title: The association of JAK2V617F mutation and leukocytosis with thrombotic events in essential thrombocythemia.
abstract: OBJECTIVE
  The Janus kinase 2 mutation, JAK2 (V617F), and megakaryocytic mutations, MPL (W515L/K), have been identified and correlated with a subtype of essential thrombocythemia (ET) patients. We investigated the frequency of mutations in ET patients and analyzed the relationship with their clinical features.
  
  
  METHODS
  Fifty-three ET patients were enrolled in the study. The amplification refractory mutation system was applied for the mutation survey of the JAK2V617F, while the polymerase chain reaction with sequencing was used for the mutation survey of MPLW515L/K.
  
  
  RESULTS
  Thirty-five (66%) patients harboring the JAK2 (V617F) mutation, including 3 homozygous and 32 heterozygous changes, but no MPLW515L/K mutation, were found. During follow-up, 17 (32.1%) patients suffered from documented thrombotic events, with 15 having JAK2V617F mutations. Statistical analysis showed that patients with the JAK2 mutation had significantly higher leukocytes, hemoglobin level, and thrombotic event (p = 0.043, p = 0.001, and p = 0.029, respectively). Thrombotic events were also significantly correlated with leukocytosis and older age.
  
  
  CONCLUSIONS
  The JAK2V617F mutation was noted in a certain population of ET patients and correlated with leukocytosis, high hemoglobin level, and thrombosis. Therefore, detection of the JAK2V617F mutation can affect not only the diagnosis, but also the management of ET patients.
authors.affiliation: Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Hui-Hua
authors.initials: HH
authors.lastname: Hsiao
authors.forename: Ming-Yu
authors.initials: MY
authors.lastname: Yang
authors.forename: Yi-Chang
authors.initials: YC
authors.lastname: Liu
authors.forename: Ching-Ping
authors.initials: CP
authors.lastname: Lee
authors.forename: Wen-Chi
authors.initials: WC
authors.lastname: Yang
authors.forename: Ta-Chih
authors.initials: TC
authors.lastname: Liu
authors.forename: Chao-Sung
authors.initials: CS
authors.lastname: Chang
authors.forename: Sheng-Fung
authors.initials: SF
authors.lastname: Lin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004252:DNA Mutational Analysis; D019468:Disease Management; D005260:Female; D005838:Genotype; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D053614:Janus Kinase 2 / Q000235:genetics*; D007964:Leukocytosis / Q000150:complications*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D012307:Risk Factors; D013920:Thrombocythemia, Essential / Q000150:complications* / Q000235:genetics; D013927:Thrombosis / Q000209:etiology*
chemical_list: D006454:Hemoglobins; D053614:Janus Kinase 2