@article{3129416,
    title = "Direct evidence for normalization of platelet function resulting from platelet count reduction in essential thrombocythemia",
    author = "Tsantes, A.E. and Nikolopoulos, G.K. and Tsirigotis, P. and Zoi, K. and Zomas, A. and Kapsimali, V. and Kopterides, P. and Chondropoulos, S. and Dervenoulas, J. and Mantzios, G.",
    journal = "Blood Coagulation and Fibrinolysis",
    year = "2011",
    volume = "22",
    number = "6",
    pages = "457-462",
    issn = "0957-5235, 1473-5733",
    doi = "10.1097/MBC.0b013e3283488494",
    keywords = "adenosine diphosphate;  adrenalin;  collagen;  Janus kinase 2;  von Willebrand factor, adult;  article;  blood clotting parameters;  clinical article;  ex vivo study;  gene mutation;  hematological parameters;  human;  leukocyte count;  priority journal;  protein blood level;  thrombocyte aggregation;  thrombocyte count;  thrombocyte function;  thrombocythemia, Adenosine Diphosphate;  Adult;  Aspirin;  Blood Platelets;  Collagen;  Epinephrine;  Female;  Greece;  Humans;  Hydroxyurea;  Interferon-alpha;  Janus Kinase 2;  Longitudinal Studies;  Male;  Middle Aged;  Platelet Aggregation;  Platelet Count;  Platelet Function Tests;  Point Mutation;  Regression Analysis;  Thrombocythemia, Essential;  von Willebrand Factor",
    abstract = "Essential thrombocythemia is characterized by persistent elevation and functional disturbances of platelets. Both the platelet function analyzer-100 (PFA-100) collagen-epinephrine (CEPI) cartridge and aggregometry with epinephrine are considered sensitive and valid methods in detecting abnormal platelet function in essential thrombocythemia. We attempted to confirm that restoration of abnormal platelet function results from platelet count reduction in essential thrombocythemia, by using these two methods. Thirty-nine essential thrombocythemia patients were divided into two groups on the basis of their platelet count. Group A participants (n = 20) exhibited platelet counts greater than 500 × 10 9/l, whereas group B participants (n = 19) had platelet counts below this limit. Hematological parameters, plasma von Willebrand factor (vWF) antigen and activity levels were assessed. Platelet function was analyzed by the PFA-100 and light transmission aggregometry with epinephrine, collagen, and ADP. The point mutation JAK2 V617F was identified and its effect on platelet function tests was also investigated. By using logistic regression analysis, white blood cell count, vWF activity level, and the measurements of aggregation in response to epinephrine were significantly different between the two groups. Epinephrine-induced aggregation retained the statistical significance in the multivariable procedure (P: 0.002). PFA-100 CEPI closure times were lower-but not statistically significant-in group B. Neither the JAK2 V617F positivity nor different cytoreductive treatments had any influence on ex-vivo platelet function tests. Our findings demonstrate normalization of platelet function resulting from platelet count reduction in essential thrombocythemia and reinforce the concept of lowering platelet counts in these patients. © 2011 Wolters Kluwer Health | Lippincott Williams &Wilkins."
}