No abstract

Abstract. Serum guanase has been observed to rise sensitively in hepatitis but was a quite insensitive indicator of extrahepatic jaundice and liver cirrhosis. Thus serum guanase determination, despite its relative specificity for liver damage, appears not to be sensitive enough for an indicator test of liver disease. In respect to sensitivity the serum γ‐glutamyl transpeptidase (γ‐GT) test was observed to fulfil best the expectations also in anicteric patients, and was elevated particularly in extrahepatic biliary obstruction. Serum ornithine carbamoyl transferase (OCT) activity was observed to rise in hepatitis and in extrahepatic jaundice. Because of its specificity for liver tissue, OCT is the most certain test for detection of liver damage. The differentiation of hepatocellular jaundice from extrahepatic obstruction was noted to be best achieved by means of the serum guanase and alkaline phosphatase ratio. This still leads in about 10% to a misleading diagnosis in the differentiation of these clinical states.