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PubMed1997

[Polycythemia caused by liver carcinoma in cattle and sheep].

Polycythemia associated with hepatic carcinoma was diagnosed in a 10-year-old cow, an 8-month-old heifer and a 3-year-old sheep. The cow was referred to our clinic because of weight loss, reduced appetite, hematuria, marked reddening of the mucosa of the tear canal, oral cavity and vestibule and an increased hematocrit. Clinical examination also revealed injected scleral vessels. The erythrocyte count, the PCV, hemoglobin concentration and the activities of the hepatic enzymes were increased. Ultrasonographic examination revealed a very large liver with a focal echogenic lesion. Based on all findings, a diagnosis of polycythemia associated with a liver tumor, was made. The cow was slaughtered. Multifocal liver tumors were diagnosed histologically as hepatocellular carcinoma. The heifer and sheep had similar clinical and hematological findings. Hepatocellular carcinoma was diagnosed in the heifer and cholangiocellular carcinoma in the sheep. It was concluded that in all three patients, polycythemia was caused by hepatic carcinoma.

Animals↗
PubMedDate not supplied

[Postpolycythemic myeloid metaplasia in patients with polycythemia vera].

This study group comprised 58 patients with polycythemia vera. A retrospective study included 23/58 (39.60%) patients treated from 1968 to 1987, while a prospective study included 35/58 (60.34%) patients. Over the period 1986.-1996., 19/58 (32.76%) patients died: 10/23 (43.48%) from the retrospective group where mean disease duration was 12.7 years (6-24), and 9/35 (25.71%) from the prospective group where mean disease duration was 2.22 years (1-4). Erythrocytic phase of the disease was established in 50/58 (86.21%) patients; in 2/58 (3.45%) patients phase of spent hematopoiesis and postpolycythemic myeloid metaplasia in 6/58 (10.34%) patients. Postpolycythemic myeloid metaplasia has occurred after a mean time of 10.33 years (6-15) from establishing the first polycythemia. Two patients (10.53%) with postpolycythemic myeloid metaplasia died, one immediately after the diagnosis was established, the other patient two years after establishing the diagnosis. 16/19 (84.21%) patients died during the erythrocytic phase of the polycythemia vera, while 1/19 (5.26%) patient died in the phase of spent hematopoiesis. In regard to alive patients postpolycythemia myeloid metaplasia has been established in 4/39 (10.26%) patients, the phase of spent hematopoiesis in 1/39 (2.56%), while 34/39 (87.18%) patients are in the erythrocytic phase.

Adult↗
PubMed1998

[Convulsions in relation to polycythemia: literature review and case description].

Polycythemia--characterized by an excessive number of erythrocytes--is a rare disease in the dog with a chronic progressive course and unspecific symptoms. There are several forms: a primary, a secondary adequate or a secondary inadequate polycythemia. The clinical workup is done step by step and after stabilization of critical patients, the remaining therapy must address the primary cause. We report on a five year old male Leonberger dog suffering from secondary, inadequate polycythemia. He was presented with apathy, gait disturbances and disorientation. On the basis of the diagnostic workup a pathological process in the kidneys was postulated. Initially focal seizures became generalized later, most probably because of formation of a forebrain thrombus with secondary hypoxia. Even after emergency treatment the general state deteriorated. The course indicated possible sepsis. Because of the critical picture with secondary complications and the poor prognosis, the dog was euthanised. The histopathological results showed T-cell renal lymphoma and secondary injury to the forebrain.

Animals↗
PubMed1997

[Activating blood circulation and removing stasis in treating polycythemia vera: clinical observation and therapeutical mechanism].

OBJECTIVE: To assess the efficacy of "method of activating blood circulation and removing stasis (ABCRS)" in treating polycythemia vera. METHODS: 28 cases of polycythemia vera were treated with ABCRS and observed with bone marrow colonies. RESULTS: 15 casses were responsibe, of them 4 cases reached clinical remission, 11 cases were improved. Both bone marrow colonies of colony forming unit-erythroid dependent of erythropoietin (EPO + CFU-E) and colonies of CFU-E independent of EPO. (EPO-CFU-E) from these cases decreased significantly, especially the latter. ABCRS mainly suppressed the proliferation and differentiation of EPO-CFU-E. In addition, bone marrow colonies of colony formng unit-fibroblastoids (CFU-F) from these cases also changed obviously. CONCLUSION: ABCRS is effective in treating polycythemia vera.

Adult↗
PubMed1998

Serum transferrin receptor in polycythemia.

We measured serum transferrin receptor (sTfR) levels in 22 patients with polycythemia vera and in 26 cases of secondary polycythemia. In our study, raised sTfR levels in both polycythemia groups were related to iron deficiency.

Adult↗
PubMed1999

[Headache caused by polycythemia vera. Classification of a headache under the heading of metabolic disturbances].

UNLABELLED: As polycythemia vera is a myeloproliferative syndrome, it is based on an autonomic increase in the proliferation of all hematopoetic cells--mostly of erythropoesis. An increase in blood viscosity induces disturbed microcirculation, resulting in headaches with clinical symptoms. So far, the headache in polycythemia vera has not been classified. METHODS: We would like to demonstrate a case of a female patient aged 58 years who had been complaining of persistent hemicranial right-sided headaches for the last 16 days, alternating between throbbing and stabbing pain as well as a retrobulbar feeling of pressure. Blood chemistry demonstrated pronounced changes: hemoglobin, 20,1 g/dl; hematocrit, 58%; erythrocytes, 6,8 T/l (6,800,000/microl) leucocytes, 14,400/microl; thrombocytes, 543,000/microl A punch biopsy from the pelvic rim showed cell-rich bone marrow, demonstrating a myeloproliferative syndrome suggestive of polycytemia vera. RESULTS: Following hemodilution, the headache disappeared within 3 days following normalization of blood chemistry: hemoglobin, 14.9 g/dl; hematocrit, 44%; erythrocytes, 5.2 T/l (5,200,000/microl; leucocytes, 13,100/microl. Further diagnosis of the headache by means of MRI of the head, extra and transcranial doppler sonography as well as MRI of the cervical spine did not produce findings with the exception of retrospondylophyth at C5-6. The patient was therefore managed on aspirin 300 mg daily and was given weekly isovolemic bleeding. The headaches did not recur. CONCLUSION: We diagnosed a headache caused by polycythemia vera and recommend classification of this headache under the heading of metabolic disturbances, because this classification meets the diagnostic criteria of the international headache classification.

English Abstract↗
PubMed2004

CD177: A member of the Ly-6 gene superfamily involved with neutrophil proliferation and polycythemia vera.

Genes in the Leukocyte Antigen 6 (Ly-6) superfamily encode glycosyl-phosphatidylinositol (GPI) anchored glycoproteins (gp) with conserved domains of 70 to 100 amino acids and 8 to 10 cysteine residues. Murine Ly-6 genes encode important lymphocyte and hematopoietic stem cell antigens. Recently, a new member of the human Ly-6 gene superfamily has been described, CD177. CD177 is polymorphic and has at least two alleles, PRV-1 and NB1. CD177 was first described as PRV-1, a gene that is overexpressed in neutrophils from approximately 95% of patients with polycythemia vera and from about half of patients with essential thrombocythemia. CD177 encodes NB1 gp, a 58-64 kD GPI gp that is expressed by neutrophils and neutrophil precursors. NB1 gp carries Human Neutrophil Antigen (HNA)-2a. Investigators working to identify the gene encoding NB1 gp called the CD177 allele they described NB1. NB1 gp is unusual in that neutrophils from some healthy people lack the NB1 gp completely and in most people NB1 gp is expressed by a subpopulation of neutrophils. The function of NB1 gp and the role of CD177 in the pathogenesis and clinical course of polycythemia vera and essential thrombocythemia are not yet known. However, measuring neutrophil CD177 mRNA levels has become an important marker for diagnosing the myeloproliferative disorders polycythemia vera and essential thrombocythemia.

Journal Article↗
PubMed2000

Myeloproliferative Disease: Polycythemia Vera: The Packed Cell Volume and The Curious Logic of The Red Cell Mass.

Since the first systematic blood volume studies of polycythemia in the 1920s, measurement of blood volume and red cell mass (RCM) has become routine. However, the radionuclide-labeling methods promulgated by the International Committee for Standardization in Haematology (ICSH) remain complex and poorly understood. Many hematologists and other clinicians err in the belief that these methods permit "direct measurement" of RCM, whereas the ICSH method is indirect: it requires calculation of RCM from (PCV) x (whole blood volume). The use of an elevated value of PCV to calculate RCM in order to evaluate the same elevated value of PCV is a curiously circular logic that is embraced by most clinicians and most hematologists. Analysis of published data in 186 cases of polycythemia vera indicates that RCM is an exponential function of PCV. In most cases, PCV alone suffices to document normal or increased RCM. Relative polycythemia results from dehydration, not from stress. Clinicians need to be aware of the range of physiologic fluctuations that normally occur in plasma volume. Realistic criteria for normal ranges of PCV, Hb concentration and RCM should be adopted in clinical laboratories so that clinicians will not be misled to undertake futile and costly investigations of results that are in the upper percentiles of the normal distribution, as exemplified by the Ulysses Syndrome.

Journal Article↗
PubMed2004

A prospective analysis of thrombotic events in the European collaboration study on low-dose aspirin in polycythemia (ECLAP).

BACKGROUND: - The clinical course of polycythemia vera (PV) is often complicated by arterial and venous thrombosis. Current information on these vascular complications derives from very few prospective clinical trials and several retrospective studies. The purpose of this analysis is to report the incidence, clinical features and risk factors for thrombosis in a large number of patients prospectively followed in a multicountry European study. METHODS: - The European collaboration on low-dose aspirin in polycythemia vera (ECLAP) study is a multicenter project aimed at describing the natural history of PV. Overall, 1630 PV patients (57% males, median age at recruitment 65 years) were enrolled in the study. Five hundred and eighteen (32%) of these patients are entered into a parallel, double-blind, placebo-controlled, randomized clinical trial aimed at assessing the efficacy and safety of low-dose aspirin. The remaining 1112 (68%) are entered into an ongoing, observational, prospective, cohort study. The mean follow-up duration was 2.7 years (range 0-5.3). FINDINGS: - The cumulative incidence rate of cardiovascular events (i.e. cardiovascular death and non-fatal thrombotic events) was 5.5 events/100 persons per year. Thrombosis was the main cause of death. Age greater than 65 years and positive history of thrombosis were the two most important predictors of cardiovascular events. Smoking, hypertension and congestive heart failure were other significant risk factors for thrombosis. Platelet counts and myelosuppressive drugs were not associated with the risk of cardiovascular events. Antiplatelet therapy was the only variable associated with a lower risk of thrombosis. CONCLUSION: - Cardiovascular events remain a major cause of mortality and morbidity in PV but the thrombotic risk seems to be more related to the patients' characteristics (age, previous thrombosis, cardiovascular risk factors) than to the disease itself. Thus, control of red cell mass and antithrombotic therapy appear to be effective treatments in limiting the risk of thrombosis.

Aged↗
PubMed2001

Pathogenetic mechanisms of polycythemia vera and congenital polycythemic disorders.

The absolute polycythemias--those with increased red blood cell mass--can be divided into two groups: primary, caused by acquired or inherited mutations leading to a "gain-of-function" abnormalities expressed within the erythroid progenitors; and secondary, due to circulating serum factors, typically erythropoietin, stimulating erythropoiesis. This overview concentrates on the molecular biology of polycythemia vera (PV) discussed in the context of other polycythemic disorders. Recent advances in the regulation of erythropoiesis, as they may relate to polycythemic states, are discussed as a background for those well-defined polycythemic states wherein the molecular defect has not yet been elucidated. A number of cellular abnormalities associated with PV, including the hyperresponsiveness of PV progenitors to many cytokines as well as decreased expression of the thrombopoietin receptor on platelets and increased expression of Bcl-xL, suggest that the PV defect alters a number of cellular functions and is not restricted to cytokine receptor signal transduction. The increasing number of recognized instances of familial incidence of PV suggests that in these families the predisposition for PV is inherited as a dominant trait, and that PV is acquired as a new mutation that leads to a clonal hematopoiesis and may be due to loss of heterozygosity. The existence of these families provides a unique opportunity for isolation of the mutations in the gene leading to PV. Semin Hemaol 38(suppl 2):10-20.

Cytokines↗
PubMed2001

Evaluation of diagnostic criteria in polycythemia vera.

There is no single diagnostic marker for the only known type of primary acquired erythrocytosis, polycythemia vera (PV). The Polycythemia Vera Study Group (PVSG) used a combination of major and minor diagnostic criteria. However, these guidelines have some limitations and in the presence of newer diagnostic tools, have been re-evaluated. The recommendations of the Radionuclide Panel of the International Council for Standardization Hematology based on surface area are recommended over red blood cell mass (RCM) mL/kg expressions. Absolute erythrocytosis can be assumed in males and females with packed cell volume (PCV) values greater than 0.60 and greater than 0.56, respectively. A satisfactory strategy of investigation for a secondary erythrocytosis must be used. Hypoxemia, as well as renal and hepatic pathology, must be excluded. In unexplained absolute erythrocytoses, pO(2)(50) values and serum erythropoietin (EPO) levels should be examined. The latter can be disappointing in the confirmation of a secondary erythrocytosis, but elevated values contraindicate a diagnosis of a primary erythrocytosis. Establishment of a clonal marrow population supports a diagnosis of PV. Thus an acquired karyotypic abnormality is a major criterion. Palpable splenomegaly remains an important diagnostic marker. Scanning techniques to demonstrate splenic enlargement should be used with caution. Allowance must be made for interobserver and intraobserver differences and variation in normal spleen size with age and size of the subject. Splenomegaly demonstrated in this way should be taken as a minor criterion. An increased neutrophil count (>10 x 10(9)/L and >12.5 x 10(9)/L in smokers) is readily measurable and should replace total white blood cell count. The error in measurement of neutrophil alkaline phosphatase (NAP) score is large, making it an unsuitable diagnostic criterion. Neutrophil and platelet counts (>400 x 10(9)/L) should be taken as separate minor criteria. Endogenous erythroid colonies (EEC) grown from the peripheral blood have been used as a marker of PV, but it is an expensive technique that is not standardized and not totally specific for PV. Low serum EPO values found in the majority of patients with PV should hold a linked minor criterion position with EEC. Expert opinions should be obtained if bone marrow histology is to be used in the diagnosis of PV, but histology holds an important role in confirming the diagnosis. Semin Hematol 38(suppl 2):21-24.

Diagnosis, Differential↗
PubMedDate not supplied

Congenital erythrocytosis and polycythemia vera in childhood and adolescence.

Polycythemia vera - the most frequent form of a primary erythrocytosis in adult patients - represents an extremely rare disease in pediatric and juvenile patients as do congenital primary and secondary erythrocytoses. Frequently, in patients with these diseases clinical problems do not occur before adulthood. Systematic data on clinical and laboratory evaluations as well as on treatment regimens are sparse. In addition, in the majority of cases with congenital erythrocytosis, the etiology is unknown. For those reasons, a protocol (PV-ERY-KA 03) for the systematic collection of clinical, hematological, biochemical, biological as well as treatment data of children and adolescents with polycythemia vera or congenital erythrocytosis including the hemoglobinopathies with high affinity hemoglobin, familial 2,3-BPG deficiencies, and those of unknown origin, has been developed. These data are combined with molecular analyses which focus initially on EPO-receptor and vHL-gene examination, but will later be extended into presently unexplored pathophysiologic regulatory circuits. In addition, pathophysiologic changes due to the erythrocytosis will be studied. The co-ordinated medical care for patients with those rare diseases within a collaborative trial accompanied by scientific projects is aimed at the improvement of the treatment of these patients as well as to a better understanding of the underlying biological processes.

2,3-Diphosphoglycerate↗
PubMed2006

The haematocrit and platelet target in polycythemia vera.

Polycythemia vera (PV) is a chronic myeloproliferative disorder whose major morbidity and mortality are thrombohaemorragic events and progression to acute leukaemia or myelofibrosis. Whether the haematocrit and platelet count predict such complications remains unclear. The European Collaboration on Low-dose Aspirin in Polycythemia Vera prospective study included 1638 PV patients. A total of 164 deaths (10%), 145 (8.85%) major thrombosis and 226 (13.8%) total thrombosis were encountered during 4393 person-years follow-up (median 2.8 years). In time-dependent multivariable analysis, a haematocrit in the evaluable range of 40-55% was neither associated with the occurrence of thrombotic events, mortality nor with haematological progression in the studied population. The haematocrit of patients in the highest and lowest deciles at baseline was maintained within a narrow interval of haematocrit values ranging from 40% to 47% throughout follow-up. High platelet count was associated with a lower progression rate to acute leukaemia/myelofibrosis, whereas it had no significant relationship with thrombotic events or mortality. Our findings do not suggest that the range of haematocrit (<55%) and platelet counts (<600 x 10(9)/l) we encountered in our population had an impact on the outcome of PV patients treated by current therapeutic strategies.

Aged↗
PubMed2003

Quantification of PRV-1 mRNA distinguishes polycythemia vera from secondary erythrocytosis.

To date, the diagnosis of polycythemia vera (PV) relies on clinical criteria. We have recently described the overexpression of a hematopoietic receptor, polycythemia rubra vera-1 (PRV-1), in patients with PV. Here, we report a quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) assay for the measurement of PRV-1 mRNA levels. We have determined PRV-1 expression in 71 patients with PV, 11 patients with secondary erythrocytosis (SE), as well as in 80 healthy controls. PV patients express significantly higher amounts of PRV-1 than healthy controls or patients with SE (P <.0001). Because there is no overlap between the PRV-1 expression in PV patients versus healthy controls or SE patients, the assay has a very high sensitivity and specificity for the diagnosis of PV in our population. In patients with erythrocytosis, the quantitative RT-PCR assay described here therefore provides a rapid, highly specific and sensitive tool for the diagnosis of PV.

Adolescent↗
PubMed2006

Leukocytosis as a major thrombotic risk factor in patients with polycythemia vera.

In polycythemia vera, vascular risk assessment is based on age and thrombotic history, while the role of other potential predictors of this risk is still uncertain. Thus, we exploited the large database collected by the observational study of the European Collaboration on Low-Dose Aspirin in Polycythemia Vera (ECLAP) to investigate the association of hematologic variables and cardiovascular risk factors with the thrombotic risk. Among 1638 polycythemic patients followed for 2.7 +/- 1.3 years, there were 205 thromboses. Subjects with hypertension had a mild nonsignificant increase in the risk of arterial thrombosis, while this risk was significantly increased by smoking (hazard ratio [HR], 1.90; 95% confidence interval [CI], 1.15-3.14; P = .012). The time-dependent analysis adjusted for potential confounders showed that patients with a white blood cell count above 15 x 10(9)/L, compared with those with a white blood cell count below 10 x 10(9)/L, had a significant increase in the risk of thrombosis (HR, 1.71; 95% CI, 1.10-2.65; P = .017), mainly deriving from an increased risk of myocardial infarction (HR, 2.84; 95% CI, 1.25-6.46; P = .013). Thus, leukocyte count may help in defining the vascular risk of polycythemic subjects.

Aged↗
PubMed2002

Overexpression of the polycythemia rubra vera-1 gene in essential thrombocythemia.

PURPOSE: To examine the utility of polycythemia rubra vera-1 (PRV-1)-specific reverse transcriptase polymerase chain reaction (RT-PCR) to discriminate essential thrombocythemia (ET) and polycythemia vera (PV) from secondary thrombocytosis (ST) or secondary erythrocytosis (SE). PATIENTS AND METHODS: We analyzed the expression of PRV-1 in granulocytes isolated from 37 patients with ET, 37 patients with PV, 25 patients with ST, 10 patients with SE, 25 patients with secondary leukocytosis (SL), five patients with chronic myelogenous leukemia (CML), five patients with chronic idiopathic myelofibrosis (IM), five patients with myelodysplastic syndrome (MDS), and 20 normal individuals by PRV-1-specific RT-PCR. In female patients, PRV-1 expression was correlated with clonality analysis as assessed by the human androgen receptor polymorphism assay. RESULTS: PRV-1 was not expressed in granulocytes isolated from normal individuals or from patients with ST, SE, CML, IM, MDS, and inflammatory/infectious SL. On the contrary, all ET patients, 35 of 37 PV patients, and five patients with acute postsurgery and posttraumatic SL overexpressed PRV-1. All the cases with monoclonal hematopoiesis (17 of 21 with ET and 12 of 12 with PV) expressed PRV-1, yet PRV-1 overexpression extended also over the cases of ET showing polyclonal hematopoiesis (four of 20). CONCLUSION: The overexpression of PRV-1 seems to be a useful tool for discriminating ET and PV from ST and SE, thus offering an innovative diagnostic approach on the basis of the detection of positive diagnostic criteria instead of exclusion criteria.

Adult↗
PubMed1981

Polycythemia: mechanisms and management.

The principal function of erythrocytes is the transport of oxygen. Erythropoiesis proceeds at a rate consistent with the demand for oxygen-carrying capacity, and the major regulator of erythrocyte production is erythropoietin. Erythropoietin is produced primarily by the kidney under control of a tissue oxygenation sensor. The recently developed erythropoietin radioimmunoassay should provide a clinically useful tool. Erythrocytosis is a pathologic state characterized by an elevated erythrocyte mass, which may result from increased proliferation of erythroid progenitors due to an intrinsic cellular defect or in response to extrinsic signals. Secondary erythrocytosis results from either physiologically appropriate compensation for inadequate tissue oxygenation or from inappropriate stimulation of erythropoiesis. Erythrocytosis increases oxygen-carrying capacity of the blood, but at high hematocrit levels increased blood viscosity may result in decreased tissue oxygen delivery. Polycythemia vera is a hematopoietic stem cell disease of clonal origin. Initial results from the Polycythemia Rubra Study Group suggest that therapy with chlorambucil is associated with an unacceptably high risk for development of acute leukemia, and 32P is preferred for situations in which phlebotomy alone is insufficient.

Blood Gas Analysis↗
PubMed1987

Usefulness of the assessment of erythroid progenitors growth for differential diagnosis of primary and secondary polycythemias.

Erythropoietic progenitors from bone marrow of patients with polycythemia vera (PV), secondary polycythemia (SP) and healthy subjects (HS) were cultured in plasma clot diffusion chambers in vivo. The chambers were inserted into the peritoneal cavities of rats, which 24 and 2 h before implantation received an injection of phenylohydrazine. Control experiments were done without erythropoietin (Epo) stimulation. Colonies after 2 and 7 days of culture were considered to be formed by mature erythropoietic progenitors (CFU-D-E) and burst forming cells (BFU-D-E), respectively. PV-erythroid progenitors, both BFU-D-E and CFU-D-E produced markedly more colonies than those from SP and HS, especially in experiments without Epo stimulation (p less than 0.01). The plating efficiency in SP was comparable to that noted in HS (p greater than 0.05). These results have led us to postulate that the study of erythroid progenitor clonal proliferation in plasma clot diffusion chamber can be helpful in the differential diagnosis of PV and SP, when other clinical and laboratory findings are not sufficiently convincing.

Biopsy, Needle↗