Serum antioxidant activity and related variables in rheumatoid arthritis. Behaviour during sulphydrylant treatment.

Some parameters (serum antioxidant activity, -SH groups, ceruloplasmin, copper) involved in the mechanisms of defence against oxygen free radicals were investigated in 25 rheumatoid patients and in 15 control subjects, matched for sex and age. When comparing the results obtained in the two groups, there is in rheumatoid arthritis a marked increase in the serum-specific antioxidant activity, related to ceruloplasmin, ESR, haemoglobin and Ritchie's index and a net decrease in the -SH groups inversely related to Ritchie's index and to ceruloplasmin. On analysing the sensitivity of the various parameters in discriminating between rheumatoid and healthy subjects, it is found that the -SH groups are the most sensitive, followed by the specific antioxidant activity, copper content, and ceruloplasmin. The evaluation of the same parameters in a group of 14 rheumatoid patients before and after 6 months of therapy with an antioxidant drug, viz. Tiopronin, confirms their usefulness in providing information regarding response to the treatment and on the recovery from the disease.