Stability and predictive value of anti-JCV antibody index in multiple sclerosis: A 6-year longitudinal study.
BACKGROUND
Risk of natalizumab-related progressive multifocal leukoencephalopathy is associated with the presence of anti-JC-virus (JCV) antibodies.


OBJECTIVE
To investigate the longitudinal evolution of anti-JCV antibody index and to determine the predictive value of baseline anti-JCV antibody index for long-term stability of anti-JCV antibody status.


METHODS
MS patients from the MS centre of Medical University of Innsbruck, who had serum sampling for a time period of 4-6 years at intervals of 6±3 months, were included in this retrospective, longitudinal study. Anti-JCV antibody serological status and index were determined by 2-step second-generation anti-JCV antibody assay.


RESULTS
154 patients were included in this study. Median follow-up time was 63.7 months, with median 11 samples available per patient. At baseline, 111 (72.1%) patients were anti-JCV antibody positive. Baseline anti-JCV antibody index significantly correlated with age (R = 0.22, p = 0.005); there was no difference with respect to sex, disease duration or previously used disease-modifying treatment. During follow-up anti-JCV antibody status changed from negative to positive or vice versa in 17% of patients. In seronegative patients at baseline, baseline anti-JCV antibody index was significantly lower in those remaining seronegative at follow-up compared to those converting to seropositivity (median 0.16 vs. 0.24, p = 0.002). In seropositive patients at baseline, index was higher in those remaining seropositive compared to those reverting to seronegativity (2.6 vs. 0.45, p<10-7). Baseline anti-JCV antibody index >0.90 predicted stable positive serostatus (sensitivity 88.7%, specificity 96.5%) and <0.20 stable negative serostatus (sensitivity 61.3%, specificity 97.6%).


CONCLUSIONS
Anti-JCV antibody index remained relatively stable over 6-year follow-up with annual serostatus change of ~3%. Baseline anti-JCV antibody index predicted stable negative and stable positive JCV serostatus.
Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria.
Harald
http://orcid.org/0000-0002-2833-6337
H
Hegen
Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria.
Michael
M
Auer
Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria.
Gabriel
G
Bsteh
Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria.
Franziska
F
Di Pauli
Biogen, Cambridge, Massachusetts, United States of America.
Tatiana
T
Plavina
Department of Statistics, Faculty of Economics and Statistics, University of Innsbruck, Innsbruck, Austria.
Janette
J
Walde
Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria.
Florian
F
Deisenhammer
Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria.
Thomas
T
Berger
D000293:Adolescent; D000328:Adult; D000368:Aged; D000914:Antibodies, Viral / Q000097:blood* / Q000187:drug effects; D018450:Disease Progression; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007155:Immunologic Factors / Q000627:therapeutic use; D007577:JC Virus / Q000276:immunology*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000097:blood* / Q000188:drug therapy / Q000276:immunology* / Q000821:virology; D000069442:Natalizumab / Q000627:therapeutic use; D011379:Prognosis; D012372:ROC Curve; D012189:Retrospective Studies; D000069078:Seroconversion / Q000187:drug effects; D055815:Young Adult
D000914:Antibodies, Viral; D007155:Immunologic Factors; D000069442:Natalizumab