Levels of circulating endothelial adhesion molecules in patients with myelodysplastic syndromes.

Intensity and specificity of leukocyte endothelial interaction may differ in various subtypes of myelodysplastic syndromes. To assess endothelial activation, plasma levels of endothelial adhesion molecules (E-selectin, VCAM-1 and ICAM-1) were analyzed in 65 patients with MDS using commercially available immunoassays. In MDS patients, high levels of sVCAM-1 were closely related to circulation of monocytic cells in the peripheral blood and splenic enlargement. Patients with CMML showed the highest sE-selectin, sICAM-1 and sVCAM-1 levels, whereas receptor levels in low-risk MDS (RA, RARS) were not significantly different from those in high-risk MDS (RAEB, RAEB-t). Similar receptor concentrations were measured in bone marrow aspirations and samples from peripheral blood. Based on levels of circulating endothelial adhesion molecules there is no clear-cut evidence for a general endothelial cell activation in MDS. Furthermore, levels of circulating endothelial adhesion molecules had no prognostic significance in MDS. Concerning MDS subtypes, patients with CMML demonstrate the highest endothelial activation based on cCAM levels obtained. Thus, increased leukocyte endothelial interaction may account for the higher incidence of extramedullary infiltrations in this MDS subtype.