applicability of a shortened APTT is limited.

OBJECTIVES

The present study aimed to characterize dynamic APTT profiles in patients with previously documented venous thrombosis and hypothesized that the APTT-MaxVel was significantly elevated in patients with a history of venous thrombosis as compared with healthy controls.

METHODS

We performed a case control study, enrolling a total of 38 patients, 17 males and 21 females, with a verified recent venous thrombotic event, as well as 88 healthy controls. Fifty-three per cent of patients were found to have a biochemical risk factor. A standard APTT was recorded in platelet-poor plasma, and the digital clotting signal was processed using simple algorithms developed to derive dynamic coagulation parameters.

RESULTS

Patients had a significantly higher mean APTT-MaxVel (195.5 s(-1) ; SD = 57; 95% CI, 176.8-214.1) as compared with healthy controls (137.3 s(-1) ; SD = 21; 95% CI, 130.7-143.8). Patients also had significantly shorter mean APTTs (26.9 s; SD = 3.2; 95% CI, 25.9-28.0) than healthy controls (28.5 s; SD = 2.8; 95% CI, 27.9-29.0). While only one out of 38 patients (2.6%) had a standard APTT below the lower reference interval, 15 of the 38 patients (38.5%) had an APTT-MaxVel above the upper reference limit. Regression analysis revealed linear correlation between FVIII:C, the level of fibrinogen and APTT-MaxVel (R(2) = 0.89, P < 0.05).

CONCLUSIONS

Simple signal processing of the APTT and the use of dynamic parameters represents a stronger predictive marker for hypercoagulation in patients with verified venous thrombosis than the standard APTT measurement.

Haematological changes at altitude

Hypobaric hypoxia is associated with an increase in erythropoesis and an increased thrombotic risk. This is true of long haul air travel, mountaineering expeditions and longer stays at altitude. Studies looking at clotting on mountaineering expeditions are further complicated by the effects of exercise, plasma volume changes and the catecholamine response to hypoxia. This review examines the evidence for changes in clotting factors and functional clotting at altitude and considers the implications of altitude travel for those with pre-existing medical conditions.