Interferon-gamma-inducing factor (IL-18) and interferon-gamma in inflammatory CNS diseases

Objective: To examine the intrathecal production of a newly identified cyto kine, interferon-gamma-inducing factor (IL-18), together with interferon-ga mma itself, in inflammatory diseases of the CNS (i.e., bacterial meningitis , viral meningoencephalitis, and MS). Results: IL-18 concentrations in CSF were significantly increased in bacterial meningitis and tended toward incr eased levels in viral meningoencephalitis. In contrast, IL-18 was detectabl e only in a few patients with MS and healthy controls. Interestingly, inter feron-gamma was significantly increased selectively in CSF of patients with viral meningoencephalitis. Conclusion: The observation of an intrathecal r elease of IL-18 in patients with meningitis argues for a pathophysiologic r ole of this novel cytokine in immunity against invading microorganisms the CNS.