title: Occurrence of demyelinating diseases after anti-TNFα treatment of inflammatory bowel disease: A Danish Crohn Colitis Database study.
abstract: BACKGROUND
  It remains uncertain whether patients with inflammatory bowel disease (IBD) are at increased risk of developing demyelinating diseases, primarily multiple sclerosis (MS) and whether the introduction of biologic drugs in the treatment of IBD has altered this risk.
  
  
  OBJECTIVE
  The aim was to conduct a systematic review of literature on occurrence of demyelinating diseases in IBD patients, to assess a national Danish anti-TNFα treated IBD cohort in order to search for and describe the IBD cases with coexisting demyelinating diseases, and finally to compare the occurrence of MS in the anti-TNFα cohort to the occurrence in the general Danish population. A systematic MEDLINE literature search was conducted, medical files were scrutinized for identification and description of cohort patients with demyelinating disease, and risk of MS was calculated as a standardized morbidity ratio (SMR) using general population data for comparison.
  
  
  RESULTS
  Four studies on the risk of demyelinating diseases in IBD were identified. One study revealed an observed prevalence of MS at onset of IBD at 3.7 times the expected (95% CI, 0.8-10.8). In the Danish anti-TNFα IBD cohort, 4 out of 651 patients developed demyelinating disorders after anti-TNFα treatment. The SMR for developing MS among Danish IBD patients treated with anti-TNFα was 4.2 (95% CI, 0.1-23.0).
  
  
  CONCLUSIONS
  The literature review revealed an up to four-fold increased risk of demyelinating diseases, in particular MS, in IBD patients in general. The risk of developing MS in the anti-TNFα treated Danish cohort did apparently not exceed this risk.
authors.affiliation: Department of Medical Gastroenterology C, Herlev University Hospital, Denmark.
authors.forename: Nynne Nyboe
authors.initials: NN
authors.lastname: Andersen
authors.forename: Sarah
authors.initials: S
authors.lastname: Caspersen
authors.forename: Tine
authors.initials: T
authors.lastname: Jess
authors.forename: Pia
authors.initials: P
authors.lastname: Munkholm