Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.6 (thromboplastin)
 13,278 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hepatic veno-occlusive disease (VOD) is a major regimen-related toxicity after bone marrow transplantation (BMT). Endothelial injury, leading to deposition of coagulation factors within the terminal hepatic venules, is believed to be the key event in the pathogenesis of VOD. To evaluate the benefit and the safety of a VOD prophylaxis with anticoagulants, we conducted a prospective randomized trial of continuous infusion of low-dose heparin among 161 patients under-going either allogeneic (n = 79) or autologous BMT (n = 81). Patients were randomized to receive (n = 81) or not receive (n = 80) prophylactic heparin 100 U/kg/d by continuous infusion from day -8 until day +30 post-BMT. Heparin was found to be highly effective in preventing VOD, which occurred in 11 of 80 patients (13.7%) in the control group versus 2 of 81 (2.5%) in the heparin group (P less than .01). Furthermore, none of the 39 patients in the heparin group developed VOD after allogeneic BMT, versus 7 of 38 (18.4%) in the control group (P less than .01). This prophylactic effect was achieved without added risk of bleeding. Indeed, the low-dose heparin we used did not prolong the partial thromboplastin time and did not increase the red blood cell and platelet requirements. It is therefore recommended that heparin prophylaxis be part of early mortality prevention programs after BMT.
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PMID:Prevention of hepatic veno-occlusive disease after bone marrow transplantation by continuous infusion of low-dose heparin: a prospective, randomized trial. 139 66

A 37-year-old man with acute myeloblastic leukemia (FAB M2) in first remission underwent a bone marrow transplant (BMT) following conditioning with high-dose cytarabine and total body irradiation. The donor was an HLA-identical brother. Graft rejection occurred and a second BMT was performed from the same donor following conditioning with cyclophosphamide. Engraftment was achieved, but the patient developed severe jaundice and died of respiratory failure on day +46 after the second BMT. Liver biopsy revealed luminal narrowing of the central veins and a diagnosis of hepatic veno-occlusive disease (VOD) was made. The coagulation studies showed a prolonged kaolin clotting time which was not corrected by 1:1 mixture with normal plasma, and the platelet neutralization test was positive. Dilute tissue thromboplastin time and dilute Russell viper venom time were also prolonged. These results fulfilled the criteria for lupus anticoagulant, which may have contributed to VOD in this patient.
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PMID:Hepatic veno-occlusive disease in a patient with lupus anticoagulant after allogeneic bone marrow transplantation. 193 57

Twenty-eight patients undergoing marrow transplantation participated in a pilot study to determine the safety of continuous infusion heparin for the prevention of veno-occlusive disease (VOD) of the liver. Four doses of continuous infusion heparin were administered, ranging from a dose prolonging the partial thromboplastin time (PTT) to 1.5-2.0 times the patients' baseline value, to a dose prolonging the PTT to less than 1.2 times the patients' baseline value. Seven patients (25%) received a full course of heparin, beginning from the day the preparative therapy started through day 14 post-transplant (range 20-26 days on heparin). In 21 patients infusions were ended before day 14 post-transplant, a median of 16 days on heparin (range 1-26 days). Of these, 14 patients were withdrawn from heparin because of bleeding and seven were withdrawn because of anticipated bleeding. Bleeding was observed in 27 patients and was minor in 25. Two patients developed major bleeding in the gastrointestinal tract which was not fatal. Minor bleeding was observed in 27 of 28 case control patients who did not receive heparin. The sites of bleeding were similar in control and heparin treated patients. VOD developed in 20 patients (71%) and was sever or fatal in four (14%). The prevalence of VOD was not influenced by the dosage of heparin or the duration of its administration. We conclude that low dose heparin resulting in marginal prolongation of the PTT may be infused into patients undergoing marrow transplantation with a low risk of serious bleeding. Further studies are needed to evaluate its efficacy.
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PMID:A pilot study of continuous infusion heparin for the prevention of hepatic veno-occlusive disease after bone marrow transplantation. 236 81

The pathogenesis of veno-occlusive disease (VOD) of the liver appears to be secondary to endothelial damage of terminal hepatic venules, which leads to activation of the coagulation cascade, fibrin deposition, and eventual fibrous obliteration of the hepatic venules. Patients with VOD usually present with jaundice, hepatomegaly, weight gain, and ascites. This complication is usually associated with a high mortality rate. We report here the frequency and treatment of VOD in our autologous bone marrow transplant (BMT) patient population. Three of 15 (20%) children (median age 9 years) developed VOD and were treated with recombinant tissue plasminogen activator (rt-PA). Two of these three patients were prepared for BMT with busulfan (16 mg/kg) and cyclophosphamide (Cytoxan, 200 mg/kg), while the other child received cytosine arabinoside (ARA-C 18 g/m2), Cytoxan (3,600 mg/m2) and total body irradiation (TBI, 1,400 y). VOD developed between days 7-24 posttransplant. Clotting studies obtained pretransplant and during VOD included prothrombin time (PT), partial thromboplastin time (PTT), fibrinogen, fibrin-degradation product (FDP), proteins C and S, and platelet count. There was no correlation between the incidence of VOD and coagulation status. All patients had normal pretransplant clotting studies. However, protein C levels were noted to be consistently low for those patients at the time of VOD. All three patients received rt-PA at a dose of 0.25-0.5 mg/kg for 4 days. This dose produced increased levels of FDP but did not significantly prolong PT nor PTT. Two of the patients had dramatic responses and had complete resolution of VOD within 6-12 days from the start of therapy. The other patient died of fulminant hepatic failure. It seems that rt-PA is effective in VOD of the liver, which may be associated with low protein C level.
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PMID:Recombinant tissue plasminogen activator (rt-PA) for veno-occlusive liver disease in pediatric autologous bone marrow transplant patients. 819 48

Severe thrombotic alterations, such as veno-occlusive disease of the liver, may occur in the early phase following high-dose chemoradiotherapy and BMT. In this study, performed in patients with hematological malignancies subjected to allogeneic (10 cases) and autologous (20 cases) BMT, we have monitored laboratory hemostatic parameters to better understand the pathogenetic mechanism of thrombosis and particularly of veno-occlusive disease. Prothrombin time, activated partial thromboplastin time, plasma fibrinogen, markers of hypercoagulability (thrombin-antithrombin complex and prothrombin fragment F1+2); natural anticoagulants (protein C, protein S and antithrombin) together with fibrinolytic parameters (plasminogen, alpha 2-antiplasmin, tissue-plasminogen activator, plasminogen activator inhibitor and D-dimer) were assessed before transplant, on day 0 and weekly for 1 month thereafter. A hypercoagulability state, not related to an impairment of the anticoagulant and fibrinolytic systems, was documented before and after autologous and allogeneic transplant. Two patients developed veno-occlusive disease: they did not show any difference from the other patients before transplant while they presented a decrease of the natural anticoagulants along with altered fibrinolytic parameters only at the clinical onset of veno-occlusive disease. In conclusion, in this study a state of marked hypercoagulability was documented in BMT patients and the hemostatic laboratory parameters evaluated were not able to predict the occurrence of the thrombotic complications.
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PMID:Hypercoagulability in patients undergoing autologous or allogeneic BMT for hematological malignancies. 824 85

Alterations of the coagulation system that may lead to coagulation activation and thrombosis are common sequelae after allogeneic bone marrow transplantation (BMT). We performed prophylactic anticoagulation by low dose heparin (50 units/kg/day) and substitution of antithrombin (AT) concentrate to sustain plasma levels above 90% of pooled normal human plasma. Conventional tests for plasmatic hemostasis and substitution of AT concentrate were recorded for 50 patients until day +50 after BMT. Incidence of sepsis, graft-versus-host-disease [GVHD], capillary leakage syndrome [CLS] and veno-occlusive disease of the liver [VOD] were investigated and compared with the results of patients without any of these complications. Patients with proven sepsis (n = 6) showed decreased activity of AT, and a prolonged activated partial thromboplastin time (aPTT), while fibrinogen levels were slightly increased. This constellation was interpreted as mild to moderate activation of the humoral coagulation cascade. Patients with VOD (n = 10) showed an increased consumption of AT concentrate at day +7 followed by a decrease of prothrombin time, of clotting factors II and VII, and a prolongation of aPTT at days +11 to +18 after BMT. This suggests, that activation of coagulation precedes decreased synthesis of coagulation factors. Patients with CLS (n = 15) or GVHD > or = II degree (n = 14) showed no major alterations of coagulation parameters. In conclusion, after BMT, two types of coagulopathy were observed: (i) an activation of the coagulation cascade (i.e. sepsis and VOD) which was followed by (ii) a diminished synthesis of coagulation factors (VOD). In order to perform timely therapeutic interventions in the coagulation system in patients with sepsis and/or VOD it appears to be important to assess the clinical value of parameters for early detection of coagulation activation as thrombin-AT complexes, D-dimers and F1 + 2 fragments.
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PMID:Humoral coagulation and early complications after allogeneic bone marrow transplantation. 929 52

The efficacy of low molecular weight heparin (LMWH) in the treatment of thrombosis is increasing interest in its clinical potential. However, the measurement of in vitro anticoagulant activities of LMWH has been controversial for its appropriate clinical dose. The study has been carried out to compare two methods for measurement of anti-factor Xa activity of LMWH (fragmin). One is 'HEPTEST' recently developed as a new clotting assay method and the other is an authentic chromogenic assay using S-2222. The coefficients of variation in intra-assay were 1.87-2.75% in clotting assay, and 0.61-0.89% in chromogenic assay. The sensitivity to detect minimum concentration was 0.02 IU/ml in clotting assay, and 0.04 IU/ml in chromogenic assay. The correlation between two methods was good (r = 0.935), whereas clotting assay has been revealed as a very simple rapid method. LMWH (fragmin) with 75 IU/kg/day was administered to three patients with coagulopathy; two disseminated intravascular coagulopathy (DIC) and one veno-occlusive disease (VOD). Hemostatic abnormalities have been improved serially after treatment in all patients. During treatment, the plasma concentration of LMWH was measured, showing 0.05-0.23 IU/ml in DIC and 0.02-0.10 IU/ml in VOD. These results suggest that measurement of plasma concentration of LMWH using the easy and rapid clotting assay method as 'HEPTEST' is clinically useful for monitoring to detect clinical dose of LMWH for DIC and thrombosis.
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PMID:[Monitoring of plasma concentration of low molecular weight heparin--comparative evaluation with chromogenic and clotting assays]. 1059 Jun 82

Plasminogen activator inhibitor 1 is known to be elevated in patients with hepatic VOD after intensive chemotherapy. To re-establish endogenous fibrinolysis and to inhibit thrombin formation, we used non-APC (zymogen) to normalize PAI-1 levels. As a consequence of thrombin formation inhibition and the consecutive inhibition of the coagulation cascade, this treatment is expected to reduce the elevated D-dimer level. Six pediatric stem cell recipients with moderate or severe VOD after busulfan or total body irradiation conditioning regimen are reported here who were therapy-refractory to defibrotide or rt-PA therapy. All patients had low levels of PC activity (16-39%). The administration of PC (60-240 IU/kg) led to a rapid and sustained rise in PC activity (target level >80%) with near normalization of prothrombin and partial thromboplastin time in all patients. Elevated PAI-1 levels declined. Five of the six patients showed a good clinical response with prompt resolution of clinical, sonographic, and laboratory signs of hepatic blood flow obstruction, while one patient with severe VOD, as well as concomitant liver GVHD and CMV disease, had a slow but detectable response to PC therapy. All patients survived.
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PMID:Favorable response of pediatric stem cell recipients to human protein C concentrate substitution for veno-occlusive disease. 1723 23