Immunochemical and enzymatic study of ceruloplasmin in rheumatoid arthritis

Forty adult patients (30 women and 10 men) with rheumatoid arthritis (RA), treated with nonsteroidal anti-inflammatory drugs, were studied. Serum leve ls of immunoreactive ceruloplasmin, oxidase activity of the ceruloplasmin a nd total copper, as well as the specific oxidase activity (enzyme activity per unit of mass) and the copper/immunoreactive ceruloplasmin relationship were significantly higher in the group of patients than in the healthy cont rol group (p<0.001). However, no significant difference was found for the c oncentration of non-ceruloplasmin copper between both groups. A statistical ly significant negative correlation was obtained for the concentration of s erum thiobarbituric acid-reacting substances with the immunoreactive cerulo plasmin and its oxidase activity in the group of patients (p<0.005). These results suggest that in RA increases of serum copper are produced at the ex pense of the fraction linked to the ceruloplasmin, diminishing the proporti on of apoceruloplasmin and other forms poor in copper. Although the increas e in the serum concentration of ceruloplasmin might offer an additional saf eguard against oxidative stress, it does not appear to have a beneficial ef fect upon the activity of the illness as evaluated by means the biological inflammation markers C-reactive protein, erythrocyte sedimentation rate and sialic acid.