ALT/GPT is present in high concentration in liver and to a lesser extent in kidney, heart, skeletal muscle, pancreas, spleen and lung. Increased levels of ALT/GPT however is generally a result of liver disease associated with some degree of hepatic necrosis such as cirrhosis, viral or toxic hepatitis and obstructive jaundi­ce. Characteristically ALT/GPT is generally higher than AST/GPT in acute viral or toxic hepatitis, whereas for most patients with chronic hepatic disease, ALT/GPT levels are generally lower than AST/GPT levels. Elevated ALT/GPT levels have also been found in extensive trauma and muscle disease, circulatory failure with shock, hypoxia, myocardial infarction and haemolytic disease.