MxA mRNA expression as a biomarker of interferon beta response in multiple sclerosis patients.

Myxovirus resistance protein A (MxA) is a molecule induced after interferon-β injection. The aim of this study was to investigate whether MxA determination one year after starting interferon-β can predict treatment response in multiple sclerosis patients. MxA mRNA expression was evaluated in blood samples obtained at baseline and at month 12. Clinical variables were prospectively recorded. A threshold of 5 was defined to establish MxA induction. On survival analysis, time to the next relapse and to EDSS progression were significantly longer in patients showing MxA induction, suggesting that MxA induction after one year may be useful to identify interferon-β responders.