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

This study was designed to assess whether factors other than high haemoglobin, thrombocytosis and abnormal platelet function predispose to thrombosis in polycythaemia rubra vera (PRV). Components of the fibrinolytic system and concentrations of the naturally occurring anticoagulants were measured in patients and controls in the resting state; the fibrinolytic capacity was reassessed after venous occlusion. The results were related to presence or absence of a history of thromboembolism. Under resting conditions, patients with PRV had reduced plasminogen activator inhibitor antigen levels and higher fibrin plate lysis area and tissue plasminogen activator activity. Protein C, protein S and factor V levels were reduced. Those patients with a history of thromboembolism had decreased tissue plasminogen activator activity after venous occlusion compared to those who had not experienced a thrombosis. We conclude that reduced fibrinolytic capacity may predispose to thrombosis in PRV. Despite treatment to normalize haemoglobin levels, the patients have persistent activation of their fibrinolytic systems. This, and reduced levels of proteins C and S, may be secondary to a chronic, clinically occult, disseminated intravascular coagulation.
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PMID:The fibrinolytic system and proteins C and S in treated polycythaemia rubra vera. 148 3

More than a dozen primary hematologic disorders have been associated with ischemic stroke. Inherited deficiencies of antithrombin III, protein C, and protein S have been linked with stroke in case reports; optimal screening requires functional as well as antigenic assays. Antiphospholipid antibodies and lupus anticoagulants are the most frequently identified acquired states associated with ischemic stroke. Polycythemia vera, sickle cell anemia, sickle-C disease, and essential thrombocythemia are the major disorders of formed blood elements causing stroke. Special, step-wise screening for occult prothrombotic entities in stroke patients is recommended for young persons with stroke of uncertain cause, for those with prior venous thrombosis, for those with a family history of unusual thrombosis, and for those with no other explanation for recurrent stroke. Acquired, perhaps transient, abnormalities of platelets, coagulation inhibition, and fibrinolysis may contribute importantly to brain ischemia in synergy with other mechanisms, but at present these remain ill-defined. The contribution of prothrombotic diatheses to stroke is probably underrecognized and warrants further investigation.
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PMID:Hematologic disorders and ischemic stroke. A selective review. 186 63

Venous thromboembolic diseases are of major importance with respect to morbidity and mortality. Therefore, efficient prophylaxis is essential. Indication for thromboprophylaxis has to be made individually: In high risk situations, especially in orthopedic surgery, every patient should receive medical prophylaxis, e.g. with heparin, in addition to other preventive measures such as the wearing of elastic stockings or physiotherapy until full mobilization. For high-risk patients having a history of recurrent venous thromboembolism or which are suffering from a thrombogenic disease (e.g. myeloproliferative disorder, especially polycythemia vera, paroxysmal nocturnal hemoglobinuria, systemic lupus erythematosus, homocystinuria) or a hereditary thrombophilia (e.g. deficiency of antithrombin III, protein S, protein C or APC resistance), prophylactic measures should be more generally applied. In these patients, risk factors (e.g. oral contraceptive medication) or risk situations (e.g. long-distance travelling by car or airplane) have to be avoided whenever possible. In inevitable risk situations (e.g. perioperative or peripartal period) prophylaxis is mandatory. It is generally limited to the period of elevated thrombogenic risk and is often effected by application of a low molecular weight heparin. Patients with a history of recurrent thromboembolic events despite elimination of all avoidable risk factors should get a lifelong prophylaxis, usually with oral anticoagulants.
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PMID:[Prevention of venous thromboembolism--in whom, when and how?]. 783 22

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.
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PMID:High plasma levels of plasminogen activator inhibitor 1 (PAI-1) in polycythemia vera and essential thrombocythemia are associated with thrombosis. 799 52

Patients with polycythemia vera (PV) or essential thrombocythemia (ET) show a high frequency of thrombosis. The reduction of hematocrit after phlebotomy and normalization of platelet counts do not completely eliminate thrombotic risk. Some preliminary studies reported a reduction in the concentration of natural anticoagulants (NA) in this group of patients. For this reason we evaluated protein S (PS) total antigen, antithrombin III (AT III), and protein C (PC) activity in 81 patients with chronic myeloproliferative disorders (33 with PV and 48 with ET). Data were compared with those obtained in 70 healthy sex- and age-matched subjects. Fifty-seven percent of patients (46 out of 81) showed one or more thrombotic episodes at diagnosis or during follow-up. Interestingly, we found a NA deficit in 43.5% of patients with thrombosis versus only 5.7% in the group of patients without thrombosis. These results may suggest new interpretations about the pathogenesis of thrombosis in PV or ET patients.
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PMID:Reduction of antithrombin III, protein C, and protein S levels and activated protein C resistance in polycythemia vera and essential thrombocythemia patients with thrombosis. 863 6

Patients with polycythemia vera (PV) have a high risk of thrombosis. However, thrombosis is not sufficiently predictable with standard diagnostic procedures. We report on a patient with PV and recurrent thrombosis who nevertheless had a low platelet count while under therapy with hydroxyurea. As a result of duodenal ulcer and gastrointestinal bleeding, treatment with phenprocoumon was stopped years ago. Recently, heterozygosity for the factor V gene defect was diagnosed and anticoagulation therapy was reconsidered. In conclusion, the presence of resistance to activated protein C was an additional thrombotic risk factor that was important for our decision to change the treatment strategy in our patient.
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PMID:APC resistance as an additional thrombotic risk factor in a patient suffering from polycythemia vera and recurrent thrombosis. 903 17

A 26-year-old woman, after cesarean section in the 33rd week of gestation, developed after delivery thrombosis of the popliteal vein, pulmonary embolism and thrombosis of the portal vein. After completion of a six month period of oral anticoagulation, laboratory investigations revealed diminished levels of plasminogen and free protein S antigen as well as APC-resistance due to heterozygous FV R506Q mutation. After six uneventful years, abdominal sonography and magnetic resonance examination, performed because of abdominal pain, showed liver cirrhosis with Budd-Chiari syndrome. Additional hematological investigations led to the diagnosis of polycythemia vera. Association of myeloproliferative disorders, mainly polycythemia vera, with splanchnic venous thrombosis is well known and should always be looked for.
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PMID:[A 26-year-old woman with splanchnic vein thrombosis as the initial manifestation of polycythemia vera]. 1051 20

A case of multiple thrombotic diatheses discovered in the setting of mesenteric venous infarction is discussed. The patient had deficiencies of protein C, protein S, antithrombin III; was heterozygous for factor V Leiden; and had polycythemia vera. Adequate anticoagulation could not be established with heparin administration and hirudin was used. The diagnosis of mesenteric venous infarction, thrombotic tendency of multiple coagulation diatheses, and use of hirudin are discussed.
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PMID:Successful anticoagulation with hirudin in a patient with mesenteric venous thrombosis and multiple coagulation abnormalities. 1110 98

Polycythemia Vera (PV) and Essential Thrombocythemia (ET) are chronic myeloproliferative disorders complicated by a high incidence of thrombotic complications. Extensive coagulation studies failed to demonstrate a consistent pattern of abnormalities associated with thrombosis. Recently, a poor anticoagulant response to activated protein C (APC), due to a mutation of factor V (FV Leiden), has been identified as the most frequent hereditary disorder associated with venous thrombophilia. We investigated in 304 patients with PV and ET whether the presence of FV Leiden could be a risk factor for thrombosis. FV Leiden was found in 14/304 patients (4.6%) and was associated with venous thromboembolism (VTE) occurred before and at diagnosis (5/27,16%, with a significant difference of prevalence in comparison of that observed in asymptomatic patients, 9/263, 3%, p = 0.003). Carriership of FV Leiden was associated with VTE relapse, with a prevalence of 3.6% in asymptomatic patients, 6.9% in patients with a single episode of VTE and 18.1% in patients with recurrent VTE. The prevalence of FV Leiden in patients with and without arterial thrombosis was similar (5/79, 6% and 9/211, 4%, respectively, p = 0.337). This study indicates that the prevalence of the FV Leiden mutation in patients with PV and ET is comparable with that observed in the general population. FV Leiden mutation is a risk factor for VTE before and at time of diagnosis and for VTE recurrences. Screening for FV Leiden may be considered to identify PV and ET patients at higher risk of recurrences.
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PMID:Factor V Leiden mutation carriership and venous thromboembolism in polycythemia vera and essential thrombocythemia. 1222 65

The Budd-Chiari syndrome is a heterogeneous group of disorders characterized by obstruction of hepatic venous outflow at any level from the small hepatic veins to the junction of the inferior vena cava with the right atrium. We present two cases of Budd- Chiari syndrome with severe ascites associated with polycythemia vera in first case and protein C deficiency in the second, in both cases transjugular intrahepatic portosystemic shunt were placed, with excellent control of symptoms, no mortality were observed, and just one episode of pulmonary venous thrombosis was observed. To our knowledge this is the first time that transjugular intrahepatic portosystemic shunt are used and reported in Budd-Chiari syndrome in Mexico.
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PMID:Early experience of Budd-Chiari syndrome treatment with transjugular intrahepatic portosystemic shunt. 1706 Aug 71


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