Elevated Hypercoagulability Markers In Hemoglobin Sc Disease.

Hemoglobin SC disease is a very prevalent hemoglobinopathy, however very little is known specifically about this condition. There appears to be an increased risk of thromboembolic events in hemoglobin SC disease, but studies evaluating the hemostatic alterations are lacking. We describe a cross-sectional observational study evaluating coagulation activation markers in adult hemoglobin SC patients, in comparison with sickle cell anemia patients and healthy controls. A total of 56 hemoglobin SC and 39 sickle cell anemia patients were included in the study, all in steady state, and 27 healthy controls. None of the patients were in use of hydroxyurea. Hemoglobin SC patients presented a significantly up-regulated relative expression of tissue factor, as well as elevations in thrombin-antithrombin complex and D-dimer, in comparison to controls (p<0.01). Hemoglobin SC patients presented lower tissue factor expression, and thrombin-antithrombin complex and D-dimer levels when compared to sickle cell anemia patients (p<0.05). Endothelial activation (soluble thrombomodulin and soluble vascular cell adhesion molecule-1), and inflammation (tumor necrosis factor-alpha) markers were both significantly elevated in hemoglobin SC patients when compared to controls, being as high as the levels seen in sickle cell anemia. Overall, in hemoglobin SC patients, higher hemolytic activity and inflammation were associated with a more intense activation of coagulation, and hemostatic activation was associated with two very prevalent chronic complications seen in hemoglobin SC disease: retinopathy and osteonecrosis. In summary, our results demonstrate that hemoglobin SC patients present a hypercoagulable state, although this manifestation was not as intense as that seen in sickle cell anemia.

Homocysteine-lowering treatment with folic acid, cobalamin, and pyridoxine does not reduce blood markers of inflammation, endothelial dysfunction, or hypercoagulability in patients with previous transient ischemic attack or stroke - a randomized substudy

Background and Purpose - Epidemiological and laboratory studies suggest that increasing concentrations of plasma homocysteine ( total homocysteine [tHcy]) accelerate cardiovascular disease by promoting vascular inflammation, endothelial dysfunction, and hypercoagulability. Methods - We conducted a randomized controlled trial in 285 patients with recent transient ischemic attack or stroke to examine the effect of lowering tHcy with folic acid 2 mg, vitamin B-12 0.5 mg, and vitamin B-6 25 mg compared with placebo on laboratory markers of vascular inflammation, endothelial dysfunction, and hypercoagulability. Results - At 6 months after randomization, there was no significant difference in blood concentrations of markers of vascular inflammation (high-sensitivity C-reactive protein [P = 0.32]; soluble CD40L [ P = 0.33]; IL-6 [P = 0.77]), endothelial dysfunction ( vascular cell adhesion molecule-1 [P = 0.27]; intercellular adhesion molecule-1 [P = 0.08]; von Willebrand factor [P = 0.92]), and hypercoagulability (P-selectin [P = 0.33]; prothrombin fragment 1 and 2 [P = 0.81]; D-dimer [P = 0.88]) among patients assigned vitamin therapy compared with placebo despite a 3.7-mumol/L (95% CI, 2.7 to 4.7) reduction in total homocysteine (tHcy). Conclusions - Lowering tHcy by 3.7 mumol/L with folic acid-based multivitamin therapy does not significantly reduce blood concentrations of the biomarkers of inflammation, endothelial dysfunction, or hypercoagulability measured in our study. The possible explanations for our findings are: ( 1) these biomarkers are not sensitive to the effects of lowering tHcy (eg, multiple risk factor interventions may be required); ( 2) elevated tHcy causes cardiovascular disease by mechanisms other than the biomarkers measured; or ( 3) elevated tHcy is a noncausal marker of increased vascular risk.

Evaluation of the marker of hypercoagulability prothrombin fragment F 1+2 in patients with mechanical or biological heart valve prostheses

OBJECTIVE: To investigate whether patients with heart valve prostheses and similar International Normalized Ratios (INR) have the same level of protection against thromboembolic events, that is, whether the anticoagulation intensity is related to the intensity of hypercoagulability supression. METHODS: INR and plasma levels of prothrombin fragment 1+2 (F1+2) were assessed in blood samples of 27 patients (7 with mechanical heart valves and 20 with biological heart valves) and 27 blood samples from healthy donors that were not taking any medication. RESULTS: Increased levels of F1+2 were observed in blood samples of 5 patients with heart valve prostheses taking warfarin. These findings reinforce the idea that even though patients may have INRs, within the therapeutic spectrum, they are not free from new thromboembolic events. CONCLUSION: Determination of the hypercoagulability marker F1+2 might result in greater efficacy and safety for the use of oral anticoagulants, resulting in improved quality of life for patients.

Problem behavior of dementia patients predicts low-grade hypercoagulability in spousal caregivers

Low-grade hypercoagulability might be one pathway to explain how the chronic stress of dementia caregiving increases cardiovascular disease risk, but the specific aspects of caregiver stress that elicit hypercoagulability are elusive. We hypothesized that dementia patients' problem behaviors and negative reactions of caregivers to these behaviors would relate to hypercoagulability in caregivers.

Effects of Pentoxyfilline and Heparin on Reperfusion Injury Island Skin Flaps in Rats Exposed to Tobacco

Background. Ischemia-reperfusion injury is believed to be a major cause of transferred skin flap failure. Cigarette smoking is known to be associated with endogenous antioxidant depletion, hypercoagulability, and cutaneous vasoconstriction. This investigation was carried out to study possible effects of pentoxyfilline or heparin on rat skin reperfusion injury under tobacco exposure. Materials and Methods. Thirty-six rats were randomized into two major groups: 18 were exposed to cigarette smoke during a 4 wk period prior to surgery; the remaining 18 underwent a sham smoking procedure. Each group was further divided into three equal subgroups: heparin, pentoxyfilline, and saline solution. One identical skin flap was raised in each animal. The vasculature of the flap was clamped for 3 h and reperfused for 5 min. A venous blood sample was obtained from the flap after reperfusion for serum malondialdehyde (MDA) and myeloperoxidase (MPO) analysis. Flap survival was assessed 7 d after the procedure. Results. The lipid peroxidation levels and flap necrosis were significantly higher in the cigarette-smoking group skin flaps. There was also a decrease of MPO activity in this group compared with the nonsmoking group. Heparin-treated rats had significantly lower MDA levels and showed the most viable percent area among smoking rats. Conclusions. These data suggest that heparin had a significant beneficial effect both on flap survival and on the lipid peroxidation reduction after smoke exposure in the rat axial-pattern skin flap subjected to ischemia and reperfusion injury. Pharmacologic therapy may represent an alternative way to counteract tobacco effects in flap surgery in emergency situations. (C) 2010 Elsevier Inc. All rights reserved.

Hepatoportal Sclerosis and Extrahepatic Portal Venous Obstruction Associated with Anti-phospholipid Antibody Syndrome in Child

We report a 2-year-old child with extrahepatic portal venous obstruction, hepatoportal sclerosis and pulmonary thromboembolism whose sole hypercoagulability factor was the presence of anti-phospholipid antibodies.

Analysis and clinical relevance of microparticles from red blood cells.

PURPOSE OF REVIEW: The mechanisms involved in the formation of red blood cell (RBC) microparticles in vivo as well as during erythrocyte storage are reviewed, and the potential role of microparticles in transfusion medicine is described. RECENT FINDINGS: Microparticles release is an integral part of the erythrocyte ageing process, preventing early removal of RBCs. Proteomics analyses have outlined the key role of band 3-ankyrin anchoring complex and the occurrence of selective RBC membrane remodelling mechanisms in microparticles formation. The presence of several RBC antigens, expressed on microparticles, has been demonstrated. The potential deleterious effects of RBC microparticles in transfused recipients, including hypercoagulability, microcirculation impairment and immunosuppression, are discussed. SUMMARY: Formation and role of RBC microparticles are far from being completely understood. Combining various approaches to elucidate these mechanisms could improve blood product quality and transfusion safety. Implementation of RBC microparticles as biomarkers in the laboratory routine needs to overcome technical barriers involved in their analysis.

Normal range values for thromboelastography in healthy adult volunteers

Thromboelastography (TEG®) provides a functional evaluation of coagulation. It has characteristics of an ideal coagulation test for trauma, but is not frequently used, partially due to lack of both standardized techniques and normal values. We determined normal values for our population, compared them to those of the manufacturer and evaluated the effect of gender, age, blood type, and ethnicity. The technique was standardized using citrated blood, kaolin and was performed on a Haemoscope 5000 device. Volunteers were interviewed and excluded if pregnant, on anticoagulants or having a bleeding disorder. The TEG® parameters analyzed were R, K, α, MA, LY30, and coagulation index. All volunteers outside the manufacturer’s normal range underwent extensive coagulation investigations. Reference ranges for 95% for 118 healthy volunteers were R: 3.8-9.8 min, K: 0.7-3.4 min, α: 47.8-77.7 degrees, MA: 49.7-72.7 mm, LY30: -2.3-5.77%, coagulation index: -5.1-3.6. Most values were significantly different from those of the manufacturer, which would have diagnosed coagulopathy in 10 volunteers, for whom additional investigation revealed no disease (81% specificity). Healthy women were significantly more hypercoagulable than men. Aging was not associated with hypercoagulability and East Asian ethnicity was not with hypocoagulability. In our population, the manufacturer’s normal values for citrated blood-kaolin had a specificity of 81% and would incorrectly identify 8.5% of the healthy volunteers as coagulopathic. This study supports the manufacturer’s recommendation that each institution should determine its own normal values before adopting TEG®, a procedure which may be impractical. Consideration should be given to a multi-institutional study to establish wide standard values for TEG®.

Increased expression of tissue factor and protease-activated receptor-1 does not correlate with thrombosis in human lung adenocarcinoma

A correlation between cancer and hypercoagulability has been described for more than a century. Patients with cancer are at increased risk for thrombotic complications and the clotting initiator protein, tissue factor (TF), is possibly involved in this process. Moreover, TF may promote angiogenesis and tumor growth. In addition to TF, thrombin seems to play a relevant role in tumor biology, mainly through activation of protease-activated receptor-1 (PAR-1). In the present study, we prospectively studied 39 lung adenocarcinoma patients in relation to the tumor expression levels of TF and PAR-1 and their correlation with thrombosis outcome and survival. Immunohistochemical analysis showed TF positivity in 22 patients (56%), most of them in advanced stages (III and IV). Expression of PAR-1 was found in 15 patients (39%), most of them also in advanced stages (III and IV). Remarkably, no correlation was observed between the expression of TF or PAR-1 and risk for thrombosis development. On the other hand, patients who were positive for TF or PAR-1 tended to have decreased long-term survival. We conclude that immunolocalization of either TF or PAR-1 in lung adenocarcinoma may predict a poor prognosis although lacking correlation with thrombosis outcome.

Caractérisation de l'état hypercoagulable associé à l'hyperadrénocorticisme chez le chien

Cette étude avait comme objectif d’évaluer la coagulation par l’utilisation de la thrombélastographie (TEG®) et de la génération de thrombine (GT) chez des beagles en santé recevant de la prednisone ainsi que chez des chiens atteints d’hyperadrénocorticisme (HAC). Dans un premier temps, six beagles adultes en santé ont été évalués dans une étude prospective longitudinale au courant de laquelle chaque individu recevait 1 mg/kg/jour de prednisone par la voie orale pendant 2 semaines. Après un arrêt de traitement d’une durée de 6 semaines, ils ont finalement reçu 4 mg/kg/jour de prednisone pour encore 2 semaines. Les tracés TEG® et les mesures de la GT ont été obtenus au temps 0, à la fin des 6 semaines d’interruption de traitement, ainsi qu’à la suite des 2 dosages de prednisone. Suite aux 2 traitements avec la prednisone, des résultats significatifs,lorsque comparés aux valeurs de base, ont été obtenus pour la cinétique du caillot (« clot kinetics » ou K), l’angle alpha (α) et l’amplitude maximale (« maximal amplitude » ou MA). La GT avait augmenté de manière significative mais seulement après la dose de 1 mg/kg/jour de prednisone. Dans un deuxième temps, 16 chiens atteints d’HAC ont été évalués avant l’initiation d’un traitement pour leur condition. Quinze chiens ont été évalués par TEG® et 15 par GT. Les données obtenues ont ensuite été comparées aux valeurs normales. L’analyse par TEG® a démontré que 12/15 chiens avaient au moins un paramètre suggérant un état d’hypercoagulabilité. L’analyse par GT a démontré que 4/15 chiens avaient des changements compatibles avec un état d’hypercoagulabilité. Un test t-pairé pour des valeurs de variance inégales a démontré que le groupe de chiens atteints d’HAC avait des tracés hypercoagulables et un potentiel endogène de thrombine (« endogenous thrombin potential » ou ETP) plus élevé, lorsque comparé à la population de référence.

Le rôle du récepteur B1 des kinines dans l'insulite et dans les complications du diabète de type 1 dans un modèle de choc spectique

Les kinines sont des peptides vasoactifs et des neuromédiateurs centraux impliqués dans le contrôle cardiovasculaire, la douleur et l’inflammation. Leurs actions sont relayées par deux types de récepteurs couplés aux protéines G : le récepteur B2 (RB2), constitutif, et le récepteur B1 (RB1), inductible en présence de lésions tissulaires, de cytokines pro-inflammatoires, d’endotoxines bactériennes et dans certaines pathologies tel que le diabète. Le diabète sucré augmente à l’échelle mondiale et son étiologie est complexe; il aggrave les infections sévères et augmente la mortalité par hyperbactériémie résistante à un contrôle thérapeutique et une prise en charge en soins intensifs. Les décès surviennent dans la grande majorité des cas à la suite de l'apparition d'une coagulation intra- vasculaire disséminée (CIVD). Ce projet a pour but d’étudier le rôle du RB1 dans la CIVD dans un modèle de diabète de type 1 induit par la streptozotocine (STZ) (Article 1) et dans l’insulite (Article 2). La CIVD est produite par l’injection de lipopolysaccharide (LPS, 2 mg/kg, i.p.), 4 jours après le traitement à la STZ (65 mg/kg, i.p.). Dans le premier article, nous avons montré une augmentation significative de l'œdème et de la perméabilité vasculaire par le bleu d’Évans dans le rein, le poumon, le coeur et le foie chez les rats traités au LPS et/ou à la STZ, une situation qui favorise une hémoconcentration et le développement d'un état d'hypercoagulabilité. Nous avons aussi montré la présence d'indices de thrombus et de lésions tissulaires dans l'étude histologique ainsi qu’une augmentation de l'expression du RB1 dans le coeur, le rein et les plaquettes sanguines. Un traitement avec l’antagoniste du RB1, le SSR240612, a corrigé l’apparition de ces anomalies et a rendu normale la glycémie chez les rats STZ et l’hyperthermie induite par le LPS. De même, le SSR240612 a nettement amélioré la survie des animaux. Les bénéfices du SSR240612 ont été reproduits par l’inhibition de la iNOS avec le 1400W et de la COX-2 avec l’acide niflumique, suggérant que les médiateurs de ces enzymes pro-inflammatoires agissent en aval du RB1.Dans le deuxième article, le rat STZ est traité du jour 4 au jour 7 avec le SSR240612 (10 mg/kg/jr per os). Cet antagoniste du RB1 bloque l’infiltration du pancréas par les macrophages et les lymphocytes TCD4+ qui sont porteurs du RB1. L’antagoniste prévient aussi l’augmentation de l’expression de la iNOS, du TNF-α, du RB1 et du TRPV1 dans le pancréas des rats diabétiques. Le traitement avec l’antagoniste du RB1 a limité la perte des cellules β des îlots de Langerhans et a corrigé l’hypoinsulinémie et l’hyperglycémie. Ces deux études mettent en lumière un rôle important du RB1 dans la létalité associée au choc septique, à la thrombose et à l’insulite. Par conséquent, le RB1 représente une cible thérapeutique prometteuse dans le traitement du diabète et de ses complications.

Propriedades antioxidante, anti-hemostástica e antiproliferativa de galactanas sulfatadas da alga vermelha hypnea musciformis (wulfen) j. V. Lamouroux

Marine algae are one of the major sources of biologic compounds. In extracellular matrix of these organisms there are sulfated polysaccharides that functions as structural components and provides protection against dehydration. The fraction 1.0 (F1.0) rich in sulfated galactans obtained from red seaweed Hypnea musciformis was physicochemical characterized and evaluated for pharmacologic activity through antioxidant activity, cytotoxic action on erythrocytes, anticoagulant, stimulatory action under antithrombotic heparan sulfate synthesis and their effects on cell proliferation and cycle cell progression. The main components of F1.0 were carbohydrates (49.70 ± 0.10%) and sulfate (44.59 ± 0.015%), presenting phenolic compounds (4.79 ± 0.016%) and low protein contamination (0.92 ± 0.001%). Fraction 1.0 showed polidisperse profile and signs in infrared analysis in 1262, 1074 and 930, 900 and 850 attributed to sulfate esters S=O bond, presence of a 3,6- anidrogalactose C-O bond, non-sulfated β-D-galactose and a C-O-SO4 bond in galactose C4, respectively. The fraction rich in sulfated galactans exhibited strong antioxidant action under lipid peroxidation assay with IC50 of 0.003 mg/mL. Besides the inhibition of hemolysis induced by H2O2 in erythrocytes treated with F1.0, this fraction did not promote significant cytotoxity under erythrocytes membranes. F1.0 exhibited low anticoagulant activity causing moderate direct inhibition of enzimatic activity of thrombin. This fraction promoted stimulation around of 4.6 times on this synthesis of heparan sulfate (HS) by rabbit aortic endothelial cells (RAEC) in culture when was compared with non treated cells. The fraction of this algae displayed antiproliferative action under RAEC cells causing incresing on cell number on S fase, blocking the cycle cell progression. Thus F1.0 presented cytostatic and no cytotoxic action under this cell lineage. These results suggest that F1.0 from H. musciformis have antioxidant potential which is a great effect for a compound used as food and in food industry which could be an alternative to food industry to prevent quality decay of lipid containing food due to lipid peroxidation. These polysaccharides prevent the lipid peroxidation once the fraction in study exhibited strong inhibitory action of this process. Furthermore that F1.0 present strong antithrombotic action promoting the stimulation of antithrombotic HS synthesis by endothelial cells, being important for thrombosis preventing, by its inhibitory action under reactive oxygen species (ROS) in some in vitro methods, being involved in promotion of hypercoagulability state.

Estado nutricional relacionado à vitamina K de pacientes portadores de doença vascular em tratamento anticoagulante oral ambulatorial com varfarina sódica

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Inibição e reversão da agregação plaquetária de eqüinos in vitro com o uso de ketoprofeno, fenilbutazona e flunixim meglumine

Como são várias as enfermidades e os distúrbios que induzem à hipercoagulabilidade e à pré-ativação de plaquetas em eqüinos. A atividade de medicamentos utilizados para controle dessas enfermidades sobre a agregação de plaquetas pode, não apenas servir para avaliar sua evolução, como também a resposta terapêutica. Com o objetivo de avaliar a prevenção e a reversão da agregação plaquetária de eqüinos in vitro foram utilizados os antiinflamatórios não esteroidais (AINES): ketoprofeno, fenilbutazona e flunixim meglumine. A comparação demonstrou que a fenilbutazona e o ketoprofeno previnem a agregação de plaquetas de eqüinos induzida pelo ADP, de forma mais eficaz do que o flunixim-meglumine e, superior ao fragmento monoclonal de anticorpo Reopro, sendo semelhante a dos bloqueadores de receptores de membrana Ro-438857 e RGDS. Quanto a reverão da agregação plaquetária tanto a fenilbutazona quanto o ketoprofeno demonstraram efeitos dose-dependente.