Elderly-onset rheumatoid arthritis: ageing as an independent marker for better joint prognosis

Abstract

To study the contribution of age to the outcome of rheumatoid arthritis (RA), 133 elderly-onset RA (ERA) patients (onset above 60-year-old) were selected out of 2164 out-patients with RA who (i) first visited the hospital within 2 years after onset of the disease, (ii) received no remission inducing drugs previously and (iii) who were treated in this hospital regularly without interruption for more than 2 years. The joint score of ERA patients between initial visit and final visit to the hospital was compared with that of matched 133 younger-onset RA (YRA) patients (onset below 60-year-old). Results indicated that, in ERA, the patients with no active joints requiring no remission inducing drugs were increased on final visit (P<0.001). Joint score at disease onset or on initial visit to the hospital was similar in the two groups, whereas joint score on final visit was significantly decreased in ERA (P=0.0001). In ERA, progression of the small joint disease and joint erosion was not accelerated, and the small joint disease was in fact decelerated as compared with YRA (P<0.0001) during initial visit and final visit. Discriminant function analysis of patients with or without no active joints on final visit reveals that joint erosion, in small joints on initial visit is a predictor of joint prognosis in ERA. The two groups were similar with regards to sex, disease duration, onset type and rheumatoid factor/antinuclear antibody positivity. Thus, older age is an independent marker of better joint prognosis of RA