Early Diagnosis of Rheumatoid Arthritis Combining the Japan College of Rheumatology Diagnostic Criteria for Detecting Rheumatoid Arthritis and Serum-level Anticyclic Citrullinated Peptide Antibodies

Early diagnosis and treatment may prevent irreversible damage arising from rheumatoid arthritis (RA). However, the American College of Rheumatology (ACR) classification criteria has suggested difficulties with early diagnosis. While the Japan College of Rheumatology (JCR) diagnostic criteria for early RA may be useful, their low specificity implies inadequacy. Therefore, the combined use of serum-level of a anticyclic citrullinated peptide (anti-CCP) antibody test with JCR diagnostic criteria was evaluated. Seventy patients with recent-onset undifferentiated arthritis for 1.9±2.7 months who did not meet the ACR 1987 classification criteria were evaluated in a prospective study. The patients were examined to determine whether they met the JCR diagnostic criteria and then tested for serum levels of anti-CCP antibodies. They were re-evaluated at one year after onset for the diagnosis of RA using the ACR classification criteria. All eight patients who met the JCR diagnostic criteria with positive anti-CCP antibodies were diagnosed RA, suggesting that the combination of these two items is highly likely to determine RA. Among nine patients with negative anti-CCP antibodies - but who met the JCR diagnostic criteria; namely three were diagnosed RA; the other hand, among eight patients who did not meet the JCR diagnostic criteria - but with positive anti-CCP antibodies, six were diagnosed RA; and among 45 patients who did not meet the JCR diagnostic criteria and exhibited negative anti-CCP antibodies, five progressed to RA. These findings suggest that a combination of the JCR diagnostic criteria and anti-CCP antibody test can improve the accuracy of early RA diagnosis.