title: Transfer of myxovirus-protein-A mRNA assay for interferon-β bioactivity measurement in multiple sclerosis patients to routine laboratory practice. A 4-year experience.
abstract: BACKGROUND
  As new biomarkers are validated and their significance in the natural history of specific diseases is established, these technologies can be rapidly transferred to clinical application. Since it has been shown that a single post-interferon-β (IFNβ) injection measurement of myxovirus-protein-A (MxA) mRNA correlates with IFNβ bioactivity in IFNβ treated patients with multiple sclerosis (MS), we had previously validated an assay for its quantification.
  
  
  METHODS
  We introduced a real-time PCR relative quantification assay into routine clinical practice and measured MxA mRNA expression in 564 samples from 500 unselected IFNβ treated MS patients over a 4-year period.
  
  
  RESULTS
  We confirmed that the assay is reproducible over time, and found that the percentage of patients lacking MxA mRNA induction is comparable to that described in studies performed worldwide after patient selection by pre-screening for the presence of anti-IFNβ antibodies.
  
  
  CONCLUSIONS
  In view of its simplicity and reproducibility, this MxA assay is an alternative to anti-IFNβ antibody determinations for use in routine clinical practice.
authors.affiliation: Laboratory of Biotechnology, Department of Diagnostics, Spedali Civili, Brescia, Italy.
authors.forename: Cinzia
authors.initials: C
authors.lastname: Zanotti
authors.forename: Claudia
authors.initials: C
authors.lastname: Ghidini
authors.forename: Cinzia
authors.initials: C
authors.lastname: Lamorgese
authors.forename: Luigi
authors.initials: L
authors.lastname: Caimi
authors.forename: Ruggero
authors.initials: R
authors.lastname: Capra
authors.forename: Luisa
authors.initials: L
authors.lastname: Imberti
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D016899:Interferon-beta / Q000378:metabolism* / Q000627:therapeutic use; D007753:Laboratories; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000175:diagnosis / Q000188:drug therapy / Q000378:metabolism*; D009975:Orthomyxoviridae; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013205:Staphylococcal Protein A / Q000235:genetics*; D013997:Time Factors; D016896:Treatment Outcome; D014764:Viral Proteins / Q000235:genetics*
chemical_list: D012333:RNA, Messenger; D013205:Staphylococcal Protein A; D014764:Viral Proteins; D016899:Interferon-beta