JC-virus seroconversion in multiple sclerosis patients receiving natalizumab.
The objectives of this study were to evaluate the rate of JC virus (JCV) seroconversion/seroreversion in a French cohort of multiple sclerosis (MS) patients receiving natalizumab (NTZ), describe the characteristics of this population, identify risk factors for JCV seropositivity and analyse the additional value of quantitative JCV serology results in this context.



MS patients from two French MS centres, whose JCV serological status in 2011 while receiving NTZ was known (n=357; first-generation enzyme-linked immunosorbent assay (ELISA) test (Gen1)), were proposed for inclusion in this study. We evaluated the rate of JCV seroconversion over a period of one year with a second-generation ELISA test (Gen2; n=303) and analysed the quantitative results. Multivariate analysis was performed to identify risk factors for JCV seropositivity.



Among the patients with Gen2 JCV serology (n=303) that had been JCV-seronegative one year before (n=165), the rate of JCV seroconversion was 26.67% (44/165). We observed a higher proportion of anti-JCV antibody seroconverters (14.5%) than expected (≤3%) but also increasing index values of anti-JCV antibody over time.



Our data suggest that JCV reactivation occurs during NTZ therapy and leads to an increase in the anti-JCV antibodies titre, thus making them more easily detectable by the second-generation ELISA test.
Department of Neurology, Université Lille Nord de France (EA2686), France olivier.outteryck@chru-lille.fr.
Olivier
O
Outteryck
Department of Neurology, Université Lille Nord de France (EA2686), France.
Hélène
H
Zéphir
Department of Biostatistics, Université Lille Nord de France (CERIM EA2694), France.
Julia
J
Salleron
Department of Neurology, University Hospital of Strasbourg, France.
Jean-Claude
JC
Ongagna
Department of Neurology, Université Lille Nord de France (EA2686), France.
Ana
A
Etxeberria
Department of Neurology, University Hospital of Strasbourg, France.
Nicolas
N
Collongues
Department of Neurology, Université Lille Nord de France (EA2686), France.
Arnaud
A
Lacour
Department of Neurology, University Hospital of Strasbourg, France.
Marie-Céline
MC
Fleury
Department of Neurology, University Hospital of Strasbourg, France.
Frédéric
F
Blanc
Department of Neurology, Université Lille Nord de France (EA2686), France.
Marianne
M
Giroux
Department of Neurology, University Hospital of Strasbourg, France.
Jérôme
J
de Seze
Department of Neurology, Université Lille Nord de France (EA2686), France.
Patrick
P
Vermersch
D000328:Adult; D000914:Antibodies, Viral / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005602:France; D006801:Humans; D016867:Immunocompromised Host; D007166:Immunosuppressive Agents / Q000009:adverse effects*; D007577:JC Virus / Q000276:immunology* / Q000472:pathogenicity; D007968:Leukoencephalopathy, Progressive Multifocal / Q000175:diagnosis / Q000276:immunology* / Q000821:virology; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000175:diagnosis / Q000188:drug therapy* / Q000276:immunology; D000069442:Natalizumab / Q000009:adverse effects*; D009894:Opportunistic Infections / Q000175:diagnosis / Q000276:immunology* / Q000821:virology; D012307:Risk Factors; D000069078:Seroconversion; D012698:Serologic Tests; D013997:Time Factors
D000914:Antibodies, Viral; D015415:Biomarkers; D007166:Immunosuppressive Agents; D000069442:Natalizumab
JC virus; Multiple sclerosis; natalizumab; progressive multiple leukoencephalopathy; quantitative results