What is ALT (alanine aminotransferase)?

What is ALT – Alanine aminotransferase

Alanine aminotransferase (ALT) is an enzyme that is normally found in liver cells and some other tissues in the body. ALT is a measure of liver function and an increase in its levels in the blood may indicate damage or disease in liver cells.

Why is ALT analyzed?

The ALT value is often used together with other blood tests such as AST (aspartate aminotransferase), ALP (alkaline phosphate) and bilirubin to diagnose and monitor liver diseases. The ALT value is useful in early diagnosis when clinical findings are absent. Here are a couple of reasons to analyze ALT:

ALT is more specific for the liver than AST and is mainly found in liver cells. This makes it an important marker for detecting damage and diseases affecting the liver.
Elevated ALT levels are seen in liver damage, this can be used as an early indicator to identify liver problems, especially in acute damage caused by, for example, viral hepatitis or toxic substances.
When analyzing both ALT and AST, doctors can tell the difference if it is the liver or some other organ that has been damaged. If the AST value is more elevated, this may indicate damage to another organ, such as the heart.
Monitoring and treatment of the liver diseases hepatitis and cirrhosis caused by factors such as viruses, drugs and alcohol is done by monitoring ALT values.

What can an elevated value of ALT mean?

An increased level of alanine aminotransferase (ALT) can be seen in a variety of conditions, including viral hepatitis, obesity, toxic liver damage, alcoholic hepatitis, obstruction of the bile ducts, liver tumors, preeclampsia, hemochromatosis, and in conditions that lead to acute oxygen deficiency in the liver. It is important to carry out further tests and investigations to determine the cause of the elevated ALT level and assess the severity of the underlying problem.

About ALT and AST

ALT, alanine aminotransferase, and AST, aspartate aminotransferase, are two enzymes found, among other things, inside the cells of the liver. These can leak into the blood if the liver is irritated or inflamed, which gives elevated values. The test can be done if liver cell damage is suspected and during follow-up of chronic liver disease.