The clinical and radiographic course of early undifferentiated arthritis is not dependent on the presence of erosions in ≥3 joints, which is the definition of radiographic disease as defined by the European League Against Rheumatism (EULAR) task force, according to results published in RMD Open.
These results indicated that all patients with suspected rheumatoid arthritis (RA) should be treated equally until the clinical course indicates whether or not clinical remission and radiographic non-progression can be achieved.
The study included 592 participants with early undifferentiated arthritis (disease duration ≤1 year) who had not received any previous disease-modifying antirheumatic drugs (DMARDs). Participants who did not meet the American College of Rheumatology/EULAR (ACR/EULAR) 2010 criteria for RA were separated into radiographic and nonradiographic groups, depending on whether or not they had radiographic changes that met the EULAR task force criteria for erosive disease (≥3 joints with erosions). The primary outcome measure was the radiographic progression detected with the Ratingen erosion score. The secondary outcomes were Health Assessment Questionnaire (HAQ) and the Disease Activity Score assessing 28 joints (DAS28).
A total of 240 participants were not classified as having RA according to 2010 ACR/EULAR criteria at baseline. For 57 of these participants, radiographs at the first visit were unavailable. The other participants had radiographic (n=133) and nonradiographic arthritis (n=50).
All participants initiated treatment with DMARDs. During an average follow-up of 4 years, there were no differences in DAS28 and HAQ scores between participant groups.
Participants with initially radiographic arthritis had higher average erosion scores. However, participants with initially nonradiographic arthritis had higher progression of erosion scores with less subsequent radiologic progression (3.3 vs 0.4 erosions per year, respectively; P <.0001).
“These data strongly suggest that…[the] presence of 3 or more joints with erosions at disease onset does not reliably select patients with more clinical activity or radiographic progression during the further course of the disease,” the researchers wrote.
Disclosures: The study was conducted without special funding. The Swiss Clinical Quality Management cohort has received grants from the Swiss Health authorities, the Swiss academy for Medical Sciences and private companies (Pfizer, AbbVie, MSD, Aventis, Bristol- Myers, Mepha, Merck, Novartis and Roche).
Mueller RB, Kaegi T, Haile SR, et al. Clinical and radiographic course of early undifferentiated arthritis under treatment is not dependent on the number of joints with erosions at diagnosis: results from the Swiss prospective observational cohort [published online June 6, 2018]. RMD Open. doi:10.1136/ rmdopen-2018-000673