Alanine Aminotransferase (ALT/SGPT) Unit Conversion

Alanine aminotransferase (glutamate pyruvate transaminase) belongs to the transaminases, which catalyze the interconversion of amino acids and α‑ketoacids by transfer of amino groups. Although most activity of the enzyme is found in the liver, significant activity has also been seen in the kidneys, heart, skeletal muscle, pancreas, spleen and lung tissue.

Since the specific activity of ALT in the liver is approximately 10 times that of heart and skeletal muscle, elevated serum ALT activity is mainly regarded as an indicator of parenchymal liver disease. ALT is present in the cytosol of hepatocytes, and increased serum levels indicate deterioration in the integrity of the hepatocyte plasma membrane. ALT has greater diagnostic sensitivity for hepatobiliary disease than AST. Activities >50 times the upper reference limit are mainly associated with acute viral hepatitis, acute disorders of liver perfusion and acute liver necrosis due to ingestion of toxins including paracetamol and carbon tetrachloride. Markedly elevated serum ALT levels may be found in a variety of diseases involving the liver, including hepatitis, mononucleosis and cirrhosis. Elevated ALT levels may be detected in viral hepatitis and other forms of liver disease prior to development of overt clinical symptoms such as jaundice. Levels greater than 15 times the upper reference limit are always indicative of acute hepatocellular necrosis of viral, toxic or circulatory origin. Increased ALT levels may also be detected in cirrhosis and extrahepatic cholestasis.

Slight or moderate increases in ALT levels may also be observed after ingestion of alcohol, or administration of drugs including penicillin, salicylates or opiates.

Method based on the recommendations of the “International Federation for Clinical Chemistry” (IFCC).