title: Role of blood cells dynamism on hemostatic complications in low-risk patients with essential thrombocythemia.
abstract: Patients with essential thrombocythemia (ET) aged less than 60 years, who have not suffered a previous vascular event (low-risk patients), may develop thrombotic or hemorrhagic events. So far, it has not been possible to identify useful markers capable of predicting which of these patients are more likely to develop an event and therefore who needs to be treated. In the present study, we analysed the relationship between vascular complications and longitudinal blood counts of 136 low-risk ET patients taken over a sustained period of time (blood cells dynamism). After a median follow-up of 60 months, 45 out of 136 patients (33%) suffered 40 major thrombotic and 5 severe hemorrhagic complications. A total number of 5,781 blood counts were collected longitudinally. Thrombotic and hemorrhagic events were studied together (primary endpoint) but also separately (thrombotic alone = secondary endpoint; hemorrhagic alone = tertiary endpoint). The primary endpoint showed no significant association between platelet and WBC count at diagnosis and risk of any event (platelet, p = 0.797; WBC, p = 0.178), while Hb at baseline did show an association (p = 0.024). In the dynamic analysis with Cox regression model, where the blood count values were studied by time of follow-up, we observed that the risk for Hb was 1.49 (95% CI 1.13-1.97) for every increase of 1 g/dL, and that this risk then marginally decreased during follow-up. WBC was associated with an increased risk at baseline for every increase of 1 × 10(9)/L (hazard ratio (HR) 1.07, 95% CI 1.01-1.13, p = 0.034), the risk was stable during follow-up (HR 0.95, p = 0.187 at 60 months). Also, for each increment at baseline of 100 × 10(9) platelets/L, HR was increased by 1.08 (95% CI 0.97-1.22, p = 0.159) and decreases during follow-up. In conclusion, this study is the first to evaluate in ET low-risk patients, the risk of developing a thrombotic/hemorrhagic event considering blood counts over time. Overall our study shows that the risk changes over time. For example, the risk associated with WCC is not linear as previously reported. An interesting new finding is that PLT and even Hb contribute to the risk of developing vascular events. Future treatments should take into consideration these findings and aim to control all parameters over time. We believe this early study may help develop a dynamic analysis model to predict thrombosis in the single patient. Further studies are now warranted to further validate our findings.
authors.affiliation: Department of Haematology, San Maurizio Regional Hospital, Bolzano, South Tyrol, Italy, apiccin@gmail.com.
authors.forename: Andrea
authors.initials: A
authors.lastname: Piccin
authors.forename: Michael
authors.initials: M
authors.lastname: Steurer
authors.forename: Manfred
authors.initials: M
authors.lastname: Mitterer
authors.forename: Elisabeth Maria
authors.initials: EM
authors.lastname: Blöchl
authors.forename: Luigi
authors.initials: L
authors.lastname: Marcheselli
authors.forename: Irene
authors.initials: I
authors.lastname: Pusceddu
authors.forename: Alessandra
authors.initials: A
authors.lastname: Marabese
authors.forename: Irene
authors.initials: I
authors.lastname: Bertozzi
authors.forename: Daisy
authors.initials: D
authors.lastname: Corvetta
authors.forename: Maria Luigia
authors.initials: ML
authors.lastname: Randi
authors.forename: Elena
authors.initials: E
authors.lastname: Elli
authors.forename: Enrico Maria
authors.initials: EM
authors.lastname: Pogliani
authors.forename: Dino
authors.initials: D
authors.lastname: Veneri
authors.forename: Omar
authors.initials: O
authors.lastname: Perbellini
authors.forename: Mauro
authors.initials: M
authors.lastname: Krampera
authors.forename: Enrica
authors.initials: E
authors.lastname: Pacquola
authors.forename: Michele
authors.initials: M
authors.lastname: Gottardi
authors.forename: Mario
authors.initials: M
authors.lastname: Tiribelli
authors.forename: Anna
authors.initials: A
authors.lastname: Guella
authors.forename: Barbara
authors.initials: B
authors.lastname: Innella
authors.forename: Paolo
authors.initials: P
authors.lastname: Vivaldi
authors.forename: Ercole
authors.initials: E
authors.lastname: De Biasi
authors.forename: Rosaria
authors.initials: R
authors.lastname: Sancetta
authors.forename: Roberta
authors.initials: R
authors.lastname: Rocconi
authors.forename: Renato
authors.initials: R
authors.lastname: Bassan
authors.forename: Filippo
authors.initials: F
authors.lastname: Gherlinzoni
authors.forename: Giovanni
authors.initials: G
authors.lastname: Pizzolo
authors.forename: Günther
authors.initials: G
authors.lastname: Gastl
authors.forename: Sergio
authors.initials: S
authors.lastname: Cortelazzo
mesh_terms: D000293:Adolescent; D000328:Adult; D001772:Blood Cell Count; D018572:Disease-Free Survival; D005500:Follow-Up Studies; D006470:Hemorrhage / Q000209:etiology*; D006801:Humans; D008875:Middle Aged; D016016:Proportional Hazards Models; D018570:Risk Assessment; D012307:Risk Factors; D013920:Thrombocythemia, Essential / Q000097:blood* / Q000150:complications*; D013927:Thrombosis / Q000209:etiology*; D055815:Young Adult