IL-18 in patients with multiple sclerosis.

IL-18 is a cytokine which plays an important role in Th-1 response through its ability to induce IFN-gamma production in T cells and NK cells. The purpose of the study was to measure IL-18 levels in serum and CSF of 21 patients with the relapsing-remitting form of MS, 9 with active gadolinium enhancing lesions in MR I and 12 without enhancing lesions, and to compare results with control group consisting of 11 patients with diagnosis of neurasthenia and tension headache. IL-18 concentration in the CSF and sera was measured by ELISA. We found a highly significant increase of both IL-18 CSF and serum levels in MS patients in comparison with the control group. In patients with active MRI lesions the levels of IL-18 in CSF and serum were significantly higher in comparison with the levels found in patients without enhancing lesions. The results suggest involvement of IL-18 in immunopathogenesis of MS especially in the active stages of the disease.