Efficacy of three ELISA measurements of anti-cyclic citrullinated peptide antibodies in the early diagnosis of rheumatoid arthritis.
ABSTRACT The objective of the present study was to determine the efficacy of anti-cyclic citrullinated peptide (anti-CCP) antibody detection in the early diagnosis of rheumatoid arthritis (RA), as well as to compare three commercially available enzyme-linked immunosorbent assay (ELISA) kits used to detect such antibodies. We analysed the presence of anti-CCP antibodies in the sera of 78 patients who had been newly referred from primary healthcare centres to the Early Polyarthritis Unit. We also included in the study a group of 50 healthy controls. None of the patients had previously received treatment for the disease. After 1-year follow-up, the diagnosis of RA was confirmed in 53 of these patients. The ELISA kits under study were IMMUNOSCAN RA (Euro-Diagnostica AB), QUANTA Lite CCP IgG ELISA (INOVA Diagnostic) and DIA-STAT Anti-CCP (Axis-Shield Diagnostics); the sensitivity obtained was 52.8%, 58.5% and 52.8%, respectively, with 100% specificity for all three kits. Anti-CCP antibodies detected the presence of RA in 26% of patients without positive rheumatoid factor (RF). The sum of anti-CCP antibodies or the presence of RF gave a sensitivity of up to 67%, with specificity ranging between 94 and 97%. Anti-CCP antibodies show high specificity for the diagnosis of RA. The three ELISAs analysed offer the same degree of diagnostic accuracy.
SourceAvailable from: Sonja Genco Genadieva Stavric
[Show abstract] [Hide abstract]
ABSTRACT: Aim: The aim of this study was to compare the diagnostic values of laboratory variables, to present quantitative evaluations of the anti citrullinated protein/peptide antibody (ACPA), or anti CCP(anti-cyclic citrullinated peptide,anti-CCP2) antibodies in second generation antibody assay diagnostic test with reference to sensitivity and specificity, the predictive value of the positive and negative test and precision of the test for ACPA antibodies, rheumatoid factor-reactive protein and DAS 28 index, in the early diagnosis of untreated rheumatoid arthritis. Material and Methods: 70 participants (35 patients with rheumatoid arthritis not treated, 35 individuals as healthy controls) took part in the study. Their serum was examined using ELISA technology of DIA-STAT TM Anti-CCP (Axis–Shield Diagnostics). Rheumatoid factor was examined with the test for agglutination (Latex RF test). Results: We found the presence of ACPA antibodies (sensitivity of the test 65.71%) in 23 of the 35 examined patients with rheu-matoid arthritis while rheumatoid factor appeared in 17 patients (sensitivity of the test 48.57%). Twelve patients were ACPA and rheumatoid factor positive, 11 were ACPA positive, but rheumatoid factor negative. Five patients were ACPA negative and rheumatoid factor positive. In 17 rheumatoid factor positive patients, ACPA antibodies were positive in 12 patients. Of 18 rheu-matoid factor negative patients, 11 were ACPA positive. In the healthy control group, 1 patient was anti-CCP 2 positive, while 2 patients were rheumatoid factor positive. Conclusion: ACPA antibodies have higher sensitivity and specificity than rheumatoid factor in rheumatoid arthritis.
Annals of internal medicine 06/2007; 146(11):797. DOI:10.7326/0003-4819-146-11-200706050-00008 · 16.10 Impact Factor