title: Influenza vaccination increases anti-JC virus antibody levels during treatment with Natalizumab: Case report.
abstract: BACKGROUND
  Natalizumab (NTZ) is an effective therapy for multiple sclerosis (MS). A common concern related to NTZ therapy is the risk of developing progressive multifocal leukoencephalopathy (PML).
  
  
  METHODS
  A patient that after seven years on NTZ therapy, testing on every 3 months repeated evaluations negative for anti-JCV status became positive (>3 units) 4 weeks after receiving influenza vaccine. Despite continuous therapy on NTZ for additional 2 years her anti-JCV index progressively declined to a level 0.6 units
  
  
  CONCLUSIONS
  Our case raises the consideration to include vaccination as a factor that can affect JCV index and should be tallied during NTZ treatment mitigation.
authors.affiliation: Department of Neurology, Hospital General Universitario Gregorio Marañon, C/ Doctor Esquerdo, 46, 28007 Madrid, Spain. Electronic address: jahirmiranda@yahoo.com.co.
authors.forename: Jahir Andres
authors.initials: JA
authors.lastname: Miranda Acuña
authors.affiliation: University at Buffalo, Jacobs School of Medicine and Biomedical Sciences, United States; Jacobs MS Center for Treatment and Research, United States; Jacobs Pediatric MS Center of Excellence, United States; New York State MS Consortium UBMD Neurology, United States.
authors.forename: Bianca
authors.initials: B
authors.lastname: Weinstock-Guttman
mesh_terms: D000328:Adult; D000914:Antibodies, Viral / Q000097:blood*; D005260:Female; D006801:Humans; D007155:Immunologic Factors / Q000009:adverse effects* / Q000627:therapeutic use; D007252:Influenza Vaccines / Q000009:adverse effects*; D007577:JC Virus / Q000276:immunology*; D007968:Leukoencephalopathy, Progressive Multifocal / Q000209:etiology / Q000276:immunology; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000150:complications / Q000188:drug therapy* / Q000276:immunology; D000069442:Natalizumab / Q000009:adverse effects* / Q000627:therapeutic use; D014611:Vaccination
chemical_list: D000914:Antibodies, Viral; D007155:Immunologic Factors; D007252:Influenza Vaccines; D000069442:Natalizumab
keywords: Influenza vaccination; JC virus; Natalizumab; Progressive multifocal leukoencephalopathy