Alanine aminotransferase (ALT or GPT) test
Liver Function Panel
Definition and Patient Education
This topic is for general information about ALT test but it includes sections for medical technicians and medical lab specialist and links referring to these sections. If you want to read the technical sections, follow the links that refer to it.
2) What is the ALT?
We all hear about liver enzymes that are tested to detect liver diseases. These enzymes are:-
- ALT or Alanine Aminotransferase enzyme – previously known as Serum Glutamic-Pyruvic Transaminase; SGPT; GPT.
- AST or Aspartate Aminotransferase (AST) – previously known as Glutamic-oxaloacetic transaminase (GOT)
AST is present with a large amount in the liver, kidneys, cardiac muscle, and skeletal muscle and with small amounts in the brain, pancreas, and lungs. ALT found principally in the liver with only small amounts in other organs.
When the liver cell damaged due to virus infection, for example, these enzymes will exit from the cell to the blood circulation and thus their presence in high amounts in the blood indicate liver cell damage. Although AST and ALT are raised due to liver damage, ALT is more specific for detecting liver damage than AST because it found principally in liver cells.
Also AST is raised in case of heart or skeletal muscles damage.
3) Why it is required?
To detect and investigate liver is damage and to monitor the patient who take drugs that may cause damage to liver cells such as antiretroviral drugs which is used to control HIV infections. In addition, it is required to monitor the risk of hepatitis virus infection if you are infected.
4) When should you get tested?
When the physician thinks that you have symptoms of a liver disorder such as:-
- Weakness, fatigue
- Loss of appetite
- Nausea, vomiting
- Abdominal swelling and/or pain
- Dark urine, light-colored stool
Also, the physician requests this test to follow up the effect of the drug you take for treatment of hepatitis infection or when the patient has an increased risk for liver disease since many people with mild liver damage will have no signs or symptoms. For example:-
- Persons who have a history of known or possible exposure to hepatitis viruses.
- People drink alcohols.
- A family history of liver disease.
- Persons who take drugs that might damage the liver
- Obese or diabetic patients.
5) What are the needed preparations before the test?
No special preparations are required before testing.
This is section for medical technicians or medical lab specialists. If you want to read it, read in Required sample for ALT test in lab.
This is section for medical technicians or medical lab specialists. If you want to read it, read in Procedure of ALT test in lab.
This is section for medical technicians or medical lab specialists. If you want to read it, read in Sources of errors in ALT test in lab.
V) Quality Control:-
This is section for medical technicians or medical lab specialists. If you want to read it, read in Quality control of ALT test in lab.