Effect of RF and Anti-CCP antibody for Rheumatoid Arthritis diagnosis: A comparative study

Rheumatoid arthritis (RA) is a long-term autoimmune disease that needs to be diagnosed as soon as possible in order to achieve maximum treatment results. Although rheumatoid factor (RF) has been a conventional serologic test, the anti-cyclic citrullinated peptide (anti-CCP) antibodies are now considered a more specific diagnostic test. Therefore, it is of interest to determine the diagnostics performance of RF and anti-CCP antibody tests in suspected RA patients in a tertiary care hospital. One hundred and eighty participants will be recruited, that is, 120 participants diagnosed with RA clinically (according to the 2010 ACR/EULAR definitions) and 60 age-matched controls. RF in serum samples was studied by nephelometry and the anti-CCP antibodies through enzyme-linked immunosorbent assay (ELISA). Anti-CCP antibodies were more specific (96.7% vs. RF, 78.3%), whereas the sensitivity was also similar (81.7% vs. 75.0% respectively). Anti-CCP (96.1) had a better positive predictive value than RF (85.7%). The sensitivity (88.3%) and specificity (95.0%) with combined testing were improved. Anti-CCP was found to have significant correlations with disease activities and radiological erosions. Data shows uphold anti-CCP antibodies as a better diagnostic tool than RF in Diagnosing RA and the combination of the two tests provides the best diagnostic value in the early stages of the disease and prognostication.