“…These disadvantages also apply to isocitrate dehydrogenase (Watts, 1966;Goldberg et al, 1966) despite earlier reports that its activity in serum is usually normal in hepatobiliary obstruction but almost invariably raised in parenchymal disease of the liver (Bell, Shaldon, and Baron, 1962). However, it is much more specific for liver disease than the aminotransferases and is somewhat more sensitive in detecting acute hepatic damage, especially that due to drugs (Watts and Griffiths, 1964), alcohol (Goldberg and Watts, 1965), and infectious mononucleosis (Dunnet, 1963). Serum adenosine deaminase activity was shown by the author to be raised in hepatic parenchymal disease, but is usually normal in extrahepatic obstruction (Goldberg, 1965;Goldberg et al, 1966).…”