-
Clinical Advances in Hematology &... Dec 2011
Topics: Biomedical Research; Humans; Mutation; Polycythemia; Von Hippel-Lindau Tumor Suppressor Protein
PubMed: 22252661
DOI: No ID Found -
Seminars in Hematology Jan 2001The 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... (Review)
Review
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.
Topics: Cytokines; Erythropoiesis; Family Health; Humans; Polycythemia; Polycythemia Vera
PubMed: 11242597
DOI: 10.1016/s0037-1963(01)90135-0 -
Nouvelle Revue Francaise D'hematologie Apr 1994An increased hematocrit can be caused by primary proliferative polycythemia (PPP), by secondary polycythemia, by relative polycythemia (reduced plasma volume with a... (Review)
Review
An increased hematocrit can be caused by primary proliferative polycythemia (PPP), by secondary polycythemia, by relative polycythemia (reduced plasma volume with a normal red cell mass), or by modifications of the red cell mass and the plasma volume within their normal ranges. As an increased hematocrit by itself is a risk factor for thrombosis, it is important to diagnose not only polycythemia, but also its possible cause, in order to offer optimal therapy. Smoking is the most frequent cause of an increased hematocrit. Splenomegaly, aquagenic pruritus, and erythromelalgia often exist in PPP, whereas other symptoms such as dyspnea are more likely to be associated with secondary polycythemia. Smokers with an increased hematocrit will be asked to stop smoking before ordering blood volume studies. These studies are not indicated in patients with obvious pulmonary disease. Male patients with an hematocrit over 60% and female patients with an hematocrit over 55% always have absolute polycythemia. The associations of an increased hematocrit with splenomegaly, a raised white blood cell count or thrombocytosis are indicators for PPP. The necessity for blood volume studies is questionable in these patients. However, blood volume studies are useful in patients with an increased hematocrit and no other clinical or biological signs suggestive of any form of polycythemia.
Topics: Blood Cell Count; Blood Volume Determination; Female; Hematocrit; Humans; Male; Polycythemia; Risk Factors
PubMed: 8036131
DOI: No ID Found -
Indian Pediatrics Apr 1990Polycythemia (venous PCV greater than 65%) in neonates is not an infrequent occurrence. Over the last 2 years out of approximately 1500 admissions to the Neonatal Unit,...
Polycythemia (venous PCV greater than 65%) in neonates is not an infrequent occurrence. Over the last 2 years out of approximately 1500 admissions to the Neonatal Unit, polycythemia was detected in 46 babies (3.06%). Seventeen (36%) of these babies were preterm and 29 (63%) were term. Approximately one third were small for dates while 2 babies (4%) were large for dates. Four of them had been born to mothers with gestational diabetes and 7 were twin deliveries. Severe perinatal asphyxia (5 minute Apgar score less than or equal to 5) was present in 12 cases (26%). Symptoms suggestive of polycythemia included lethargy in 15%, refusal to feed in 13%, respiratory distress in 10%, vomiting in 8% and abdominal distension in 6%. Associated hypoglycemia was seen in 5 cases (10.8%) while twelve babies (26%) had significant jaundice (bilirubin greater than or equal to 12 mg/dl). Twenty eight babies (60.8%) were given a partial plasma exchange transfusion through the umbilical route. There was 6.5% mortality in these 46 babies with polycythemia. Blood letting through a peripheral vein along with a plasma infusion may be a safer alternative to partial plasma exchange transfusion through umbilical route in babies with polycythemia.
Topics: Bloodletting; Hospitals, University; Humans; India; Infant, Newborn; Plasma Exchange; Polycythemia; Retrospective Studies
PubMed: 2210821
DOI: No ID Found -
American Family Physician Feb 1984Neonatal polycythemia occurs in 2 to 12 percent of all newborn infants. It may be the result of placental transfusion but may also be associated with placental...
Neonatal polycythemia occurs in 2 to 12 percent of all newborn infants. It may be the result of placental transfusion but may also be associated with placental insufficiency, congenital abnormalities and endocrine or metabolic disorders. Polycythemia of the newborn requires treatment because the associated blood hyperviscosity may lead to permanent neurologic impairment. Central hematocrits over 65 percent necessitate reduction transfusion using an umbilical venous or arterial catheter.
Topics: Blood Transfusion; Blood Transfusion, Intrauterine; Blood Viscosity; Hematocrit; Humans; Infant, Newborn; Polycythemia
PubMed: 6702518
DOI: No ID Found -
Transfusion and Apheresis Science :... Apr 2013To evaluate the efficacy and safety of erythrocytapheresis (ECP) in the treatment of polycythemia. (Clinical Trial)
Clinical Trial
PURPOSE
To evaluate the efficacy and safety of erythrocytapheresis (ECP) in the treatment of polycythemia.
METHODS
Patients diagnosed with polycythemia were included in this retrospective analysis and treated with ECP (n=20) or conventional treatments (exsanguination; n=20). Blood laboratory values and adverse effects were recorded.
RESULTS
In ECP-treated patients mean red blood cell (RBC) collection time was 25.7±4.5min (range: 19-37min), with a mean collection volume of 773.5±129.3mL (range: 600-1002mL). From baseline, ECP reduced the mean number of RBCs (0.6×10(12)/L [7.6%]), mean hemoglobin (31.1g/L [14.8%]), and mean hematocrit (13.1% [20.2%]) (P<0.001 for each). After ECP, a marked reduction in symptoms associated with polycythemia was also observed.
CONCLUSIONS
Treatment of patients with polycythemia using ECP reduces RBC count, hemoglobin, and hematocrit. The advantages associated with ECP over conventional therapy should be considered when choosing a treatment plan for patients with polycythemia.
Topics: Cytapheresis; Erythrocyte Count; Female; Humans; Male; Middle Aged; Polycythemia; Retrospective Studies
PubMed: 23428426
DOI: 10.1016/j.transci.2013.01.011 -
Neurology India Jan 2024
Topics: Humans; Polycythemia
PubMed: 38443036
DOI: 10.4103/NI.Neurol-India-D-23-00612 -
Current Hematology Reports May 2005This review will focus on the molecular basis of certain polycythemic disorders. Primary polycythemias are characterized by acquired somatic or inherited germ-line... (Review)
Review
This review will focus on the molecular basis of certain polycythemic disorders. Primary polycythemias are characterized by acquired somatic or inherited germ-line mutations expressed within hematopoietic progenitors that cause increased accumulation of red blood cells. Polycythemia vera (PV), an acquired condition, is the most common primary polycythemia; although some progress has been made in the understanding of PV, its molecular basis remains unknown. In contrast, recent advances in delineating the molecular defects of some inherited polycythemias have greatly furthered our knowledge of the regulation of erythropoiesis and hypoxia sensing; however, more work needs to be done.
Topics: Adult; Animals; Child; Cohort Studies; DNA-Binding Proteins; Disease Models, Animal; Erythropoiesis; Erythropoietin; Ethnicity; Female; Founder Effect; GPI-Linked Proteins; Germ-Line Mutation; Humans; Hypoxia; Hypoxia-Inducible Factor 1; Hypoxia-Inducible Factor 1, alpha Subunit; Isoantigens; Janus Kinase 2; Male; Membrane Glycoproteins; Mice; Nuclear Proteins; Polycythemia; Polycythemia Vera; Proteasome Endopeptidase Complex; Protein Processing, Post-Translational; Protein-Tyrosine Kinases; Proto-Oncogene Proteins; Receptors, Cell Surface; Receptors, Erythropoietin; Russia; Transcription Factors; Tumor Suppressor Proteins; Ubiquitin; Ubiquitin-Protein Ligases; Von Hippel-Lindau Tumor Suppressor Protein
PubMed: 15865879
DOI: No ID Found -
Advance For Nurse Practitioners May 2002
Topics: Erythrocyte Count; Erythrocyte Indices; Humans; Nursing Assessment; Plasma Volume; Polycythemia
PubMed: 12420524
DOI: No ID Found -
Revue Medicale Suisse Nov 2014
Topics: Aged; Female; Ferritins; Humans; Male; Middle Aged; Polycythemia
PubMed: 25549379
DOI: No ID Found