Serum Anti-JCV antibody status in Western Australian patients with multiple sclerosis

Background: The presence of anti-JCV antibodies is one of the risk factors for the development of progressive multifocal leukoencephalopathy (PML) among patients with multiple sclerosis (MS) treated with natalizumab or other disease modifying therapies (DMTs). Objective: The aim of this study was to evaluate the anti-JCV antibody status and index among Western Australian MS patients before and during treatment with natalizumab. Methods: We performed a cross-sectional study in 221 Western Australian MS patients to evaluate their JCV status using the STRATIFY JCVTM Test, a two-step enzyme-linked immunosorbent assay (ELISA; Unilabs, Copenhagen, Denmark). Associations with demographic and clinical characteristics were also investigated. Results: From a total of 221 patients included, 49% (n=108) were seropositive for anti-JCV antibodies, among which 53% (n=57) had an anti-JCV index ⩾1.5. Among 221 subjects analysed, 111 (50%) underwent repeated testing and within this group 15 (14%) seroconverted. All patients had relapsing-remitting disease course. Patients with JCV positive serostatus were of older age (42 vs 40 years), however this difference was not statistically significant. From the total Western Australian MS population investigated 47% of females and 54% of males were anti-JCV antibody seropositive. Conclusions: Anti-JCV antibody prevalence in our population is lower than in other reported cohorts, however over 50% of JCV seropositive patients had high JCV antibody index