title: Adalimumab trough serum levels and anti-adalimumab antibodies in the long-term clinical outcome of patients with Crohn's disease.
abstract: OBJECTIVE
  Few data are available on the relevance of adalimumab (ADA) trough serum levels and anti-ADA antibodies (AAA) during long-term follow-up of patients with Crohn's Disease (CD), and their association with disease outcome. In this study, our aim was to assess ADA trough serum levels and the presence of AAA according to disease activity and clinical response during long-term follow-up in a series of patients with CD treated with ADA monotherapy.
  
  
  METHODS
  We prospectively evaluated 23 consecutive, infliximab-naïve CD patients who achieved clinical remission/response after induction and were in maintenance treatment with ADA, and who were followed-up for at least 72 weeks. Blood samples were drawn at standardized time points to assess ADA through levels, AAA.
  
  
  RESULTS
  At week 48, we found significantly (p = 0.027) different ADA trough serum levels in patients in remission (10.1 mcg/mL), mild (7.4 mcg/mL), and moderate/severe disease (4.5 mcg/mL). Median ADA trough levels were significantly lower in patients with AAA (3.7 mcg/mL versus 9.3 mcg/mL, p = 0.006). At the end of follow-up (median 102 weeks, range 73-112 weeks), ADA trough serum concentrations were significantly higher (11.9 mcg/mL) as compared to patients with mild and moderate/severe disease (5.5 mcg/mL, p = 0.0002). Furthermore, median ADA trough concentrations showed a trend towards lower levels in AAA positive patients (5.2 mcg/mL versus 7.2 mcg/mL, p = 0.371).
  
  
  CONCLUSIONS
  Our results emphasize the relevance of therapeutic drug monitoring in CD patients on biologic treatment. ADA trough serum levels and the presence of AAA are important features in the management of patients on ADA treatment.
authors.affiliation: a Gastroenterology Unit, Department of Internal Medicine , University of Genoa , Genoa , Italy ;
authors.forename: Giorgia
authors.initials: G
authors.lastname: Bodini
authors.affiliation: a Gastroenterology Unit, Department of Internal Medicine , University of Genoa , Genoa , Italy ;
authors.forename: Edoardo G
authors.initials: EG
authors.lastname: Giannini
authors.affiliation: a Gastroenterology Unit, Department of Internal Medicine , University of Genoa , Genoa , Italy ;
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Savarino
authors.affiliation: a Gastroenterology Unit, Department of Internal Medicine , University of Genoa , Genoa , Italy ;
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Del Nero
authors.affiliation: a Gastroenterology Unit, Department of Internal Medicine , University of Genoa , Genoa , Italy ;
authors.forename: Gaia
authors.initials: G
authors.lastname: Pellegatta
authors.affiliation: a Gastroenterology Unit, Department of Internal Medicine , University of Genoa , Genoa , Italy ;
authors.forename: Costanza
authors.initials: C
authors.lastname: De Maria
authors.affiliation: a Gastroenterology Unit, Department of Internal Medicine , University of Genoa , Genoa , Italy ;
authors.forename: Isabella
authors.initials: I
authors.lastname: Baldissarro
authors.affiliation: b Gastroenterolgy Unit, Department of Surgery, Oncology and Gastroenterology , University of Padua , Padua , Italy.
authors.forename: Edoardo
authors.initials: E
authors.lastname: Savarino
mesh_terms: D000068879:Adalimumab / Q000097:blood* / Q000276:immunology / Q000627:therapeutic use*; D000328:Adult; D000368:Aged; D000893:Anti-Inflammatory Agents / Q000097:blood* / Q000627:therapeutic use; D000906:Antibodies / Q000097:blood*; D003424:Crohn Disease / Q000097:blood* / Q000188:drug therapy* / Q000276:immunology; D016903:Drug Monitoring / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007558:Italy; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000893:Anti-Inflammatory Agents; D000906:Antibodies; D000068879:Adalimumab
keywords: Inflammatory bowel disease; loss of response; therapeutic drug monitoring