title: Anti-John Cunnigham virus antibody prevalence in multiple sclerosis patients: baseline results of STRATIFY-1.
abstract: OBJECTIVE
  A study was undertaken to define the prevalence of anti-JC virus (JCV) antibodies in multiple sclerosis (MS) patients and to evaluate the analytical false-negative rate of a 2-step anti-JC virus antibody assay.
  
  
  METHODS
  STRATIFY-1 is an ongoing, longitudinal, observational study of relapsing MS patients in the United States who are being treated or considering treatment with natalizumab. Baseline serum and plasma samples were collected for anti-JC virus antibody detection using an analytically validated, 2-step, virus-like particle-based enzyme-linked immunosorbent assay. Urine was collected for JC virus DNA detection.
  
  
  RESULTS
  At baseline (n = 1,096), overall anti-JC virus antibody prevalence was 56.0% (95% confidence interval [CI], 53.0-59.0) in STRATIFY-1 patients, with an assay false-negative rate of 2.7% (95% CI, 0.9-6.2). Prevalence was significantly lower in females (53.4%; 95% CI, 49.9-56.8) than males (64.3%; 95% CI, 58.2-70.0) and increased with age, p = 0.0019 and p = 0.0001, respectively. Prevalence was similar in patients regardless of natalizumab exposure or prior immunosuppressant use, p = 0.9709 and p = 0.6632, respectively. STRATIFY-1 results were generally consistent with those observed in another large North American cohort, TYGRIS-US (n = 1,480).
  
  
  CONCLUSIONS
  Baseline results from STRATIFY-1 are consistent with other studies utilizing this assay that demonstrate a 50 to 60% prevalence of anti-JC virus antibodies, a low false-negative rate, and an association of increasing age and male gender with increasing anti-JC virus antibody prevalence. Neither natalizumab exposure nor prior immunosuppressant use appear to affect prevalence. Longitudinal data from STRATIFY-1 will confirm the stability of anti-JC virus antibody prevalence over time.
authors.affiliation: Biogen Idec, Inc., Cambridge, MA 02142, USA. Carmen.bozic@biogenidec.com
authors.forename: Carmen
authors.initials: C
authors.lastname: Bozic
authors.forename: Sandra
authors.initials: S
authors.lastname: Richman
authors.forename: Tatiana
authors.initials: T
authors.lastname: Plavina
authors.forename: Amy
authors.initials: A
authors.lastname: Natarajan
authors.forename: James V
authors.initials: JV
authors.lastname: Scanlon
authors.forename: Meena
authors.initials: M
authors.lastname: Subramanyam
authors.forename: Alfred
authors.initials: A
authors.lastname: Sandrock
authors.forename: Gary
authors.initials: G
authors.lastname: Bloomgren
mesh_terms: D000328:Adult; D000367:Age Factors; D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use; D000914:Antibodies, Viral / Q000097:blood*; D004279:DNA, Viral / Q000652:urine*; D005260:Female; D006801:Humans; D007577:JC Virus / Q000235:genetics / Q000276:immunology*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000097:blood / Q000188:drug therapy / Q000276:immunology* / Q000652:urine; D000069442:Natalizumab; D015995:Prevalence; D014481:United States / Q000453:epidemiology
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D000914:Antibodies, Viral; D004279:DNA, Viral; D000069442:Natalizumab