What is alanine aminotransferase?

Alanine aminotransferase (or ALT) is an enzyme found mainly in the liver, which catalyzes the reversible transfer of an amino group from alanine to α-ketoglutarate to form pyruvate and glutamate. This enzyme is normally present in serum and body tissues, especially in the liver. Alanine aminotransferase is released into the serum as a result of tissue injury, hence the concentration in the serum may be increased in patients with acute damage to hepatic cells, as in viral or toxic hepatitis, infectious mononucleosis, and obstructive jaundice.

Suffered loss and function of the liver organ, involves a release of alanine aminotransferase in the blood of the patient. The liver plays several important roles within the human body. It stores fuel from food we consume, it creates proteins and helps to remove toxins from the body in the form of urine which is then excreted via the genitals of the patient. Proteins called enzymes help the liver build and break down other proteins. Alanine aminotransferase is one of these enzymes. Normally these alanine aminotransferase enzymes are found inside liver cells.


Why measure the level of alanine aminotransferase?

Measuring blood levels of alanine aminotransferase can give doctors important information about the liver of the patient, and whether a disease, inflammation, drug or any other problem is affecting the liver. The examination may be useful for evaluating the epatic functionality. It can also be an indicator of the possible toxic effects of some drug therapies depending on the prior medical history of the patient.

The alanine aminotransferase examination may be performed if your experiencing symptoms of liver diseases, including jaundice which is yellowish skin or eyes, dark urine, vomiting, nausea or abdominal pain. The examination is also useful in the diagnoses of infections on the liver such as viral hepatitis (alanine aminotransferase levels are high with acute hepatitis), to monitor patients taking medications which may cause liver related side effects, or evaluate the liver after an injury.

The alanine aminotransferase examination is usually performed as a part of a full liver function panel, which includes other liver enzyme tests. This will allow doctors to have more specific information about liver problems, by looking at the alanine aminotransferase levels, along with other liver enzymes such as aminotransferase and alkaline phosphatase.


Standard of preparation

Sampling is usually done in the morning in the hospital. There are no special preparations needed for this test. The doctor will advise and recommend if you need to be fasting prior to the blood examination. You should inform your doctor of any medication you are taking prior to the exam, as some medical treatments may interfere with the blood results.


Is the examination painful or dangerous?

The examination is neither painful nor dangerous. The patient may feel a tingling sensation with the entrance of the needle in the arm when blood is being extracted for examination.


How is the exam performed?

The exam consists of a simple blood sample test, which is neither invasive nor intrusive to the patient.