Anti-CCP generally refers to anti-cyclic citrullinated peptide antibodies and is one of the diagnostic criteria for the classification of RA (rheumatoid arthritis). It is important for the diagnosis of rheumatoid arthritis. 1. The diagnostic sensitivity of anti-cyclic citrullinated peptide antibody for rheumatoid arthritis is 50%~78%, and this antibody helps in the early diagnosis of rheumatoid arthritis. 2. Anti-cyclic citrullinated peptide antibody-positive rheumatoid arthritis patients have more severe bone destruction than negative patients, and it is positively correlated with the activity of rheumatoid arthritis. Patients with rheumatoid arthritis often develop irreversible bone and joint damage within two years of the onset of the disease. 3. The normal value of anti-cyclic citrullinated peptide antibody varies according to the different testing reagents and methods used in each hospital. The level of the result is closely related to the prognosis of recovery. The lower the result, the better the prognosis and the lower the risk of disability. Higher results indicate a poorer prognosis and a greater risk of disability. If the anti-cyclic citrullinated peptide antibody is positive and the test result is high, you should go to the hospital for further examination to identify rheumatoid arthritis and take appropriate treatment as prescribed by the doctor.