Background and purpose: 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.
Keywords: JC virus; anti-JCV antibody; enzyme-linked immunosorbent assay; epidemiology; multiple sclerosis; prevalence.
© 2013 Biogen Idec Inc. European Journal of Neurology © 2013 EFNS.