title: Clinical risk factors of thrombosis in patients with Ph-negative myeloproliferative neoplasms, who had experienced radiation exposure due to the Chornobyl accident.
abstract: OBJECTIVE
  The objective of this study was to determine the predictive value of a factor of age over 60 years, history of thrombosis, and cardiac risk factors (CRF) for the thrombosis in patients with Ph-negative myeloproliferative neoplasm (Ph-negative MPN), namely the essential thrombocythemia (ET), polycythemia vera (PV) and primary myelofibrosis (IMF), who had experienced radiation exposure due to the Chornobyl accident and without radiation anamnesis.
  
  
  METHODS
  There were 216 patients with Ph-negative MPN included in the study. Prevalence of thrombosis and presence of CRF were determined by processing the medical documentation.
  
  
  RESULTS
  The age older than 60 years (RR=1.73, 95% confidence interval [CI] 1.00-2.98; p=0.043 and RR=2.04, 95% CI =1.12-3.68; p=0.02) and CRF (RR=2.25, 95% CІ =1.21-4.16; p=0.005 and RR=2.31, 95% CІ =1.20-4.41; p=0.008) are predictors of thrombosis in all patients with PV and with spontaneous PV, respectively. Age over 60 years and CRF in all patients with ET associates with an increase of the relative risk of thrombosis (RR=2.5, 95% CІ =1.05-5.92; p=0.047 and RR=2.74, 95% CІ =1.18-6.23; p=0.026). Frequency of recurrent thrombotic complications in patients with ET and thrombosis in anamnesis is significantly higher than in patient's without history of thrombotic complication (RR=2.75, 95% CІ =1.15-6.51; p=0.035).
  
  
  CONCLUSIONS
  Our findings confirm previous results of other studies reporting that the age over 60 years, history of thrombosis, CRF influences on thrombosis development in Ph-negative MPN patients.
authors.forename: O Y
authors.initials: OY
authors.lastname: Mishcheniuk
authors.forename: S V
authors.initials: SV
authors.lastname: Klymenko
mesh_terms: D000367:Age Factors; D000368:Aged; D016022:Case-Control Studies; D047852:Chernobyl Nuclear Accident; D015331:Cohort Studies; D004781:Environmental Exposure / Q000032:analysis; D006331:Heart Diseases / Q000097:blood / Q000209:etiology; D006801:Humans; D054438:Leukemia, Myeloid, Chronic, Atypical, BCR-ABL Negative / Q000097:blood / Q000150:complications* / Q000453:epidemiology; D008875:Middle Aged; D015995:Prevalence; D011379:Prognosis; D011848:Radioactive Pollutants; D012008:Recurrence; D012307:Risk Factors; D013927:Thrombosis / Q000097:blood / Q000453:epidemiology / Q000209:etiology*; D014455:Ukraine
chemical_list: D011848:Radioactive Pollutants
keywords: Ph-negative chronic myeloproliferative neoplasms; cardiac risk factors; recurrent thrombotic episodes; risk factor for thrombosis; thrombotic complication