Interferon-beta response in multiple sclerosis associated with pre-treatment disability

Aim. To study pre-treatment clinical features and influence of neutralising antibodies (NABs) in clinical response to interferon-beta (IFNB). Patients and methods. We analysed clinical characteristics and NABs to IFNB in 96 multiple sclerosis patients treated with IFNB. Clinical response was established by clinical criteria: >= 1 relapse or an increase >= 0.5 or 1 point in the Expanded Disability Status Scale (EDSS) score after one year of treatment compared with the year prior to IFNB therapy. Results. Baseline clinical characteristics were similar for responders and non-responders, except for a significantly higher baseline mean EDSS score in non-responders. Time-to-first- relapse was longer and the number of patients relapse-free was higher for NAB-negative patients, but we were unable to show an association with the disability status, probably due to sample size. Conclusions. Response to IFNB was significantly associated with pre-treatment disability measured by the EDSS. The presence of NABs to IFNB presented a delayed negative effect for relapses.