Interleukin-12 is detectable in sera of patients with multiple sclerosis - association with chronic progressive disease course?

Multiple sclerosis (MS) is widely accepted as a systemic T-cell-mediated autoimmune disease with a T-helper type-1 (TH-1) profile of cytokine production, We addressed the question whether interleukin-12 (IL-12), as a central mediator of TH-1-cell activities, is detectable in sera of MS patients, and if there is any association with disease activity. We analysed 171 sera of patients with MS and meningitis, and healthy controls. IL-12 p40 protein was detectable at low levels in MS patients (median 43 pg/ml) and controls (median 49 pg/ml). Analysing different disease courses and activities, a significant elevation in stable primary progressive MS cases compared with controls (median 66 pg/ml) was found. IL-12 p40 protein was not detectable in cerebrospinal fluid probes of 10 patients. We conclude that the function of IL-12 in MS depends on expression and degradation of the different proteins. These could act proinflammatory as web as limiting the disease process, fur J Neurol 6:591-596 (C) 1999 Lippincott Williams & Wilkins.