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

## TL;DR

This study compares the effectiveness of RF and anti-CCP antibody tests for diagnosing rheumatoid arthritis and finds that anti-CCP is more specific and better for early diagnosis.

## Contribution

The study provides a direct comparison of RF and anti-CCP antibody diagnostic performance in a clinical setting.

## Key findings

- Anti-CCP antibodies showed higher specificity (96.7%) compared to RF (78.3%).
- Combined testing improved sensitivity (88.3%) and specificity (95.0%).
- Anti-CCP correlated significantly with disease activity and radiological erosions.

## Abstract

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.