Serum xanthine oxidase in jaundice.

Serum xanthine oxidase activity was measured by a radiochemical method in 137 consecutive patients with jaundice of varying etiology and in 40 non-jaundiced patients with liver or other disease. Serum xanthine oxidase was markedly increased, up to 50 times the upper normal limit (mean + 2 S.D.), in 32 out of 34 patients with infectious hepatitis. A slight elevation of serum xanthine oxidase, up to twice the upper normal limit, was found in 2 out of 49 patients with extrahepatic obstructive jaundice and in 4 out of 20 patients with chronic renal failure. In comparison to serum glutamic-oxaloacetic transaminase and lactate dehydrogenase serum xanthine oxidase appeared to be the more sensitive and specific indicator of acute hepatocellular damage.