Transaminases, also known as aminotransferases, are a group of enzymes that are found in our liver cells. These enzymes are involved in the synthesis and breakdown of proteins, and they play an important role in the metabolism of amino acids.

ALT (alanine aminotransferase) and AST (aspartate aminotransferase) are two types of transaminases that are commonly measured in blood tests. Abnormalities in the levels of transaminases can indicate potential liver issues, but they can also be a sign of other conditions.

What are Transaminases?

Transaminases are enzymes that are primarily found in the liver, but they can also be found in small amounts in other organs like the heart, kidneys, and muscles.

These enzymes help to transfer amino groups from amino acids to alpha-ketoglutarate, which is a part of the citric acid cycle. This process is known as transamination, and it is an important step in the metabolism of amino acids.

ALT is found predominantly in liver cells, whereas AST is present in liver cells as well as heart, muscles, and other tissues.

When liver cells are damaged or destroyed, the ALT and AST enzymes are released into the bloodstream, causing an increase in their blood levels. This is why elevated levels of transaminases are usually considered as indicators of possible liver damage or inflammation.

What Causes Abnormal Transaminases?

There are various reasons why transaminase levels may rise in the blood. Here are some of the possible causes of abnormal transaminases:.

Liver Diseases

Liver damage or inflammation, such as hepatitis (A, B, or C), non-alcoholic fatty liver disease (NAFLD), alcoholic liver disease, cirrhosis, and liver cancer, can cause a significant increase in ALT or AST levels.

In general, ALT is more specific to liver injury, whereas AST can be elevated in liver and other cellular injuries.

Medications

Some medications can cause liver damage, which may result in elevated transaminase levels. Some of the common examples include acetaminophen (Tylenol), antibiotics, cholesterol-lowering medications, antifungal drugs, and anti-seizure medications.

Alcohol Abuse

Chronic heavy drinking can damage the liver and cause an increase in ALT and AST levels.

Infections

Certain viral infections like hepatitis A, B, and C can cause inflammation of the liver and lead to abnormal transaminase levels in the blood. Other infections like mononucleosis, cytomegalovirus, and herpes simplex can also affect liver function.

Genetic Disorders

Some genetic disorders like hemochromatosis, Wilson’s disease, and alpha-1 antitrypsin deficiency can affect liver function and lead to elevated transaminases.

Autoimmune Diseases

Autoimmune diseases like primary biliary cholangitis, autoimmune hepatitis, and primary sclerosing cholangitis can cause inflammation and damage to the liver.

Trauma or Surgery

Physical trauma to the liver or surgery involving the liver may lead to an increase in transaminase levels.

Interpreting Abnormal Transaminase Levels

Interpreting the meaning of abnormal transaminase levels requires a careful evaluation of the symptoms, medical history, physical examination, and other laboratory tests.

Mild to moderate elevation in transaminase levels usually doesn’t cause any symptoms in most cases. However, significant elevations can cause symptoms such as fatigue, nausea, vomiting, abdominal pain or swelling, and jaundice.

Below are some general guidelines for interpreting abnormal transaminase levels:.

ALT

A normal ALT level is generally between 10-40 units/L for men and 7-35 units/L for women. The level of ALT is usually higher than AST in most liver diseases.

In general, a level greater than 50-60 units/L suggests a potential liver problem that may require further testing such as imaging or liver biopsy.

AST

A normal AST level is generally between 10-34 units/L for men and 9-30 units/L for women. AST levels may be elevated in various conditions, including liver disease, heart disease, muscle injury, and other conditions.

An AST level that is more than twice the normal upper limit suggests some form of liver injury, but it may also be due to other non-liver related factors such as muscle injury.

Conclusion

Abnormal transaminase levels can indicate potential liver damage or inflammation, but they can also be a sign of other conditions.

A careful evaluation of symptoms, medical history, physical examination, and other laboratory tests is usually required to determine the underlying cause of elevated transaminases. Treatment depends on the underlying condition and severity of the disease. So, it’s important to take any abnormal test results seriously and follow through with any further testing recommended by your healthcare provider.