Copper, ceruloplasmin and superoxide dismutase in patients with Alzheimer's disease . a case-control study.

The copper-containing enzyme superoxide dismutase (SOD) is a key enzyme in suppressing the amounts of superoxide anion radicals. Ceruloplasmin, the copper-transporting protein in plasma, also possesses an important redox capacity. In this study the levels of copper and ceruloplasmin as well as SOD-activity and ceruloplasmin oxidative activity were analyzed in order to throw some light on possible defects in copper mechanisms in patients diagnosed with Alzheimer's disease (AD). The study included 44 patients with AD and their healthy age- and gender-matched controls. No difference of significance was seen when comparing the copper or ceruloplasmin concentration in plasma of AD patients to that of their paired controls. The SOD activity in red blood cells was significantly lower in the patients than in their controls (p = 0.019). The ceruloplasmin oxidative activity in plasma of Alzheimer's patients was greatly reduced as compared to that of age- and gender-matched controls and the difference was highly significant (p = 0.0005). Ceruloplasmin activity and SOD activity were not found to be intrinsically correlated. It was postulated that reduced oxidative activity of ceruloplasmin in plasma might be either a cause or a consequence of AD and that reduced SOD activity might further add to the oxidative disturbances in AD due to defective ceruloplasmin activity.