Cytokines as Biomarkers of Treatment Response to IFN β in Relapsing-Remitting Multiple Sclerosis.

Background. MS patients show a remarkable heterogeneity in their response to disease modifying treatments. Given the need for early treatment initiation and the diversity of available options, a predictive marker that indicates good or poor response to treatment is highly desirable. Objective. To find a biomarker for treatment response to IFNβ among pro- and anti-inflammatory cytokines. Materials and Methods. IFN-γ, TNF-α, IL-2, IL-4, IL-6, IL-10, IL-17A, and TGF-β1 levels were measured in serum and CSF of 43 patients with RR-MS who were followed up for a mean period of 5.3 years. Thirty-five patients received IFNβ treatment and were divided into good responders (GR, n = 19) and poor responders (PR, n = 16). The remaining 8 patients showed a very favorable outcome and remained untreated (noRx). Results. GR had significantly higher serum baseline levels of IL-17A than PR and significantly higher serum levels of IL-17A, IFN-γ, TNF-α, and IL-2 than noRx. PR had significantly higher IFN-γ serum levels than noRx. No significant differences were observed in serum levels of IL-6, IL-4, IL-10, and TGF-β1 or the levels of all cytokines measured in CSF between the 3 groups of patients. Conclusions. Baseline serum levels of IL-17A can be used as a biomarker of IFNβ treatment response.