title: Therapeutic drug monitoring is predictive of loss of response after de-escalation of infliximab therapy in patients with inflammatory bowel disease in clinical remission.
abstract: BACKGROUND
  There is no evidence that therapeutic drug monitoring is helpful in patients with inflammatory bowel disease patients in clinical remission with infliximab therapy.
  
  
  METHODS
  Eighty consecutive inflammatory bowel disease patients in clinical remission on infliximab maintenance therapy were included and followed-up for at least one year. Infliximab trough level and antibody to infliximab concentration were measured prior to enrollment. At the time of enrollment, physicians in charge were free to alleviate infliximab therapy. Discrepancies between blind and therapeutic drug monitoring-based adjustments were assessed at the end of the follow-up period. Relapse-free survival was analyzed using univariate and multivariate analyses.
  
  
  RESULTS
  The mean infliximab trough level was 3.1 μg/mL. Antibody to infliximab was found in 15 (19%) patients. At the end of the follow-up period, 18 (22.5%) patients experienced a relapse. The 3, 6, 9 and 12-month relapse-free rates were 98%, 87%, 86% and 80%, respectively. In our multivariate analysis, relapse-free survival was negatively associated with discrepancies between therapeutic drug monitoring-based and blind adjustments of infliximab therapy, absence of concomitant immunomodulator, the absence of mucosal healing, prior use of infliximab, infliximab therapy duration>2 years and C-reactive protein levels>5mg/L at the time of enrollment.
  
  
  CONCLUSIONS
  In patients with inflammatory bowel disease in clinical remission on infliximab therapy, de-escalation of infliximab therapy should be considered based on therapeutic drug monitoring rather than according to symptoms and CRP.
authors.affiliation: Department of Gastroenterology, Henri-Mondor Hospital, DHU VIC, AP-HP, 94000 Créteil, France; University of Paris Est Creteil, 94000 Créteil, France; LIC, Laboratoire d'Investigation Clinique EA 4393, 94000 Créteil, France. Electronic address: aurelien.amiot@hmn.aphp.fr.
authors.forename: Aurélien
authors.initials: A
authors.lastname: Amiot
authors.affiliation: University of Paris Est Creteil, 94000 Créteil, France; Laboratory of Pharmacology-Toxicology, Henri-Mondor Hospital, DHU VIC, AP-HP, 94000 Créteil, France; Laboratory of Biological Immunology, Henri-Mondor Hospital, DHU VIC, AP-HP, 94000 Créteil, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Hulin
authors.affiliation: Department of Gastroenterology, Henri-Mondor Hospital, DHU VIC, AP-HP, 94000 Créteil, France; University of Paris Est Creteil, 94000 Créteil, France.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Belhassan
authors.affiliation: University of Paris Est Creteil, 94000 Créteil, France; Laboratory of Biological Immunology, Henri-Mondor Hospital, DHU VIC, AP-HP, 94000 Créteil, France; INSERM, Unit U-955, IMRB, 94000 Créteil, France.
authors.forename: Chantal
authors.initials: C
authors.lastname: Andre
authors.affiliation: Department of Gastroenterology, Henri-Mondor Hospital, DHU VIC, AP-HP, 94000 Créteil, France; University of Paris Est Creteil, 94000 Créteil, France.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Gagniere
authors.affiliation: Department of Gastroenterology, Henri-Mondor Hospital, DHU VIC, AP-HP, 94000 Créteil, France; University of Paris Est Creteil, 94000 Créteil, France.
authors.forename: Yann
authors.initials: Y
authors.lastname: Le Baleur
authors.affiliation: University of Paris Est Creteil, 94000 Créteil, France; Laboratory of Biological Immunology, Henri-Mondor Hospital, DHU VIC, AP-HP, 94000 Créteil, France; INSERM, Unit U-955, IMRB, 94000 Créteil, France.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Farcet
authors.affiliation: Department of Gastroenterology, Henri-Mondor Hospital, DHU VIC, AP-HP, 94000 Créteil, France; University of Paris Est Creteil, 94000 Créteil, France.
authors.forename: Jean-Charles
authors.initials: JC
authors.lastname: Delchier
authors.affiliation: University of Paris Est Creteil, 94000 Créteil, France; Laboratory of Biological Immunology, Henri-Mondor Hospital, DHU VIC, AP-HP, 94000 Créteil, France; INSERM, Unit U-955, IMRB, 94000 Créteil, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Hüe
mesh_terms: D000328:Adult; D016903:Drug Monitoring; D005260:Female; D005765:Gastrointestinal Agents / Q000008:administration & dosage*; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000188:drug therapy*; D000069285:Infliximab / Q000008:administration & dosage*; D008297:Male; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012074:Remission Induction; D055815:Young Adult
chemical_list: D005765:Gastrointestinal Agents; D000069285:Infliximab