Abstract 2182: Diagnostic and Prognostic Accuracy of Anti-Cyclic Citrullinated Peptide Antibody and Rheumatoid Factor for Early Rheumatoid Arthritis. A Meta-Analysis
Authors
K. Nishimura, D. Sugiyama, A. Morinobu, S. Kumagai
Purpose:
To compare the diagnostic accuracy of anti-CCP antibody and RF for the diagnosis of early RA.
Methods:
This was a meta-analysis using MEDLINE data through 2006 to identify studies that examined anti-CCP and RF for diagnosing patients with known or suspected early RA. Weighted sensitivity and specificity and summary receiver-operating characteristic (sROC) curve were calculated. Meta-regression was used to identify the source of heterogeneity.
Results:
18 studies involving 5230 patients met inclusion criteria for anti-CCP antibody, and 12 studies involving 2838 patients met criteria for RF. The pooled sensitivity and specificity for anti-CCP were 56% (53% to 58%) and 96% (95% to 96%), respectively; those for IgM-RF were 62% (60% to 65%) and 87% (85% to 88% ), respectively. The AUC for anti-CCP was 0.911 [S.E. = 0.0144], while the AUC for IgM-RF was less [0.836 (S.E. = 0.0182); P =0.0006]. The pooled odds ratio of developing RA related to anti-CCP positivity using the originally described CCP assay was 9.68. (95% CI, 4.00 to 23.41) and that for the CCP2 assay was 16.77 (95% CI, 7.86 to 35.81). In contrast, the pooled odds ratio of developing RA related to RF positivity was 3.32 (95% CI, 1.31 to 8.42).
Conclusions:
Anti-CCP is more specific and more accurate than RF for diagnosis of early RA.
Editorial Comment:
While this conclusion has been demonstrated by previous individual studies, this is the first meta-analysis on the topic to my knowledge. It reinforces the higher specificity of anti-CCP antibody, compared to RF, testing for the diagnosis of RA. What the authors did not present was the enhanced sensitivity and specificity for the diagnosis of RA conveyed by the two tests combined compared to each individual test alone. The combined testing is the manner in which we would clinically approach the diagnosis of early RA to maximize sensitivity and specificity.
