title: Systematic review: antibodies and anti-TNF-α levels in inflammatory bowel disease.
abstract: BACKGROUND
  The associations between clinical efficacy and infusion reactions with anti-TNF-α drug levels and the presence of antibodies against the drug have been described. However, the clinical utility of these tests in routine clinical practice remains unclear.
  
  
  OBJECTIVE
  To examine the clinical significance of the development of antibodies against anti-TNF-α drugs and the relationship between the efficacy of these drugs and their serum levels. We also studied the clinical utility of testing for anti-TNF-α antibodies and measuring drug serum levels to optimise treatment of patients with inflammatory bowel disease (IBD) receiving these agents.
  
  
  METHODS
  A systematic review was undertaken based on electronic searches of the PubMed database from the earliest record to February 2012. The reference lists of all relevant articles and abstracts from meetings were also consulted.
  
  
  RESULTS
  We observed a close relationship between trough levels of anti-TNF-α drug and maintenance of response to these drugs. The role of antibodies in loss of response seems to be limited to their effect favouring the clearance of the drug. The risk of infusion reactions, but not of delayed hypersensitivity reactions, is higher in patients with antibodies against the anti-TNF-α drug. Testing anti-TNF-α drug and antibody levels, together with clinical and endoscopic or radiological assessment, seems useful when attempting to optimise therapy and prevent inappropriate management of IBD patients.
  
  
  CONCLUSIONS
  Measurement of serum anti-TNF-α trough levels and antibody titres could prove useful in therapeutic drug monitoring in IBD patients treated with anti-TNF-α agents.
authors.affiliation: Department of Gastroenterology, Hospital Universitario de La Princesa, Instituto de Investigación Sanitaria Princesa (IP), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Madrid, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Chaparro
authors.forename: I
authors.initials: I
authors.lastname: Guerra
authors.forename: P
authors.initials: P
authors.lastname: Muñoz-Linares
authors.forename: J P
authors.initials: JP
authors.lastname: Gisbert
mesh_terms: D000818:Animals; D000906:Antibodies / Q000097:blood / Q000276:immunology; D000911:Antibodies, Monoclonal / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000188:drug therapy* / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors*
chemical_list: D000906:Antibodies; D000911:Antibodies, Monoclonal; D014409:Tumor Necrosis Factor-alpha