Reduced adhesion of pbmncs to endothelium in methylprednisolonetreated ms patients

Vlethylprednisolone (MP). is a synthetic steroid commonly used in tlie treatment of Multiple Sclerosis (MS) relapses. It has a wide spectrum of activities on immune cells: it might also act by preventing mononuclear cell/endothelium adhesion. We studied adhesion phenomena between cultured human umbilical vein endothelial cells (HUVECs) and PBMNCs (CD45 ⁺, CD14 ⁺) from 6 MS patients treated in vivo with MP. We also studied fluctuations in CD1 la and CD18 levels on lymphocytes and monocytes, as well as changes in serum sICAM-1 andsVCAM-1 concentrations. After treatment with MP, 1000 mg in 250 ml saline ,i.v., over 1 hour, PBMNCs adhesion to endothelium decreased at 3 hours, while it went back to baseline levels at 24 hours. The fluctuations in adhesiveness were not explained by MP-induced shifts in the number of circulating monocytes and lymphocytes. A tendency to increase in both CDlla and CD 18 on the surface of lymphocytes was detected, while an increase in serum sVCAM-1 was seen at 3 hours. This increase in sVCAM-1 could partly explain the reduction in adhesion at 3 hours, as well as the findings reported by Droogan (Droogan et al. Neurology 1996) of reduced VLA-4 density on the surface of monocytes drawn from MP-treated MS patients at 6 hours, by an in vivo mechanism of VLA-4 masquerading.