Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0032463 (polycythemia vera)
 3,374 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We attempted to determine if a hypercoagulability state exists in patients with polycythemia vera (PV) and essential thrombocythemia (ET). We studied the hematocrit level, platelet count, use of any antiaggregant drugs, thrombotic or bleeding accidents and plasma levels of antithrombin III, protein C, total protein S, free protein S, vWF:Ag (Von Willebrand's factor related antigen), thrombin-antithrombin complexes, D-dimer, fibrinolytic activity, tissue plasminogen activator, plasminogen and PAI-1 in 33 patients (19 with ET and 14 with PV). PAI-1 plasma concentration was significantly higher in, both ET and PV patients than in the control group, and were higher in those patients with previous thrombotic episodes than in asymptomatic patients or with previous bleeding episodes. Increasing age was associated to more thrombotic episodes while younger patients presented with more hemorrhagic complications. A linear correlation between platelet count and PAI-1 levels in PV patients (r = 0.44, p < 0.05) and ET patients (r = 0.30, p < 0.05) was found. Fibrinolytic activity in patients with ET was significantly decreased when compared to the control group. A hypofibrinolytic state could be an additional factor which could be used as a predictive index of the thrombotic or bleeding tendency in each patient.
 ...
PMID:High plasma levels of plasminogen activator inhibitor 1 (PAI-1) in polycythemia vera and essential thrombocythemia are associated with thrombosis. 799 52

Thrombohemorrhagic complications are a major cause of morbidity and mortality in patients with essential thrombocythemia (ET) and polycythemia vera (PV). The pathogenesis of these complications is not completely clarified. Several studies have described abnormalities of red blood cells and platelets in these patients. However, no studies are available on changes in the polymorphonuclear leukocytes (PMNs), which can play an important role in the activation of the hemostatic system. In patients with ET (n = 37) and PV (n = 34), a series of PMN activation parameters (PMN membrane CD11b and leukocyte alkaline phosphatase [LAP] antigen expression, cellular elastase content, plasma elastase, and myeloperoxidase levels) was evaluated simultaneously with the levels of plasma markers of endothelial damage (thrombomodulin and von Willebrand factor antigen) and hypercoagulation (thrombin-antithrombin complex, prothrombin fragment 1 + 2, and D-dimer). The results show the occurrence of PMN activation in both groups of patients compared with a control group of healthy subjects. An increase in CD11b and LAP expression by PMN membrane was observed, together with a significant increase in cellular elastase content, plasma elastase, and myeloperoxidase levels. In addition, patients had high plasma levels of endothelial and hypercoagulation markers compared with controls. For the first time, these data show that in ET and PV, 2 hematologic conditions that place patients at increased risk for thrombosis, an in vivo leukocyte activation occurs and is associated with laboratory signs of endothelium and coagulation system activation. (Blood. 2000;96:4261-4266)
 ...
PMID:Polymorphonuclear leukocyte activation and hemostasis in patients with essential thrombocythemia and polycythemia vera. 1111 Jul

Inherited and acquired tendency to the formation of clots represents an important cause of morbidity and mortality for ischemic events in young people (aged between 40 and 50 years) that is more and more frequently identified. The haemostasis' disorders may happen on the venous or arterial side. Arterial thrombus is a 'white' thrombus, also called temporary thrombus. It consists of aggregate platelets only. On the contrary, venous thrombus is 'red' or permanent thrombus composed of platelets, red cells and fibrin. The first is the result of platelets' adhesion or aggregation. Instead, the permanent thrombus derives from the coagulant factors successively acting on 'white' thrombus. The different pathogenesis justifies both the distinction between 'hypercoagulability' and 'thrombophilia' and the different treatments employed. Antiphospholipid antibody syndrome, polycythemia vera, atrial fibrillation-acquired hyperhomocysteinemia, diabetes mellitus and myeloproliferative disease are the most frequent causes of acquired hypercoagulable state, prevalently responsible for deep venous thrombosis. Among the inherited forms, congenital hyperhomocysteinemia, factor V Leiden mutation, proteins C and S deficiency and antithrombin mutation are included. These may induce both venous and arterial acute events. Hyperhomocysteinemia can be congenital and acquired and is more correctly named as 'thrombophilia' rather than 'hypercoagulability'. That happens because it involves the platelets' aggregation rather than the coagulant cascade. The optimal treatment of thrombophilias consists of oral (warfarin) or injectable (heparins) anticoagulants. Direct thrombin inhibitors, platelet glycoprotein IIb/IIIa antagonists, and tissue factor inhibitors also appear to be some attractive approaches. For acquired forms, treatments of their aetiologies must also be carried out. For acquired hyperhomocysteinemia, both antiplatelets' therapy (aspirin + clopidogrel) and new direct thrombin inhibitors (as dabigatran) could be considered. Finally, as secondary prevention of an arterial acute event (stroke, IMA or peripheral ischemia) due to hyperhomocysteinemia, lifetime dual antiplatelets' therapy should be used.
 ...
PMID:Some considerations about the hypercoagulable states and their treatments. 2134 57

Hemostatic disorders are a major clinical problem in patients with myeloproliferative neoplasms (MPNs) and they are the second most common cause of death in MPN patients, after infections. The aim of this study was to assess the fibrinolytic potential of the blood of patients with MPNs. The study involved 112 patients with MPNs diagnosed at the Hematology Clinic Dr J. Biziel University Hospital No. 2 in Bydgoszcz, Poland. The study group included 63 patients with essential thrombocythemia, 29 with polycythemia vera, 11 with chronic myelogenous leukemia (CML) and nine with primary myelofibrosis. The control group consisted of 25 healthy volunteers who were age and sex-matched. The following parameters were determined: concentration of tissue plasminogen activator antigen (t-PA:Ag), plasminogen activator inhibitor type 1 antigen concentration (PAI-1:Ag), D-dimer, thrombin-antithrombin complexes, fibrinogen, activated partial thromboplastin time and international normalized ratio. The study showed significantly increased t-PA:Ag, PAI-1:Ag and D-dimer levels in patients with MPNs. Moreover, we found increased concentrations of thrombin-antithrombin complexes and fibrinogen, as well as elevated platelet counts. Detailed analysis revealed that t-PA:Ag concentration was elevated in patients with essential thrombocythemia, CML and polycythemia vera. Concentration of PAI-1:Ag was increased in patients with essential thrombocythemia and polycythemia vera; D-dimer was significantly higher in essential thrombocythemia, polycythemia vera, CML and primary myelofibrosis patients. Increased concentrations of t-PA:Ag and D-dimer indicate secondary activation of the fibrinolytic system in patients with MPNs. Elevated levels of PAI-1 in MPN patients may result from its increased production by elevated number of activated platelets and vascular endothelial damage. PAI-1 by having an inhibitory effect on fibrinolysis manifests its procoagulant activity.
 ...
PMID:Selected parameters of hemostasis in patients with myeloproliferative neoplasms. 2450 38

Thrombosis is a potential life-threatening complication in patients undergoing cardiac surgery. Various clinical and heritable conditions, like cancer, trauma, immobilization, the presence of factor V Leiden or prothrombin 20210A, deficiency of or resistance to the inhibitor proteins C, S, or antithrombin, elevated levels of coagulation proteins, antiphospholipid antibody syndrome, pregnancy, and the use of exogenous hormones, may contribute to catastrophic thrombosis. Massive thrombi with cerebrovascular and cardiovascular events develop in patients with polycythemia vera (PV). However, thrombus formation in the cardiac chambers is extremely rare. We report a case of massive intracardiac thrombosis in a patient undergoing coronary artery bypass grafting.
...
PMID:Massive intracardiac thrombosis during coronary artery bypass grafting surgery. 2581 Sep 67