High-dose methylprednisolone reduces cytokine-induced adhesion molecules on human brain endothelium

Objective: We investigated the in vitro effects of low- and high-dose methylprednisolone (MP) on the cytokine-induced expression of HLA-DR, ICAM-1 and VCAM-1 on human brain microvessel endothelial cells (HBMECs). Methods: Brain endothelium was obtained from microvessels included in the apparently normal white matter of surgical specimens of nine patients. Cells were stained with monoclonal antibodies anti-HLA-DR, anti-ICAM-1 and anti-VCAM-1 and analysed by flow cytometry as fluorescence histograms. The mean fluorescence intensity (MFI) of HBMECs treated with different stimuli was calculated. Results: γ-IFN-induced HLA-DR was down-regulated in a dose-dependent manner by MP. High-dose MP reduced the TNF-α-induced ICAM-1 and VCAM-1 expression. Conclusions: The down-regulation of adhesion molecules on cerebral endothelial cells could decrease mononuclear cell transmigration through the blood brain barrier and consequently the perivascular infiltrates. The results add support to the rationale for high-dose MP treatment in multiple sclerosis relapses.