title: Leukocytosis in polycythemia vera and splenomegaly in essential thrombocythemia are independent risk factors for hemorrhage.
abstract: BACKGROUND
  Long-term outcomes are favorable for patients with polycythemia vera (PV) and for patients with essential thrombocythemia (ET). However, hemorrhage is a significant cause of morbidity and mortality in those patients.
  
  
  METHODS
  We retrospectively recruited 247 patients who had received a diagnosis of PV (n = 101) or ET (n = 146) during the period 2001-2010.
  
  
  RESULTS
  After a median follow-up period of 36.2 months, the cumulative incidence of hemorrhage was 39.6% in patients with PV (6.2% per person-year) and 29.7% in patients with ET (5.9% person-years). Episodes of major bleeding occurred in 9.9% of patients with PV and in 14.4% of patients with ET. Overall survival was significantly shorter among patients with hemorrhage than among those without said complication (P < 0.001 for overall patients; P = 0.002 for patients with PV; P = 0.026 for patients with ET). In the univariate analysis, age ≥ 60 yr (OR: 4.77, P = 0.046) and WBC ≥ 16 × 10(9) /L (OR: 4.15, P = 0.010) were predictors of hemorrhage in patients with PV, and age ≥ 60 yr (OR: 3.25, P = 0.040), WBC ≥ 16 × 10(9) /L (OR: 2.89, P = 0.024), albumin <4.0 g/dL (OR: 4.10, P = 0.002), and splenomegaly (OR: 5.19, P = 0.002) were predictors of hemorrhage in patients with ET. Multivariate analysis showed that WBC ≥ 16 × 10(9) /L was the only significant risk factor for hemorrhage in patients with PV (OR: 3.51, P = 0.026) and that splenomegaly was the only risk factor for hemorrhage in patients with ET (OR: 3.00, P = 0.048).
  
  
  CONCLUSIONS
  Leukocytosis in PV and splenomegaly in ET are independent risk factors for hemorrhage.
authors.affiliation: Division of Hematology and Oncology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; National Yang-Ming University School of Medicine, Taipei, Taiwan.
authors.forename: Yi-Sheng
authors.initials: YS
authors.lastname: Chou
authors.forename: Jyh-Pyng
authors.initials: JP
authors.lastname: Gau
authors.forename: Yuan-Bin
authors.initials: YB
authors.lastname: Yu
authors.forename: Jih-Tung
authors.initials: JT
authors.lastname: Pai
authors.forename: Liang-Tsai
authors.initials: LT
authors.lastname: Hsiao
authors.forename: Jin-Hwang
authors.initials: JH
authors.lastname: Liu
authors.forename: Ying-Chung
authors.initials: YC
authors.lastname: Hong
authors.forename: Chun-Yu
authors.initials: CY
authors.lastname: Liu
authors.forename: Ching-Fen
authors.initials: CF
authors.lastname: Yang
authors.forename: Po-Min
authors.initials: PM
authors.lastname: Chen
authors.forename: Tzeon-Jye
authors.initials: TJ
authors.lastname: Chiou
authors.forename: Cheng-Hwai
authors.initials: CH
authors.lastname: Tzeng
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006470:Hemorrhage / Q000150:complications* / Q000401:mortality / Q000473:pathology; D006801:Humans; D015994:Incidence; D007958:Leukocyte Count; D007962:Leukocytes / Q000473:pathology; D007964:Leukocytosis / Q000150:complications* / Q000401:mortality / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011087:Polycythemia Vera / Q000150:complications* / Q000401:mortality / Q000473:pathology; D012189:Retrospective Studies; D012307:Risk Factors; D013163:Splenomegaly / Q000150:complications* / Q000401:mortality / Q000473:pathology; D015996:Survival Rate; D013920:Thrombocythemia, Essential / Q000150:complications* / Q000401:mortality / Q000473:pathology