Background/Purpose: Magnetic resonance imaging (MRI) is increasingly used as an adjunct to the physical examination in early rheumatoid arthritis (RA). Characteristic differences in MRI findings between patients with early seropositive and seronegative RA have not previously been described. We aimed to determine whether hand and/or wrist MRI findings differed between patients with incident RA based on autoantibody status.

Methods: Patients with incident RA from a population-based cohort between 1999-2014 who fulfilled either the 1987 or 2010 ACR/EULAR classification criteria for RA were retrospectively reviewed. Patients who underwent MRI of the hand and/or wrist within ± 1 year of fulfillment of the earlier of 1987 or 2010 classification criteria as part of their routine clinical care were identified using Current Procedural Terminology (CPT) codes. Studies were confirmed via manual chart review. MRI images were reviewed and scored according to the Outcome Measures in Rheumatology Clinical Trials (OMERACT) RA MRI scoring system (RAMRIS), by an experienced musculoskeletal radiologist blinded to patients’ clinical data. Studies with incomplete images or artifact precluding scoring were excluded at the radiologist’s discretion. Serial studies of the ipsilateral hand or wrist were excluded for each patient. RAMRIS scores were compared between seronegative (RF-, CCP-) and seropositive (RF+ and/or CCP+) patients using generalized linear models, with random intercepts to account for multiple studies per patient.

Results: 86 patients with a total of 137 MRI studies of the hand and/or wrist were included for RAMRIS scoring. RF and/or CCP were negative in 53 (62%) of patients. Patients were 71% female, mean age 54.7 (SD 12.5) years, 95% white, 19% current smokers with no significant differences between groups.

57 total hand studies were scored. Mean total hand RAMRIS score was 7.4 (SD 5.1) for seropositive and 8.9 (SD 6.3) for seronegative patients. Mean synovitis, bone erosions, and bone marrow edema scores were comparable between groups (Table).

55 total wrist studies were scored. Mean total wrist RAMRIS score was 9.8 (SD 13.9) for seropositive and 7.8 (SD 6.1) for seronegative patients. Mean total wrist bone marrow edema score was 7.3 (SD 11.3) for seropositive and 2.4 (SD 3.2) for seronegative patients. Mean synovitis and bone erosions scores were comparable between groups (Table).

Estimates using generalized linear models showed that wrist bone marrow edema scores were on average 4.9 RAMRIS units higher in seropositive vs seronegative patients (p=0.014). There was a trend toward higher hand bone marrow edema scores in seronegative vs seropositive patients by 1.07 RAMRIS units that did not reach significance (p=0.067). Other mean RAMRIS scores did not differ significantly between groups.

Conclusion: RAMRIS scores for MRIs of the hands and wrists performed as part of routine clinical care for patients with early, incident RA varied widely. Mean wrist bone marrow edema score was significantly higher in seropositive vs seronegative patients, though mean total RAMRIS scores, synovitis scores, and bone erosions scores did not differ significantly based upon autoantibody status.

« Back to ACR Convergence 2021

ACR Meeting Abstracts - https://acrabstracts.org/abstract/magnetic-resonance-imaging-findings-in-early-rheumatoid-arthritis-are-there-differences-based-on-autoantibody-status/