title: Clinical relevance of monitoring serum levels of adalimumab in patients with rheumatoid arthritis in daily practice.
abstract: OBJECTIVE
  The aim of this paper is to assess the usefulness of measuring serum levels of adalimumab (ADL) and anti-ADL antibodies in 57 patients with rheumatoid arthritis (RA) treated with ADL for at least 3 months in daily practice.
  
  
  METHODS
  All patients received concomitant disease-modifying anti-rheumatic drug (DMARD). Receiver-operator characteristics (ROC) analysis was used to obtain the cut-off value of ADL for low disease activity (DAS28-ESR ≤3.2).
  
  
  RESULTS
  Anti-ADL antibodies were detected in 4 (7%) patients with a mean (SD) DAS28 score of 4.6 (0.9). Patients with positive anti-ADL antibodies had significantly lower levels of ADL and higher DAS28 scores than those with negative antibodies. Patients with DAS28 ≤3.2 as compared with patients with DAS28 >3.2 showed significantly better SDAI score, higher serum concentrations of ADL and none of them showed anti-ADL antibodies. The cut-off of serum level of ADL for DAS28 <3.2 was 4.3 mg/L. According to serum levels of ADL, patients were grouped into group 1 (low level) <5.5 mg/L, group 2 (medium level) 5.5-11.3 mg/L and group 3 (high level) >11.3 mg/L. Patients in the medium group were closed to clinical remission (median DAS28 2.7) and patients in the high group were on clinical remission (DAS28 2.1).
  
  
  CONCLUSIONS
  Serum levels of ADL should be maintained >4.3 mg/L. In patients with ADL levels >11.3 mg/L, a decrease of the dose of ADL or an increase in the interval between doses may be planned. The presence of anti-ADL antibodies was associated with a loss of clinical efficacy of ADL.
authors.affiliation: Department of Rheumatology, Marina Baixa Hospital, Villajoyosa, Alicante, Spain. j.rosas.gs@gmail.com.
authors.forename: José
authors.initials: J
authors.lastname: Rosas
authors.forename: Francisca
authors.initials: F
authors.lastname: Llinares-Tello
authors.forename: Inmaculada
authors.initials: I
authors.lastname: de la Torre
authors.forename: Carlos
authors.initials: C
authors.lastname: Santos-Ramírez
authors.forename: José Miguel
authors.initials: JM
authors.lastname: Senabre-Gallego
authors.forename: Lara
authors.initials: L
authors.lastname: Valor
authors.forename: Xavier
authors.initials: X
authors.lastname: Barber-Vallés
authors.forename: Diana
authors.initials: D
authors.lastname: Hernández-Flórez
authors.forename: Gregorio
authors.initials: G
authors.lastname: Santos-Soler
authors.forename: Esteban
authors.initials: E
authors.lastname: Salas-Heredia
authors.forename: Luis
authors.initials: L
authors.lastname: Carreño
mesh_terms: D000068879:Adalimumab; D000368:Aged; D061067:Antibodies, Monoclonal, Humanized / Q000008:administration & dosage / Q000097:blood* / Q000276:immunology; D018501:Antirheumatic Agents / Q000008:administration & dosage / Q000097:blood* / Q000276:immunology; D019540:Area Under Curve; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy* / Q000276:immunology; D015415:Biomarkers / Q000097:blood; D003430:Cross-Sectional Studies; D016903:Drug Monitoring; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012372:ROC Curve; D013030:Spain; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D018501:Antirheumatic Agents; D015415:Biomarkers; D000068879:Adalimumab