Patients with chronic myeloproliferative disorders (CMD) show a high frequency of thrombosis. For this reason we evaluated endothelial cell markers, soluble adhesion molecule E-selectin (sELAM), and thrombomodulin (TM) in 25 patients with CMD. Among them nine presented thromboses in their past history. Data were compared with those obtained in a group of healthy subjects and a group of patients with secondary thrombocytosis.
The mean plasma concentrations of sELAM were elevated in patients with CMD, as compared with healthy subjects (81.27 ± 42.8 ng/ml vs. 41.75 ± 13; P < 0.02). Similarly, the mean plasma concentrations of sTM were increased in CMD patients in comparison with the control group (102.0 ± 73 ng/ml vs. 16.7 ± 9.6; P < 0.01). More markedly elevated sELAM levels were observed in CMD patients with thrombosis than in patients without thrombosis (113.16 ± 29.5 ng/ml vs. 55.11 ± 19.1 ng/ml; P < 0.001), while no significant difference was found between CMD patients without thrombosis and secondary thrombocytosis (50.72 ± 10.8 ng/ml). Plasma thrombomodulin values in CMD patients with thrombosis (131 ± 93.8 ng/ml) were higher than those without thrombosis (65.77 ± 43.9 ng/ml; P < 0.02). sTM values were also significantly increased in patients with secondary thrombocytosis (P < 0.01).
It is speculated that the plasma, sELAM levels may reflect endothelium activation and that it is possibly useful in predicting the thrombotic risk in myeloproliferative disorders.