Fibroblast Growth Factor-2 and Lactate Dehydrogenase Levels in Patients with Essential Thrombocythemia Treated with Anagrelide.

Abstract 4981 Essential thrombocythemia (ET) is characterized by platelet-coagulant-endothelial activation. Fibroblast growth factor-2 (FGF-2) is released and upregulated by platelet-fibrinogen(Fg)-endothelial activation and induces vascular and myeloid proliferation. Anagrelide (ANA) is a platelet-lowering drug that inhibits platelet activation. Therefore, we evaluated platelets, platelet factor 4 (PF4) and fibrinogen (Fg), as markers of platelet and coagulant activation, tissue factor pathway inhibitor (TFPI), tissue factor (TF) and von Willebrand factor (vWF), as markers of endothelial activation, FGF-2, vascular endothelial growth factor (VEGF), as indicator of angiogenesis, and white blood cell (WBC) count and haemoglobin (HB), as myeloproliferative indexes. As lactate dehydrogenase (LDH) is a cell cytolysis-associated marker, we determined LDH. To ensure that FGF-2 elevation did not associate with prefibrotic myelofibrosis, we evaluated the CD34 levels. We recruited 21 patients with ET (13 males and 8 females, mean age 52 years) who fulfilled PVSG and WHO. Their mean duration of disease was 9 years (range, 5-21 years). ANA was administered in dose of 0.5 mg/day, with increases of 0.5 mg/day every 7 days until the platelets decreased below 400×109/L and with a average maintenance dosage of 2.1 mg/day. PF4, Fg, FGF-2, VEGF, platelets, WBC, HB, TFPI, TF, vWF and LDH were measured before cytoreduction and to complete response defined as platelets PLT /10 6 and VEGF PLT /10 6 ). Platelets, WBC and HB were measured by automated analyser. Before ANA all patients had marked platelets (1005±314×109/L), high PF4 (127±45 IU/ml vs 4.1±2.4 IU7ml) (p PLT (0.08±0.08 pg/10 6 vs 0.01±0.001 pg/10 6 ) (p PLT ( 1.8±1.1 pg/10 6 vs 0.5±0,5 pg/10 6 ) (p 9 /L vs 5.2±1.1×10 9 /L) (p PLT (0.01±0.0 pg/10 6 ), VEGF PLT ( 1.1±0.6 pg/10 6 ), WBC (7.4±1.4×10 9 /L), HB (12.6±1.1 g/dL), and LDH (225±23 UI/L). A positive correlation there was between PF4 and platelets and Fg and TFPI and TF and vWF (p PLT and LDH (p PLT (p=0.010) and FGF-2 PLT and LDH and TFPI and TF and vWF (p=0.003 and p PLT and VEGF PLT (p=0.011) and WBC and HB (p=0.011 and p=0.016, respectively). A significant correlation there was between FGF-2 PLT and LDH (p PLT and CD34. These data suggest that FGF-2 PLT and LDH are platelet-endothelial activation-associated prognostic factors reversed by ANA. Disclosures No relevant conflicts of interest to declare.