Laboratory measures of copper metabolism in the differentiation of chronic active hepatitis and Wilson disease in children.

The accuracy of the serum ceruloplasmin level in distinguishing chronic active hepatitis from Wilson disease was compared to the 24-hour urinary copper excretion and hepatic copper content in 20 untreated patients with chronic active hepatitis and 25 with Wilson disease. Serum ceruloplasmin levels were decreased in five patients (25%) with chronic active hepatitis and were normal in seven patients (28%) with Wilson disease at the time of diagnosis. The 24-hour urinary copper excretion failed to provide accurate discrimination between the two groups, being elevated in all patients with Wilson disease and in five of eight patients with chronic active hepatitis studied. All patients with Wilson disease had hepatic copper levels greater than 400 microgram/gm dry weight, whereas patients with chronic active hepatitis had levels less than 300 microgram/gm dry weight. The discriminatory value of hepatic copper concentration makes this the most reliable test for differentiating chronic active hepatitis and Wilson disease in children and adolescents. The serum ceruloplasmin level may not be significantly accurate for definitive diagnosis in this age group.