To compare late onset with adult onset rheumatoid arthritis.
Fifty-eight patients with late onset rheumatoid arthritis (LORA) were compared to 117 patients with adult onset rheumatoid arthritis (AORA) with respect to clinical and functional parameters. Furthermore, in 104 patients serum cartilage oligomeric matrix protein (COMP) was measured. Results were compared by means of ANOVA and possible influences of age, gender and clinical parameters were evaluated by Spearman rank correlation.
Except a different distribution in gender (40% males in the LORA group) and a higher ESR, no differences could be found with respect to clinical parameters. However, a significantly higher HAQ score and significantly higher serum-COMP levels could be shown in the LORA group. HAQ scores correlated not only with disease activity parameters (C-reactive protein, disease activity score) but also with the age. Serum-COMP levels did show a correlation with the age as well, but not with disease activity.
It is concluded that the higher serum-COMP levels in late onset rheumatoid arthritis could be due to concomitant osteoarthritic processes in larger joints, which are not symptomatic. The age dependence of the HAQ score is only weak, but may be the reason why patients with LORA show a worse functional capacity compared to patients with adult onset rheumatoid arthritis.