Osteopontin concentrations are increased in cerebrospinal fluid during attacks of multiple sclerosis

Background:The cytokine osteopontin (OPN) is a potential key player in the immunopathogenesis of multiple sclerosis (MS) and a candidate biomarker for disease activity. Objective:The objective of this study was to examine concentrations of OPN in the cerebrospinal fluid (CSF) across the clinical spectrum of MS. Methods:Our research consisted of a cross-sectional study of patients from two randomized, placebo-controlled trials. Concentrations of OPN and other blood and CSF markers were determined using an enzyme-linked immunosorbent assay (ELISA). Samples were obtained from untreated patients with exacerbation of clinically isolated syndrome (CIS) (n = 25) and relapsing–remitting MS (RRMS) (n = 41) of whom 48 participated in clinical trials, randomly allocated to treatment with placebo or methylprednisolone (MP) and undergoing repeated sampling after 3 weeks. Furthermore, we obtained CSF and blood samples from patients with primary progressive MS (PPMS, n = 9), secondary progressive MS (SPMS, n = 28) and other neurological disorders (OND, n = 44), and blood samples from 24 healthy subjects. Results:OPN concentrations were significantly increased in the CSF of patients with CIS (p = 0.02) and RRMS (p