title: Anti-JCV antibody prevalence in a French cohort of MS patients under natalizumab therapy.
abstract: To measure the prevalence of JCV-specific antibodies in a French cohort of MS patients treated with natalizumab and to identify risk factor(s) of JCV seropositivity. Progressive multifocal leukoencephalopathy (PML) risk may be stratified by anti-JCV antibody status, duration of natalizumab therapy (≥24 months) and prior exposure to immunosuppressive (IS) drugs. No data are available in France on the prevalence of anti-JCV antibodies and distribution of PML risk factors in patients treated with natalizumab. Sera of 361 patients under natalizumab therapy in two MS centers were analyzed using a previously validated ELISA test. We studied different characteristics: demographic, ethnic, radiological, clinical, prior use of immunomodulatory (IM) or IS drugs and natalizumab exposure duration. The JCV seropositivity rate was 51 % for the whole cohort. Mean natalizumab exposure duration was 27.27 months ± 15.57 (mean ± SD), and prior use of IS drugs was observed in 15.24 % of patients. Twenty-three patients (6.4 %) presented the three PML risk factors. By multivariate analysis, presence of anti-JCV antibodies was significantly linked to age, North African origin and natalizumab exposure duration. Anti-JCV antibody prevalence was similar to previously published data. Anti-JCV antibody status was linked to age. We also suggested that anti-JCV antibody status could be linked to natalizumab exposure duration and ethnic characteristics.
authors.affiliation: Department of Neurology, University Hospital of Lille, Université Lille Nord de France, Hôpital Roger Salengro, 1 rue Emile Laine, 59037, Lille Cedex, France. olivier.outteryck@chru-lille.fr
authors.forename: Olivier
authors.initials: O
authors.lastname: Outteryck
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Ongagna
authors.forename: Alain
authors.initials: A
authors.lastname: Duhamel
authors.forename: Hélène
authors.initials: H
authors.lastname: Zéphir
authors.forename: Nicolas
authors.initials: N
authors.lastname: Collongues
authors.forename: Arnaud
authors.initials: A
authors.lastname: Lacour
authors.forename: Marie-Céline
authors.initials: MC
authors.lastname: Fleury
authors.forename: Anne-Sophie
authors.initials: AS
authors.lastname: Berteloot
authors.forename: Frédéric
authors.initials: F
authors.lastname: Blanc
authors.forename: Marianne
authors.initials: M
authors.lastname: Giroux
authors.forename: Patrick
authors.initials: P
authors.lastname: Vermersch
authors.forename: Jérôme
authors.initials: J
authors.lastname: de Sèze
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D061067:Antibodies, Monoclonal, Humanized / Q000008:administration & dosage / Q000009:adverse effects*; D000914:Antibodies, Viral / Q000096:biosynthesis*; D015331:Cohort Studies; D005260:Female; D005602:France / Q000453:epidemiology; D006801:Humans; D007577:JC Virus / Q000276:immunology*; D007968:Leukoencephalopathy, Progressive Multifocal / Q000453:epidemiology* / Q000276:immunology / Q000821:virology; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000188:drug therapy / Q000453:epidemiology* / Q000276:immunology*; D000069442:Natalizumab; D015995:Prevalence; D055815:Young Adult
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D000914:Antibodies, Viral; D000069442:Natalizumab