Effect of long-term penicillamine therapy on erythrocyte CuZn superoxide dismutase activity

The effect of long-term penicillamine therapy on erythrocyte CuZn superoxide dismutase activity was investigated. For comparison the serum ceruloplasmin and serum copper contents were also analysed. Seven of the 11 penicillamine-treated patients had CuZn superoxide dismutase activities below the reference interval of the parameter. Levels down to about 50% of the mean of controls were observed in several cases. In five and in four of the 11 patients respectively decreases in serum ceruloplasmin and serum copper were found. Whereas among the penicillamine-treated patients there was a good correlation between serum ceruloplasmin and serum copper, the correlation between these parameters and erythrocyte CuZn superoxide dismutase was only fair. Erythrocyte CuZn superoxide dismutase is probably a suitable parameter for monitoring intracellular copper availability during penicillamine therapy.