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)

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

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

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

Essential thrombocythemia and polycythemia vera are myeloproliferative disorders (MPD) with an elevated thrombotic risk. Leukocytosis has recently emerged as a new risk factor and there is increasing evidence that polymorphonuclear neutrophils (PMN) are involved. Procoagulant activity (PCA) of PMN in MPD has not yet been investigated. PCA of PMN from 22 patients with JAK2(V617F) positive MPD and 26 healthy subjects was studied using calibrated automated thrombography: in vitro thrombin generation induced with 1 pM tissue factor in the presence of added procoagulant phospholipids. There were no differences between patients and controls regarding the ability of PMN to increase thrombin generation. More surprisingly, basal thrombin generation in acellular MPD-plasma was found decreased for as yet unknown reasons. The presence of an active protein C pathway or platelets might provide a better insight into the coagulation phenotype in MPD.
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PMID:Polymorphonuclear neutrophils from JAK2(V617F) positive MPD patients do not support hypercoagulability: A study with calibrated automated thrombography (CAT). 2130 25

Budd Chiari syndrome is a rare disorder resulting from hepatic venous outflow tract obstruction anywhere from the small hepatic veins to the suprahepatic inferior vena cava. This patient has a hypercoagulable state secondary to heterozygous mutation of factor V and the JAK2 mutation and is being anticoagulated. We hypothesize that the low protein C and low antithrombin III levels seen in this patient resulted from decreased synthetic function of the liver and were not indicative of actual deficiencies. Indeed, reports of coexisting protein C and antithrombin III deficiencies are not existent in the literature and likely are not compatible with life. All patients with BCS warrant a hypercoagulable work up and JAK2 mutation is increasingly recognized as a contributing factor, even in those patients without obvious signs of polycythemia vera.
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PMID:Clinical case of the month. A rare case of Budd Chiari syndrome. 2227 54

In patients with liver cirrhosis the contribution of inherited and acquired prothrombotic disorders in the development of non-malignant portal vein thrombosis (PVT) is inconclusive. The purpose of this retrospective study was to examine the prevalence of thrombophilia in this setting at our center from January 2012 to November 2019. Tests included gene mutational analysis for Factor V Leiden, prothrombin G20210A, JAK2 (V617F), Calreticulin (CARL), in addition to activated protein C resistance, antithrombin III, protein C and S levels, and antiphospholipid antibodies. We included 77 patients, six of whom (7.8%) had a thrombophilic disorder: antiphospholipid syndrome in four patients, prothrombin gene mutation in one and factor V Leiden mutation in one. This latter patient had also been diagnosed with polycythemia vera years before PVT development. Complete thrombosis of the main portal vein and re-thrombosis after stopping anticoagulation were more frequent in patients with thrombophilia, but the rates of recanalization under anticoagulant therapy were similar among groups. No other difference was accounted between groups. The low prevalence of acquired and inherited thrombophilia found in patients with cirrhosis and PVT support testing for these disorders on an individual basis and avoiding universal screening to reduce costs and unwarranted testing.
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PMID:Portal Thrombosis in Cirrhosis: Role of Thrombophilic Disorders. 3287 64