Anti-CCP antibodies have more diagnostic impact than rheumatoid factor (RF) in a population tested for RF

Abstract

To compare the diagnostic powers of rheumatoid factor (RF) and anti-cyclic citrullinated peptide (CCP) in a population selected for its high statistical relevance, over a 6-month period, an informed consent to test for anti-CCP was obtained from 1,025 consecutive patients for whom RF was ordered at a University laboratory. Within 1 year, a diagnosis was obtained without informing the physician about the anti-CCP result. Extensive statistical analyses were performed. A total of 768 patients satisfied the inclusion criteria, and 132 were classified as having RA, yielding a pre-test probability of RA of 17%. The sensitivities for anti-CCP and RF were 62 and 64% (P = 0.83), and the specificities were 97 and 90% (P < 0.001), respectively. The positive predictive value (PPV) was 79% for anti-CCP and 56% for RF (P < 0.001), whereas the negative predictive value was 92% for both. The likelihood ratio (LR) was 17.9 for anti-CCP and 6.2 for RF (P < 0.005). Forty RA patients were diagnosed with RA of less than 2 years length, and the same significant statistic differences between anti-CCP and RF were observed. Placing the results of both tests together, or using different cutoff points, increased the diagnostic utility of the tests. The anti-CCP test has statistically shown significant higher specificity, PPV, and LR for RA than the RF test in a clinically diverse population. If new criteria are to be devised to help diagnose early RA, anti-CCP should be included because it has a greater diagnostic impact than RF.

Animal models of rheumatoid arthritis: How informative are they?

“…Rheumatoid factor (RF) is found in 70-90% of RA patients but is also detected in healthy individuals and patients with other autoimmune disorders Dorner and Hansen, 2004). The presence of anti-citrullinated protein antibodies (ACPA) is also highly specific to RA (over 90%) and linked with a more progressive, destructive arthritis (Klareskog et al, 2008;Silveira et al, 2007;Snir et al, 2010). ACPA have been described up to 10 years before disease onset and are additionally correlated with RA risk factors such as smoking and periodontal disease (Hensvold et al, 2015;Mahdi et al, 2009;Wegner et al, 2010).…”

Autoanticorpos na artrite reumatoide inicial: coorte Brasília - resultados de uma análise seriada de três anos

“…21,22 According to some authors, CCP2 seems to be as sensitive as RF IgM and more specifi c. Its advantage is to detect antibodies in approximately 15% of RA patients who are negative for RF. [23][24][25][26][27][28][29][30][31] However, Nishimura et al, 8 in their meta-analysis about anti-CCP and RF accuracy for RA, have concluded that isolated positivity for anti-CCP is more specifi c than isolated positivity for RF IgM in the RA diagnosis.…”

“…Therefore, in isolation, CCP2, CCP3 and CCP3.1 showed, in our study, anti-CCP prevalence below that of RF IgM and similar to that of RF IgA, which differs from many studies previously reported. [23][24][25][26][27][28][29][30][31] The sensitivity, specifi city and cost-benefi t difference between the three techniques to detect anti-CCP is still a controversial subject in the literature, requiring further studies in different populations. 32 In 2005, a third generation of anti-CCP (CCP3) was made available for RA laboratory diagnosis.…”

Anti-citrullinated protein antibody and rheumatoid factor in patients with end-stage renal disease

“…Anti-CCP antibodies are highly specific for RA (95%-98%), and may predict the development of RA before occurrence of the first symptoms of the disease, as well as being good indicators or prognosis (2,5,6). Anti-CCP antibodies are more specific than RF for diagnosing RA, and are better predictive factors for an erosive course of disease (7).…”