title: Anti-citrullinated protein antibodies are linked to erosive disease in an observational study of patients with psoriatic arthritis.
abstract: OBJECTIVE
  ACPAs are associated with bone destruction in RA. The aim of this study was to evaluate the association between ACPA and bone destruction in patients with a distinct inflammatory disorder, PsA.
  
  
  METHODS
  We used baseline data from a large observational study of PsA patients preparing to initiate treatment with adalimumab to analyse demographic and disease characteristics by ACPA status. To ensure a homogeneous PsA study population, only patients with active psoriatic skin manifestations who met Classification of Psoriatic Arthritis criteria for PsA were included in the analyses, thereby minimizing the risk of including misdiagnosed RA patients. Multiple logistic regression analyses were used to explore potential associations between ACPA seropositivity and bone destruction.
  
  
  RESULTS
  Of 1996 PsA patients who met the strict inclusion criteria, 105 (5.3%) were positive for ACPA. ACPA-positive patients had significantly higher swollen joint counts and 28-joint DAS values than ACPA-negative patients and significantly higher rates of erosive changes and dactylitis. Multiple logistic regression analysis confirmed the association of ACPA seropositivity with a 2.8-fold increase in the risk of erosive disease.
  
  
  CONCLUSIONS
  As has been previously shown for RA, ACPA is associated with bone destruction in PsA, suggesting that the osteocatabolic effect of ACPA is not confined to RA but is also detectable in the different pathogenetic context of a distinct disease entity.
  
  
  BACKGROUND
  ClinicalTrials.gov, NCT01111240.
authors.affiliation: Division of Rheumatology, University Hospital Frankfurt, Goethe University Project Group Translational Medicine & Pharmacology TMP, Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Frankfurt am Main.
authors.forename: Frank
authors.initials: F
authors.lastname: Behrens
authors.affiliation: Division of Rheumatology, University Hospital Frankfurt, Goethe University Project Group Translational Medicine & Pharmacology TMP, Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Frankfurt am Main.
authors.forename: Michaela
authors.initials: M
authors.lastname: Koehm
authors.affiliation: Comprehensive Center of Inflammation Medicine, University Hospital Schleswig-Holstein Campus, Lübeck.
authors.forename: Diamant
authors.initials: D
authors.lastname: Thaçi
authors.affiliation: GKM Gesellschaft für Therapieforschung mbH, München.
authors.forename: Holger
authors.initials: H
authors.lastname: Gnann
authors.affiliation: AbbVie Deutschland GmbH & Co KG, Wiesbaden, Germany.
authors.forename: Gerd
authors.initials: G
authors.lastname: Greger
authors.affiliation: AbbVie Deutschland GmbH & Co KG, Wiesbaden, Germany.
authors.forename: Bianca
authors.initials: B
authors.lastname: Maria Wittig
authors.affiliation: Division of Rheumatology, University Hospital Frankfurt, Goethe University Project Group Translational Medicine & Pharmacology TMP, Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Frankfurt am Main harald.burkhardt@kgu.de.
authors.forename: Harald
authors.initials: H
authors.lastname: Burkhardt
mesh_terms: D000068879:Adalimumab / Q000627:therapeutic use; D018501:Antirheumatic Agents / Q000627:therapeutic use; D015535:Arthritis, Psoriatic / Q000188:drug therapy / Q000276:immunology*; D001323:Autoantibodies / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000276:immunology; D010456:Peptides, Cyclic / Q000276:immunology*
chemical_list: D018501:Antirheumatic Agents; D001323:Autoantibodies; D010456:Peptides, Cyclic; C487763:cyclic citrullinated peptide; D000068879:Adalimumab
keywords: adalimumab; anti-citrullinated protein antibodies; erosions; observational study; osteoporosis; psoriatic arthritis