RT Journal Article SR Electronic T1 Neutralizing antibodies to interferon JF Neurology JO Neurology FD Lippincott Williams & Wilkins SP S16 OP S22 DO 10.1212/01.wnl.0000277705.63813.84 VO 68 IS 24 suppl 4 A1 Avertano Noronha YR 2007 UL http://n.neurology.org/content/68/24_suppl_4/S16.abstract AB The impact of neutralizing antibodies (NAbs) to interferon-beta (IFN-β) on clinical and imaging parameters in multiple sclerosis (MS) is reviewed. An effect on relapse rates and imaging parameters was noted in patients who tested positive for NAbs, but disability measures were unaffected or showed a trend toward improvement. Patients who developed NAbs during treatment with IFN-β1a tended to remain NAb+, whereas those who developed NAbs during IFN-β1b treatment tended to revert to NAb− over time. NAbs were more persistent in patients with high titers. The prevalence of NAbs was lower when a higher-than-standard dose of IFN-β1b was given in a dose-comparison study. The prevalence of NAbs in an observational study of MS patients who exhibited suboptimal treatment responses to IFN-β1b was significantly less than the reported prevalence in clinical trials. An immunoregulatory effect of immune complexes of cytokine and anticytokine antibodies is proposed to account for the variability of clinical responses seen in patients who develop NAbs to IFN-β1b.