Increased Levels of Serum Intercellular Adhesion Molecule 1 in HIV Infection Are Related to Immune Activation

Abstract

Cytopathic mechanisms in human immunodeficiency virus type 1 (HIV-1) infection involve syncytia formation, and it appears likely that increased expression of intracellular adhesion molecule 1 (ICAM-1) is involved in these cell adhesion phenomena. In this study, we determined serum concentrations of soluble ICAM-1 (sICAM-1) in 27 patients with HIV-1 infection and a control group. In addition, we compared sICAM-1 values to CD4+ T-cell counts, serum β₂-microglobulin (β₂M) and serum neopterin levels. HIV-l-infected patients had significantly higher sICAM-1, β₂M and neopterin levels than controls. The subgroup of patients with Walter-Reed stages 3-6 had only slightly higher sICAM-1 concentrations in serum than Walter-Reed stages 1-2. The sICAM-1 concentrations in HIV-1-seropositive patients correlated with β₂M levels but neither with neopterin nor with CD4+ T-cell counts. Increased sICAM-1 may result from immune activation, which enhances the expression of ICAM-1 in patients with HIV-1 infection.