Serum alkaline phosphatase isoenzymes as markers of liver disease.

A perspective on serum alkaline phosphatase isoenzymes in liver disease is provided with a brief discussion of the location of the enzyme in liver and its presumed function. Mechanisms of entry of alkaline phosphatase into serum in liver disease are discussed. Characterization of high molecular weight alkaline phosphatase in obstructive jaundice is reviewed. The relationship between blood group O and the appearance of the intestinal enzyme in sera of such subjects with cirrhosis of liver is discussed. Properties of hepatoma alkaline phosphatase and the genesis of liver alkaline phosphatase in diseases not related to the liver are explored. Methods for detection of serum alkaline phosphatase isoenzymes in liver disease are discussed from the standpoint of the limitations of electrophoretic procedures, and the promise of procedures such as isoelectric focusing and high performance liquid chromatography that are currently non-routine.