title: Idiopathic erythrocytosis, diagnosis and clinical management.
abstract: By definition, idiopathic erythrocytosis (IE) applies to a group of patients characterised by having a measured RCM above their predicted normal range (an absolute erythrocytosis) and following investigation do not have a form of primary or secondary erythrocytosis. Patients with IE are heterogenous. The possibilities include physiological variation, 'early' polycythaemia vera (10-15% develop clear features of PV over a few years), unrecognized congenital erythrocytosis, unrecognized or unrecognizable secondary acquired erythrocytosis or a currently undescribed form of primary or secondary erythrocytosis. Patients are more commonly male with a median age at presentation of 55-60 years. Approximately half of the patients present with vascular occlusive complications. Retrospective evidence indicates that vascular occlusion occurs less frequently when the PCV is controlled at normal levels. Venesection is the treatment of choice to lower the PCV. As a general approach to management, all patients with a PCV above 0.54 should be venesected to a PCV less than 0.45. This target PCV should also apply to patients with lesser degrees of raised PCV who have additional other risk factors for vascular occlusion.
authors.affiliation: Department of Haematological Medicine, Guy's, King's and St Thomas' School of Medicine, St Thomas' Hospital, London SE1 7EH, UK.
authors.forename: T C
authors.initials: TC
authors.lastname: Pearson
authors.forename: M
authors.initials: M
authors.lastname: Messinezy
mesh_terms: D000368:Aged; D001157:Arterial Occlusive Diseases / Q000209:etiology; D001853:Bone Marrow / Q000473:pathology; D002699:Chlorambucil / Q000009:adverse effects / Q000627:therapeutic use; D003937:Diagnosis, Differential; D004700:Endocrine System Diseases / Q000150:complications; D004911:Erythrocyte Volume; D015672:Erythroid Precursor Cells / Q000473:pathology; D004921:Erythropoietin / Q000097:blood; D020022:Genetic Predisposition to Disease; D006801:Humans; D000860:Hypoxia / Q000150:complications; D007674:Kidney Diseases / Q000150:complications; D007938:Leukemia / Q000139:chemically induced; D007953:Leukemia, Radiation-Induced / Q000209:etiology; D008875:Middle Aged; D010761:Phosphorus Radioisotopes / Q000009:adverse effects / Q000627:therapeutic use; D011086:Polycythemia / Q000145:classification / Q000151:congenital / Q000175:diagnosis / Q000209:etiology / Q000628:therapy; D011087:Polycythemia Vera / Q000175:diagnosis; D017467:Receptors, Erythropoietin / Q000172:deficiency / Q000235:genetics; D017384:Sequence Deletion; D012907:Smoking / Q000097:blood; D020521:Stroke / Q000209:etiology
chemical_list: D010761:Phosphorus Radioisotopes; D017467:Receptors, Erythropoietin; D004921:Erythropoietin; D002699:Chlorambucil