Myeloproliferative Disease: Markers of Endothelial and Platelet Status in Patients with Essential Thrombocythemia and Polycythemia Vera

Vascular complications are the main cause of morbidity in polycythemia vera (PV) and essential thrombocythemia (ET). To investigate plasma concentrations of soluble P-selectin (sP-Sel.), soluble E-selectin (sE-Sel.) and soluble thrombomodulin (sTM) in relation to the presence of thromboembolic events 38 patients with Chronic Myeloproliferative Disorders (CMD) (14 PV pts and 24 ET pts), 15 age - matched controls and 15 patients with secondary thrombocytosis were studied. Plasma levels of P-Sel., E-Sel. and TM were significantly increased in the group of patients as compared with control subjects (respectively p < 0.001, p < 0.04 and p < 0.01). sP-Sel. levels showed no significant difference between the patients and those with secondary thrombocytosis. No difference in sP-sel levels were also observed between subgroups of CMD patients with and without vascular complications. However, among patients with ET, those with thrombosis had higher sP-Sel levels than those without thrombosis (1.177 +/- 110.48 ng/ml vs 816.25 +/- 99.27 ng/ml). High levels of sE-Sel and sTM were found in CMD patients (71.93 +/- 39.08 ng/ml and 35.81 +/- 20.79 ng/ml, respectively). Plasma sE-Sel. concentration was significantly higher in CMD patients with thrombosis than that in CMD patients without thrombosis (p < 0.001). There was no difference in sTM concentration between two groups. These findings indicate that sustained endothelium and platelet activation is present in patients with ET and PV and it might contribute to the pathogenesis of thromboembolic events in these patients.

Increased levels of the soluble adhesion molecule E-selectin in patients with chronic myeloproliferative disorders and thromboembolic complications

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.

Increased levels of the soluble adhesion molecule E-selectin in patients with chronic myeloproliferative disorders and thromboembolic complications

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.

Circulating levels of intercellular adhesion molecule-1 (ICAM-1) and soluble interleukin 2 receptors (IL-2R) in patients with B cell chronic lymphocytic leukaemia

The serum concentrations of circulating ICAM-1 (cICAM-1) and soluble receptors for interleukin-2 (sIL-2R) were evaluated on 48 patients with B-cell chronic lymphocytic leukaemia (B-CLL) and on 15 healthy control subjects. The mean +/- SD concentration of cICAM-1 was significantly higher (p < 0.002) in B-CLL patients (407.7 +/- 164.3 ng/ml) than in healthy controls (245.4 +/- 76.7 ng/ml). Patients with progressive disease had higher cICAM-1 levels than patients with "indolent" disease (440.38 +/- 32.3 ng/ml versus 321.36 +/- 14.45 ng/ml; p < 0.0001). Serum levels of cICAM-1 were also significantly higher (p < 0.0002) in patients with advanced stage (III-IV) than in those with early stage (I-II). The increase of cICAM-1 levels was positively correlated to increases of soluble receptors for interleukin-2 (r = 0.9; p < 0.0001). These results seem to show that the measurement of serum levels of cICAM-1 may be an useful tool for monitoring disease activity and tumoral mass in patients with B-CLL. However, further studies are needed to define the functional role of high cICAM-1 levels in the immunological dysregulation of patients with malignancy.