Elevated transaminases alanine aminotransferase (ALT) and aspartate aminotransferase (AST) or transaminitis, also known as liver enzymes, are a common finding in routine blood tests. Transaminases are enzymes that are found in liver cells and are involved in the metabolism of amino acids. Transaminitis can indicate liver injury or disease, and require further evaluation to determine the underlying cause.
Which are the two main transaminases and their normal values?
There are two main transaminases that are measured in blood tests: alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Normal levels of ALT are between 7 and 56 units per liter (U/L) for men and 5 to 40 U/L for women, while normal levels of AST are between 10 and 40 U/L for men and women. Elevated levels of these enzymes are generally defined as values that are more than twice the upper limit of normal.
Which are the causes of transaminitis?
Transaminitis, or elevated levels of transaminases in the blood, can be caused by a variety of conditions. Here is a comprehensive list of some of the most common causes of transaminitis:
- Nonalcoholic fatty liver disease (NAFLD)
- Alcohol-related liver disease
- Viral hepatitis (hepatitis A, B, C, D, and E)
- Autoimmune hepatitis
- Primary biliary cholangitis
- Primary sclerosing cholangitis
- Wilson’s disease
- Hemochromatosis
- Alpha-1 antitrypsin deficiency
- Celiac disease
- Drug-induced liver injury (e.g., acetaminophen, statins, antibiotics, anticonvulsants, chemotherapy)
- Acute liver failure
- Chronic liver disease (e.g., cirrhosis)
- Gallbladder disease (e.g., cholecystitis, gallstones)
- Pancreatitis
- Acute or chronic inflammation of the liver (e.g., nonalcoholic steatohepatitis, autoimmune hepatitis)
- Liver cancer (hepatocellular carcinoma)
- Metabolic disorders (e.g., glycogen storage disease, tyrosinemia)
- Inherited disorders affecting liver function (e.g., alpha-fetoprotein deficiency, familial hypercholesterolemia)
- Cardiac failure with liver congestion
This list is not exhaustive and there may be other rare causes of transaminitis that are not included. Also, some individuals may have elevated transaminases without an identifiable cause (i.e., idiopathic).
What information can the level of transaminitis provide?
The level of transaminitis, specifically alanine aminotransferase (ALT) and aspartate aminotransferase (AST), can provide some information about the severity and extent of liver damage or injury.
In general, mild-to-moderate elevations of ALT and AST (up to 3 times the upper limit of normal) can indicate a range of conditions, including:
- Nonalcoholic fatty liver disease (NAFLD)
- Alcohol-related liver disease
- Viral hepatitis
- Medication-induced liver injury
- Autoimmune hepatitis
- Acute liver injury or inflammation
In some cases, mild-to-moderate elevations of ALT and AST may not be accompanied by any symptoms or may only cause mild symptoms such as fatigue or abdominal discomfort. In other cases, these elevations may be a sign of more significant liver damage or injury.
Severe elevations of ALT and AST (>10 times the upper limit of normal) are more concerning and may indicate acute liver failure or a severe underlying liver condition, such as:
- Drug-induced liver injury
- Viral hepatitis (particularly hepatitis B or C)
- Ischemic liver injury (caused by reduced blood flow to the liver)
- Autoimmune hepatitis
- Acute alcoholic hepatitis
- Acute liver failure
Severe elevations of ALT and AST are often accompanied by symptoms such as jaundice (yellowing of the skin and eyes), abdominal pain, and altered mental status.
The level of elevation of transaminases is not always indicative of the severity of liver damage or injury. Some individuals may have significant liver damage with only mild elevations of transaminases, while others may have less severe liver disease with marked elevations of transaminases. In general, the diagnosis and management of liver disease requires a comprehensive evaluation by a gastroenterologist, including additional laboratory and imaging studies as needed.
Evaluation and management of transaminitis AST & ALT
If you have transaminitis, your gastroenterologist will likely order additional tests to determine the underlying cause. These may include blood tests to check for viral hepatitis or autoimmune hepatitis, imaging tests (such as an ultrasound or CT scan) to evaluate the liver, and possibly a liver biopsy to obtain a sample of liver tissue for analysis.
The management of transaminitis depends on the underlying cause. For example, if the cause is NAFLD, lifestyle modifications such as weight loss and regular exercise may be recommended. If the cause is hepatitis, antiviral medications may be prescribed. If a medication is causing the liver injury, it may need to be discontinued or replaced with an alternative medication.
In some cases, transaminitis may be a sign of a more serious liver disease, such as cirrhosis or liver cancer. Your gastroenterologist will determine the cause of your elevated transaminases and develop a treatment plan.
What does AST/ALT ratio show?
The AST/ALT ratio is a laboratory test that compares the levels of two liver enzymes in the blood: aspartate aminotransferase (AST) and alanine aminotransferase (ALT). The ratio is calculated by dividing the level of AST by the level of ALT.
In general, a normal AST/ALT ratio is around 1, meaning that the level of AST is roughly equivalent to the level of ALT. However, when liver cells are damaged, these enzyme levels can become elevated, and the ratio can change.
The AST/ALT ratio can provide some information about the underlying cause of liver injury. Some general interpretations of the AST/ALT ratio include:
- Viral hepatitis: In acute viral hepatitis, the AST/ALT ratio is typically less than 1 (i.e. the level of ALT is higher than the level of AST). In chronic viral hepatitis, the ratio can be more variable.
- Alcohol-related liver disease: In alcohol-related liver disease, the AST/ALT ratio is often greater than 1 (i.e. the level of AST is higher than the level of ALT).
- Nonalcoholic fatty liver disease (NAFLD): In NAFLD, the AST/ALT ratio is often less than 1, similar to acute viral hepatitis.
- Cirrhosis: In cirrhosis, the AST/ALT ratio can be greater than 1 or less than 1, depending on the underlying cause.
The AST/ALT ratio is not a definitive diagnostic tool and should not be used in isolation to diagnose a liver condition. Additional tests, such as imaging studies or liver biopsies, may be necessary to confirm a diagnosis. Additionally, there may be other factors that can affect the AST/ALT ratio, such as age, sex, and body mass index.
In summary, the AST/ALT ratio is a laboratory test that can provide some information about the underlying cause of liver injury. However, it should be interpreted in conjunction with other laboratory and imaging studies and should not be used in isolation to diagnose a liver condition.
When may a liver biopsy of a patient with transaminitis be considered?
Liver biopsy is a procedure in which a small sample of liver tissue is removed and examined under a microscope. It is often used to help diagnose and monitor liver diseases, including those that can cause elevated transaminases (specifically, alanine aminotransferase or ALT and aspartate aminotransferase or AST). The decision to perform a liver biopsy in a patient with elevated transaminases will depend on several factors, including the cause and severity of the elevation and other clinical factors.
In general, a liver biopsy may be considered in patients with transaminitis when:
- The cause of the elevation is unclear: In some cases, transaminitis may be a sign of a serious underlying liver condition, such as viral hepatitis, autoimmune hepatitis, or nonalcoholic fatty liver disease. However, in other cases, the cause of the elevation may not be clear based on laboratory and imaging studies alone. In these cases, a liver biopsy may be useful in helping to determine the cause and severity of liver disease.
- The elevation persists over time: In some cases, transaminitis may be transient and resolve on their own. However, if the elevation persists for several weeks or months, a liver biopsy may be considered to help determine the underlying cause and monitor disease progression.
- The patient has other risk factors for liver disease: Patients with other risk factors for liver disease, such as a history of heavy alcohol use, obesity, or diabetes, may be at increased risk for developing serious liver conditions. In these cases, a liver biopsy may be considered to screen for and monitor liver disease.
Liver biopsy is an invasive procedure that carries some risks, including bleeding, infection, and damage to surrounding organs. As such, the decision to perform a liver biopsy should be carefully weighed against the potential benefits and risks and made in consultation with a gastroenterologist.
When may transient elastography of a patient with elevated transaminases be recommended?
Transient elastography is a non-invasive imaging test that uses ultrasound to measure liver stiffness, which can be an indicator of liver fibrosis (scarring). It can be a useful tool in the evaluation of patients with elevated transaminases, as liver fibrosis can be a complication of many chronic liver diseases.
Transient elastography may be recommended in patients with transaminitis when:
- The cause of the elevation is unclear: As with liver biopsy, transient elastography may be useful in helping to determine the cause and severity of liver disease when other diagnostic tests are inconclusive.
- The patient has a known risk for liver fibrosis: Patients with risk factors for liver fibrosis, such as a history of chronic viral hepatitis, nonalcoholic fatty liver disease (NAFLD), or alcohol-related liver disease, may benefit from transient elastography to screen for and monitor fibrosis.
- The patient has elevated transaminases over time: Persistent elevation of transaminases may indicate ongoing liver damage and can increase the risk for developing liver fibrosis. In these cases, transient elastography may be useful in monitoring disease progression over time.
Transient elastography is not a definitive test for liver fibrosis and cannot replace a liver biopsy in all cases. In some cases, a liver biopsy may be necessary to confirm a diagnosis and determine the severity of liver fibrosis. The decision to perform transient elastography or liver biopsy in a patient with transaminitis should be made in consultation with a gastroenterologist based on individual clinical factors.
High cholesterol and liver enzymes
Bottom line
Elevated transaminases or transaminitis ALT and AST are a common finding in routine blood tests and can indicate liver injury or disease. There are many different causes of elevated transaminases, and further evaluation is necessary to determine the underlying cause. The management of elevated transaminases depends on the underlying cause and may include lifestyle modifications, medications, or other treatments. If you have transaminitis, your gastroenterologist will determine the cause and develop a treatment plan.
How can I contact gastroenterologist Dr. Zavos for an appointment?
Dr. Chris Zavos is a board-certified gastroenterologist and hepatologist, located in Thessaloniki Greece, and specifically in Kalamaria suburb, about 7 kilometres (4 miles) southeast of downtown Thessaloniki. His private office is at: Fanariou 8 street (near Aigaiou and Adrianoupoleos avenues), Kalamaria (Thessaloniki), Greece.
Thessaloniki International Airport is only 10 km away from his private office in Kalamaria and can be reached by taxi within 13 minutes from the airport.
Dr. Chris Zavos performs endoscopies at Bioclinic private hospital in downtown Thessaloniki (Mitropoleos 86 street).
You can contact Dr. Zavos at phone numbers: (+30)-6976596988 and (+30)-2311283833, or you can email him at czavos@ymail.com. Dr. Zavos responds to Greek and English languages.