Diagnosis, prognosis and classification of early arthritis: results of a systematic review informing the 2016 update of the EULAR recommendations for the management of early arthritis

OBJECTIVE: To update the evidence pertaining to the diagnosis, prognosis and classification of patients with early arthritis (EA), and to inform the 2016 European League Against Rheumatism (EULAR) recommendations for the management of patients with EA. METHODS: MEDLINE, EMBASE and Cochrane databases were searched up to October 2015. The first part of the systematic literature review (SLR) involved a search for studies investigating the recognition and referral of EA. The second part involved a search for studies to identify the place of laboratory and imaging tests in establishing a diagnosis and a prognosis in patients with EA. RESULTS: Regarding the issue of referral of patients with EA (1643 hits), 4 studies were included. These studies were in support of early referral for patients with EA. Regarding the issue of diagnosis and prognosis of patients with EA (11 435 hits), 88 studies were included, evaluating mainly the value of rheumatoid factor (RF) and anticitrullinated-peptide antibodies (ACPAs). Sensitivity of these antibodies for a RA diagnosis in patients with EA was moderate (40–80%). Specificity was higher, notably for ACPAs (frequently >80%). ACPAs also showed better prognostic performance than RF (negative predictive values around 80%). We confirmed that structural damage on baseline X-rays is predictive of further radiographic progression in patients with EA. Regarding other imaging modalities, data are sparse. CONCLUSIONS: This SLR highlights the importance of early referral for patients with EA and confirms that RF and mainly ACPAs as well as a search for structural X-rays changes may help in the diagnosis and prognosis of patients with EA.