Alanine aminotransferase, or ALT, and aspartate aminotransferase, or AST, are enzymes found in body cells that are involved in amino acid metabolism. They are located only in the cells of organ tissues, and enter the bloodstream only when the cell disintegrates due to traumatic injuries or pathologies.

Types of diseases

Excessive ALT content indicates the development of pathology of the organ in the cells of which its largest amount exists. The causes of increased alanine aminotransferase are liver pathologies. A feeling of discomfort and pain in the right hypochondrium, diarrhea, icteric discoloration of the skin and mucous membranes, flatulence, and bitter belching are signs of an increase in ALT. When conducting a blood test, increased ALT and AST are accompanied by an increase in bilirubin levels when hepatitis develops. More often, an increase in ALT levels indicates the occurrence of other diseases. The concentration of ALT has a direct relationship with the severity of the pathology.

The necrotic process in the heart muscle causes the release of these enzymes into the blood. Their increased content in the serum also indicates the development of other cardiopathologies: failure, inflammation of the heart muscle. Additionally, the reasons for the increase in serum ALT concentration may be existing injuries in the body, which are associated with damage to muscle tissue, and pancreatitis.

If the ALT and AST blood test (interpretation) showed less than twice the normal values, it is necessary to organize observation and a 2-fold examination. This tactic is optimal for patients.

Blood test ALT and AST - interpretation for some diseases

A slight increase in transferases is indicative of fatty liver damage of the non-alcoholic type, including “fatty liver”, non-alcoholic steatohepatosis, and chronic viral hepatitis.

A moderate increase may exist in viral or alcoholic liver inflammation and various chronic liver diseases with or without cirrhotic damage.

Elevated levels are typical of severe acute hepatitis, toxic or drug necrosis, shock or hepatic ischemia.

Excessively high levels (more than 2000-3000 U/l) exist with an overdose of acetaminophen and when using the drug in alcohol-dependent patients, with shock and/or hepatic ischemia.

It should be noted that since ALT is found in red blood cells, it is necessary to prevent their breakdown when preparing serum for analysis. ALT may decrease when serum is stored for several days.

The role of medicines, herbs and other substances

A thorough history and interpretation of laboratory results are important to identify drug-induced increases in transferases. Similar liver damage is detected in 1-2% of cases of chronic liver inflammation. They are associated with the use of antibiotics, antiepileptic drugs, hydroxymethylglutaryl-CoA reductase inhibitors, non-steroidal anti-inflammatory drugs and medications for the treatment of tuberculosis.

The easiest way to determine the dependence of an increase in aminotransferases with some drug is to cancel it and observe the level of enzymes. Without discontinuing the drug, this dependence cannot be determined.

AST and ALT— marker enzymes necessary to determine liver pathologies. Ast and Alt are found in the cells of different organs and enter the blood only when they are destroyed. Transferase levels increase during pregnancy, with liver pathology, after a course of certain medications, or after physical exercise. Transferases are determined by biochemical blood, which is considered the most informative for identifying liver diseases at the initial stage.

The peculiarity of the development of liver diseases is that they develop painlessly. The liver does not hurt because it has no nerve endings. Pain in the right hypochondrium, after which a person usually goes to the doctor for the first time, is caused by pathologies of the gallbladder. Only regular donation of blood biochemistry during the process will make it possible to identify liver pathologies before they reach the point of irreversibility.

What is ALT?

ALT acts predominantly in the cytoplasm of hepatocytes, in the epithelium of the renal glomeruli, and slightly less in the heart. During developing destructive processes at the cellular level, Alt is released from them and penetrates into the bloodstream, where its increase is detected. The growth of ALT directly depends on the degree of organ damage and is an important indicator of necrotic changes in organ tissue.

To assess the performance of the liver, heart, pancreas, and spleen, transaminases are used - alanine aminotransferase (ALT) and aspartic transaminase (AST). Specific proteins are present in all cells of the body and participate in the formation of amino acids. If ALT and AST are elevated in a biochemical blood test, we may be talking about the development of diseases.

Elevated levels of ALT and AST indicate the development of diseases

Functions of ALT and AST in the body

Intracellular enzymes - transaminases or aminotransferases - perform a transport function in the body, actively participating in the formation of amino acids:

• alanine aminotransferase transports alanine;
• aspartic transaminase – aspartic acid.

Hence the name of specific proteins. In addition, each group has its place in the human body. The maximum concentration of ALT is observed in the liver, and AST in the heart.

Transaminases are found only inside cells and enter the bloodstream as a result of tissue destruction. Therefore, an increase in aminotransferases in the blood indicates pathological processes - pancreatitis, hepatitis, heart attack.

Enzyme indicator standards

The presence of small amounts of aminotransferases in the blood is considered normal. The coefficient may differ for adults and children, men and women. Indicators during pregnancy are slightly elevated.

Table “Normal ALT and AST”

Why are ALT and AST levels higher than normal?

To identify the specific cause of the increase in markers in blood biochemistry, it is important to determine the extent of the isolated increase in ALT or AST transferases.

1. A slight increase (several times higher than normal) occurs with viral hepatitis, fatty liver disease, and steatohepatosis. Other markers of blood biochemistry also change - bilirubin and alkaline phosphatase increase.
2. Moderate increase (from 5 to 20 times) – inflammation in the liver tissues of a chronic or acute nature, viral, alcoholic hepatitis, development of cirrhosis.
3. A pronounced degree of increase in aminotransferases (more than 20 times) - severe drug or toxic liver destruction, acute hepatitis, pancreatitis or atrophy of liver tissue, myocarditis, ischemia. Not only transaminases increase, but also cholesterol and bilirubin.
4. Critical indicators (exceeding 2000–3000 U/l) are evidence of the death of the muscular parts of the heart (extensive myocardial infarction), cancer cells in the liver tissue, and an overdose of certain drugs (acute intoxication).

One week before the test, you should not drink alcohol.

What to do if ALT and AST are higher than normal

When plasma transaminases increase, it is not the symptoms that need to be treated, but the pathogen. Only after making an accurate diagnosis can the doctor prescribe drug therapy, which is recommended to be supported by folk remedies.

Treatment with drugs

Depending on the cause of the increase in aminotransferases, the specialist prescribes effective drugs for the treatment of a specific disease.

Table “Groups of drugs to reduce ALT and AST in the blood”

Drug treatment is prescribed exclusively by a specialist after a complete and thorough examination. It is prohibited to take medications on your own without an accurate diagnosis.

How to reduce levels using folk remedies

It is possible to normalize the functioning of internal organs and lower aminotransferases in the blood with the help of traditional medicine.

Collection of herbs for liver diseases

It is necessary to mix 20 g of celandine with immortelle and St. John's wort (40 g each). Place the crushed raw materials in a thermos and pour 1.5 liters of boiling water. The infusion is ready for use after 10–12 hours. You need to take the medicine 4 times a day for 14 days. This will help reduce transaminase levels by restoring liver cells.

Adonis infusion for heart pathologies

Brew 1 tsp in a glass of boiling water. medicinal herb, wrap it and let it brew for at least 2 hours. The liquid should be taken on an empty stomach, and then several times during the day. Dosage – 1 tbsp. l. The course of treatment is 12–15 days.

Adonis infusion helps with heart disease

Brew the crushed seeds of the plant (1 tsp) with 250 ml of boiling water and let it brew for 15–20 minutes. Strain and drink ½ glass in the morning and evening, half an hour before meals. Duration of treatment is 2-3 weeks. The drug is effective for pancreatitis, hepatitis, and liver ischemia. Quickly brings ALT and AST markers back to normal.

Milk thistle decoction will help lower aminotransferase levels in the blood

Place dandelion flowers in a jar (0.5 l) and fill with vodka (150 ml). The liquid needs to stand for at least a day to acquire medicinal properties. You need to take 2 tbsp of the tincture daily. l. 3 times a day. Results are visible after just a week of treatment. Therapy lasts 14–21 days.

Dandelion flower tincture normalizes ALT and AST levels

Pour crushed corn cob hairs (2 tsp) into 400 ml of boiling water. After 20 minutes, strain and take 1 glass twice a day for 14–21 days.

Corn silk effectively lowers aminotransferases

Lowering transaminases using folk remedies should be agreed with your doctor. The specialist will individually select recipes and suggest a dosage that will not harm your health.

Diet

To quickly normalize ALT and AST levels in the blood, you need to strictly adhere to dietary nutrition. The diet should be enriched with foods with vitamin D and completely exclude junk foods.

Table “Permitted and prohibited products for elevated transaminase levels”

Prevention

An increase in aminotransferases can be prevented by following basic preventive measures:

1. Lead a healthy lifestyle, play sports, give preference to walking.
2. Completely stop eating junk food and alcohol. No smoking.
3. Monitor physical labor and do not overwork the body.

Walking is very good for your health

If you carefully monitor your health and do not ignore the first symptoms of diseases, you can prevent the development of severe pathologies.

Transaminases ALT and AST in the human body perform an important function - they participate in the synthesis of amino acids. Enzymes are contained inside the cells of vital organs. A sharp increase in a specific protein in the blood may indicate serious abnormalities in the functioning of the liver, heart or pancreas. The content of ALT and AST helps to identify many diseases in the early stages. That is why it is so important to monitor such markers and regularly take blood biochemistry tests.

To diagnose a number of diseases, an ALT blood test is prescribed, what is it? Alanine aminotransferase (ALT, AlAt) is an enzyme involved in the transport of the amino acid alatine. ALT is found ubiquitously in all cells of the body; it can be found in large quantities:

• in muscles, including the heart;
• in the cells of the pancreas, liver and kidneys.

For an adult, the normal level of ALT in the blood is:

• in men – 39-40 U/l;
• in women – 29-30 U/l.

During inflammatory processes, necrosis and other destruction of internal organs, ALT increases. Therefore, if the blood contains more ALT than required by the standard, this makes it possible to determine the stage to which the organ damage has reached. An ALT test is often prescribed in conjunction with another biochemical test, AST. Simultaneous blood testing for AST and ALT allows for a more accurate diagnosis. AST is an enzyme that transports the amino acid aspartate. The largest amount of AST is found:

• in the liver;
• in skeletal muscles and heart;
• in the kidneys.

Prescribed as additional diagnostic measures in combination with other studies.

The ALT enzyme is found in greater quantities in liver cells; when these cells are damaged, it is released into the circulatory system, which makes it possible to diagnose cirrhosis, hepatitis and other diseases in which the liver primarily suffers. The AST enzyme is present in a larger volume in the myocardial muscle tissue, therefore, in case of ischemia, myocardial infarction, myocarditis and other heart diseases, the increased content of AST in the blood makes it possible to detect pathology.

Which doctor will prescribe the test?

Most often, a biochemical blood test for AST and ALT is prescribed by a cardiologist or gastroenterologist. What other doctors can give a referral for this study?

• gynecologist;
• endocrinologist;
• orthopedist;
• nephrologist.

A blood test for AST and ALT can be taken in any public clinic and in almost every private laboratory. It is better to order the examination together with a transcript, since laboratory data may be presented differently in the report depending on the standards of a particular institution.

How to take an ALT and AST test

Enzyme levels are affected by stress, alcohol and drug intoxication. Therefore, in order for the test data to reflect the real situation, the patient needs special preparation:

• stop drinking alcohol and drugs within 7 days;
• refrain from strong excitement and stress;
• 10 hours before the tests, abstain from food and drink nothing but plain water.

If the patient is taking any medications, the attending physician must be informed. Many medications (especially steroids and enzyme agents) can affect test results. In men, the enzyme composition of the blood quickly reacts to intense physical activity (weight lifting, running, sports training), so before the tests you need to refrain from going to the gym and other strenuous muscular work. In men and women, the enzyme composition of the blood is sensitive to nervous overstrain and stress. To get results that correspond to the real situation, you should get good sleep before donating blood and limit conflict situations.

What diseases require AST and ALT tests?

ALT and AST analysis is used to diagnose the following diseases:

1. Viral hepatitis, liver cirrhosis, liver tumors, including cancer, mononucleosis.
2. Heart failure, coronary heart disease, myocardial infarction, inflammation of the heart muscle (myocarditis, pericarditis).
3. Diseases of skeletal muscles, inflammatory processes in muscles, myositis, myopathy.
4. Pulmonary infarction.
5. Hypothyroidism.
6. Hemolytic anemia.
7. Injuries, shock, burns, hypoxia.

Elevated ALT and AST indicate necrotic changes and are therefore widely used to quickly determine the severity of the disease. The results of the analysis are deciphered by the attending physician. The AST and ALT indicators are influenced by many factors that the doctor takes into account when interpreting the results:

• pregnancy;
• obesity;
• gender, age;
• chronic diseases;
• taking medications, for example, hormonal contraceptives, non-steroidal anti-inflammatory drugs.

Due to the destruction of muscle tissue and liver cells, ALT is increased due to severe mental shock, extensive burns, pain shock and injuries.

In conditions that threaten the patient's life, a biochemical blood test for ALT and AST is not used, but is widely used to diagnose diseases of the heart muscle and liver.

Decoding the results

AST and ALT indicators are measured in conventional units per liter (U/l). Some laboratories use different units of measurement, so when analyzing data, you need to clarify how to translate results from one system to another. How does the amount of these enzymes change as a person ages?

• the optimal indicator for a newborn baby up to 5 days of life is 49 U/l;
• the norm for children under 6 months is 56 U/l;
• from 6 months to 1 year – 54 U/l;
• from 1 year to 3 years – 33 U/l;
• from 3 to 6 years – 29 U/l;
• from 6 to 12 years – 39 U/l.

Fluctuations in AST and ALT levels are associated with human growth. For each age, a person has a certain hormonal background and biochemical composition of the blood. A slight increase in enzymes in children does not necessarily indicate any serious illness. In adolescents from 12 to 14 years of age, AST and ALT levels gradually reach values ​​characteristic of adults. Normal levels of ALT and AST in the blood for adults:

• in men, optimal indicators are up to 40 U/l;
• in women – up to 30 U/l.

For diagnosis, it is not the indicators of ALT (ALT in the Latin abbreviation) and AST (AST) themselves that matter, but their ratio. This coefficient is named after Dr. de Ritis (DRr). To calculate it, the AST indicator must be divided by ALT. You will get a number from which you can conclude about the presence or absence of pathology. For men and women, the de Ritis coefficient is estimated equally.

In case of hepatitis, the DRr coefficient is less than one, in case of degenerative processes in the liver it is greater than or equal to one. For a more accurate clinical picture, an albumin test is used. If the DRr coefficient is greater than 2 and the albumin value is less than 35 g/l, this indicates liver necrosis. AST and ALT blood tests can detect viral hepatitis A 2 weeks before jaundice begins, and viral hepatitis B 2-10 weeks before obvious changes. The diagnosis is never made solely on the basis of the DRr coefficient; the attending physician also prescribes other studies.

Changes in indicators for various diseases

As an additional diagnostic measure, a biochemical blood test for AST and ALT is used to monitor the condition of the liver and heart, and less commonly, the pancreas. How do enzyme levels change relative to the norm during pathological processes in the heart and liver?

1. Preeclampsia. If AST and ALT levels normally increase in the first trimester of pregnancy, what does this mean? Most often, the reason is not any serious disease, but a lack of vitamin B6. For normal fetal development, a large amount of vitamin B6 is required, which is involved in the synthesis of the enzymes AST and ALT. When vitamin B6 deficiency is compensated, homeostasis of the liver and muscle tissue is restored. In the 2-3 trimesters, the level stabilizes, which indicates that the woman’s liver and kidneys are coping with the increased load. If the indicators are significantly higher than normal, this indicates gestosis.
2. Hepatitis. Acute viral hepatitis leads to an increase in ALT to 500-3000 U/l. The indicator reaches peak values ​​2-3 weeks after infection, then begins to decline. A repeated increase in ALT levels indicates liver cirrhosis. With alcoholic hepatitis, ALT and AST indicators are 500-600 U/l. With a biochemical blood test, it is possible to detect diseases that do not have symptoms in the early stages, for example, viral hepatitis B.
3. Hyperfermentation. Moderate hyperfermentation of the liver gives an increase in ALT and AST by 1.5-5 times, moderate hyperfermentation - by 6-10 times, severe - an increase of more than 10 times compared to the norm. A change in the volume of enzymes circulating in the circulatory system allows us to conclude that there is a serious disorder in the liver. If these enzymes enter the blood in large volumes, what does this mean? Liver cells are damaged and destroyed by the pathological process. Other studies specify what kind of pathology we are talking about. If the increase in AST is greater than ALT, hyperfermentation may indicate cirrhosis, metastases of a malignant tumor to the liver, intrahepatic cholestasis and infectious mononucleosis.
4. Heart diseases. During myocardial infarction, the increase in enzyme levels does not occur synchronously. AST increases by 8-10 times, and ALT by 1.5-2 times. After an attack, an increase in AST and ALT occurs within 6-8 hours, the maximum value is reached after 16-48, the values ​​return to normal values ​​after 3-6 days.

During myocardial infarction, the increase in enzyme levels does not occur synchronously. AST increases by 8-10 times, and ALT by 1.5-2 times.

To ensure that the test data is reliable, the doctor evaluates not only AST and ALT, but also other liver enzymes:

• bilirubin;
• creatine kinase;
• alkaline phosphatase;
• gamma glutamyl transferase;
• lactate dehydrogenase.

An increase in liver enzymes by 5-10% in the first trimester of pregnancy is the norm in women. The examination is usually carried out once per pregnancy, most often in the 2-3 trimesters, if there are no indications for urgent analysis. If heart disease is suspected, in addition to AST and ALT, a biochemical blood test includes:

• myoglobin;
• C-reactive protein;
• troponins;
• MB fractions of creatine kinase.

It is used not only for diagnosis, but also for disease control.

The half-life of AST and ALT is from 12 to 24 hours, therefore, when monitoring the patient’s condition, studies are carried out no more than once every 2 days. In adult men and women, indicators can fluctuate during the day within 10-30% of normal. AST in women increases naturally during pregnancy; within 2-3 months after conception, enzyme levels normalize.

The indicator is below normal

Reduced AST and ALT levels are determined in tests due to two disorders:

• lack of vitamin B6, which is involved in the synthesis of these enzymes;
• severe cirrhosis of the liver, in which the organ can no longer produce enzymes in sufficient quantities.

Vitamin B6 does not accumulate in cells, therefore, for effective synthesis of AST and ALT, its constant intake from food is necessary. By what signs can one suspect vitamin B6 deficiency?

• from the immune system: decreased immunity, vulnerability to infectious diseases;
• from the heart: surges in blood pressure, dizziness, fainting, lack of blood supply;
• diseases of the nervous system and psyche: depression, anxiety, insomnia, decreased concentration;
• from the muscles: cramps, myalgia;
• from the skin: decreased rate of tissue regeneration;
• from the liver: lack of liver enzymes, which leads to digestive disorders.

B6 deficiency negatively affects the functioning of all organs and systems of the body without exception. B6 - pyridoxine is a substance that is indispensable in many chemical reactions. Therefore, if you suspect vitamin B6 deficiency, it is useful to take a biochemical blood test.

Alanine aminotransferase and aspartate aminotransferase are endogenous enzymes and are significant markers in biochemical blood tests.

Although an elevated ALT level does not clearly indicate the occurrence of health problems, both enzymes are simply not present in the blood in large volumes.

Yes, both ALT and AST levels can increase with liver problems (such as cirrhosis or hepatitis), but other markers also need to be carefully analyzed. By the way, ALT levels may be elevated if myocardial infarction is diagnosed.

Aminotransferases are a group of enzymes capable of catalyzing transamination reactions, playing a leading role in protein metabolism, as well as maintaining a connection between the metabolism of proteins and carbohydrates. The most significant natural catalysts for transamination reactions in the human body are alanine aminotransferase (otherwise ALT, ALT) and aspartate aminotransferase (otherwise AST, AST).

These enzymes are present in the tissues of many organs. Normally, aminotransferases are practically undetectable in the blood. The minimal activity of enzymes is caused by natural regenerative processes in the body. Increased levels of ALT and AST are highly sensitive markers of damage to the tissues in which they are contained.

The method for determining aminotransferases in a biochemical blood test has found wide application in clinical practice due to its high sensitivity and specificity.

AsAT and AlAT. Norm

Normally, aspartate aminotransferase does not exceed 31 U/L in women and 37 U/L in men. In newborns, the level should not exceed 70 U/l.

ALT in women normally does not exceed 35 U/l, and in men – 40 U/l.

Also, the analysis results can be presented in mol/hour*l (from 0.1 to 0.68 for ALT and from 0.1 to 0.45 for AST).

What can affect transaminase levels?

The following can lead to distortion of analysis results:

• use of certain medications:
  • nicotinic acid,
  • immunosuppressants,
  • choleretics,
  • hormonal contraceptives, etc.),
• obesity,
• pregnancy,
• physical inactivity or excessive physical activity.

How the research is carried out

For analysis, blood is taken from a vein. Results for urgent research are provided within 1-2 hours. With standard diagnostics - within 24 hours.

To obtain the most reliable results you must:

• Avoid taking medications a week before taking tests (if this is not possible, you must notify your doctor about the medications you are taking);
• donate blood exclusively on an empty stomach;
• the day before the study, physical activity, smoking, alcoholic beverages, fatty and fried foods are excluded - two days.

What can an analysis of ALaT and AST tell you about?

Alanine aminotransferase and aspartate aminotransferase are characterized by selective tissue activity. If considered in
in descending order of the content of these enzymes in organs and tissues, the list will look like this:

• alanine aminotransferase: liver, kidneys, myocardium, muscles;
• aspartate aminotransferase: myocardium, liver, muscles, brain, kidneys.