Up to 50% of people with RA have negative anti-CCP and RF tests the first time. Up to 20% of these people continue to have ...

The usefulness of rheumatoid factor (RF) is hampered by low specificity and possible absence in the first year of the disease. Antibodies to cyclic citrullinated peptide (CCP) have high ...

Additionally, people who test positive for both rheumatoid factor and anti-CCP are more likely to have a rapid progression of joint damage than people who are positive for one or the other.

Rheumatoid factor is felt to be less useful in diagnosing RA in this population, as the prevalence of autoantibodies increases with age. Anticyclic citrullinated antibody (CCP) may be a more ...

Each patient was also genotyped for markers in the HLA region and tested for two hallmarks of the disease: rheumatoid factor (RF) and antibodies to cyclic citrullinated peptides (CCP). Comparisons ...