title: Obesity decreases clinical efficacy and levels of adalimumab in patients with ankylosing spondylitis.
abstract: OBJECTIVE
  Obesity can be a factor that affects response to anti-TNF drugs. However, studies on patients with ankylosing spondylitis (AS) are rare. We aimed to determine whether obesity affects serum levels of adalimumab (ADL), and immunogenicity and clinical efficacy of the drug in patients with AS.
  
  
  METHODS
  A cross-sectional study on 57 patients with axial AS receiving ADL was conducted. They received DMARD per standard of care at their rheumatologist's discretion. Patients' body mass index (BMI) was obtained when ADL treatment began. Clinical response was evaluated using the Spanish versions of the BASDAI index and the ASDAS ESR index. Serum concentrations of free ADL (trough level) and anti-ADL antibodies were measured using Promonitor-ADL and Promonitor Anti-ADL ELISA kits (Progenika Grifols SA, Spain), just prior to the next subcutaneous injection of ADL.
  
  
  RESULTS
  Patients with BMI >30 kg/ m2 (obese) as opposed to BMI <25 kg/ m2 (normal), presented lower blood ADL levels [5.0 (5.52) vs. 9.14 (4.3), p=0.032], increased ASDAS scores (2.58 [0.79] vs. 1.9 [0.83], p=0.03), and shorter ADL treatment time: 1.01 [0.84] vs. (1.85 [1.65]; p=0.08]), and increased BASDAI results (5.04 [2.5] vs. 3.5 [1.88]; p=0.06). Obese patients showed a lower probability of clinical response to ADL versus non-obese patients with regard to achieving BASDAI ≤4 (OR: 3.5, 95%CI: 0.84-17.19; p=0.05) or ASDAS ≤2.1 (OR: 4.64, 95%CI: 1.02-24.13; p=0.02).
  
  
  CONCLUSIONS
  Of the AS patients receiving treatment with ADL, those that are obese had significantly lower serum ADL levels and decreased clinical response without an increase in immunogenicity.
authors.affiliation: Rheumatology Department, Marina Baixa Hospital, Villajoyosa, Alicante, Spain. j.rosas.gs@gmail.com.
authors.forename: José
authors.initials: J
authors.lastname: Rosas
authors.affiliation: Laboratory Department, Marina Baixa Hospital, Villajoyosa, Alicante, Spain.
authors.forename: Francisca
authors.initials: F
authors.lastname: Llinares-Tello
authors.affiliation: Rheumatology Department, Marina Baixa Hospital, Villajoyosa, Alicante, Spain.
authors.forename: José Miguel
authors.initials: JM
authors.lastname: Senabre-Gallego
authors.affiliation: CIO-Universidad Miguel Hernández, Elche, Alicante, Spain.
authors.forename: Xavier
authors.initials: X
authors.lastname: Barber-Vallés
authors.affiliation: Rheumatology Department, Marina Baixa Hospital, Villajoyosa, Alicante, Spain.
authors.forename: Gregorio
authors.initials: G
authors.lastname: Santos-Soler
authors.affiliation: Rheumatology Department, Marina Baixa Hospital, Villajoyosa, Alicante, Spain.
authors.forename: Esteban
authors.initials: E
authors.lastname: Salas-Heredia
authors.affiliation: Rheumatology Department, Marina Baixa Hospital, Villajoyosa, Alicante, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Pons Bas
authors.affiliation: Rheumatology Department, Marina Baixa Hospital, Villajoyosa, Alicante, Spain.
authors.forename: Catalina
authors.initials: C
authors.lastname: Cano Pérez
authors.affiliation: Systemic Autoimmune Disease Research Unit HGR-36-CIBIOR IMSS Puebla; and Department of Rheumatology and Immunology, Benemérita Universidad Autónoma of Puebla, México.
authors.forename: Mario
authors.initials: M
authors.lastname: García-Carrasco
mesh_terms: D000068879:Adalimumab / Q000097:blood / Q000627:therapeutic use*; D000328:Adult; D018501:Antirheumatic Agents / Q000097:blood / Q000627:therapeutic use*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications*; D013167:Spondylitis, Ankylosing / Q000150:complications / Q000188:drug therapy*; D016896:Treatment Outcome
chemical_list: D018501:Antirheumatic Agents; D000068879:Adalimumab