In patients with early rheumatoid arthritis, combining the 2010 RA classification criteria with bone marrow edema as seen on MRI was a more sensitive and accurate diagnostic approach than using the 2010 criteria alone, researchers reported in Annals of the Rheumatic Diseases.
"The present findings are the first evidence that the diagnostic probability of early RA using the 2010 RA classification criteria is improved by combining these criteria with MRI-detected bone marrow edema of the wrist and finger joints," said Dr. Mami Tamai at Nagasaki University in Japan and associates.
The investigators studied 166 patients with early arthritis and a median disease duration of 2 months. They defined RA as using disease-modifying antirheumatic drugs (DMARDs) within the first year or as fulfilling the 1987 RA criteria at 1 year, they said (Ann. Rheum. Dis. 2014 [doi:10.1136/annrheumdis-2013-205074]).
Combining the 2010 criteria with bone marrow edema of the wrists or finger joints on MRI yielded a higher sensitivity (76.3%), negative predictive value (69.3%), and accuracy (75.9%) than did using the 2010 criteria alone with the DMARD-based definition as the reference standard. Applied alone, the 2010 RA classification had a sensitivity of only 61.9%, a negative predictive value of 60.6%, and an accuracy of 70.5%. Results were similar when they used the 1987 definition as the reference standard, the investigators said.
Bone marrow edema had a higher positive predictive value than did MRI-detected bone erosion or symmetrical synovitis when added to the 2010 RA classification criteria. "Our study may strengthen the statements of the European League Against Rheumatism recommendations for the use of imaging," they added.
Funding information for the study was not available. The authors reported no conflicts of interest.