MRI activity and neutralising antibody as predictors of response to interferon beta treatment in multiple sclerosis

Objective: To prospectively validate MRI activity and neutralising anti-interferon antibody (NAb) during the first 6 months of interferon β treatment as response indicators in multiple sclerosis (MS). Methods: Patients with relapsing–remitting MS were followed during the first 2 years of treatment. Neurological assessments were performed every 3 months or when a relapse was suspected. MRI scans performed at baseline and at 3, 4, 5 and 6 months after the start of treatment were assessed centrally for disease activity: new T2 or gadolinium enhancing T1 lesions. NAb were assessed using the MxA protein assay; positivity was defined as two consecutive titres ⩾20 NU/ml. We evaluated the predictiv…