Background: Interleukin-15 (IL-15) is a proinflammatory cytokine. RANTES is a member of the beta chemokines subfamily with strong chemoattractant activity for T lymphocytes and monocytes.

Methods: We measured by enzyme-like immunosorbent assay (ELISA) serum levels of IL-15 and RANTES in 24 patients with MS in relapse, 27 patients with stable MS and 21 healthy subjects. Serum levels of IL-15 and RANTES were also measured before, 5 days and 1 month after onset of treatment with methylprednisolone i.v.

Results: IL-15 serum levels were higher in patients with relapse compared with patients in stable stage of the disease and healthy subjects (p=0.001 and p=0.008 respectively). RANTES serum levels were increased in patients with relapse and stable disease as compared to healthy subjects (p=0.01). IL-15 and RANTES levels were not decreased after treatment with corticosteroids.

Conclusions: Our findings suggest a possible role of IL-15 and RANTES in MS. Treatment with methylprednisolone in relapse had no effect on serum IL-15 and RANTES levels.