title: Natalizumab saturation: biomarker for individual treatment holiday after natalizumab withdrawal?
abstract: BACKGROUND
  More and more patients with multiple sclerosis (MS) switch from natalizumab to fingolimod because of the risk of progressive multifocal leukoencephalopathy. The duration of the treatment holiday is still under debate referring to a possible recurrence of disease activity.
  
  
  OBJECTIVE
  The aim of this study was to evaluate the prognostic value of natalizumab saturation on T cells for the recurrence of clinical and radiological disease activity.
  
  
  METHODS
  Cell surface-bound natalizumab saturation (in%) of CD8+ and CD4+ T cells from five patients with MS was determined before initiation of fingolimod by flow cytometry and related to clinical and MRI outcome during a 6-month follow-up.
  
  
  RESULTS
  In two patients with either clinical or radiological disease activity, the natalizumab saturation on CD8+ and CD4+ T cells was <30%. In contrast, the remaining three patients with absence of disease activity had a median natalizumab saturation of 70% (range 59-79%) on CD4+ and 66% (range 52-68%) on CD8+ T cells.
  
  
  CONCLUSIONS
  The data of this pilot study indicate that clinical and radiological disease activity is closely linked to natalizumab saturation at the time point of switch. The determination of natalizumab saturation may be an essential tool to monitor cessation of natalizumab treatment.
authors.affiliation: Department of Neurology, Christian-Doppler-Klinik, Paracelsus Medical University, Salzburg, Austria.
authors.forename: P
authors.initials: P
authors.lastname: Wipfler
authors.forename: A
authors.initials: A
authors.lastname: Harrer
authors.forename: G
authors.initials: G
authors.lastname: Pilz
authors.forename: K
authors.initials: K
authors.lastname: Oppermann
authors.forename: S
authors.initials: S
authors.lastname: Afazel
authors.forename: E
authors.initials: E
authors.lastname: Haschke-Becher
authors.forename: J
authors.initials: J
authors.lastname: Sellner
authors.forename: E
authors.initials: E
authors.lastname: Trinka
authors.forename: J
authors.initials: J
authors.lastname: Kraus
mesh_terms: D000328:Adult; D061067:Antibodies, Monoclonal, Humanized / Q000009:adverse effects* / Q000378:metabolism*; D005260:Female; D000068876:Fingolimod Hydrochloride; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000188:drug therapy* / Q000473:pathology; D000069442:Natalizumab; D011409:Propylene Glycols / Q000627:therapeutic use; D013110:Sphingosine / Q000031:analogs & derivatives / Q000627:therapeutic use; D013997:Time Factors
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D007166:Immunosuppressive Agents; D000069442:Natalizumab; D011409:Propylene Glycols; D000068876:Fingolimod Hydrochloride; D013110:Sphingosine
keywords: biomarker; fingolimod; multiple sclerosis; natalizumab saturation; treatment holiday