Home About us Contact
|
Home About us Contact | ||
|
|
||
Thrombin-antithrombin Complex (thrombin-antithrombin + complex)
Selected AbstractsProspective study of hemostatic alterations in children with acute lymphoblastic leukemia,AMERICAN JOURNAL OF HEMATOLOGY, Issue 5 2010Paola Giordano In a group of newly diagnosed acute lymphocytic leukemia (ALL) children we evaluated a number of hemostatic and inflammatory markers at diagnosis and at different time points during chemotherapy for the remission induction to identify alterations in the plasma levels of prothrombotic markers before and during the course of chemotherapy. The following plasma markers were evaluated: thrombin-antithrombin complex (TAT), D-Dimer, plasminogen activator inhibitor 1 (PAI-1), antithrombin, fibrinogen, von Willebrand factor (VWF) antigen and high molecular weight VWF (HMW-VWF) multimers, P-selectin, tumor necrosis factor alpha (TNF-,), and interleukin 6 (IL-6). Plasma samples were collected at the following time points: at T0 (baseline) and T1 (+24 days of therapy), T2 (+36 days therapy), and T3 (+64 days therapy). The results show that, at diagnosis, ALL children presented with laboratory signs of increased thrombin generation and fibrin formation (i.e. high TAT and D-dimer levels), fibrinolysis inhibition (i.e. high PAI-1 level), endothelial activation (i.e., high HMW-VWF and soluble P-selectin levels) and inflammation (i.e. high TNF-alpha and IL-6 levels). After starting induction therapy, the thrombin generation markers and inflammatory cytokines significantly decreased. To the opposite, PAI-1 and P-selectin significantly increased, suggesting an insult by chemotherapy on the vascular endothelium. These effects were more evident during steroid administration. Symptomatic venous thromboembolism (VTE) episodes developed in two cases during induction therapy, which did not allow the evaluation of the predictive value for VTE of laboratory markers. Am. J. Hematol., 2010. © 2010 Wiley-Liss, Inc. [source] Thrombin activatable fibrinolysis inhibitor activity, thrombin-antithrombin complex and D-dimer levels in preterm neonates with early respiratory distress syndromeAMERICAN JOURNAL OF HEMATOLOGY, Issue 1 2008Tugba Gursoy Intraalveolar fibrin deposition found in neonates with respiratory distress syndrome (RDS) is explained by the activation of the coagulation system and inefficient fibrinolysis. However, thrombin activatable fibrinolysis inhibitor activity (TAFIa), an inhibitor of fibrinolysis, and the ratio of D-dimer to thrombin,antithrombin complex (D-dimer/TAT), an index of fibrinolytic activity, have not been reported previously in neonatal RDS. Aim of this study is to evaluate the influence of plasma TAFIa levels on the fibrinolytic state in neonatal RDS. The RDS group (Group 1) consisted of 29 neonates, and 18 neonates served as the control group (Group 2). Plasma TAFIa levels and D-dimer/TAT ratios were evaluated in all neonates in the first 6 hr of life. Neonates in the RDS group were further divided into two subgroups; Group 1a consisted of 12 neonates with evidence of mild asphyxia (Apgar score at 5 min <7 and cord pH <7.26), and Group 1b consisted of 17 nonasphyxiated neonates. No significant difference was found in TAFIa levels and D-dimer/TAT ratios between Groups 1 and 2 [214% (56.2,361%) and 124.3 (4.4,3,921) in Group 1 and 201% (60.3,381%) and 147 (5.9,1,426) in Group 2]. There were negative correlations between cord pH and TAFIa levels in both groups. Increased TAFIa levels and decreased D-dimer/TAT ratios and platelet counts were detected in mildly asphyxiated neonates when compared with nonasphyxiated ones. TAFIa is not responsible for the hypofibrinolytic state reported in RDS. However, asphyxia influences TAFIa levels and increased TAFIa levels depress fibrinolysis. Am. J. Hematol., 2008. © 2007 Wiley-Liss, Inc. [source] Ex Vivo Biocompatibility of Avidin-Agarose: A New Device for Direct Adsorption of Biotinylated Antibodies from Human Whole BloodARTIFICIAL ORGANS, Issue 9 2000T. Bosch Abstract: Radioimmunotherapy using radiolabeled antitumor antibodies (RAA) is limited by the toxicity of unbound antibodies in the circulation. Removal of excessive antibodies by affinity-adsorption could therefore allow the administration of increased dosages of RAA while decreasing their adverse effects. Recently, avidin-agarose (AA) minicolumns were used in animal experiments for the removal of biotinylated antibodies from whole blood exploiting the high affinity binding of biotin to avidin (pK 1015 M,1). This study was performed to evaluate the ex vivo biocompatibility of AA minicolumns with human blood. Ten ml AA minicolumns were perfused online ex vivo in the single pass mode with fresh blood from 8 healthy donors at a flow rate of 6.25 ml/min. The anticoagulation consisted of 0.5 IU heparin plus 0.0,2.1 mg citrate per ml of blood. In Part 1 of the study (40 min perfusion, n = 4), the optimal anticoagulation was found to be 0.5 IU heparin plus about 1 mg citrate per ml of blood. In Part 2 of the study, four 80 min test-runs were performed. No signs of hemolysis were found, and the thrombogenicity of the AA gel was negligible. Cell counts and column inlet pressures remained constant; toward the end of the 80 min test-runs, some activation of blood cells (elastase, ,-thromboglobulin), the complement system (C3a, C5a) and the plasmatic coagulation (thrombin-antithrombin complex) was detectable. A moderate initial bradykinin release rapidly subsided to very low levels. In summary, AA minicolumns showed good biocompatibility upon contact with human whole blood and merit further investigation in a closed-loop system for a potential application of direct tumor antibody removal by hemoperfusion. [source] Very severe thrombocytopenia and fragmentation hemolysis mimicking thrombotic thrombocytopenic purpura associated with a giant intracardiac vegetation infected with Staphylococcus epidermidis: Role of monocyte procoagulant activity induced by bacterial supernatantAMERICAN JOURNAL OF HEMATOLOGY, Issue 8 2007Kathleen Selleng Abstract The pathogenesis of very severe thrombocytopenia in bacterial endocarditis is uncertain. We report a 50-year-old male with platelet counts < 10 × 109/l and fragmentation hemolysis complicating Staphyloccoccus epidermidis pacemaker endocarditis with a giant vegetation. Antibiotics, corticosteroids, high-dose intravenous gammaglobulin, and plasmapheresis (for initially-suspected thrombotic thrombocytopenic purpura) failed to produce significant platelet count increase. However, therapeutic-dose heparin anticoagulation was associated with a platelet count increase from <10 to ,40 × 109/l, with parallel reduction in thrombin-antithrombin complexes (from 8.9 to 3.5 ,g/l), facilitating surgical intervention. The thrombocytopenia promptly resolved following surgical removal of the vegetation. Culture supernatant from S. epidermidis isolated from the patient's blood induced monocytes to express procoagulant activity (assessed by factor Xa generation) equivalent to lipopolysaccharide (1 ,g/ml), with half-maximal activation seen with culture supernatant diluted to 1:12,800. These data are consistent with previous animal models of endocarditis demonstrating staphylococci-induced procoagulant changes in monocytes. This case demonstrates that heparin anticoagulation can be therapeutic in infective endocarditis-associated severe thrombocytopenia in a non-bleeding patient, and that such therapy may ameliorate the platelet count enough to permit surgical intervention. Am. J. Hematol 2007. © 2006 Wiley-Liss, Inc. [source] | ||||||||||