title: Anti-adalimumab antibodies in juvenile idiopathic arthritis: frequent association with loss of response.
abstract: OBJECTIVE
  We aimed to determine how loss of response (LOR) to adalimumab (ADA) in juvenile idiopathic arthritis (JIA) may be related to anti-ADA antibodies (AAA).
  
  
  METHODS
  AAA and ADA levels were measured in 23 consecutive patients with JIA responding significantly to treatment with ADA.
  
  
  RESULTS
  Six out of 23 (26%) patients developed AAA and had low ADA levels. Five out of six AAA-positive patients experienced LOR. In these patients use of concomitant methotrexate (MTX) was significantly lower.
  
  
  CONCLUSIONS
  The occurrence of AAA is a frequent event associated with LOR. Monitoring of AAA and serum ADA levels should be considered in JIA patients under ADA therapy.
authors.affiliation: a Department of Paediatrics and Adolescent Medicine , Medical University Graz , Austria.
authors.forename: A
authors.initials: A
authors.lastname: Skrabl-Baumgartner
authors.affiliation: b Institute of Medical and Chemical Laboratory Diagnostics , Medical University Graz , Austria.
authors.forename: W
authors.initials: W
authors.lastname: Erwa
authors.affiliation: a Department of Paediatrics and Adolescent Medicine , Medical University Graz , Austria.
authors.forename: W
authors.initials: W
authors.lastname: Muntean
authors.affiliation: a Department of Paediatrics and Adolescent Medicine , Medical University Graz , Austria.
authors.forename: J
authors.initials: J
authors.lastname: Jahnel
mesh_terms: D000068879:Adalimumab / Q000097:blood / Q000276:immunology* / Q000627:therapeutic use*; D000293:Adolescent; D000888:Antibodies, Anti-Idiotypic / Q000097:blood* / Q000276:immunology; D018501:Antirheumatic Agents / Q000097:blood / Q000276:immunology* / Q000627:therapeutic use*; D001171:Arthritis, Juvenile / Q000097:blood / Q000188:drug therapy* / Q000276:immunology; D015415:Biomarkers / Q000097:blood; D002648:Child; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D008297:Male; D008727:Methotrexate / Q000627:therapeutic use; D012720:Severity of Illness Index; D017211:Treatment Failure; D016896:Treatment Outcome; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors
chemical_list: D000888:Antibodies, Anti-Idiotypic; D018501:Antirheumatic Agents; D015415:Biomarkers; D014409:Tumor Necrosis Factor-alpha; D000068879:Adalimumab; D008727:Methotrexate