Red blood cell copper, zinc superoxide dismutase activity is higher in Alzheimer's disease and is decreased by D-penicillamine.

Copper, zinc superoxide dismutase (Cu, Zn SOD) activity was measured in red blood cells (RBC) of 32 patients affected by Alzheimer's disease (AD), eight other AD patients treated with the copper-chelating agent D-penicillamine, 13 first-degree relatives and 22 controls. All AD patients enrolled in our study showed a higher level of Cu, Zn SOD activity early in the disease. No correlation between apolipoprotein E genotype and SOD activity was found in AD patients. D-penicillamine treatment of AD patients for 24 weeks lowered the enzyme activity even below the control value. These results support the hypothesis that a higher level of Cu, Zn SOD activity in RBC can be an early diagnostic peripheral marker of this disease and a sensor to monitor treatments with copper-chelating drugs.