Differential up-regulation of circulating soluble selectins and endothelial adhesion molecules in Sicilian patients with Boutonneuse fever

In 150 patients with Boutonneuse fever (BF), caused by Rickettsia conorii, we studied the plasma levels of soluble L-selectin (sL-selectin), vascular cell adhesion molecule-1 (sVCAM-1), intercellular adhesion molecule-1 (sICA M-1) and E-selectin (sE-selectin) in various phases of disease to clarify t heir role in disease evolution. Results indicate that during the acute phas e of BF there is a significant increase in the serum levels of sL-selectin, sE-selectin, sVCAM-1 and sICAM-1, sL-selectin and sVCAM-1 returned to norm al levels in the third week of disease, whereas sE-selectin and sICAM-1 per sisted at significantly high levels even after the third week. The secretio n of these soluble CAMs in BF is mainly the result of leucocyte expression and endothelial cell activation, but secretion also appears to mediate anti inflammatory activities, moderating leucocyte adhesion and reducing in part icular lymphocyte and monocyte infiltration. Only sL-selectin serum levels were found to correlate with the acute phase of infection characterized by fever.