Hepatic collagen proline hydroxylase activity in primary biliary cirrhosis.

The enzyme collagen proline hydroxylase has been measured in liver biopsies from fourteen patients with primary biliary cirrhosis. The activity was elevated in ten of the patients, but not to the degree previously found in patients with active cirrhosis. There was no correlation between the enzyme activity and the liver copper concentration, which was elevated in all except one of those measured. This suggests that excessive collagen synthesis in PBC is not directly related to the high liver copper concentrations.