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PubMedDate not supplied

Anesthesia for polycythemia vera.

Cystoscopy was postponed on an 80-year-old male found to have a hematocrit of 57%. After the diagnosis of polycythemia vera was made, he was phlebotomized and treated with hydroxyurea. He was readmitted 2 months later for transurethral resection of the prostate. After the induction of general endotracheal anesthesia with thiopental and succinylcholine, anesthesia was maintained with nitrous oxide, oxygen, thiopental, and atracurium. Recovery was uneventful. Polycythemia vera is a disease process in which control prior to surgery decreases the frequency of perioperative complications. A discussion and short literature review on polycythemia vera and anesthesia are included.

Aged↗

PubMed2006

Polycythemia vera and its molecular basis: an update.

The molecular basis of polycythemia vera is discussed in the context of the JAK2 V617F mutation, in our view the most important advance in understanding the pathogenesis of polycythemia vera. This chapter discusses the nature of the JAK2 V617F mutation including the studies demonstrating its role in erythropoietin independence and hypersensitivity and endogenous erythroid colony formation. The evolving evidence that JAK2 V617F is not specific for polycythemia vera pathogenesis and the development of disease phenotype is presented as well as alternative candidates for pathogenic mutations such as the protein tyrosine phosphatases and SOCS-3. Finally, the clinical correlations and implications of the JAK2 V617F mutation are discussed.

Humans↗

PubMed2005

[Polycythemia vera and pregnancy: difficulties for diagnosis and treatment].

Polycythemia vera is a myeloproliferative syndrome. This clonal disorder involves a pluripotent stem cell capable of differentiating into red blood cells, granulocytes, and platelets. Polycythemia vera is characterized by the overproduction of mature red blood cells in the bone marrow. Myeloid and megakaryocytic elements are also often increased. Polycythemia vera (PV) is rarely associated with pregnancy. About 20 cases have been reported. Prognosis of PV is not influenced by pregnancy. Conversely, pregnancy outcome is poor, due to the occurrence of gestational hypertension, stillbirth and induced prematurity. During pregnancy, clinical management needs to be close including a collaborative approach between obstetricians, hematologists and anesthesists. The risk of poor outcome may be reduced by the association of antiaggregant and anticoagulant therapy. Phlebotomy can be provided in order to maintain hemoglobin level under 42%.

Adult↗

PubMed1997

Polycythemia secondary to focal nodular hyperplasia.

An otherwise healthy 14-year-old girl presented with polycythemia and elevated serum erythropoietin. A lesion was identified in the liver by ultrasound scan and computerized axial tomography. The pathology findings of the mass excised by hepatic segmentectomy showed focal nodular hyperplasia that stained positively for erythropoietin by immunohistochemistry. Resection resulted in a cure of the polycythemia with serum erythropoietin, hemoglobin, and hematocrit returning to normal range in subsequent follow-up. To our knowledge, this is the first report of focal nodular hyperplasia resulting in secondary polycythemia.

Adolescent↗

PubMed2001

Preclinical phase of polycythemia vera in pregnancy.

BACKGROUND: In some cases, complications of pregnancy are related to thrombophilia. We describe a preclinical phase of polycythemia vera. CASE: A woman, who experienced perinatal deaths in her first two pregnancies, was diagnosed with polycythemia vera during antenatal counseling for a third pregnancy. During this pregnancy, phlebotomies, low molecular weight heparin, and low-dose aspirin treatments resulted in the delivery of a healthy baby. CONCLUSION: Polycythemia vera is a rare condition in women of childbearing age and can exist in a preclinical phase for many years. During pregnancy, it can cause severe but preventable thrombotic complications of placental origin.

Counseling↗

PubMed2001

A rare case of renal hemangioma presenting as polycythemia.

Instances of renal cell carcinoma and erythropoietin-producing renal cysts presenting as polycythemia are well documented. To our knowledge, no case of hemangioma presenting as polycythemia has been reported. We present a case of a 39-year-old man with a 5-year history of polycythemia requiring phlebotomy every 3 months. Computed tomography revealed a 6 to 7-cm right upper pole renal mass. The patient underwent right radical nephrectomy, and pathologic examination revealed the mass to be a capillary hemangioma. The patient has not required phlebotomy for 1 year since the removal of the hemangioma.

Adult↗

PubMed1982

A matched-pair control study of postrenal transplant polycythemia.

Polycythemia developed in 18 of 133 first kidney allograft recipients (13.5%) with onset from the third month to the fifth year posttransplantation. A group of matched nonpolycythemic patients were used as case controls to compare multiple variables in order to identify predisposing factors. In the polycythemia group, there were: (1) significantly more patients who had not undergone pretransplant nephrectomy; (2) significantly more patients who had glomerulonephritis as original disease; (3) significantly more patients who had received pretransplant transfusions; and (4) significantly more patients who were hypertensive posttransplant. Thus, the factors of the presence of native kidneys, original disease, pretransplant transfusions as well as hypertension posttransplant are factors associated with the presence of posttransplant polycythemia. This condition is usually self-limiting and benign.

Adolescent↗

PubMed2004

[Polycythemia vera and pregnancy].

Polycythemia vera is a rare chronic myeloproliferative disease. Its exceptional association with pregnancy can lead to severe complications. Antithrombotic treatment could prevent such adverse outcome. A patient with two previous pregnancies complicated by preeclampsia, was treated by hydroxyurea for polycythemia vera. She started a new unexpected gestation without this myelosuppressive treatment and the pregnancy was conducted uneventfully with low molecular weight heparin and low dose aspirin. Thrombotic complications required the reintroduction of hydroxyurea. Diagnosis of polycythemia vera during pregnancy is a very difficult task due to physiologic changes occurring during gestation. Adverse outcome including severe vascular complications can be a preclinical phase of the disease. An adequate therapy could prevent these complications.

Adult↗

PubMed1996

Polycythemia vera.

OBJECTIVES: To review the proliferative nature of polycythemia vera (PV), clinical features, laboratory findings, treatment options and controversies, and nursing management. DATA SOURCES: Textbook chapters and review articles that pertain to polycythemia vera. CONCLUSIONS: Polycythemia vera is a chronic myeloproliferative disorder that can evolve into acute leukemia. Treatment options include phlebotomy, myelosuppressive agents, interferon, and platelet inhibitors. IMPLICATIONS FOR NURSING PRACTICE: Nursing management of the patient with PV is challenging because of the evolving nature of the disease and treatment-related complications. Close monitoring and compliance with the treatment plan is necessary.

Algorithms↗

PubMed2000

Impaired dark adaptation in polycythemia. Improvement after treatment.

PURPOSE: To determine if dark adaptation is reduced in individuals with polycythemia and if so whether there is any improvement in dark adaptation after treatment. METHODS: Dark adaptation was recorded monocularly by automatic dark adaptometry in ten consecutive patients with polycythemia before and after treatment. Analogue investigations were performed in 31 healthy control subjects. RESULTS: Dark adaptation was markedly impaired in the patients as compared with the control subjects. After reduction of the red cell count and normalization of the hematocrit and hemoglobin the dark adaptation was markedly improved. There was no significant change in dark vision in the control subjects negating a confounding learning effect. CONCLUSION: The findings indicate a sustained but reversible neuronal hypofunction secondary to polycythemia. As the rheological abnormality was normalized, dark adaptation was improved, probably secondary to normalized microcirculation within the retina or the brain, or both, possibly with reactivation of formerly inactive neuronal cells.

Adult↗

PubMed2002

Disruption of oxygen homeostasis underlies congenital Chuvash polycythemia.

Chuvash polycythemia is an autosomal recessive disorder that is endemic to the mid-Volga River region. We previously mapped the locus associated with Chuvash polycythemia to chromosome 3p25. The gene associated with von Hippel-Lindau syndrome, VHL, maps to this region, and homozygosity with respect to a C-->T missense mutation in VHL, causing an arginine-to-tryptophan change at amino-acid residue 200 (Arg200Trp), was identified in all individuals affected with Chuvash polycythemia. The protein VHL modulates the ubiquitination and subsequent destruction of hypoxia-inducible factor 1, subunit alpha (HIF1alpha). Our data indicate that the Arg200Trp substitution impairs the interaction of VHL with HIF1alpha, reducing the rate of degradation of HIF1alpha and resulting in increased expression of downstream target genes including EPO (encoding erythropoietin), SLC2A1 (also known as GLUT1, encoding solute carrier family 2 (facilitated glucose transporter), member 1), TF (encoding transferrin), TFRC (encoding transferrin receptor (p90, CD71)) and VEGF (encoding vascular endothelial growth factor).

Adolescent↗

PubMed1997

The gene encoding hematopoietic cell phosphatase (SHP-1) is structurally and transcriptionally intact in polycythemia vera.

Polycythemia vera (PV) is an acquired clonal disorder characterized by increased production of mature red cells and growth of erythroid colonies in the absence of erythropoietin. Mutation of the erythropoietin receptor has been demonstrated to cause familial polycythemia, but no mutations have been found in PV. Moreover, both erythroid and myeloid progenitors from patients with PV have been reported to be hypersensitive to a number of different growth factors. Attention has therefore focused on post-receptor signal transduction pathways. The SHP-1 gene is an especially attractive candidate gene. Firstly, SHP-1 binds to and negatively regulates signalling from the erythropoietin receptor and is likely to regulate other cytokine receptors in a similar manner. Secondly, absence of SHP-1 protein in the motheaten mouse is accompanied by increased sensitivity of hematopoietic progenitors to a number of cytokines including erythropoietin. Thirdly, familial or sporadic polycythemia in man may result from mutations of the SHP-1 binding domain of the erythropoietin receptor. We have therefore searched for mutations of the SHP-1 gene in genomic DNA from patients with PV. In this disease the majority of peripheral blood lymphocytes are not part of the malignant clone and a variable proportion of myeloid cells may arise from normal progenitors. We have therefore chosen to study DNA from purified peripheral blood granulocytes obtained from nine women in whom the granulocytes were clonally derived. Southern analysis was used to show that the gene was not rearranged and densitometry confirmed the presence of two copies of the gene in each DNA sample. Sequencing of the entire coding region and all splice junctions revealed no mutations. Hematopoietic transcription factor binding sites in the SHP-1 promoter region were intact and the methylation status of the two SHP-1 promoters in PV patients was identical to that in three normal controls. Finally, we showed that levels of SHP-1 protein in granulocytes from patients was similar to those from normal controls. These results demonstrate that the SHP-1 gene is structurally and transcriptionally intact in patients with PV.

Aged↗

PubMed2002

Therapeutic options for essential thrombocythemia and polycythemia vera.

Several options exist for treating essential thrombocythemia and polycythemia vera. One approach is to assign the patient to a risk category from which treatment recommendations follow. The principal risks of essential thrombocythemia include thrombosis, major hemorrhage, and conversion to leukemia or myelofibrosis. Risk factors for thrombosis include age and prior thrombosis. Smoking and obesity have been implicated in isolated series. High-risk patients with essential thrombocythemia can be defined as those 60 years of age or older or those who have had a thrombosis at any age. These patients should be treated with hydroxyurea. If hydroxyurea cannot be tolerated, anagrelide and interferon-alpha (IFN-alpha) are alternatives. Low-dose aspirin (40 to 325 mg) can be used for patients whose platelet counts are < 1,500 x10(9)/L. Low-risk patients are those less than 60 years old who have not had thrombosis, who have no cardiovascular risk factors, and whose platelet counts are < 1,500 x 10(9)/L. These patients can be observed or placed on low-dose aspirin. Intermediate-risk patients are those less than 60 years who have not had thromboses, but who have platelet counts > 1,500 x 10(9)/L or who have significant cardiovascular risk factors. These patients should have their risk factors treated and may be given low-dose aspirin if the platelet count is < 1,500 x 10(9)/L. They can be observed or treated with anagrelide, hydroxyurea, or IFN-alpha. The Mayo Clinic experience suggests that no specific treatment affects outcomes of pregnancies. In high-risk pregnant women who need treatment, IFN-alpha is used. The principal risks of polycythemia vera are thrombosis, postpolycythemia myeloid metaplasia, and acute leukemia. Risk factors for thrombosis include age, the use of phlebotomies, the rate of phlebotomies, and a prior history of thrombosis. Platelet counts have not been definitively linked to an increased risk of thrombosis. High-risk polycythemia vera patients are those 60 years of age or older (some groups use 70 years) or those of any age who have had thrombosis. They should be treated with phlebotomy and hydroxyurea or IFN-alpha. Selected patients may be treated with anagrelide. A typical target range for phlebotomy is a hematocrit of < 42% for women and < 45% for men. Low-dose aspirin can be used if the platelet count is < 1,500 x 10(9)/L. Low-risk patients are those less than 60 years old who have had no thrombosis, no cardiovascular risk factors, and whose platelets are < 1,500 x 10(9)/L. These patients can be managed with phlebotomy alone or phlebotomy and low-dose aspirin. Intermediate-risk patients are those who are less than 60 years old, who have not had thrombosis, but who have platelet counts > 1,500 x 10(9)/L or who have cardiovascular risk factors. The cardiovascular risk factors should be treated, along with phlebotomy alone or with IFN-alpha. Low-dose aspirin is reasonable for those with platelet counts < 1,500 x 10(9)/mL. Anagrelide can be used with phlebotomy in selected patients. Women of childbearing age who are in the low-risk or intermediate-risk group can be treated with phlebotomy alone and low-dose aspirin if the platelet count is < 1,500 x 10(9)/L. For high-risk patients or pregnant patients, IFN-alpha can be added.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed2003

Polycythemia and hyperviscosity in the newborn.

Research from the past 15 to 20 years has led to a comprehensive understanding of the etiology and effects of polycythemia and hyperviscosity in the newborn. Polycythemia and hyperviscosity are generally a result of a poor intrauterine environment or hypoxic complications during labor and delivery. Changes in blood viscosity are a direct result of changes in hematocrit because the plasma viscosity in the newborn is virtually always normal. Polycythemia and hyperviscosity are associated with decreases in blood flow to the brain, heart, lung, intestines, and carcass. Renal blood flow is not affected, but renal plasma flow is diminished, resulting in a lower glomerular filtration rate (GFR). The elevated hemoglobin and hematocrit are associated with an increase in the arterial oxygen content. It is the increase in arterial oxygen content, not the hyperviscosity, that is directly responsible for the decreased blood flow in the brain and heart as well as cardiac output. As a result, brain and cardiac oxygenation is normal. Decreased pulmonary blood flow appears to be the result of hyperviscosity and can result in system hypoxia. This can be corrected by a partial exchange transfusion to lower the hematocrit and viscosity. This will also improve renal function by increasing plasma flow. Because the abnormalities in brain function are due to a primary hypoxia event and not reduced cerebral blood flow, a partial exchange transfusion will not improve short-term or long-term abnormalities in neurological functioning.

Blood Viscosity↗

PubMed2006

Vascular complications in Chuvash polycythemia.

Chuvash polycythemia is characterized by a homozygous 598C> T germline mutation in the von Hippel-Lindau gene ( VHL), upregulation of hypoxia-inducible factor-1alpha during normoxia, and resulting augmentation of erythropoietin and several other hypoxia-controlled genes. Although endemic to the Chuvash population of Russia, this mutation occurs worldwide and usually originates from a single ancient event. Matched-cohort and case-control analyses have shown that VHL 598C> T homozygosity is associated with lower peripheral blood pressures, varicose veins, vertebral hemangiomas, lower white blood cell and platelet counts, and elevated serum concentrations of vascular endothelial growth factor and plasminogen activator inhibitor-1. These studies have also shown associations with arterial and venous thrombosis, major bleeding episodes, cerebral vascular events, and premature mortality. Spinocerebellar hemangioblastomas, renal carcinomas, and pheochromocytomas typical of classical VHL tumor predisposition syndrome have not been found, and no increased risk of cancer has been demonstrated. Retrospective analyses among patients with Chuvash polycythemia have not shown benefit for therapy with phlebotomy or aspirin, but these and other modes of therapy should be studied prospectively. Further investigation of the vascular complications of Chuvash polycythemia may increase our fundamental knowledge of thrombophilia, bleeding diatheses, and protection from cancer.

Aspirin↗

PubMed1976

Polycythemia vera: stem-cell and probable clonal origin of the disease.

Two women with polycythemia vera and heterozygosity (GdB/GdA) at the X-chromosome-linked locus for glucose-6-phosphate dehydrogenase were studied to determine the nature of the cellular origin of their polycythemia. In contrast to unaffected tissue, such as skin fibroblasts, which consisted of both B and A types, the glucose-6-phosphate dehydrogenase of the patients' erythrocytes, granulocytes and platelets was only of Type A. These results provide direct evidence for the stem-cell nature of polycythemia vera and strongly imply a clonal origin for this disease. The fact that no descendants of the presumed normal stem cells were found in circulation suggests that bone-marrow proliferation in this disorder is influenced by local (intramarrow) regulatory factors.

Blood Platelets↗

PubMed1981

Increased incidence of acute leukemia in polycythemia vera associated with chlorambucil therapy.

In studies to determine the optimal treatment for polycythemia vera, 431 previously untreated patients whose disease met established diagnostic criteria were entered into a prospective, randomized controlled trial between 1967 and 1974. Three treatment regimens were used: phlebotomy alone, chlorambucil supplemented by phlebotomy, or radioactive phosphorus supplemented by phlebotomy. Despite minor differences in age and sex, the three groups were comparable in initial hematocrit, white-cell and platelet counts, and disease-related symptoms. The median duration of follow-up is now more than 6 1/2 years. As of February 15, 1980, there were no statistically significant differences in survival among the groups. However, the risk of acute leukemia in patients given chlorambucil was 2.3 times that in patients given radioactive phosphorus and 13 times that in patients treated with phlebotomy alone. The increased incidence of leukemia during chlorambucil treatment is statistically significant (P less than or equal to 0.002); accordingly, the Polycythemia Vera Study Group has discontinued the use of chlorambucil in the treatment of polycythemia vera.

Acute Disease↗

PubMed1989

Transmembrane domain of the envelope gene of a polycythemia-inducing retrovirus determines erythropoietin-independent growth.

Both the polycythemia-inducing and the anemia-inducing strains of Friend spleen focus-forming virus can induce acute erythroleukemia in susceptible adult mice. However, only cells infected with the polycythemia-inducing strain become erythropoietin-independent for proliferation and differentiation. The sequences responsible for the altered erythropoietin responsiveness have previously been localized to a 678-base-pair EcoRI-Cla I fragment at the 3' end of the envelope gene. This region is now further analyzed by dividing it into two fragments by using the Fok I restriction site. Two recombinants were made by replacing either the 558-base-pair EcoRI-Fok I or the 113-base-pair Fok I-Cla I env gene fragments from the anemia-inducing strain of spleen focus-forming virus with sequences derived from the polycythemia-inducing strain. Our results indicate that the 113-base-pair Fok I-Cla I fragment, which encodes primarily the transmembrane domain of the envelope protein, determines erythropoietin-independent growth.

Amino Acid Sequence↗