Plasma copper and antioxidant status in Wilson's disease.

It has been demonstrated that the level of serum copper unbound to ceruloplasmin (loosely bound copper) is increased in Wilson's disease, although the total serum copper concentration is usually low, reflecting a low ceruloplasmin level. To assess the contribution of free radical reactions catalyzed by nonceruloplasmin copper to the development of complications in this disease, we investigated copper and antioxidant status in four untreated patients who had hepatic dysfunction with or without hemolytic anemia and made a comparison with five patients controlled on penicillamine therapy and 19 age-matched healthy children. We found that loosely bound copper in plasma measured by the phenanthroline assay was detectable in three of four untreated patients with Wilson's disease, but was not detectable in the patients during therapy or in the healthy controls. Among the various antioxidants, the ascorbate and urate levels were markedly reduced before treatment (mean +/- SD, 23 +/- 16 microM for ascorbate and 90 +/- 59 microM for urate) compared with the values in the patients during treatment with penicillamine (67 +/- 19 and 302 +/- 78 microM, p < 0.05) and in control children (60 +/- 8 and 254 +/- 48 microM, p < 0.05). We also demonstrated that the plasma concentration of allantoin, an oxidation product of uric acid and a possible marker of radical generation in vivo, was markedly elevated in the untreated patients (11.0 +/- 1.8 versus 4.3 +/- 0.5 microM in patients on therapy and 6.5 +/- 0.8 microM in controls, p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)