Three-year clinical outcome following baseline magnetic resonance imaging in anti-citrullinated protein antibody-positive arthralgia patients: an exploratory study.

Three-year clinical outcome following baseline magnetic resonance imaging in anti-citrullinated protein antibody-positive arthralgia patients: an exploratory study ABSTRACT Objective: To investigate whether magnetic resonance imaging (MRI) can visualize subclinical synovitis in arthralgia patients with positive anti-citrullinated protein antibodies (ACPA), and to determine the relationship between MRI and development of clinical arthritis during 3 years of followup. Methods: MRI scans of both hands/wrists of 28 patients were scored for synovitis and bone marrow edema (BME) according to OMERACT RAMRIS. Cumulative MRI scores (range 0-288) were composed by summing joint scores (synovitis and BME) of wrists, metacarpophalangeal and proximal interphalangeal joints. Development of clinical arthritis was monitored annually during at least 3 consecutive years. MRI scans in healthy volunteers (n=4) were included for comparison. Results: MRI depicted signs of inflammation in at least 1 hand/wrist joint in 26/28 (93%) patients. within the arthritis group, a score 2 synovitis on MRI was associated with a short-term (< 1 year) development of clinical arthritis in at least 1 joint. A higher level of cumulative MRI score was related to aging, both in patients and healthy controls. Conclusion: (Mild) inflammatory joint signs are frequently present on MRI of hand/wrists in ACPA-positive arthralgia patients without clinical arthritis. Strikingly, only a part of the MRI positive patients developed clinical arthritis during 3 years of followup and MRI abnormalities were also observed in healthy controls. The high frequency of MRI abnormalities may be partly related to aging.