Neutralizing antibody (NAb) assays in multiple sclerosis patients receiving interferon-β therapy
Interferon-β (IFN-β), a type I cytokine, is first-line therapy for relapsing-remitting multiple sclerosis (RRMS), a progressive neurological disease that can result in severe disability. As with all protein-based therapies, treatment with IFN-β can result in the development of neutralizing antibodies (NAbs), which has been shown to reduce the efficacy of the regimen. Recently, assays that evaluate patients for the presence of NAbs have received increased attention as a potentially valuable diagnostic tool in assessing the therapeutic effect of a chosen IFN-β regimen. However, despite the clinical desire to consistently monitor NAb levels in these patients, no standardized NAb assay has yet been identified. A lack of method standardization can lead to confusion when comparing NAb results over time and reduces the overall diagnostic value of assessing NAb status. This review will offer a summary of current NAb diagnostic methods and the factors that limit their consistency and practicality in the clinical setting. Alternatives to current methods for assessing NAb status will also be briefly discussed. Multiple Sclerosis 2007; 13: S44—S48. http://msj.sagepub.com