Immunomodulating effects of extracorporeal photochemotherapy in rat experimental allergic encephalomyelitis

Experimental allergic encephalomyelitis (4E) is a well-established model of human multiple sclerosis that is commonly used to evaluate the possible ef fectiveness of new treatments in this disease. Extracorporeal photochemothe rapy (ECP) is an immunomodulating procedure currently used in several non-n eurological diseases that, like multiple sclerosis, are likely to be due to T-cell-mediated autoimmunity. in this study we examined the effect of ECP using the EAE paradigm in the Lewis rat. In our model, ECP induced a signif icant modulation in peripheral blood T-cell distribution, changes which are typical of EAE. Remarkably this effect was closely correlated with the cli nical and pathological results, which showed reduced severity of the diseas e in the ECP-treated EAE animals vs, the EAE alone rats. We conclude that E CP induces modifications in the immunological events that occur during the course of EAE in rats, thus giving support to the hypothesis that it could be used in the treatment of multiple sclerosis.