The Uses of the SGOT Test

The SGOT (Serum Glutamic-Oxaloacetic Transaminase) test is commonly done as part of an expanded chemistry panel and is considered by most to be a good measure of the health of the liver. The SGOT is also called the aspartate transaminase test or AST. While it is believed to be a measure of liver health, the SGOT is not just found only in the liver. This means that other issues could affect the SGOT level besides the liver.

The SGOT is found in the heart, liver, kidneys, skeletal muscle, red blood cells and brain. It is the enzyme that catalyzes the conversion of the amino acid aspartate and alpha-ketoglutarate into glutamate and oxaloacetate.

The SGOT is part of the liver function studies that include the ALT and alkaline phosphatase. If there is liver damage, the tissue in the liver releases these enzymes and the SGOT would be elevated. You would also find elevations of the ALT and alkaline phosphatase. If there is heart damage, the SGOT will be elevated as well. Certain muscle injuries also will show elevations of the SGOT.

The problem with diseases of the liver is that there are few symptoms of a damaged liver. The patient may have an enlarged liver but this is something only a doctor can determine at the time of an examination. The patient may have a decreased level of consciousness and jaundice but this is only when the damage to the liver is severe. The most severe manifestation of a bad liver is a hepatic coma, which is actually quite rare as liver diseases go.

If the heart is damaged and revealing an elevated SGOT, there will likely also be an elevated CPK and LDH level. LDH can be found in other muscles besides the cardiac muscle but there are tests that can determine the origin of the particular kind of LDH found in the blood.

Kidney damage, pancreatic damage, skeletal muscle damage and red blood cell damage can also show SGOT elevations but they often show other elevations that are more specific to the organ. For example, pancreatic damage, while showing elevations in the SGOT, will also show marked elevations in the amylase and lipase levels. These enzymes are considered much more specific to the pancreas and are better tests than the SGOT alone.

The SGOT is a nonspecific marker for liver disease and can be elevated in a viral infection of the liver, in chemical hepatitis, in infectious mononucleosis, in gallbladder disease, in toxic disease of the liver, in alcoholic liver disease and in many types of cancer that begin or go to the liver. It takes further evaluation with viral titers, gallbladder evaluation, a good history, and possibly a biopsy of the liver or Ultrasound scan of the liver in order to determine what really is the problem. The SGOT test is therefore just a screening test that leads the doctor to finding out what’s really going on.