title: Impact of leukocytosis on thrombotic risk and survival in 532 patients with essential thrombocythemia: a retrospective study.
abstract: Established risk factors for thrombosis in essential thrombocythemia (ET) include age (≥ 60 years) and previous vascular events. Recently, also leukocytosis has been proposed in risk stratification of ET patients. We report a retrospective study on 532 ET patients followed for a median of 7.6 years. Sixty-four patients (12%) developed 95 thrombotic events during follow-up. Together with the high-risk condition, a white blood cell (WBC) value above 11 × 10⁹/L, corresponding to the fourth percentile value, significantly correlated with a higher thrombotic risk (p = 0.033) by Cox proportional hazards. Moreover, the cumulative risk of thrombosis was significantly higher in high-risk patients with WBC >11 × 10⁹/L. JAK2 V617F mutation did not correlate with thrombosis. Overall, 123 (23%) patients died. Three independent parameters were noted as prognostic factors for survival in multivariate analysis: age > 60 years, leukocytosis >11 × 10⁹/L, and hemoglobin level below normal values. Based on these parameters, three groups of risk were defined, with significantly different survivals. Baseline leukocytosis correlated with a higher thrombotic risk in high-risk patients and identified a cohort of patients with worse survival.
authors.affiliation: Department of Hematology and Oncology L. e A. Seràgnoli, St. Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Palandri
authors.forename: Nicola
authors.initials: N
authors.lastname: Polverelli
authors.forename: Lucia
authors.initials: L
authors.lastname: Catani
authors.forename: Emanuela
authors.initials: E
authors.lastname: Ottaviani
authors.forename: Michele
authors.initials: M
authors.lastname: Baccarani
authors.forename: Nicola
authors.initials: N
authors.lastname: Vianelli
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D005260:Female; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D007958:Leukocyte Count; D007964:Leukocytosis / Q000150:complications*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D016019:Survival Analysis; D013920:Thrombocythemia, Essential / Q000150:complications*; D013927:Thrombosis / Q000209:etiology* / Q000401:mortality; D055815:Young Adult
chemical_list: D006454:Hemoglobins