Increased levels of soluble cell adhesion molecules (sCAM) have been reported in HIV-1 infection and may possibly contribute to altering the adhesion mechanisms of phagocytic cells. We evaluated the effect of highly active antiretroviral therapy (HAART) on plasma levels of sl-selectin, sE-selectin, intercellular cell adhesion molecule-1 (sICAM-1), sICAM-3, and vascular cell adhesion molecule-1 (sVCAM-1). Study participants included 22 HIV-1-infected patients with a CD4(+) T-cell count/mu l below 500 who were started on a HAART regimen and followed up for 9 months. After the initiation of therapy, plasma sl-selectin concentrations progressively decreased to normal ranges in the majority of our patients (P