title: Brief Report: Association of Rheumatoid Factor and Anti-Citrullinated Protein Antibody Positivity With Better Effectiveness of Abatacept: Results From the Pan-European Registry Analysis.
abstract: To investigate the role of rheumatoid factor (RF) status and anti-citrullinated peptide antibody (ACPA) status as predictors of abatacept (ABA) effectiveness in patients with rheumatoid arthritis (RA).
  
  
  
  We conducted a pooled analysis of data from 9 observational RA registries in Europe (ARTIS [Sweden], ATTRA [Czech Republic], BIOBADASER [Spain], DANBIO [Denmark], GISEA [Italy], NOR-DMARD [Norway], ORA [France], Reuma.pt [Portugal], and SCQM-RA [Switzerland]). Inclusion criteria were a diagnosis of RA, initiation of ABA treatment, and available information on RF and/or ACPA status. The primary end point was continuation of ABA treatment. Secondary end points were ABA discontinuation for ineffectiveness or adverse events and response rates at 1 year (good or moderate response according to the European League Against Rheumatism criteria with LUNDEX adjustment for treatment continuation). Hazard ratios (HRs) and 95% confidence intervals (95% CIs) for the study end points in relation to RF and ACPA status were calculated.
  
  
  
  We identified 2,942 patients with available data on RA-associated autoantibodies; data on RF status were available for 2,787 patients (77.0% of whom were RF positive), and data on ACPA status were available for 1,903 patients (71.3% of whom were ACPA positive). Even after adjustment for sociodemographic and disease- and treatment-related confounders, RF and ACPA positivity were each associated with a lower risk of ABA discontinuation for any reason (HR 0.79 [95% CI 0.69-0.90], P < 0.001 and HR 0.78 [95% CI 0.68-0.90], P < 0.001, respectively), compared to RF-negative and ACPA-negative patients. Similar associations with RF and ACPA were observed for discontinuation of ABA treatment due to ineffectiveness, with HRs of 0.72 (95% CI 0.61-0.84) and 0.74 (95% CI 0.62-0.88), respectively (both P < 0.001).
  
  
  
  Our results strongly suggest that positivity for RF or ACPA is associated with better effectiveness of ABA therapy.
authors.affiliation: Strasbourg University Hospital and University of Strasbourg, CNRS, Institut de Biologie Moléculaire et Cellulaire, Immunopathologie, et Chimie Thérapeutique, Strasbourg, France.
authors.forename: J E
authors.initials: JE
authors.lastname: Gottenberg
authors.affiliation: University of Geneva and University Hospital of Geneva, Geneva, Switzerland.
authors.forename: D S
authors.initials: DS
authors.lastname: Courvoisier
authors.affiliation: Hospital Clinic of Barcelona and IDIBAPS, Barcelona, Spain.
authors.forename: M V
authors.identifier: 0000-0001-6657-2333
authors.initials: MV
authors.lastname: Hernandez
authors.affiliation: University of Bari and University Hospital, Bari, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Iannone
authors.affiliation: Diakonhjemmet Hospital, Oslo, Norway.
authors.forename: E
authors.initials: E
authors.lastname: Lie
authors.affiliation: University of Lisbon and Santa Maria Hospital, Lisbon, Portugal.
authors.forename: H
authors.initials: H
authors.lastname: Canhão
authors.affiliation: Institute of Rheumatology and University Hospital, Prague, Czech Republic.
authors.forename: K
authors.initials: K
authors.lastname: Pavelka
authors.affiliation: DANBIO Registry and University of Copenhagen, Copenhagen, Denmark, and Rigshospitalet, Glostrup, Denmark.
authors.forename: M L
authors.initials: ML
authors.lastname: Hetland
authors.affiliation: Lund University and Skåne University Hospital, Malmö, Sweden.
authors.forename: C
authors.initials: C
authors.lastname: Turesson
authors.affiliation: Université Paris-Sud, Hôpitaux Universitaires Paris-Sud, Hôpital Bicêtre, AP-HP, and INSERM U1184, Le Kremlin Bicêtre, France.
authors.forename: X
authors.initials: X
authors.lastname: Mariette
authors.affiliation: University of Geneva and University Hospital of Geneva, Geneva, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Finckh
mesh_terms: D000069594:Abatacept / Q000627:therapeutic use*; D018501:Antirheumatic Agents / Q000627:therapeutic use*; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000188:drug therapy*; D001323:Autoantibodies / Q000097:blood*; D005060:Europe; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010456:Peptides, Cyclic / Q000276:immunology*; D011237:Predictive Value of Tests; D012042:Registries; D012217:Rheumatoid Factor / Q000097:blood*; D016896:Treatment Outcome
chemical_list: D018501:Antirheumatic Agents; D001323:Autoantibodies; D010456:Peptides, Cyclic; C487763:cyclic citrullinated peptide; D000069594:Abatacept; D012217:Rheumatoid Factor