Comparison of the Farr radioimmunoassay, 3 commercial enzyme immunoassays and Crithidia luciliae immunofluorescence test for diagnosis and activity assessment of systemic lupus erythematosus.

Abstract

BACKGROUNDS:

Among anti-double-strand (ds)DNA antibody assays, Farr radioimmunoassay is decreasingly used because it requires radioactive material and is labor intensive. We evaluated the performance of Farr, three commercial enzyme immunoassays (EIAs) and the Crithidia luciliae immunofluorescence test (CLIFT) in systemic lupus erythematosus (SLE).

METHODS:

Anti-dsDNA antibodies were determined in 99 SLE patients, 101 healthy subjects, and 53 patients with autoimmune rheumatic diseases.

RESULTS:

Farr performed better than the 3 EIAs and CLIFT for the diagnosis of SLE at the manufacturer's cut off and at the cut off set to achieve a specificity of 95%. To achieve a similar level of specificity, some EIAs had a decrease in sensitivity which was dramatic for some tests. Farr was also the best at distinguishing patients with quiescent to mildly active disease from patients with more active disease at the cut off value of 93 IU/ml. Using manufacturer's cut off did not allow distinguishing between patients with quiescent and active SLE.

CONCLUSIONS:

Farr was the best global test to assess the level of anti-dsDNA antibodies for both diagnosis and disease activity evaluation in SLE with adequately determined cut off values. Some EIA had low performances limiting their use in decision-making regarding diagnosis and/or treatment.

• Authors: David Launay, Jean Schmidt, Sébastien Lepers, Tristan Mirault, Marc Lambert, Xavier Kyndt, Dominique Reumaux, Alain Duhamel, Eric Hachulla, Pierre-Yves Hatron, Lionel Prin, Sylvain Dubucquoi
• Journal: Clinica chimica acta; international journal of clinical chemistry (Clin Chim Acta) Vol. 411 Issue 13-14 Pg. 959-64 (Jul 04 2010) ISSN: 1873-3492 [Electronic] Netherlands
• PMID: 20303931 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright 2010 Elsevier B.V. All rights reserved.

Chemical References

• Antibodies

Topics

• Adolescent
• Adult
• Aged
• Antibodies (analysis, immunology)
• Case-Control Studies
• Crithidia
• Female
• Fluorescent Antibody Technique (methods)
• Humans
• Immunoenzyme Techniques (methods)
• Lupus Erythematosus, Systemic (diagnosis, immunology)
• Male
• Middle Aged
• Radioimmunoprecipitation Assay (methods)
• Rheumatic Diseases (diagnosis, immunology)
• Young Adult