Importance of reactive oxygen species in rheumatoid arthritis.

Free radical oxidation--peroxidation products, superoxide dismutase (SOD) activity--and nonproteic thiols were measured in blood from 10 normal subjects and 10 patients with rheumatoid arthritis (RA). Peroxidation products and SOD activity have been found significantly elevated, while blood nonproteic thiols have been found significantly lower in RA patients, as compared to normal controls. Also, plasmatic concentration of ceruloplasmin has been found significantly higher in RA patients than in controls.