title: Correlations between Janus kinase 2 V617F allele burdens and clinicohematologic parameters in myeloproliferative neoplasms.
abstract: BACKGROUND
  This study evaluated potential correlations between the allele burden of the Janus kinase 2 (JAK2) V617F mutation and clinicohematologic characteristics in patients with myeloproliferative neoplasms (MPN).
  
  
  METHODS
  Clinical and hematologic features were reviewed for 103 MPN patients, including patients with polycythemia vera (PV, 22 patients), essential thrombocythemia (ET, 64 patients), and primary myelofibrosis (PMF, 17 patients). JAK2 V617F allele status and allele burdens were measured by allele-specific PCR and pyrosequencing, respectively.
  
  
  RESULTS
  The JAK2 V617F mutation was detected in 95.5%, 68.8%, and 52.9% of PV, ET, and PMF patients, respectively. JAK2 V617F-positive ET patients were significantly older and exhibited higher neutrophil fractions, a higher frequency of thrombotic events, and a higher myelofibrosis rate than JAK2 V617F-negative patients (P <0.05). PV patients carried the highest mean T allele burden (66.0%±24.9%) compared with ET (40.5%±25.2%) and PMF patients (31.5%±37.0%) (P =0.00). No significant correlations were detected between V617F allele burden and patient age, white blood cell count, Hb, Hct, or the platelet count for PV, ET, or PMF patients. ET patients with organomegaly had a higher JAK2 V617F allele burden (53.4%±23.7%) than patients without organomegaly (35.6%±24.3%) (P =0.03).
  
  
  CONCLUSIONS
  The JAK2 V617F mutational status and its allele burden correlate with the clinicohematologic phenotypes of ET patients, including older age, higher neutrophil count, and greater rates of organomegaly, thrombotic events, and myelofibrosis. For PV and PMF patients, larger-scale studies involving more MPN patients are needed.
authors.affiliation: Department of Laboratory Medicine, Keimyung University School of Medicine, Daegu, Korea. ksksmom@dsmc.or.kr
authors.forename: Jung-Sook
authors.initials: JS
authors.lastname: Ha
authors.forename: Yu-Kyung
authors.initials: YK
authors.lastname: Kim
authors.forename: Soon-Il
authors.initials: SI
authors.lastname: Jung
authors.forename: He-Ra
authors.initials: HR
authors.lastname: Jung
authors.forename: In-Sung
authors.initials: IS
authors.lastname: Chung
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000483:Alleles; D005260:Female; D006400:Hematocrit; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D053614:Janus Kinase 2 / Q000235:genetics*; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D009196:Myeloproliferative Disorders / Q000235:genetics* / Q000473:pathology; D011087:Polycythemia Vera / Q000235:genetics; D020641:Polymorphism, Single Nucleotide; D055728:Primary Myelofibrosis / Q000235:genetics; D013920:Thrombocythemia, Essential / Q000235:genetics
chemical_list: D006454:Hemoglobins; D053614:Janus Kinase 2
keywords: Allele; Janus kinase 2; Myeloproliferative neoplasm