Evaluation of serum levels of chemokines during interferon-β treatment in multiple sclerosis patients: A 1-year, observational cohort study

Background: The molecules that provide access to activated T cells in the CNS, including chemokines, have been considered to be a crucial step in the pathogenesis of multiple sclerosis (MS). Aims: In this study, we investigated serial serum chemokine levels in patients with relapsing-remitting MS over 1 year and the association of these chemokine levels with treatment regimens, lesions on MRI and patients' characteristics. Methods: Serum CXCL9, CXCL10, CCL2, CCL4 and CCL5 levels were evaluated using ELISA every 2 months for a year in 28 healthy controls and 28MS patients during their treatment with interferon (IFN)-β. Patients underwent MRI and were evaluated using the Expanded Disability Status Scale (EDSS) at the first and final evaluations. Results: CXCL10 serum levels were higher in MS patients compared with controls, were positively correlated with T2 lesions on MRI and were slightly increased during relapses. Treatment with IFNβ-1a or IFNb-1β was associated with increased CXCL10 levels when evaluated more than 36 hours after subcutaneous injection. The CXCL9 levels were higher afterMS relapse. There was significant variability in CCL4 and CCL5 levels in the serial evaluations, associated with gender and treatment. CCL2 levels were higher in treated MS patients than healthy controls, particularly among those patients with a stable form of the disease. Conclusion: Serum is a feasible resource for searching for an immunological marker in MS. Peripheral chemokine levels correlated in different ways with IFNb therapy and with disease and patient characteristics.