Elevated transaminases

In medicine, the presence of elevated transaminases, commonly the transaminases alanine transaminase (ALT) and aspartate transaminase (AST), may be an indicator of liver dysfunction.^[1][2] Other terms include transaminasemia,^[3] and elevated liver enzymes (though they are not the only enzymes in the liver). Normal ranges for both ALT and AST vary by gender, age, and geography and are roughly 8-40 U/L (0.14-0.67 μkal/L).^[4] Mild transaminesemia refers to levels up to 250 U/L.^[1] 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. Muscle sources of the enzymes, such as intense exercise, are unrelated to liver function and can markedly increase AST and ALT.^[5] 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; however, many people with liver disease have normal transaminases.^[6][7] 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.