title: Risk factors for vascular complications and treatment patterns at diagnosis of 2389 PV and ET patients: Real-world data from the Swedish MPN Registry.
abstract: OBJECTIVE
  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).
  
  
  METHODS
  The study comprises 1105 patients with polycythemia vera (PV) and 1284 patients with essential thrombocythemia (ET) registered in the Swedish MPN Registry.
  
  
  RESULTS
  Vascular complications, prior to diagnosis, were registered in 37% of PV patients. In multivariate analysis, low hemoglobin was the only significant risk factor (P=.0120). Among ET patients, 35% had encountered a vascular complication. Risk factors for thromboembolic complications in ET were identified as age>65 years, white cell count>12×109/L, and the presence of JAK2 V617F mutation (P=.0004, P=.0038, and P=.0016, respectively). A JAK2 V617F mutation was present in 71% of ET patients with vascular complications, compared to 60% in patients without. A majority of complications were thromboembolic, in both PV and ET.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Medical Department, Kungälv Hospital, Kungälv, Sweden.
authors.forename: Khadija
authors.initials: K
authors.lastname: Abdulkarim
authors.affiliation: Department of Education and Medical Science, Karolinska Institute at Stockholm South Hospital, Stockholm, Sweden.
authors.forename: Jan
authors.initials: J
authors.lastname: Samuelsson
authors.affiliation: Hematology section, NU hospital group, Uddevalla, Sweden.|Hematology and Coagulation section, Sahlgrenska University Hospital, Gothenburg, Sweden.
authors.forename: Peter
authors.initials: P
authors.lastname: Johansson
authors.affiliation: Hematology section, NU hospital group, Uddevalla, Sweden.
authors.forename: Björn
authors.identifier: http://orcid.org/0000-0003-1525-1331
authors.initials: B
authors.lastname: Andréasson
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood / Q000235:genetics*; D004921:Erythropoietin / Q000097:blood / Q000235:genetics*; D005260:Female; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D053614:Janus Kinase 2 / Q000097:blood / Q000235:genetics*; D007964:Leukocytosis / Q000097:blood / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009154:Mutation; D011087:Polycythemia Vera / Q000097:blood / Q000150:complications / Q000175:diagnosis* / Q000473:pathology; D011446:Prospective Studies; D012042:Registries; D012307:Risk Factors; D013548:Sweden; D013920:Thrombocythemia, Essential / Q000097:blood / Q000150:complications / Q000175:diagnosis* / Q000473:pathology; D054556:Venous Thromboembolism / Q000097:blood / Q000175:diagnosis* / Q000209:etiology / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor; C554270:EPO protein, human; D006454:Hemoglobins; D004921:Erythropoietin; C507924:JAK2 protein, human; D053614:Janus Kinase 2
keywords: essential thrombocythemia; polycythemia vera; vascular complications