Very recent onset arthritis: the value of initial rheumatologist evaluation and anti-cyclic citrullinated peptide antibodies in the diagnosis of rheumatoid arthritis

摘要

The objective of this study is to identify baseline factors associated with rheumatoid arthritis (RA) diagnosis at the end of 1-year follow-up in a cohort of patients with very recent onset arthritis. Incident cases with self-reported arthritis (≤12 weeks) referred by primary care physicians were assessed by a designated rheumatologist who predicted in those with ≥1 swollen joint the diagnosis of RA at the end of follow-up. Patients were regularly seen and diagnosed through follow-up by staff rheumatologists who were blind to diagnostic prediction. Of 119 referrals, 78 (65.5%; age 35.5 ± 13.5 years; 69 females) were diagnosed at baseline as very recent onset arthritis (median duration 6 weeks (0–12 weeks)); of 75 patients completing 1-year follow-up, 51 (66.5%) were classified as RA; 12 (16%) had self-limited arthritis; and 13 (17.5%) other diagnoses. The characteristics of patients with RA as final diagnosis were polyarthritis, morning stiffness ≥1 h, high counts of swollen joints, and low frequency of systemic symptoms. Rheumatologist prediction of RA and anti-cyclic citrullinated peptide (anti-CCP) antibodies was strongly associated with RA as a final diagnosis in the logistic regression analysis. Sensitivity and specificity of the rheumatologist prediction were 94% and 74%, for anti-CCP antibodies, 56% and 96%; the combination of both variables had a specificity of 100% and a sensitivity of 53%, and a positive predictive value of 98%. The combination of RA as predicted diagnosis by a rheumatologist and anti-CCP antibodies is highly specific for RA diagnosis in patients with very early arthritis.