title: Influence of Immunogenicity on the Efficacy of Long-Term Treatment with TNF α Blockers in Rheumatoid Arthritis and Spondyloarthritis Patients.
abstract: OBJECTIVE
  To analyze the clinical relevance of the levels of TNFα blockers and anti-drug antibodies (anti-drug Ab) in patients with rheumatoid arthritis (RA) and spondyloarthritis (SpA) treated with adalimumab (ADA), etanercept (ETA), or infliximab (INF) for a prolonged period of time.
  
  
  METHODS
  Clinical characteristics (disease activity, and adverse events), serum TNFα blockers, and anti-drug Ab levels were evaluated in 62 RA and 81 SpA patients treated with TNFα blockers for a median of 28 months.
  
  
  RESULTS
  Anti-ADA Ab were detected in 1 (4.0%) and anti-INF Ab in 14 out of 57 (24.6%) RA and SpA patients. Patient with anti-ADA Ab and 57.1% patients with anti-INF Ab were considered nonresponders to treatment. Anti-ETA Ab were not found in any of 61 ETA treated patients. Anti-ADA and anti-INF Ab levels differ between responders and nonresponders (P > 0.05). Three (5.3%) patients with high serum anti-INF Ab levels developed infusion related reactions. Patients with anti-INF Ab more often required changing to another biologic drug (OR 11.43 (95% CI 1.08-120.93)) and treatment discontinuation (OR 9.28 (95% CI 1.64-52.52)).
  
  
  CONCLUSIONS
  Patients not responding to treatment had higher serum anti-ADA and anti-INF Ab concentrations. Anti-INF Ab formation is related to increased risk of infusion related reactions, changing to another biologic drug, and treatment discontinuation.
authors.affiliation: Centre of Rheumatology, Vilnius University, Santariskiu Street 2, LT-08661 Vilnius, Lithuania ; State Research Institute, Centre for Innovative Medicine, Zygimantu Street 9, LT-01102 Vilnius, Lithuania.
authors.forename: Inesa
authors.identifier: 0000-0002-6532-9670
authors.initials: I
authors.lastname: Arstikyte
authors.affiliation: Centre of Rheumatology, Vilnius University, Santariskiu Street 2, LT-08661 Vilnius, Lithuania.
authors.forename: Giedre
authors.identifier: 0000-0001-6034-5789
authors.initials: G
authors.lastname: Kapleryte
authors.affiliation: Centre of Rheumatology, Vilnius University, Santariskiu Street 2, LT-08661 Vilnius, Lithuania ; State Research Institute, Centre for Innovative Medicine, Zygimantu Street 9, LT-01102 Vilnius, Lithuania.
authors.forename: Irena
authors.identifier: 0000-0002-3795-7741
authors.initials: I
authors.lastname: Butrimiene
authors.affiliation: Centre of Rheumatology, Vilnius University, Santariskiu Street 2, LT-08661 Vilnius, Lithuania ; State Research Institute, Centre for Innovative Medicine, Zygimantu Street 9, LT-01102 Vilnius, Lithuania.
authors.forename: Algirdas
authors.identifier: 0000-0003-0234-6040
authors.initials: A
authors.lastname: Venalis
mesh_terms: D000068879:Adalimumab / Q000008:administration & dosage*; D000328:Adult; D000368:Aged; D000888:Antibodies, Anti-Idiotypic / Q000097:blood; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000188:drug therapy* / Q000276:immunology; D000068800:Etanercept / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D000069285:Infliximab / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D025241:Spondylarthritis / Q000097:blood / Q000188:drug therapy* / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors / Q000276:immunology
chemical_list: D000888:Antibodies, Anti-Idiotypic; D014409:Tumor Necrosis Factor-alpha; D000069285:Infliximab; D000068879:Adalimumab; D000068800:Etanercept