Old age at onset of early rheumatoid arthritis (RA) is associated with more frequent bone erosions, according to a study published online Nov. 11 in the International Journal of Rheumatic Diseases

Koichi Murata, from Kyoto University in Japan, and colleagues examined how old age at disease onset affects treatment and prognosis in early RA using data from the Kyoto Rheumatoid Arthritis Management Alliance cohort.

Bone erosions

A total of 2,182 patients with RA were enrolled in the cohort from 2011 to 2015; 239 were newly diagnosed and followed for two years. The patients were classified as young-onset RA (YORA), which included patients <60 years (117 patients), and elderly-onset RA (EORA), which included patients ≥60 years (122 patients).

The researchers found that at baseline, disease activity was higher in EORA than YORA. At one or two years, disease activity was equivalent in EORA and YORA; however, there were more bone erosions at baseline and at two years among EORA patients.

About 10 percent of YORA patients had erosions; among anticitrullinated protein autoantibody-positive EORA patients without erosions at baseline, more than 25 percent had bone erosions even if they attained clinical remission at one or two years.

More than 25% of the anti?citrullinated protein autoantibody (ACPA)?positive EORA patients without erosions at baseline had bone erosions even if they attained clinical remission at 1 or 2 years, while ~10% of YORA patients had erosions.

"Optimal therapy preventing radiological damage should be considered for EORA," the authors write. Bone erosions were more frequently found in EORA. Clinical remission at 1 or 2 years was not enough to protect bone erosions in the ACPA?positive EORA patients. Optimal treatment strategies preventing radiological damage should be considered for EORA.