Clinical Parameters to Predict Response to Interferon in Relapsing Multiple Sclerosis

Abstract

Background: To identify clinical parameters of response to β-interferon (IFN-β) in relapsing-remitting multiple sclerosis (RRMS) from an East France cohort. Methods: Data from 2,645 patients, identified by Burgundy and Lorraine multiple sclerosis (MS) networks, were computerized by a neurologist using the European Database for MS software. Patient inclusion criteria were: clinically or laboratory-supported definite RRMS according to Poser’s diagnostic criteria and treatment with IFN-β for at least 6 months. Four criteria were chosen to predict a response to IFN-β. The first criterion was any patient who had a lower annualized relapse rate under IFN-β therapy than during the year preceding treatment; the second criterion was a lower relapse rate than during the 2 years preceding treatment. The third was any patient free of relapse during the first 2 years of IFN-β therapy. The last criterion concerned the variation in the degree of disability measured by the Disability Status Scale during the first year of treatment. Multivariate logistic regression analyses were performed. Results: 751 RRMS cases were included. A higher relapse rate in the year preceding IFN-β onset, an older age at MS onset and having a polysymptomatic onset of MS were significantly associated with a response for the first criterion. With the 3 other criteria, no parameter predicting response was identified. Conclusion: Only the relapse rate in the year before initiation of IFN-β treatment appears to be able to predict response to treatment but not the one of 2 years before.