Assessment of the sensitivity of anti-interferon binding and neutralizing antibody assays in patients with relapsing -remitting multiple sclerosis under interferon- beta treatment- A comparative study

Interferon beta (IFNβ) is a first line disease-modifying treatment for the management of relapsing-remitting multiple sclerosis. IFNβ preparations may elicit an immune response reflected by the development of binding- (Babs) and neutralizing- antibodies (Nabs). The detrimental effect of Nabs is depicted by attenuation of treatment effect and as a result the deterioration of clinical and radiological parameters. The incidence and titers of Nabs vary by the preparation of IFNβ used, dose, frequency and route of administration, treatment duration and type of assay being used. In this study we aimed to assess the sensitivity of the binding and the neutralizing assays in patients with relapsing-remitting multiple sclerosis under treatment with interferon-beta. The assessment of the results suggests that Western blot assay is more sensitive than ELISA for the detection of binding antibodies. The evaluation of CPE and Real-time-PCR results indicates that they possess similar sensitivity. However, CPE assay remains the gold standard method for the detection of neutralizing antibodies, based on the World Health Organization. Our results indicate that interlaboratory studies are needed for a commonly accepted assay that might reflect a reliable and cost-effective procedure for the Babs and Nabs detection in MS patients under IFNβ treatment