Transaminitis

In medicine, the presence of elevated transaminases, commonly the transaminases alanine transaminase (ALT) and aspartate transaminase (AST), may be an indicator of liver damage. Other terms employed include transaminasemia, transaminitis (which some sources consider pathologically meaningless) and elevated liver enzymes (though they are not the only enzymes in the liver). Normal ranges for both ALT and AST are 8-40 U/L with mild transaminesemia noted to the upward numerical limit of 250 U/L. Drug-induced increases such as that found with the use of anti-tuberculosis agents such as isoniazid are limited typically to below 100 U/L for either ALT or AST. Cirrhosis of the liver or fulminant liver failure secondary to hepatitis commonly reach values for both ALT and AST in the >1000 U/L range. Elevated transaminases that persist less than six months are termed 'acute' in nature, and those values that persist for six months or more are termed 'chronic' in nature.The liver has transaminases to synthesize and break down amino acids and to convert energy storage molecules. The concentrations of these transaminases in the serum (the non-cellular portion of blood) are normally low. However, if the liver is damaged, the liver cell (hepatocyte) membrane becomes more permeable and some of the enzymes leak out into the blood circulation.In general, any damage to the liver will cause medium elevations in these transaminases, but diagnosis requires synthesis of many pieces of information, including the patient's history, physical examination, and possibly imaging or other laboratory examinations. However, very high elevations of the transaminases suggests severe liver damage, such as viral hepatitis, liver injury from lack of blood flow, or injury from drugs or toxins. Most disease processes cause ALT to rise higher than AST; AST levels double or triple that of ALT are consistent with alcoholic liver disease.