Levamisole modulates experimental autoimmune encephalomyelitis (EAE) in DArats

We investigated the influence! of an antiparasitic drug, levamisole (2,3,5, 6 - tetrahydro - 6 - phenyl-imidazo (2,1 - b) thiazole hydrochloride) with potent immunomodulatory properties on the course and development of experim ental autoimmune encephalomyelitis (EAE). EAE was induced in female Dark Ag outi (DA) rats aged two months by immunization with guinea pig spinal cord in complete Freunds adjuvant. Following immunization animals were subcutane ously treated every other day with 2.2 mg/kg levamisole. The course, develo pment and characteristics of this autoimmune process were monitored as indi rect indicators of immune system activity. Our results indicate that in EAE levamisole exerts immunosuppressive effect s when administered every other day from the moment of immunization until t he end of the disease. This application regime and dose postponed the onset of the first clinical signs, shortened the duration of the disease, abroga ted the severity of clinical symptoms and accelerated the recovery of sick animals. In the period of induction and during EAE, levamisole also decreas ed the severity of changes in the cerebral perivascular spaces. In the peri pheral blood of levamisole treated animals with induced EAE, a significant increase of CD4-CD8+ T cells was demonstrated. Furthermore, ail rats with i nduced EAE had decreased numbers of CD4+CD8- T cells in their blood. These changes were in correlation with clinical signs of EAE.