losartan-potassium and Thrombocythemia--Essential

The concept of prodromal chronic myeloproliferative neoplasms has been endorsed by the WHO classification implicating a stepwise evolution of disease. Histology of the bone marrow (BM) and borderline to mildly expressed clinical features play a pivotal role for diagnosing prefibrotic-early primary myelofibrosis. By lowering the platelet count for essential thrombocythemia and regarding BM morphology, early manifestations are tackled. Pre-polycythemic stages of polycythemia vera with a low hemoglobin level at onset are diagnosed by positive JAK2V617F mutation status, a low erythropoietin value, and characteristic BM features. The revised WHO classification incorporates hematological, morphological, and molecular-genetic parameters to generate a consensus-based working diagnosis.

Topics: Bone Marrow Examination; Disease Progression; Erythrocyte Volume; Erythropoietin; Female; Humans; Janus Kinase 2; Male; Mutation; Platelet Count; Polycythemia Vera; Primary Myelofibrosis; Risk; Thrombocythemia, Essential; World Health Organization

Topics: Anemia, Hypochromic; Antineoplastic Agents; Breast Neoplasms; Carcinoma, Small Cell; Clinical Protocols; Darbepoetin alfa; Data Interpretation, Statistical; Erythropoietin; Female; Filgrastim; Follow-Up Studies; Graft vs Host Disease; Granulocyte Colony-Stimulating Factor; Granulocytes; Hematinics; Hematologic Neoplasms; Hematopoietic Cell Growth Factors; Hematopoietic Stem Cell Transplantation; Humans; Immunoglobulins, Intravenous; Lung Neoplasms; Lymphoma; Lymphoma, Non-Hodgkin; Male; Multicenter Studies as Topic; Neoplasms; Neutropenia; Platelet Aggregation Inhibitors; Polycythemia Vera; Polyethylene Glycols; Randomized Controlled Trials as Topic; Recombinant Proteins; Research Design; Survival Analysis; Thrombocythemia, Essential; Treatment Outcome

Optimal clinical management of patients with primary myelofibrosis and post-essential thrombocythemia/polycythemia vera myelofibrosis is a challenge, given the typically advanced age of presentation and variability of the disease course and prognosis. Current medical therapeutic options have not demonstrated an impact on the disease course, which exceeds the palliation of disease-related extramedullary hematopoiesis and alleviation of cytopenias. In contrast, allogeneic stem cell transplantation (SCT) can lead to 'cure' but is limited due to patient's age or comorbidities. Currently, in patients, who are reasonable candidates, SCT (frequently with a reduced intensity conditioning regimen) is employed for intermediate- to high-risk disease. Current pharmaco-medical therapy is used as a bridge to transplant, or instead of transplant in poor transplant candidates. Pathogenetic insights, especially the discovery of the Janus kinase (JAK)2(V617F) mutation, have ushered in a host of new potential therapeutic agents that may augment the role of medical therapy. Similarly, the boundaries of transplantation continue to alter with strategies that decrease conditioning-related toxicity, improved antimicrobial prophylaxis and decreased graft-versus-host disease. The potential for continued improvements in both medical and transplant therapy suggests that for the immediate future the optimal choices for an individual patient will remain potentially volatile and present complex decisions.

Topics: Adult; Androgens; Clinical Trials as Topic; Cytostatic Agents; Disease Management; Drugs, Investigational; Erythropoietin; Etanercept; Hematopoietic Stem Cell Transplantation; Humans; Immunoglobulin G; Janus Kinase 2; Middle Aged; Myeloablative Agonists; Palliative Care; Polycythemia Vera; Primary Myelofibrosis; Prognosis; Receptors, Tumor Necrosis Factor; Risk; Thrombocythemia, Essential; Transplantation Conditioning; Treatment Outcome

The clinical criteria for the diagnosis of essential thrombocythemia (ET) according to the polycythemia vera study group (PVSG) do not distinguish between ET and thrombocythemia associated with early stage PV and prefibrotic chronic idiopathic myelofibrosis (CIMF). The clinical criteria of the PVSG for the diagnosis of polycythemia vera (PV) only detects advanced stage of PV with increased red cell mass. The bone marrow criteria of the World Health Organization (WHO) are defined by pathologists to explicitly define the pathological criteria for the diagnostic differentiation of ET, PV, and prefibrotic and fibrotic CIMF. As the clinical PVSG and the pathological WHO criteria show significant shortcomings, an updated set of European Clinical and Pathological (ECP) criteria combined with currently available biological and molecular markers are proposed to much better distinct true ET from early PV mimicking ET, to distinguish ET from thrombocythemia associated with prefibrotic CIMF, and to define the various clinical and pathological stages of PV and CIMF that has important therapeutic and prognostic implications. Comparing the finding of clustered giant abnormal megakaryocytes in a representative bone marrow as a diagnostic clue to MPD, the sensitivity for the diagnosis of MPD associated with splanchnic vein thrombosis was 63% for increased red cell mass, 52% for low serum EPO level, 72% for EEC, and 74% for splenomegaly indicating the superiority of bone marrow histopathology to detect masked early and overt MPD in this setting. The majority of PV and about half of the ET patients have spontaneous EEC, low serum EPO levels and PRV-1 over-expression and are JAK2 V617F positive. The positive predictive value for the diagnosis of PV of spontaneous growth of endogenous erythroid colonies (EEC) of peripheral blood (PB) and bone marrow (BM) cells is about 80-85% when either PB or BM EEC assays, and up to 94% when BM and PB EEC assays were performed. The diagnostic impact of low serum EPO levels (ELISA assay) in a large study of 186 patients below the normal range (<3.3 IU/l) had a sensitivity specificity and positive predictive value of 87%, 97% and 97.8%, respectively, for the diagnosis of PV. There is a significant overlap of serum EPO levels in PV versus control and controls versus SE. The specificity of a JAK2 V617F PCR test for the diagnosis of MPD is high (near 100%), but only half of ET and MF (50%) and the majority of PV (up to 97%) are JAK2 V617F positi

Topics: Amino Acid Substitution; Biomarkers; Blood Cell Count; Bone Marrow; Cell Lineage; Colony-Forming Units Assay; Disease Progression; Enzyme-Linked Immunosorbent Assay; Erythrocyte Volume; Erythroid Precursor Cells; Erythropoietin; GPI-Linked Proteins; Humans; Isoantigens; Janus Kinase 2; Membrane Glycoproteins; Mutation, Missense; Point Mutation; Polycythemia Vera; Polymerase Chain Reaction; Predictive Value of Tests; Primary Myelofibrosis; Receptors, Cell Surface; Sensitivity and Specificity; Thrombocythemia, Essential; World Health Organization

Recent insights into the molecular mechanisms of polycythemia vera (PV) and essential thrombocythemia (ET) are challenging the traditional diagnostic classification of these myeloproliferative disorders (MPDs). Clonality analysis using X-chromosome inactivation patterns has revealed apparent heterogeneity among the MPDs. The recently discovered single somatic activating point mutation in the JAK2 gene (JAK2-V617F) is found in the great majority of patients with PV, but also in many patients with phenotypically classified ET and other MPDs. In contrast to the acquired MPDs, mutations of the erythropoietin receptor and thrombopoietin receptor have been identified in familial forms of nonclonal erythrocytosis and thrombocytosis, respectively. The mechanisms of major clinical complications of PV and ET remain poorly understood. Quantitative or qualitative abnormalities of red cells and platelets do not provide clear explanations for the thrombotic and bleeding tendency in these MPDs, suggesting the need for entirely new lines of research in this area. Recently reported randomized clinical trials have demonstrated the efficacy and safety of low-dose aspirin in PV, and an excess rate of arterial thrombosis, major bleeding, and myelofibrotic transformation, but decreased venous thrombosis, in patients with ET treated with anagrelide plus aspirin compared to hydroxyurea plus aspirin.

Topics: Erythropoietin; Humans; Janus Kinase 2; Polycythemia Vera; Protein-Tyrosine Kinases; Proto-Oncogene Proteins; Thrombocythemia, Essential; Thrombopoietin

Formation of endogenous erythroid colonies (EECs) or endogenous megakaryocytic colonies (EMCs) is a hallmark of myeloproliferative disorders (MPDs). The diagnostic value of EEC for polycythemia vera (PV) using standardized media has been demonstrated, and has led clinicians to consider EEC as a major diagnostic criterion in the WHO classification. The interest of EEC currently needs to be considered taking into account recent data about V617F JAK2 mutation in MPD. In particular, EECs and EMCs should be helpful for the diagnostic and the vascular risk evaluation of essential thrombocythemia (ET) and for mutation negative patients. A low serum erythropoietin (EPO) level is a consistent finding in PV. Recent studies have shown that commercial serum EPO assays provided a reliable, accurate, and low-cost criterion for the diagnosis of a significant proportion of PV. It suggests that diagnostic algorithms integrating serum EPO level could be elaborated. The diagnostic value of EPO assay for thrombocytosis has not been proved, but some data suggest a predictive value of low EPO levels for thrombosis in ET.

Topics: Colony-Forming Units Assay; Erythropoietin; Humans; Myeloproliferative Disorders; Polycythemia Vera; Thrombocythemia, Essential

Topics: Colony-Stimulating Factors; Erythropoietin; Granulocyte Colony-Stimulating Factor; Granulocyte-Macrophage Colony-Stimulating Factor; Growth Substances; Humans; Interferon Type I; Interferon-gamma; Interferons; Interleukin-3; Leukemia; Leukemia, Hairy Cell; Leukemia, Myelogenous, Chronic, BCR-ABL Positive; Myelodysplastic Syndromes; Recombinant Proteins; Thrombocythemia, Essential

The aim of the present work was to investigate the effect of hydroxyurea (HU) treatment on haematopoietic progenitors and CD34 positive (CD34+) cells in patients with polycythaemia vera (PV) and essential thrombocythaemia (ET). Of the PV patients were 10 treated with phlebotomy only and 10 were on HU therapy. Seven ET patients were untreated and 10 received HU. In each subject peripheral blood was obtained for in vitro colony growth, determination of CD34+ cells and plasma erythropoietin (EPO) concentration. The mean number of EPO independent erythroid colonies (EEC) was higher in the group of PV patients on phlebotomy therapy compared to the PV patients treated with HU (74.4 and 8.0 colonies/10(5) cells, respectively) but the difference did not reach statistical significance. The corresponding means for the untreated ET patients and ET patients treated with HU were 13.0 and 1.3 colonies/10(5) cells, respectively, this difference being statistically significant (p = 0.012). The mean EEC for combined groups of PV and ET without myelosuppressive treatment were compared with the results for PV and ET patients on HU therapy; this difference was statistically significant (p = 0.014). The same pattern was observed for total erythroid growth with EPO. The relationship between the concentration of CD34+ cells and total EEC in peripheral blood was statistically significant for both PV (p<0.005) and ET (p<0.01). This finding supports the hypothesis that the level of CD34+ cells in peripheral blood could be used as a proliferation marker in these two myeloproliferative entities. No relationship between plasma EPO and EEC was present. It therefore appears that the reported differences in plasma/serum EPO concentrations between PV patients on phlebotomy treatment compared to patients on myelosuppressive treatment are not likely to be found at the production site for erythrocytes.

Topics: Adult; Aged; Aged, 80 and over; Antigens, CD34; Cell Division; Cells, Cultured; Colony-Forming Units Assay; Erythropoietin; Female; Hematopoietic Stem Cells; Humans; Hydroxyurea; Male; Middle Aged; Phlebotomy; Polycythemia Vera; Thrombocythemia, Essential

According to the current treatment recommendations, anagrelide, an oral antiplatelet agent, is recommended as a second-line therapy for patients with high-risk essential thrombocythemia experiencing intolerance or refractoriness to first-line approach, such as hydroxyurea or pegylated interferon alpha-2a. If there is a need for introduction of cytoreductive treatment in young patients with a perspective of lifelong exposure, both the efficacy and long-term outcomes should be known. We present the analysis of 48 young patients, diagnosed with essential thrombocythemia below the age of 60, who were exposed to anagrelide treatment for over 10 years. Our observations show that the highest proportion of complete remissions without adverse events and disease progression is seen in the JAK2-mutated patients. By evaluating the changes in hemoglobin concentration and serum erythropoietin throughout the study, we were able to reveal the development of progressive anemia, resulting from diminished susceptibility to erythropoietin and unrelated to bone marrow fibrosis, in patients harboring CALR mutation. Additionally, occurrence of new bone marrow fibrosis was confirmed in seven JAK2-unmutated patients at the end of the study. In summary, in young patient population, we recommend limiting the use of anagrelide to JAK2-mutated subgroup, reducing exposure time and underline the importance of periodic monitoring for the presence of bone marrow fibrosis.

Topics: Child; Erythropoietin; Humans; Platelet Aggregation Inhibitors; Primary Myelofibrosis; Quinazolines; Thrombocythemia, Essential

Topics: Adult; Aged; Aged, 80 and over; Biomarkers; Disease Progression; Erythropoietin; Female; Humans; Male; Middle Aged; Phenotype; Polycythemia Vera; Primary Myelofibrosis; Prognosis; Thrombocythemia, Essential; Young Adult

Polycythemia Vera (PV) and essential thrombocythemia (ET) are myeloproliferative neoplasms respectively characterized by erythrocytosis and thrombocytosis; other disease features include leukocytosis, splenomegaly, thrombosis, bleeding, microcirculatory symptoms, pruritus, and risk of leukemic or fibrotic transformation.. PV is defined by a JAK2 mutation, whose absence, combined with normal or increased serum erythropoietin level, makes the diagnosis unlikely. JAK2, CALR, and MPL mutations are the mutually exclusive "driver" mutations in ET with respective incidences of 55%, 25%, and 3%; approximately 17% are triple-negative. However, the same molecular markers might also be present in prefibrotic myelofibrosis, whose morphological distinction from ET is prognostically relevant.. Median survivals are approximately 14 years for PV and 20 years for ET; the corresponding values for younger patients (age <60 years) are 24 and 33 years. Life-expectancy in ET is inferior to the control population. Driver mutational status has not been shown to affect survival in ET whereas the presence of JAK2/MPL mutations has been associated with higher risk of arterial thrombosis and that of MPL with higher risk of fibrotic progression. Risk factors for overall survival in both ET and PV include advanced age, leukocytosis and thrombosis. Leukemic transformation rates at 20 years are estimated at <10% for PV and 5% for ET; fibrotic transformation rates are slightly higher. Most recently, ASXL1, SRSF2, and IDH2 mutations have been associated with inferior overall, leukemia-free or fibrosis-free survival in PV; similarly adverse mutations in ET included SH2B3, SF3B1, U2AF1, TP53, IDH2, and EZH2.. Current risk stratification in PV and ET is designed to estimate the likelihood of recurrent thrombosis. Accordingly, PV includes two risk categories: high-risk (age >60 years or thrombosis history) and low-risk (absence of both risk factors). In ET, risk stratification includes four categories: very low risk (age ≤60 years, no thrombosis history, JAK2/MPL un-mutated), low risk (age ≤60 years, no thrombosis history, JAK2/MPL mutated), intermediate risk (age >60 years, no thrombosis history, JAK2/MPL un-mutated), and high risk (thrombosis history or age >60 years with JAK2/MPL mutation). In addition, presence of extreme thrombocytosis (platelets >1000 × 10(9)/L) might be associated with acquired von Willebrand syndrome (AvWS) and, therefore, risk of bleeding.. The main goal of therapy in PV and ET is to prevent thrombohemorrhagic complications. All patients with PV require phlebotomy to keep hematocrit below 45% and once-daily aspirin (81 mg). In addition, high-risk patients with PV require cytoreductive therapy. Very low risk ET patients might not require any form of therapy while low-risk patients require at least once-daily aspirin therapy. Cytoreductive therapy is also recommended for high-risk ET patients but it is not mandatory for intermediate-risk patients. First-line drug of choice for cytoreductive therapy, in both ET and PV, is hydroxyurea and second-line drugs of choice are interferon-α and busulfan. We currently do not recommend treatment with ruxolutinib or other JAK2 inhibitors in PV or ET, unless in the presence of severe and protracted pruritus or marked splenomegaly that is not responding to the aforementioned drugs. Screening for AvWS is recommended before administrating aspirin, in the presence of extreme thrombocytosis. Am. J. Hematol. 92:95-108, 2017. © 2016 Wiley Periodicals, Inc.

Topics: Aspirin; Calreticulin; Diagnosis, Differential; Erythropoietin; Humans; Hydroxyurea; Interferon-alpha; Janus Kinase 2; Leukemia, Myelogenous, Chronic, BCR-ABL Positive; Mutation; Polycythemia Vera; Primary Myelofibrosis; Receptors, Thrombopoietin; Risk Assessment; Thrombocythemia, Essential; Thrombocytosis

The study mainly aimed at investigating possible correlations between peripheral blood counts, erythropoietin (EPO), JAK2 V617F mutation, and vascular complications prior to diagnosis of a population-based cohort of newly diagnosed patients with myeloproliferative neoplasms (MPN).. The study comprises 1105 patients with polycythemia vera (PV) and 1284 patients with essential thrombocythemia (ET) registered in the Swedish MPN Registry.. We conclude that vascular complications among newly diagnosed patients had affected more than one-third of our study population. Risk factors for vascular complications prior to diagnosis were lower hemoglobin in PV, and the presence of JAK2 V617F mutation, higher age, and leukocytosis in ET.

Topics: Age Factors; Aged; Aged, 80 and over; Biomarkers, Tumor; Erythropoietin; Female; Hemoglobins; Humans; Janus Kinase 2; Leukocytosis; Male; Middle Aged; Mutation; Polycythemia Vera; Prospective Studies; Registries; Risk Factors; Sweden; Thrombocythemia, Essential; Venous Thromboembolism

Topics: Adult; Biomarkers, Tumor; Bone Marrow; Calreticulin; Erythropoietin; Female; Fusion Proteins, bcr-abl; Hematocrit; Hemoglobins; Humans; Janus Kinase 2; Male; Middle Aged; Mutation; Myeloproliferative Disorders; Polycythemia Vera; Receptors, Thrombopoietin; Thrombocythemia, Essential; World Health Organization

Low serum erythropoietin (EPO) is a minor criterion of Polycythaemia Vera (PV) but its diagnostic usefulness relies on studies performed before the discovery of JAK2 V617F mutation. The objective of the present study was to evaluate the diagnostic accuracy of serum EPO and JAK2 V617F allele burden as markers of PV as well as the combination of different diagnostic criteria in 287 patients (99 with PV, 137 with Essential Thrombocythaemia and 51 with non-clonal erythrocytosis). Low EPO showed good diagnostic accuracy as a marker for PV, with the area under the curve (AUC) of the chemiluminescent-enhanced enzyme immunoassay (CEIA) being better than that of radioimmunoassay (RIA) (0·87 and 0·76 for CEIA and RIA, respectively). JAK2 V617F quantification displayed an excellent diagnostic accuracy, with an AUC of 0·95. A haematocrit >52% (males) or >48% (females) plus the presence of the JAK2 V617F mutation had a sensitivity and specificity of 79% and 97%, respectively. Adding low EPO or the JAK2 V617F allele burden did not improve the diagnostic accuracy for PV whereas the inclusion of both improved the sensitivity up to 83% and maintaining 96% specificity. Haematocrit and qualitative JAK2 V617F mutation allow a reliable diagnosis of PV. Incorporation of EPO and/or JAK2 V617F mutant load does not improve the diagnostic accuracy.

Topics: Alleles; Amino Acid Substitution; Area Under Curve; Biomarkers; Diagnosis, Differential; Erythropoietin; Female; Hematocrit; Hemoglobins; Humans; Janus Kinase 2; Leukocyte Count; Male; Mutation, Missense; Platelet Count; Point Mutation; Polycythemia; Polycythemia Vera; Reproducibility of Results; ROC Curve; Sensitivity and Specificity; Thrombocythemia, Essential

Myeloproliferative neoplasms (MPNs) are associated with recurrent activating mutations of signaling proteins such as Janus kinase 2 (JAK2). However, the actual downstream signaling events and how these alter myeloid homeostasis are poorly understood. We developed an assay to measure basal levels of phosphorylated signaling intermediates by flow cytometry during myeloid differentiation in MPN patients. Our study provides the first systematic demonstration of specific signaling events and their comparison with disease phenotype and JAK2 mutation status. We demonstrate increased basal signaling in MPN patients, which occurs in both early and later stages of myeloid differentiation. In addition, the pattern of signaling is not correlated with JAK2 mutation status and signaling intensity is poorly correlated with mutant JAK2 allele burden. In contrast, signaling differences are detected between different MPN disease phenotypes. Finally, we demonstrate that signaling can be inhibited by a JAK2-selective small molecule, but that this inhibition is not JAK2 V617F specific, because MPN patients with mutant JAK2, wild-type JAK2, and control patients were inhibited to a similar degree. Our data suggest that, in addition to JAK2 mutations, other factors contribute significantly to the MPN phenotype, results that are relevant to both the pathogenesis and therapy of MPN.

Topics: Aged; Blotting, Western; Cell Line, Tumor; Erythropoietin; Female; Flow Cytometry; Genotype; Hematopoietic Stem Cells; Humans; Intracellular Space; Janus Kinase 2; Male; Middle Aged; Mutation; Myeloproliferative Disorders; Phenotype; Phosphoproteins; Phosphorylation; Polycythemia Vera; Primary Myelofibrosis; Pyrimidines; Signal Transduction; Sulfonamides; Thrombocythemia, Essential

Management of essential thrombocythemia (ET) in high-risk patients is difficult because high platelet numbers can lead to vascular occlusive events and bleeding. Therapeutic interventions in ET are limited to hydroxyurea and anagrelide; however, in Europe, anagrelide is contraindicated in patients with chronic renal disease.. The aim of this case report was to describe the use of anagrelide in a patient with ET and renal impairment.. A 73-year-old white female patient with severe renal impairment who was diagnosed with ET was receiving treatment with hydroxyurea 1 g/d since 2001. At this time she was also receiving aspirin 80 mg/d; calcium carbonate 1 g/d; pravastatin 40 mg/d; folic acid 5 mg/d; furosemide 40 mg/d; cetirizine 10 mg/d; erythropoietin 10,000 U once monthly; a vitamin B complex, 1 tablet a day; and iron tablets 105 mg/d. In February 2007, because her white blood cell count fell to 2.1 x 10(9)/L, myelodepression was suspected and hydroxyurea was stopped. This led to enhanced platelet levels and the introduction of anagrelide at an initial dose of 0.5 mg/d that was steadily increased to 2.5 mg/d. All other treatments were continued with some dosage adjustments. Sodium bicarbonate 1 g/d and vitamin D were added to her regimen. After 18 months of anagrelide treatment, a sudden but moderate fall of platelets to 142 x 10(3)/microL with severe anemia (hemoglobin, 6.5 g/dL) was observed. The patient had anemia since 2004, but the condition worsened due to bleeding related to an ulcer at the cecal valve. The patient refused blood and platelet transfusions and surgical intervention for religious reasons. Because of hemodynamic instability, she was admitted to the intensive care unit in December 2008 and died 24 hours after admission.. We report a case of ET and chronic renal failure treated with anagrelide and low-dose aspirin in a patient who did not receive transfusion and surgical intervention due to religious reasons, and had a fatal outcome.

Topics: Aged; Aspirin; Blood Cell Count; Blood Chemical Analysis; Blood Transfusion; Drug Resistance; Erythropoietin; Fatal Outcome; Female; Humans; Hydroxyurea; Jehovah's Witnesses; Kidney Failure, Chronic; Kidney Function Tests; Platelet Aggregation Inhibitors; Platelet Count; Quinazolines; Recombinant Proteins; Renal Dialysis; Thrombocythemia, Essential

Essential thrombocythemia (ET), a Philadelphia (Ph) chromosome negative chronic myeloproliferative disorder, is usually a disease of middle age and it is extremely rare in pediatric patients. In this report we studied 12 children diagnosed with ET and one child with thrombocytosis and family history of ET. We failed to detect JAK2 V617F mutation either in peripheral blood leukocytes or in separated platelets and granulocytes. Monoclonal hematopoiesis was noted in only one female patient. Erythroid progenitors of most of the patients displayed hypersensitivity to erythropoietin (Epo) in vitro; Epo-independent erythroid colonies (EECs) were detected in seven patients. Among EECs of three patients we observed rare colonies heterozygous or homozygous for the JAK2 V617F mutation. Our data suggest that childhood ET patients could bear minor JAK2 V617F-positive subclones.

Topics: Adolescent; Child; Clone Cells; Erythroid Precursor Cells; Erythropoiesis; Erythropoietin; Female; Genotype; Hematopoietic Stem Cells; Humans; Janus Kinase 2; Male; Mutation; Thrombocythemia, Essential; Thrombocytosis

Essential thrombocythemia (ET) is a chronic myeloproliferative disorder, characterized by increased proliferation of megakaryocytes and elevated platelet count that usually occurs sporadically. We report a family with seven affected individuals in three generations, including one individual with a phenotype resembling polycythemia vera, a related disorder. Megakaryocyte (CFU-MK) colony formation occurred in the absence of added cytokines in cultures of peripheral blood from affected family members. Some reports of familial ET have identified mutations in THPO and MPL, the genes for a cytokine (thrombopoietin, TPO) that regulates platelet production and its receptor (c-MPL), respectively. In this family, the MPL gene was excluded by linkage analysis. Although TPO levels were elevated in most affected family members and evidence for linkage was found between the disease and THPO (theta=0.0, Z(max)=3.0), a THPO mutation was not identified by DNA sequencing. The JAK2 V617F mutation that has been associated with 50% of sporadic cases of ET was identified as a somatic mutation, an acquired defect, in peripheral blood of the two most severely affected family members. These patients also had elevated TPO levels. Further study of familial myeloproliferative diseases will help elucidate the initiating genetic events underlying ET.

Topics: Enzyme-Linked Immunosorbent Assay; Erythropoietin; Female; Humans; Janus Kinase 2; Male; Megakaryocytes; Mutation; Pedigree; Receptors, Thrombopoietin; Thrombocythemia, Essential; Thrombopoietin; X Chromosome Inactivation

The JAK2 617V>F mutation is frequent in polycythemia vera (PV) and essential thrombocythemia (ET). Using quantitative polymerase chain reaction (PCR), we found that high levels of JAK2 617V>F in PV correlate with increased granulocytes and high levels of hemoglobin and endogenous erythroid colony formation. We detected normal progenitors and those that were heterozygous or homozygous for the mutation by genotyping ET and PV clonal immature and committed progenitors. In PV patients, we distinguished homozygous profiles with normal, heterozygous, and homozygous progenitors from heterozygous profiles with only heterozygous and normal progenitors. PV patients with a heterozygous profile had more mutated, committed progenitors than did other PV and ET patients, suggesting a selective amplification of mutated cells in the early phases of hematopoiesis. We demonstrated that mutated erythroid progenitors were more sensitive to erythropoietin than normal progenitors, and that most homozygous erythroid progenitors were erythropoietin independent. Moreover, we observed a greater in vitro erythroid amplification and a selective advantage in vivo for mutated cells in late stages of hematopoiesis. These results suggest that, for PV, erythrocytosis can occur through two mechanisms: terminal erythroid amplification triggered by JAK2 617V>F homozygosity, and a 2-step process including the upstream amplification of heterozygous cells that may involve additional molecular events.

Topics: Aged; Amino Acid Substitution; Cells, Cultured; Erythroid Precursor Cells; Erythropoietin; Female; Granulocytes; Hematopoiesis; Heterozygote; Homozygote; Humans; Janus Kinase 2; Male; Mutation, Missense; Polycythemia Vera; Thrombocythemia, Essential

The determination of serum/plasma erythropoietin (EPO) concentration has gained widespread use in the diagnosis of polycythaemia vera (PV). A reduced EPO concentration in a newly diagnosed essential thrombocythaemia (ET) seems to be a risk factor for thromboembolic events. In this study plasma EPO concentration was determined before and after initiated hydroxyurea (HU) therapy, 14 patients with PV or ET were included. After 1 month on HU therapy 11 of 14 patients had increased their EPO concentration compared with prior to medication. The plasma EPO was increased in all, except one patient, after 4 months HU therapy. If EPO is incorporated in the diagnostic or prognostic procedures it should be determined before myelosuppressive therapy is initiated.

Topics: Aged; Aged, 80 and over; Blood Platelets; Erythropoietin; Female; Humans; Hydroxyurea; Male; Middle Aged; Platelet Count; Polycythemia Vera; Thrombocythemia, Essential; Time Factors

Topics: Erythrocyte Indices; Erythropoietin; Humans; Polycythemia Vera; Sensitivity and Specificity; Thrombocythemia, Essential

Topics: Clone Cells; Erythropoietin; Female; Humans; Myelopoiesis; Risk Factors; Thrombocythemia, Essential; Thromboembolism

Serum erythropoietin (Epo) values were estimated in samples from 125 patients with erythrocytosis to examine the specificity and sensitivity of reduced and raised values in the diagnosis of polycythaemia vera (PV) and secondary erythrocytosis (SE) respectively. Additionally, Epo values were estimated in samples from 49 patients with primary thrombocythaemia (PT) to determine whether Epo values were altered. We found high specificity (92%) and moderate sensitivity (64%) of low serum Epo values (below the reference range) in the diagnosis of PV, and also poor sensitivity (47%) of raised Epo values in the diagnosis of SE. Raised Epo values were not observed in PV patients with Hb > 14.0 g/dl and were only observed in one PV patient with a relatively low Hb recovering from a gastro-intestinal haemorrhage. Raised Epo values occurred in some patients with apparent erythrocytosis (AE) and idiopathic erythrocytosis (IE), mainly at normal (rather than raised) Hb values (< 16 g/dl). Low Epo values occurred in a few AE, IE and SE patients at higher Hb values (> 16 g/dl). Low Epo values were less specific for PV when the Hb was raised, while raised Epo values were less specific for SE when the Hb was not raised. Approximately one third of patients with PT had a low (below the reference range) Epo value, this being associated with a high normal Hb (> 14 g/dl, P < 0.001) and showing a trend towards association with absence of treatment. The high normal Hb values were in turn associated with an increased incidence of thrombotic events (P < 0.05). These findings could influence the future investigation and management of PT patients.

Topics: Adult; Erythropoietin; Female; Hemoglobins; Humans; Male; Polycythemia; Predictive Value of Tests; Sensitivity and Specificity; Thrombocythemia, Essential

Plasma thrombopoietin (TPO) was measured, by immunoenzymometric assay, in 39 patients with polycythaemia vera (PV), 33 patients with essential thrombocythaemia (ET) and 10 healthy volunteers. The mean TPO concentration was significantly higher in ET patients than in PV patients (p=0.04) and normals (p<0.001). The 6 untreated ET patients had a significantly lower mean TPO concentration compared to the 27 ET patients who were on myelosuppressive regimens (p=0.01). The mean plasma TPO for the 5 PV patients treated with phlebotomy only did not differ significantly from the corresponding mean for the 34 PV patients treated with myelosuppressive agents. Concomitantly, plasma EPO was measured in 25 of the PV patients and in 30 of the ET patients by an immunoradiometric assay with normal reference interval in adults 3.7-16 IU/L. In the 14 PV patients with EPO <3.7 IU/L mean plasma TPO did not differ significantly from the mean for the 11 PV patients with EPO >or=3.7 IU/L; neither of these two groups had plasma TPO concentrations significantly different from the mean for the control subjects. The 7 ET patients with subnormal plasma EPO had significantly lower mean plasma TPO compared to the ET patients with normal and high plasma EPO concentrations (p=0.03 and p=0.02, respectively). Also, the 16 ET patients with normal plasma EPO had significantly lower plasma TPO compared to the 8 patients with high plasma EPO (p=0.04). The mean plasma TPO for each of these three groups of ET patients was significantly higher than the corresponding mean for the controls (p<0.001 for each group). The results of the present study indicate that a relationship between plasma EPO and TPO concentrations may exist and that myelosuppressive treatment affects the TPO concentration in ET but not in PV patients.

Topics: Adult; Aged; Aged, 80 and over; Case-Control Studies; Erythropoietin; Female; Humans; Male; Middle Aged; Platelet Count; Polycythemia Vera; Thrombocythemia, Essential; Thrombopoietin

By using an immunoradiometric method with a stated detection limit of < or =1 IU/l (stated normal reference limit in adults 3.7-16 IU/l) we determined EDTA-plasma erythropoietin (EPO) in 58 patients with polycythaemia vera (PV) and 49 patients with essential thrombocythaemia (ET). At the time of blood sampling, 20 of the PV patients were newly diagnosed and untreated, 23 were treated by phlebotomy only, and 30 also received myelosuppressive treatment (with 32P, hydroxyurea or alpha-interferon). Of the ET patients 24 were untreated and 28 received myelosuppressive therapy. For comparison plasma EPO was also determined in 10 patients with pseudopolycythaemia (PP). In this latter group the results for plasma EPO agreed well with the cited normal reference limits. The majority of untreated PV patients (12/20) had undetectable plasma EPO concentration, and the remainder all had values below the lower normal reference limit. Plasma EPO in PV was not significantly influenced by phlebotomy therapy. Twelve of the 24 untreated ET patients (50%) had plasma EPO values below the reference interval (undetectable in 2 patients). The mean EPO concentration was significantly lower in PV patients receiving phlebotomy therapy than in patients with untreated ET. In the total material of PV and ET treated with myelosuppressive agents the PV patients showed significantly lower values for EPO concentration than did patients with ET. The present results support the view that EPO measurements by high-detectability methods are diagnostically useful and should be included in the panel of new criteria for the diagnosis of PV.

Topics: Adult; Aged; Aged, 80 and over; Erythropoietin; Female; Hemoglobins; Humans; Hydroxyurea; Immunoradiometric Assay; Interferon-alpha; Male; Middle Aged; Phlebotomy; Platelet Count; Polycythemia Vera; Reference Values; Thrombocythemia, Essential

A 63-year-old woman was found to have thrombocythemia and was referred to our hospital for further evaluation in September 1990. Peripheral blood showed platelet 170.0 x 10(4)/microliter, WBC 14,900/microliter and Hb 9.8 g/dl. Bone marrow was hypercellular with increased megakaryocytes and normal karyotype. She was diagnosed as essential thrombocythemia (ET), and treated with 2 mg of busulfan daily for 3 months until her platelet count decreased to 33.1 x 10(4)/microliter. Busulfan was given again for 40 days (a total of 80 mg) in another hospital when the platelet count increased to 71.1 x 10(4)/microliter in September 1991. In December 1991, she was admitted to our hospital because of pancytopenia. Examination of blood revealed platelet 0.4 x 10(4)/microliter, WBC 1,800/microliter and Hb 7.0 g/dl with hypocellular marrow. A diagnosis of busulfan-induced severe bone marrow aplasia was made. We administered metenolone acetate 15 mg and G-CSF 300 micrograms daily. Blood transfusions were given frequently. However, no effect was observed during her hospitalization. After discharge, G-CSF 600 micrograms and erythropoietin 24,000 units were continued twice a week in combination with metanolone acetate. Pancytopenia gradually began to improve as of June 1992, and then trilineage recovery was achieved in March 1994 with platelet 13.3 x 10(4)/microliter, WBC 5,500/microliter and Hb 12.1 g/dl. The platelet count has been within the normal range for more than 2 years after recovery.

Topics: Anemia, Aplastic; Busulfan; Erythropoietin; Female; Granulocyte Colony-Stimulating Factor; Humans; Methenolone; Middle Aged; Remission Induction; Thrombocythemia, Essential

The present study revises the criteria of the Polycythemia Vera Group (PVSG) for the diagnoses of essential thrombocythemia (ET) and polycythemia vera (PV) in view of accumulating data on in vitro cultures of hematopoietic progenitors and by adding histopathology from bone marrow biopsies. The majority of ET patients show spontaneous megakaryocyte or erythroid growth or both, but in about 35% the growth pattern is normal. So far none of the patients with reactive thrombocytosis have shown either spontaneous megakaryocyte or erythroid colony growth. Virtually all PV patients show spontaneous or endogenous erythroid colony (EEC) formation, whereas patients with secondary erythrocytosis and healthy controls do not show any erythroid colony growth in the absence of erythropoietin (EPO). Some rare patients with a disorder other than a myeloproliferative disease (MPD) may show spontaneous growth of erythroid colonies caused by a mutation in the EPO receptor. Megakaryocytes in bone marrow smears and biopsy material from ET and PV patients are typically increased in number and size. Enlarged megakaryocytes with mature cytoplasm and multilobulated nuclei and the tendency of these megakaryocytes to cluster in a normal or slightly increased cellular bone marrow represent the diagnostic hallmark of ET. Increase and clustering of enlarged, mature, and pleiomorphic megakaryocytes in a moderate to marked hypercellular bone marrow with hyperplasia of dilated sinuses is the diagnostic feature of untreated PV. In reactive thrombocytosis and secondary erythrocytosis the size and morphology of megakaryocytes remain normal and there is no tendency of the megakaryocytes to cluster. Both spontaneous EEC and histopathology of bone marrow biopsies appear to offer specific clues to the diagnosis of overt and latent ET or PV and have the potential to differentiate ET from reactive thrombocytosis and PV from secondary erythrocytosis. Moreover, bone marrow histopathology has the diagnostic power to distinguish and to stage the various MPDs without regard to clinical and laboratory data.

Topics: Biopsy; Bone Marrow; Bone Marrow Examination; Erythroid Precursor Cells; Erythropoiesis; Erythropoietin; Female; Humans; Male; Megakaryocytes; Myeloproliferative Disorders; Polycythemia Vera; Primary Myelofibrosis; Thrombocythemia, Essential

During the last three years 77 patients with myelofibrosis were studied by scintigraphy, using 99m Tc colloids and 111 In transferrin as tracers. Low axial uptake of the colloids, extension of the indium uptake beyond the axis towards the knees and sometimes the ankles and elbows, and splenic indium uptake are valuable diagnostic criteria, particularly useful to exclude myelofibrosis associated with a malignant disorder. The clinical severity of the disease, and in particular the disappearance of a physiologically active bone marrow (indium uptake) can be predicted from isotopic studies. Bone marrow scintigraphy could contribute to the difficult decision of splenectomy.

Topics: Adult; Bone Marrow; Erythropoietin; Female; Humans; Leukemia; Male; Middle Aged; Polycythemia Vera; Primary Myelofibrosis; Prognosis; Radionuclide Imaging; Splenomegaly; Thrombocythemia, Essential

Plasma erythropoietin levels were frequently decreased in patients with essential thrombocythaemia (14/31 cases), as in polycythaemia vera. These two diseases or some forms of them might be two facets of a single disease process.

Topics: Erythropoietin; Female; Humans; Male; Thrombocythemia, Essential

A new human leukemia cell line with megakaryocytic features, designated UT-7, was established from the bone marrow of a patient with acute megakaryoblastic leukemia. Surface marker analysis revealed that the majority of the cells reacted with monoclonal antibodies against platelet glycoprotein Ib (CD42b), glycoprotein IIb/IIIa (CD41a), MY 7 (CD13), MY 9 (CD33), and glycophorin A antigens. Cytogenetic analysis showed a human male near-tetraploid karyotype with a modal chromosome number of 92-96. Flow cytometry-derived DNA histograms demonstrated that the majority of the cells spontaneously contained 4 N DNA ploidy levels. Ultrastructural study showed that platelet peroxidase activity was weakly positive but myeloperoxidase activity was negative. Ferritin and theta-granule, which have been used as ultrastructural markers for the erythroid lineage, could not be detected. In response to phorbol myristate acetate, platelet factor 4 and beta-thromboglobulin, which were specifically synthesized in the process of megakaryocyte maturation, dramatically increased in UT-7 cells. This was accompanied by an increase in cell size, ploidy level, platelet peroxidase activity, and the surface density of glycoprotein IIb/IIIa antigen. These findings suggest that UT-7 is a new leukemic cell line with megakaryocytic features and with the potential to differentiate into cells with more mature megakaryocytic properties in response to phorbol myristate acetate. This cell line showed strict dependency on interleukin 3 (IL-3), granulocyte-macrophage colony-stimulating factor, or erythropoietin. The maximal effective doses of IL-3, granulocyte-macrophage colony-stimulating factor, and erythropoietin for proliferation in liquid culture were 10 units/ml, 1 ng/ml, and 1 unit/ml, respectively. These concentrations were comparable to the doses that maximally stimulate the clonal growth of normal hemopoietic cells. IL-6 could stimulate the proliferation of UT-7 cells but not maintain the line in long-term culture. UT-7 cells may be a useful model for (a) the analysis of gene regulation of megakaryocytic maturation-associated proteins expressed in the process of megakaryocytic differentiation and (b) the study of signal transduction of hemopoietic factors associated with megakaryocytopoiesis.

Topics: Antigens, CD; beta-Thromboglobulin; Cell Division; Cell Survival; DNA, Neoplasm; Drug Synergism; Erythropoietin; Granulocyte-Macrophage Colony-Stimulating Factor; Hematopoiesis; Humans; Interleukin-3; Interleukin-6; Karyotyping; Male; Microscopy, Electron; Middle Aged; Platelet Factor 4; Tetradecanoylphorbol Acetate; Thrombocythemia, Essential; Tumor Cells, Cultured

Megakaryocyte colony formation, as identified by conventional techniques, was observed in precursor cell cultures from peripheral blood in 8 of 20 consecutive patients with diagnosis of myeloproliferative disease (4/11 patients with polycythemia vera, 3/5 with essential thrombocythemia, 1/2 with primary osteomyelofibrosis and 2 with a myeloproliferative syndrome not further assessable), but not in 50 healthy controls (p less than 0.0001). 7 cultures showed spontaneous erythroid colonies, but were negative for megakaryocyte colonies. Megakaryocyte colony formation was independent of added erythropoietin, plasma or human leukocyte-conditioned medium, but was dependent on the presence of accessory cells. The cells in megakaryocyte colonies had the characteristic morphology of megakaryocytes and stained positively with the IIIa/IIb monoclonal anti-platelet antibody. Thus, megakaryocyte colony formation by precursor cells from peripheral blood in the absence of exogenous stimulating factors seems to be a phenomenon specific for myeloproliferative disease. Differential diagnosis of thrombocythemia may be facilitated by demonstration of endogenous megakaryocyte colony formation, which does not occur in secondary disease.

Topics: Cell Nucleus; Cells, Cultured; Colony-Forming Units Assay; Culture Media; Cytoplasm; Diagnosis, Differential; Erythropoietin; Fluorescent Antibody Technique; Hematopoietic Stem Cells; Humans; Leukocytes; Megakaryocytes; Myeloproliferative Disorders; Polycythemia Vera; Primary Myelofibrosis; Thrombocythemia, Essential

To investigate erythroid colony formation in polycythaemia of different types and in thrombocythaemia, a study was performed in 121 subjects, including 13 normal volunteers (N), 30 patients with Primary Proliferative Polycythaemia (PPP), 35 with Idiopathic Erythrocytosis (IE), 19 with Secondary Polycythaemia (SP), 10 with Primary Thrombocythaemia (PT) and 14 with Secondary Thrombocytosis (ST); BFU-E colony formation from peripheral blood samples was studied in the presence of medium only, medium plus a source of burst-promoting activity (BPA) and medium BPA, plus erythropoietin (Ep). In the presence of medium only, practically no colonies were seen in cultures from N and SP, while a variable number was observed in cultures from PPP, IE and PT. Significant differences between groups were as follows: N v PPP; IE v PPP; SP v PPP; N v PT; ST v PT. Such differences persisted in the presence of BPA, but disappeared when Ep was added to the cultures. Further experiments, plating non-adherent mononuclear cells in a chemically defined serum-free medium, confirmed the growth of tiny erythropoietic colonies from circulating stem cells of patients with PPP and PT, in the absence of BPA and EP. These results provide a useful criterion to differentiate PPP, as a group, from other types of polycythaemia; individual cases of IE may need further characterization.

Topics: Blood Proteins; Cell Division; Colony-Forming Units Assay; Culture Media; Erythrocytes; Erythropoietin; Humans; Phytohemagglutinins; Polycythemia; Thrombocythemia, Essential; Thrombocytosis