A nationwide study: prevalence of rheumatoid factor and anti- citrullinated peptide positivity and their contribution to rheumatoid arthritis diagnosis

Abstrakt

AbstractAim: Rheumatoid factor (RF) and Anti Citrullinated Peptide (anti-CCP) is specific for rheumatoid arthritis (RA) diagnosis. However they could be positive in other disease and even healthy populations. It was aimed to investigate the prevalence of positive RF and anti-CCP antibodies in persons admitted to hospital for any reason and on a national scale.Material and Method: The National Electronic Health Database, which contains the clinical records of over eighty million people, is used to design this multi-center, retrospective cohort study. The subjects included in the study were divided into age groups in 10-year periods. RA cases were identified by using ICD-10 codes that included M05,M06, M08,and their subgroups. RF and anti-CCP positivity were evaluated in terms of their contribution to the risk of being diagnosed with RA, with the change according to age and genderResults: During the 1.1.2018-31.12.2021 period, 13.918.072 RF tests were performed in 11.849.440 people, whereas 1.183.607 anti-CCP test were performed in 1.020.967 people. 797.089 people had at least once both tests performed. RF positivity rate in patients who only requested RF test was 14.72% and it was 35.04% for anti-CCP positivity in only requested anti-CCP tests. The rate of concomitant RF and anti-CCP positivity was 22.56%.RA diagnosis is made in in 27.8% of RF-positive people, in 39.73% of anti-CCP-positive people and in %56.6 of co RF and anti CCP positive people. RF positivity and concomitant RF and anti-CCP positivity increased with the age and more common in females.Conclusion: RF and anti-CCP positivity could be seen in a healthy population with female predominance. As the age increases, the risk of RF positivity is increased, however anti –CCP positivity does not change. Concomitant RF and anti-CCP positivity has the highest risk of RA development with respect to either antibody positivity alone.