Application of synthetic peptides for detection of anti-citrullinated peptide antibodies.

Research output: Contribution to journalArticle

Abstract

Anti-citrullinated protein antibodies (ACPAs) are a hallmark of rheumatoid arthritis (RA) and represent an important tool for the serological diagnosis of RA. In this study, we describe ACPA reactivity to overlapping citrullinated Epstein-Barr virus nuclear antigen-1 (EBNA-1)-derived peptides and analyze their potential as substrates for ACPA detection by streptavidin capture enzyme-linked immunosorbent assay. Using systematically overlapping peptides, containing a 10 amino acid overlap, labelled with biotin C-terminally or N-terminally, sera from 160 individuals (RA sera (n=60), healthy controls (n=40), systemic lupus erythematosus (n=20), Sjögren's syndrome (n=40)) were screened for antibody reactivity. Antibodies to a panel of five citrullinated EBNA-1 peptides were found in 67% of RA sera, exclusively of the IgG isotype, while 53% of the patient sera reacted with a single peptide, ARGGSRERARGRGRG-Cit-GEKR, accounting for more than half of the ACPA reactivity alone. Moreover, these antibodies were detected in 10% of CCP2-negative RA sera. In addition, 47% of the RA sera reacted with two or three citrullinated EBNA-1 peptides from the selected peptide panel. Furthermore, a negative correlation between the biotin attachment site and the location of citrulline in the peptides was found, i.e. the closer the citrulline was located to biotin, the lower the antibody reactivity. Our data suggest that citrullinated EBNA-1 peptides may be considered a substrate for the detection of ACPAs and that the presence of Epstein-Barr virus may play a role in the induction of these autoantibodies.

Details

Authors
  • Nicole Hartwig Trier
  • Bettina Eide Holm
  • Ole Slot
  • Henning Locht
  • Hanne Lindegaard
  • Anders Svendsen
  • Christoffer Tandrup Nielsen
  • Søren Jacobsen
  • Elke Theander
  • Gunnar Houen
Organisations
External organisations
  • Danish Serum Institute, Copenhagen
  • Glostrup Hospital
  • Frederiksberg Hospital
  • Odense University Hospital
  • University of Southern Denmark
  • Copenhagen University Hospital
  • Skåne University Hospital
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Rheumatology and Autoimmunity
Original languageEnglish
Pages (from-to)87-95
JournalPeptides
Volume76
Publication statusPublished - 2016
Publication categoryResearch
Peer-reviewedYes