title: Infliximab and adalimumab are stable in whole blood clotted samples for seven days at room temperature.
abstract: BACKGROUND
  The biologic anti-tumour necrosis factor alpha (anti-TNFα) agents infliximab and adalimumab are monoclonal antibodies with binding specificity to TNFα, which are used for the treatment of Crohn's disease. Clinical response is varied from complete with mucosal healing, to primary non-response, loss of response and adverse drug reactions. Measuring trough blood levels of infliximab and adalimumab may guide clinical management. The sample handling requirements for infliximab and adalimumab were previously unknown.
  
  
  OBJECTIVE
  The aim of this study was to determine the in vitro stability of infliximab and adalimumab in samples stored for up to seven days at room temperature.
  
  
  METHODS
  Samples were stored as clotted whole blood or serum at room temperature for up to seven days, before being frozen (-20℃) and analysed as a batch for either infliximab or adalimumab.
  
  
  RESULTS
  No significant difference between the concentration of infliximab and adalimumab measured in samples stored as serum or whole blood for seven days at room temperature, as compared to baseline was found (t-test; infliximab: P = .35 [serum], P = .38 [whole blood]; adalimumab: P = .12 [serum], P = .49 [whole blood]).
  
  
  CONCLUSIONS
  The stability of infliximab and adalimumab at room temperature for seven days allows samples to be posted direct from clinics and research centres to the analysing laboratory.
authors.affiliation: Department of Blood Sciences, Royal Devon and Exeter NHS Foundation Trust, Exeter, UK Mandy.perry@nhs.net.
authors.forename: Mandy
authors.initials: M
authors.lastname: Perry
authors.affiliation: IBD Pharmacogenetics Research, University of Exeter, Exeter, UK.
authors.forename: Claire
authors.initials: C
authors.lastname: Bewshea
authors.affiliation: Department of Blood Sciences, Royal Devon and Exeter NHS Foundation Trust, Exeter, UK.
authors.forename: Richard
authors.initials: R
authors.lastname: Brown
authors.affiliation: IBD Pharmacogenetics Research, University of Exeter, Exeter, UK.
authors.forename: Kenji
authors.initials: K
authors.lastname: So
authors.affiliation: IBD Pharmacogenetics Research, University of Exeter, Exeter, UK.
authors.forename: Tariq
authors.initials: T
authors.lastname: Ahmad
authors.affiliation: Department of Blood Sciences, Royal Devon and Exeter NHS Foundation Trust, Exeter, UK.
authors.forename: Timothy
authors.initials: T
authors.lastname: McDonald
mesh_terms: D000068879:Adalimumab / Q000097:blood*; D001774:Blood Chemical Analysis; D001777:Blood Coagulation; D001800:Blood Specimen Collection / Q000379:methods*; D004355:Drug Stability; D006801:Humans; D000069285:Infliximab / Q000097:blood*; D013696:Temperature; D013997:Time Factors
chemical_list: D000069285:Infliximab; D000068879:Adalimumab
keywords: Gastro-intestinal disorders; anti-TNFα; clinical studies; drugs; in vitro stability