title: High rate of abnormal blood values and vascular complications before diagnosis of myeloproliferative neoplasms.
abstract: BACKGROUND
  Vascular complications occurring before the diagnosis of myeloproliferative neoplasms (MPN) in 612 patients from four centers in Sweden, Denmark and France were retrospectively studied.
  
  
  RESULTS
  Vascular complications were observed in 151 (25%) of the 612 patients. Of these, 66% occurred during the two years preceding diagnosis. The majority of events were thromboembolic (95%), and included myocardial infarction (n=46), ischemic stroke (n=43), transient ischemic attack (TIA) (n=22), deep vein thrombosis/pulmonary embolism (n=19), splanchnic vein thrombosis (n=7), and peripheral embolism (n=7). Bleeding was observed in only 7 (5%) of the 151 patients with vascular events (3 with intracranial bleeding, 2 with epistaxis and 2 with gastrointestinal bleeding). Full blood counts obtained at least 3 months prior to the MPN diagnosis showed that 269 (44%) had abnormal blood values, fulfilling the diagnostic criteria for MPN. During the time from the abnormal blood test to the diagnosis of MPN, 50 patients suffered from a vascular complication.
  
  
  CONCLUSIONS
  We therefore conclude that a large proportion of MPN patients suffer severe thromboembolic complications prior to diagnosis. If MPN were diagnosed earlier, a large proportion of these events might be prevented. An MPN should always be suspected and ruled out in patients with unexplained elevated hematocrit, leukocyte and/or platelet counts.
authors: Sunderby Hospital, Luleå, Sweden. Electronic address: Anneli.Enblom@nll.se.
authors: Anneli
authors: A
authors: Enblom
authors: Uddevalla Hospital, NU Hospital Group, Uddevalla, Sweden. Electronic address: emma.lindskog@vgregion.se.
authors: Emma
authors: E
authors: Lindskog
authors: Roskilde University Hospital, Roskilde, Denmark. Electronic address: hans.hasselbalch@dadlnet.dk.
authors: Hans
authors: H
authors: Hasselbalch
authors: Roskilde University Hospital, Roskilde, Denmark. Electronic address: dhersby@gmail.com.
authors: Ditte
authors: D
authors: Hersby
authors: Roskilde University Hospital, Roskilde, Denmark. Electronic address: marie_bak@hotmail.com.
authors: Marie
authors: M
authors: Bak
authors: Laboratoire D'hématologie CHU, Dijon, France. Electronic address: tetu.jennifer@gmail.com.
authors: Jennifer
authors: J
authors: Tetu
authors: Laboratoire D'hématologie CHU, Dijon, France. Electronic address: francois.girodon@chu-dijon.fr.
authors: François
authors: F
authors: Girodon
authors: Uddevalla Hospital, NU Hospital Group, Uddevalla, Sweden. Electronic address: bjorn.andreasson@vgregion.se.
authors: Björn
authors: B
authors: Andréasson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002318:Cardiovascular Diseases / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology*; D003718:Denmark; D005260:Female; D005602:France; D006400:Hematocrit; D006454:Hemoglobins; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D009196:Myeloproliferative Disorders / Q000097:blood* / Q000150:complications* / Q000175:diagnosis; D010976:Platelet Count; D012189:Retrospective Studies; D013548:Sweden
chemical_list: D006454:Hemoglobins
keywords: Essential thrombocythemia; Myelofibrosis; Myeloproliferative neoplasm; Polycythemia vera; Vascular complications