Assessment and management of neutralizing antibodies in patients with multiple sclerosis.

The development of neutralizing antibodies (NAbs) to interferon beta (IFNbeta) products during treatment of MS poses a challenge for clinicians. Given the impact of NAbs on the clinical efficacy of IFNbetas, the immunogenicity of different IFNbeta products should be one of the factors that neurologists consider in the treatment of patients with MS. However, no clear guidelines are available for the practicing neurologist concerning which patients should be tested for NAbs and how to clinically manage patients who develop NAbs. This article summarizes the content of this supplement, discusses issues related to measuring NAbs in clinical practice, and gives practical alternatives for managing MS in patients who develop NAbs during IFNbeta therapy.