title: MS arising during Tocilizumab therapy for rheumatoid arthritis.
abstract: BACKGROUND
  Interleukin-6 (IL6) blockage is a treatment strategy used in many inflammatory conditions. Trials in Neuromyelitis Optica Spectrum Disorder (NMOSD) are ongoing. Secondary auto-immunity affecting the central nervous system (CNS) is well described with some biologic agents, mainly tumor necrosis factor (TNF)-alpha inhibitors. These treatments can also aggravate patients with known multiple sclerosis (MS).
  
  
  OBJECTIVE
  To describe a case of a patient who developed MS using another biologic, IL6 receptor antibody Tocilizumab.
  
  
  RESULTS
  A 48-year-old woman developed MS while on treatment with Tocilizumab for Rheumatoid Arthritis (RA). This is the first published report of this association. It has obvious implications for NMOSD patients receiving anti-IL6 therapy. Development of new white matter lesions suggestive of MS in a patient treated with anti-IL6 therapy might represent an important complication of therapy.
  
  
  CONCLUSIONS
  This case illustrates that Tocilizumab might cause secondary auto-immunity in CNS. It is important to be aware of this potential complication as anti-IL6 therapy might become an option for the treatment NMOSD.
authors.affiliation: Hôpital de l'Enfant-Jésus du CHU de Québec, Département des sciences neurologiques, Université Laval/UBC MS Clinic, Department of Neurology, UBC, Vancouver, BC, Canada philippe.beauchemin.1@ulaval.ca.
authors.forename: Philippe
authors.initials: P
authors.lastname: Beauchemin
authors.affiliation: UBC MS Clinic, Department of Neurology, UBC, Vancouver, BC, Canada.
authors.forename: Robert
authors.initials: R
authors.lastname: Carruthers
mesh_terms: D061067:Antibodies, Monoclonal, Humanized / Q000009:adverse effects* / Q000276:immunology; D018501:Antirheumatic Agents / Q000009:adverse effects* / Q000276:immunology; D001172:Arthritis, Rheumatoid / Q000150:complications / Q000188:drug therapy*; D015551:Autoimmunity / Q000276:immunology; D005260:Female; D006801:Humans; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000139:chemically induced* / Q000276:immunology; D019947:Receptors, Interleukin-6 / Q000037:antagonists & inhibitors* / Q000276:immunology
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D018501:Antirheumatic Agents; D019947:Receptors, Interleukin-6; C502936:tocilizumab
keywords: CNS demyelinating disease; Devic’s syndrome; MRI; Tocilizumab; autoimmune diseases; multiple sclerosis