Predictive value of anti-citrullinated peptide antibodies: a real life experience

Immunol Res. 2014 Dec;60(2-3):348-55. doi: 10.1007/s12026-014-8566-4.

Abstract

Rheumatoid Arthritis (RA) is an autoimmune destructive joint disease, characterized by the presence of rheumatoid factor and anti-citrullinated peptide antibodies. Anti-citrullinated peptide antibodies were recently defined as RA criterion with sensitivity and specificity of 50-80 and 75-95 %, respectively. However, in the general population, the predictive value of anti-citrullinated peptide antibodies is yet to be determined. Herein, we aim to determine the predictive value of anti-citrullinated peptide antibodies in real life as well as clinical and serological factors related to this value. Retrospective cross-sectional study of consecutive samples evaluated for anti-citrullinated peptide antibodies in a referral autoimmune laboratory. Demographic and clinical parameters at the time the sample was drawn were collected. During November 2011 through December 2013, a total of 215 anti-citrullinated peptide antibody tests were performed in our laboratory. Data were available for 140 samples of which only 28 samples were positive for anti-citrullinated peptide antibodies. Of the 140 patients tested, 18 were diagnosed with RA, of which 12 were positive and 6 were negative for anti-citrullinated peptide antibody test. Thus, in this cohort, anti-citrullinated peptide antibodies were positive in 20 % of samples with a positive predictive value (PPV) of 43 % and a negative predictive value of 95 %. In real life, only 20 % of anti-citrullinated peptide antibody tests referred to a tertiary center where found to be positive. The negative predictive value of this test is very high and may support the common use of anti-citrullinated peptide antibody test as an exclusion criterion in the process of evaluating a patient with rheumatic disease.

MeSH terms

  • Adult
  • Aged
  • Arthritis, Rheumatoid / diagnosis*
  • Arthritis, Rheumatoid / immunology*
  • Autoantibodies / blood
  • Autoantibodies / immunology*
  • Autoantigens / immunology*
  • Citrulline / immunology*
  • Cross-Sectional Studies
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Humans
  • Male
  • Middle Aged
  • Peptides / chemistry
  • Peptides / immunology*
  • Prognosis
  • Reproducibility of Results
  • Retrospective Studies
  • Rheumatoid Factor / blood
  • Rheumatoid Factor / immunology
  • Sensitivity and Specificity

Substances

  • Autoantibodies
  • Autoantigens
  • Peptides
  • Citrulline
  • Rheumatoid Factor