title: Impact of JAK2V617F mutation on thrombosis and myeloid transformation in essential thrombocythemia: a multivariate analysis by Cox regression in 141 patients.
abstract: OBJECTIVE
  To perform a multivariate analysis by Cox proportional hazard model of the impact of JAK2 V617F mutation on thrombosis and myeloid transformations in patients with essential thrombocythemia (ET).
  
  
  METHODS
  The clinicopathologic features and outcome of a cohort of Chinese ET patients were retrospectively reviewed. JAK2 V617F mutation was detected by allele-specific polymerase chain reaction. Potential risk factors including JAK2 V617F that might impact on thrombosis and outcome were studied by multivariate analysis with Cox proportional hazard model.
  
  
  RESULTS
  Of 141 patients studied, JAK2 V617F was found in 80 cases (57%). JAK2 V617F was positively correlated with hemoglobin and leukocyte count at diagnosis. Univariate analysis showed significant thrombotic risks to be JAK2 V617F (P=0.006), hemoglobin >13 g/dl (P=0.015), and age >55 years (P=0.011). However, in multivariate analysis, only age and hemoglobin were independent risk factors. JAK2 V617F was unrelated to survival or leukemic/myelofibrotic transformation.
  
  
  CONCLUSIONS
  In Chinese patients with ET, JAK2 V617F was positively associated with age, hemoglobin, and leukocyte count, but was not an independent risk for thrombosis.
authors.affiliation: Department of Medicine and Cancer Research Centre, Queen Mary Hospital, University of Hong Kong, Hong Kong. jcschim@hkucc.hku.hk
authors.forename: C S
authors.initials: CS
authors.lastname: Chim
authors.forename: J P
authors.initials: JP
authors.lastname: Sim
authors.forename: C C
authors.initials: CC
authors.lastname: Chan
authors.forename: B C
authors.initials: BC
authors.lastname: Kho
authors.forename: J C
authors.initials: JC
authors.lastname: Chan
authors.forename: L G
authors.initials: LG
authors.lastname: Wong
authors.forename: M
authors.initials: M
authors.lastname: Law
authors.forename: R
authors.initials: R
authors.lastname: Liang
authors.forename: Y L
authors.initials: YL
authors.lastname: Kwong
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D005260:Female; D056726:Genetic Association Studies; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D053614:Janus Kinase 2 / Q000235:genetics*; D007951:Leukemia, Myeloid / Q000209:etiology / Q000235:genetics*; D007958:Leukocyte Count; D008297:Male; D008499:Medical Records; D008875:Middle Aged; D015999:Multivariate Analysis; D017354:Point Mutation; D012189:Retrospective Studies; D012307:Risk Factors; D016019:Survival Analysis; D013920:Thrombocythemia, Essential / Q000150:complications* / Q000235:genetics* / Q000401:mortality / Q000503:physiopathology; D013927:Thrombosis / Q000209:etiology / Q000235:genetics*; D055815:Young Adult
chemical_list: D006454:Hemoglobins; C507924:JAK2 protein, human; D053614:Janus Kinase 2