Transaminases AlT and AST (alanine aminotransferase, aspartate aminotransferase): concept, norm and deviations in the analysis. What is alanine aminotransferase in a blood test - the norm and interpretation of the results of a liver test What is alt and ast in the blood

Since recently, clinical examination of the population has been carried out in almost all cities of the Russian Federation, which makes it possible to identify a number of diseases at an early stage and thereby reduce the risk of premature mortality.

Basic indicators of liver function

Liver diseases are among the most common and dangerous due to their asymptomatic course. At the stage of the screening examination, along with other studies, the patient is assigned the main indicators of which are aimed at determining how the liver functions.

The level of ALT and AST in the blood completely depends on the work of the most important parenchymal organ - the liver, which performs functions such as:

1. Detoxification is the removal of toxic substances and poisons from the body.
2. Protein synthesis.
3. Production of biochemical substances necessary for the body.
4. Storage of glycogen - a polysaccharide that is necessary for the full functioning of the body.
5. Regulation of biochemical reactions of synthesis and decomposition of most microparticles.

ALT and AST are enzymes that are produced mainly by the liver and participate in all its biochemical reactions.

Norm ALT and AST inblood

The level of ALT and AST in the blood depends on many factors, including gender and age. Due to the lack of a unified standard, in almost every medical institution the laboratory sets its own standard for ALT and AST; for this reason, with all tests you need to contact the doctor supervising you, and not do the decoding yourself. The normal range is:

1. The norm of AST in the blood is from 5 to 40 IU/l.
2. The norm of ALT in the blood for women: from 7 to 35 IU/l.
3. The normal level of ALT in the blood for men: from 10 to 40 IU/l.

Norm ALT and AST inbloodAnd analysis main reasons for the increase

A slight increase in ALT and AST in the body often occurs asymptomatically, but indicates a malfunction of the liver.

The most likely cause of elevated liver enzyme levels in the blood is:

1. Fatty hepatosis.
2. Drug reaction.
3. Injury.
4. Increased ALT and AST as a consequence of diseases of other organs (pancreatitis, mononucleosis).
5. Diffuse liver damage, which can be caused by alcohol, drugs and (or) a virus.
6. Metastases or neoplasms in the liver.

Early symptoms of increased ALT and AST are:

1. Increased fatigue and weakness.
2. Decreased appetite and, as a result, weight loss.
3. Skin itching.
4. Insomnia, nervousness.

Late symptoms of increased ALT and AST:

1. Swelling of the extremities, ascites (presence of free pathological fluid in the abdomen).
2. The skin, proteins, and mucous membranes acquire a yellow tint.
3. Change - “urine the color of dark beer”, discoloration of feces.
4. Increasing symptoms of intoxication: weakness, nausea, hyperthermia, etc.).

Additional diagnostic methods:

1. Ultrasound diagnostics of the abdominal organs, and, if necessary, the thyroid gland.
2. Blood test for markers of hepatitis B, C.
3. Clinical blood test.
4. Blood test for thyroid hormones and antibodies.
5. If necessary, liver biopsy.

Reducing AST and ALT

The rules by following which a person can reduce AST and ALT levels are:

1. Eat as many fresh vegetables and fruits as possible, as well as brown rice - they contain fiber.
2. Drink green tea and herbal teas that include dandelion root, milk thistle, and burdock root.
3. Your diet should include foods containing vitamin C.
4. Follow the drinking regime at the rate of 30 ml of liquid per 1 kg of weight.
5. Do breathing exercises.
6. Take a contrast shower.

It is a huge set of different tests aimed at searching for pathology in a particular organ or system. Meanwhile, among them there are those that are suitable, as they say, for all occasions. For example, the enzymes alanine aminotransferase (AlT) and aspartate aminotransferase (AsT), called for convenience “alates” (AlAt) and “asats” (AsAt), which patients are known mainly as “liver tests”. Usually they are prescribed together when it comes to the liver, but in case of heart diseases you can find AsaT in combination with other biochemical indicators: , LDH, D-dimer, etc.

ALT is the main indicator of the functional abilities of the liver

Alanine aminotransferase is an enzyme that, in addition to the liver, where its concentration is especially high, is found in literally all parenchymal organs, occupying mainly the cytoplasm of tissue cells. It is not for nothing that ALT is considered a kind of marker of liver pathology and is regarded as a reliable sign of damage to its parenchyma, because the activity of the enzyme in the blood plasma is directly dependent on the degree of involvement of the tissue of this important organ in the pathological process.

Given this high sensitivity of ALT, it can be expected that alanine aminotransferase will be elevated in cases of the slightest damage to the hepatic parenchyma:

The level of alanine transferase activity differs by gender; in women it is slightly lower - up to 31 U/l, while in men activity up to 41 U/l is considered normal.

Normal ALT levels are not always a sign of well-being

“Good biochemistry,” as patients say, often meaning liver function tests, does not always mean that everything is really fine in the organ itself. An increase in alanine aminotransferase activity marks the debut of the disease or an exacerbation of a chronic process; the rest of the time the enzyme can behave quite calmly, so one should not think that the main goal of the treatment process is to reduce ALT.

Of course, the patient may have a completely different opinion on this matter and be sure that lowering ALT means solving the problem. Unfortunately, this is not always the case, because an increase in transaminases is caused by some kind of pathology, and it is the search for or treatment that needs to be addressed first.

The patient can use:

• Drugs that protect the liver (karsil and other hepatoprotectors);
• Agents that restore the cellular structure of the liver (essentiale);
• Enzymes that relieve the pancreas and improve digestion (mezim forte, pancreatin).

Perhaps the doctor, if he deems it necessary, will prescribe choleretic drugs, but for this you need to know the condition of the biliary tract, so it is better for the patient himself not to risk it.

If the result of an increase in transferases is the long-term use of some medications that the patient cannot do without, then he will be prescribed alternative therapy, although this will take some time.

People receiving lipid-lowering drugs should pay attention to the fact that while taking lipid-lowering drugs, an increase in both enzymes is often observed, which, however, cannot be attributed to signs of pathology. This condition does not require separate treatment, but the patient will have to periodically visit the laboratory and undergo tests. When statins are discontinued, transferases return to normal on their own.

AST is an enzyme involved in “cardiac” reactions

The enzyme aspartate aminotransferase is concentrated in the largest quantities in the tissues of the heart muscle and skeletal muscles, therefore the reasons for changes in its activity are mainly associated with pathological processes localized in these systems:

1. Dystrophic changes in muscle fibers (in particular) of various origins (hereditary and acquired).
2. Myocardial infarction. An increase in AST is observed in the patient’s serum 4-5 hours after the onset of a heart attack; by 3-5 days the activity of this enzyme reaches its maximum values.
3. Severe attack, rhythm disturbance of the type.
4. Spicy . At the initial stage of the disease, the activity of aspartic transaminase is directly dependent on the severity of the pathological process, that is, the more serious the condition, the higher the levels can be expected or, conversely, large numbers of activity are alarming and do not allow delaying the start of therapy.
5. Heavy.
6. Cardiac surgery, after which ALT remains elevated for approximately 1.5 weeks.
7. Catheterization of cardiac vessels ().
8. Impact on the liver parenchyma of various toxic compounds (chloroform, pesticides, organic poisons).
9. Infectious mononucleosis.
10. Hepatitis of any etiology.
11. Liver cirrhosis (compensated), cholangitis.
12. Severe poisoning with alcohol and its substitutes.
13. Acute inflammation of the pancreas.
14. Hemolytic syndrome.
15. Amebic infections.

Sometimes the activity of aspartic transaminase decreases. This happens in the following cases:

• Lack of vitamin B6 in the body;
• Severe pathological processes in the liver, leading to its necrosis;
• Ruptures of the liver tissue, where reduced activity of both enzymes (AlT and AST) is regarded as a sign that is not reassuring for the prognosis.

The level of aspartate aminotransferase in the blood serum is not the same in men and women, although the differences are quite insignificant. Like alanine aminotransferase, AST activity in females is lower (up to 31 U/l), while in the stronger half of humanity, AST activity up to 35 U/l or up to 41 U/l is considered normal (depending on the characteristics of the reagents and the analysis technique) .

Decoding the results of “biochemistry”, namely, liver function tests, is quite simple, and the answer forms, as a rule, indicate the norm. And patients are always well aware of the purpose for which they are prescribed this or that test. As for aminotransferases, in case of liver diseases, the study of both enzymes is usually prescribed, and in case of cardiac pathology, one (AST) is sufficient.

Video: AlT and AsT in the program “Live Healthy!”

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:
  • a 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.

The liver is the most important organ on whose work a person’s health and the beauty of his skin depend. After all, it is he who takes an active part in digestion, as well as in the neutralization of allergens, poisons and toxins that enter the body. Alanine aminotransferase (ALT) plays a key role in liver function. This endogenous enzyme, located in the organ cell, is involved in the metabolism of amino acids. It also performs an important mission - it cleanses the gland of toxins.

Small amounts of organic matter can also be found in the blood. However, if the cells are destroyed, ALT is released and its level in the blood increases. In this case, they talk about liver destruction. In order to find out whether everything is in order with this organ, doctors prescribe a biochemical blood test that reveals the level of ALT, the norm of which you will learn in an article from the website.

ALT: normal in human blood

Biochemical blood tests have been used in medical practice for quite some time. After all, it is he who helps to identify the pathology of any organ, including the liver. To examine this digestive gland, doctors order an ALT test. It allows you to accurately determine the level of enzymes in the blood and the presence of possible diseases. In order for the results to be as reliable as possible, you need to prepare a little for such an examination:
. 12 hours before the test, do not eat;
. the day before donating blood, do not take aspirin, valerian tablets, paracetamol and contraceptives;
. do not drink alcohol a week before the examination;
. Before the analysis, avoid smoking, anxiety, as well as moral and physical stress.

Blood for examination is usually taken from a vein. And the analysis results are ready on the second day after delivery. A correctly interpreted analysis shows the correct clinical picture. Only a doctor can find out whether everything is okay with the liver, based on the test results. However, every person can find out what the ALT norm is. Thus, in medical reference books it is written that the normal amount of enzymes in the blood of women is 31 U/l, and in men - 41 U/l. In children, the rate usually does not exceed 50 U/l.

Very often, ALT results are compared with the results of AST, an enzyme that is also synthesized inside the cell. In medicine, this phenomenon is known as the de Ritis coefficient.

The optimal value of the de Ritis coefficient is from 0.91 to 1.75. An indicator greater than 2 indicates damage to the heart muscle. And if the coefficient does not exceed 1, this means that there is liver disease. And the lower the indicator, the more serious the problem.

The analysis is usually prescribed as a diagnosis in cases where a person’s life contains factors that destroy liver cells: frequent consumption of alcohol and fatty foods, smoking, as well as abuse of paracetamol, contraceptives and other medications.

Doctors also recommend being examined for diabetes and excess weight. It is necessary to check the ALT level even if there has been contact with a patient with hepatitis. Often, a biochemical blood test is prescribed for pain under the right rib, nausea, and yellow skin.

In what cases is ALT level elevated?

A deviation in the level of organic matter from the norm indicates that there is a disease in the body, often associated with the liver. Thus, an increase in the amount of alanine aminotransferase tenfold indicates the presence of one of several liver diseases:
. Hepatitis. In chronic disease, the level of ALT is slightly increased, and in viral hepatitis, the amount of alanine aminotransferase is significantly exceeded. If you have hepatitis A, timely analysis allows you to identify the disease at an early stage.
. Cancer - this disease is very often a consequence of hepatitis. Thanks to an ALT test, this insidious disease can be identified quickly enough and treatment can begin on time.
. Cirrhosis. The danger of such a disease is that it does not manifest itself for a long time. A person feels only slight fatigue and pain in the liver. You can find out about the presence of the disease by exceeding the enzyme by 5 times.

An increase in enzyme levels does not always indicate a disease. ALT, the norm of which is slightly increased, very often indicates pregnancy. The fact is that in the last trimester, women often experience gestosis, which is accompanied by general weakness, dizziness and increased blood pressure. And this, in turn, leads to a deviation of the enzyme level from the norm.

There is also a decrease in the amount of organic matter. This happens in cases where the body lacks folic acid and vitamins. A significant drop in enzyme levels in liver cirrhosis indicates a lack of healthy cells.

Common symptoms of abnormal ALT

You can find out that the amount of enzymes in the blood is increased or decreased even before a biochemical examination. Often this pathology manifests itself as follows:
. pain under the right lower rib;
. nausea;
. vomit;
. weakness;
. yellowing of the skin and eyes;
. hyperthermia;
. spider veins on the body;
. abdominal enlargement;
. varicose veins of the anterior abdominal wall.

If you notice one or more symptoms, you should definitely consult a doctor. After all, these manifestations can indicate a serious illness, which, if not treated in a timely manner, can result in complications and even death.

How to normalize ALT levels in the blood

If, after taking the test, a deviation from the norm is discovered, the doctor usually prescribes an additional examination, which allows you to find out the true cause of the pathology. After it is known what exactly led to the deviation from the norm, the specialist prescribes a course of treatment, after which the ALT level should return to normal.

Also, to reduce the level of enzymes in the blood, the doctor may prescribe a special drug. The medication should be taken only under the strict supervision of the attending physician. And it is very important to read the instructions about contraindications before using the medicine.

Keep in mind that such drugs only alleviate the condition, but do not eliminate the problem. Therefore, first of all, it is still necessary to cure the disease itself by an experienced doctor. Then there will be no trace of the problem, the liver will be restored, and the skin will again acquire a healthy color.