title: Anti-JC virus (JCV) antibody prevalence in the JCV Epidemiology in MS (JEMS) trial.
abstract: OBJECTIVE
  Progressive multifocal leukoencephalopathy (PML) is caused by reactivation of JC virus (JCV) infection due to combined host and viral factors. Anti-JCV antibodies provide a means to assess JCV exposure and stratify PML risk. The reported seroprevalence of anti-JCV antibodies varies from 39% to 91% depending on assay methodology and population studied. A two-step anti-JCV antibody assay (STRATIFY JCV™; Focus Diagnostics, Cypress, CA, USA) detected anti-JCV antibodies in approximately 55% of multiple sclerosis (MS) patients. This study describes the prevalence of anti-JCV antibodies in a large, multinational MS population.
  
  
  METHODS
  This cross-sectional epidemiology study was designed to enroll a minimum of 2000 patients with an MS diagnosis of any type, irrespective of treatment, from Europe, Canada and Australia. Anti-JCV antibody prevalence was determined by STRATIFY JCV; the effects of demographic and disease characteristics were evaluated.
  
  
  RESULTS
  A total of 7724 patients from 10 countries participated in the study. Overall anti-JCV antibody prevalence was 57.1% (95% confidence interval 56.0%-58.2%). Seroprevalence was significantly associated with increasing age, gender and country of current residence (P < 0.0001). No significant differences in anti-JCV antibody prevalence were associated with MS disease characteristics, including duration and type of MS and number and duration of MS therapies.
  
  
  CONCLUSIONS
  Overall seroprevalence of anti-JCV antibodies in MS patients from Europe, Canada and Australia was consistent with previous studies using the STRATIFY JCV assay. Anti-JCV prevalence differed significantly by age, gender and country, but no geographical pattern was evident. Disease and treatment type were not associated with differences in anti-JCV antibody status.
authors.affiliation: Biogen Idec Inc., Cambridge, MA, USA.
authors.forename: C
authors.initials: C
authors.lastname: Bozic
authors.forename: M
authors.initials: M
authors.lastname: Subramanyam
authors.forename: S
authors.initials: S
authors.lastname: Richman
authors.forename: T
authors.initials: T
authors.lastname: Plavina
authors.forename: A
authors.initials: A
authors.lastname: Zhang
authors.forename: B
authors.initials: B
authors.lastname: Ticho
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000888:Antibodies, Anti-Idiotypic / Q000097:blood*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007577:JC Virus / Q000276:immunology*; D007968:Leukoencephalopathy, Progressive Multifocal / Q000097:blood / Q000453:epidemiology* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000097:blood / Q000453:epidemiology* / Q000276:immunology; D016036:Seroepidemiologic Studies; D055815:Young Adult
chemical_list: D000888:Antibodies, Anti-Idiotypic
keywords: JC virus; anti-JCV antibody; enzyme-linked immunosorbent assay; epidemiology; multiple sclerosis; prevalence