IN-VITRO INTERCELLULAR-ADHESION MOLECULE-1 EXPRESSION ON BRAIN ENDOTHELIAL-CELLS IN MULTIPLE-SCLEROSIS

To investigate the origin of intercellular adhesion molecule-1 (ICAM-1 ) and its expression on,brain endothelial cells, we studied the expres sion in vitro of ICAM-1 on human brain endothelial cells after incubat ion of T cells from patients with multiple sclerosis (MS) using a hist ochemical technique and flow cytometry. We determined soluble forms of ICAM-1 (sICAM-1) in the supernatants after mixtures of brain endothel ial cells and T cells from patients with MS using an enzyme-liked immu nosorbent assay. Flow cytometric analysis showed that a number of ICAM -1-positive cells were significantly increased after incubation of bra in endothelial cells with T cells from patients with acute relapsing M S during an exacerbation as compared with those of controls (P < 0.01) . Patients with acute relapsing MS during an exacerbation and chronic progressive MS exhibited higher levels of ICAM-1 in the supernatants o f mixtures with brain endothelial cells and lymphocytes than those of controls (P < 0.001 and P < 0.01, respectively). These results suggest that lymphocytes from patients with acute relapsing MS during an exac erbation lead to an increased expression of ICAM-1 on the brain endoth elial cells and add to evidence involving this adhesion molecule in th e pathogenesis of MS.