[The diagnostic accuracy of anti-citrullin antibody assessment in the diagnosis of patients suspected of rheumatoid arthritis by a general practitioner]

Ned Tijdschr Geneeskd. 2008 Jan 12;152(2):91-5.
[Article in Dutch]

Abstract

Objective: To determine whether assessment of antibodies directed against citrullin provides additional value in the diagnosis of rheumatoid arthritis (RA) in general practice.

Design: Retrospective.

Methods: In a 6-month period in 2004 (May-December), all sera sent to our laboratory for assessment of rheumatoid factor (RF-IgM), were also analysed for the presence of antibodies directed against citrullinated fibrinogen (anti-citrullin). We analysed 691 sera sent in by general practitioners using a homemade assay. To determine the disease classification, general practitioners were asked to provide information pertaining to the American College of Rheumatology disease classification criteria. The response was 97.6%. For patients who were referred to a rheumatologist in the last 2 years (December 2004-December 2006), the diagnosis of the rheumatologist was also considered in the analysis.

Results: A total of 28 patients (4%) were diagnosed with rheumatoid arthritis. Only 25% of these patients were positive for anti-citrullin, and only 25% were positive for RF-IgM. These 2 groups only partially overlapped. The positive and negative predictive values of anti-citrullin were 36 and 96%, respectively.

Conclusion: The presence of anti-citrullin provided no additional value compared to rheumatoid factor in classifying RA in a general practice population.

Publication types

  • English Abstract

MeSH terms

  • Antibodies, Antinuclear / blood*
  • Arthritis, Rheumatoid / blood
  • Arthritis, Rheumatoid / diagnosis*
  • Citrulline / immunology*
  • Diagnosis, Differential
  • Family Practice / methods*
  • Family Practice / standards
  • Humans
  • Immunoglobulin M / immunology
  • Retrospective Studies
  • Rheumatoid Factor / blood
  • Sensitivity and Specificity

Substances

  • Antibodies, Antinuclear
  • Immunoglobulin M
  • Citrulline
  • Rheumatoid Factor