Longitudinal interferon-β effects in multiple sclerosis: Differential regulation of IL-10 and IL-17A, while no sustained effects on IFN-γ, IL-4 or IL-13

Background: Recent studies in experimental models and in vitro indicate lowering of IL-17/Th17 as an important mechanism of interferon-beta (IFN-beta) treatment in multiple sclerosis (MS). Material and methods: In this longitudinal study of MS patients (n=25), spontaneous and myelin antigen-induced secretion of IL-4, IFN-gamma and IL-10 (ELISPOT), mitogen stimulated secretion of IL-13 and IL-17A (ELISA) and circulating cytokine levels (Luminex) were recorded at inclusion and after 1.5, 3, 6 and 12 months of IFN-beta treatment. Results: Early changes were noted for IL-4. while after one year of treatment the only recorded significant effects were a decrease in secreted IL-17A levels and an increase in IL-10 secreting cells. While IL-17A levels tended to be higher in non-responders (n=8), the decrease in IL-17A levels seemed to be more pronounced in responders (n=17) showing significantly lower IL-17A levels after one year as compared with non-responders. Conclusion: IFNI-beta. treatment seems to mainly affect IL-17/IL-10-associated pathways rather than the IFN-gamma IL-4 axis. (C) 2012 Elsevier B.V. All rights reserved.