Multiplex analysis of expression of three IFNβ-induced genes in antibody-positive MS patients

Abstract
Some interferon beta (IFNβ)–treated patients with multiple sclerosis develop antibody-mediated decreased bioactivity with resultant loss of therapeutic effect. The authors developed real-time multiplex reverse transcriptase PCR to measure expression of three IFNβ-inducible genes to directly assess IFNβ bioactivity in patients with neutralizing antibodies (NAbs). The three genes responded in tandem. Correlation of NAb level with bioactivity at low/moderate NAb levels was poor, indicating that for such patients, direct measurement of IFNβ bioactivity is most reliable.