ALT (ALT, Alanine aminotransferase, alanine transaminase, SGPT, Alanine aminotransferase)

What may affect the results

Intense physical activity the day before and even a few days before the test can lead to damage to muscle tissue (the so-called muscle fiber tear) and, accordingly, an increase in ALT levels. For the same reason, analysis taken after injury is uninformative. Taking alcohol and certain medications (antibiotics, nonsteroidal anti-inflammatory drugs, antitumor drugs, oral contraceptives, etc.) often distort the results of the study. The list of medications taken should be discussed with the doctor who prescribed the test, and those that are taken should be discontinued without risk to health.

Features of ALT norms in pregnant women

In a healthy woman, the ALT norm does not change during pregnancy and should coincide with the values ​​before conception. In cases where ALT is slightly increased during pregnancy, causes not related to diseases can be considered:

• course of intramuscular injections;
• physical activity that is excessive for a pregnant woman;
• addiction to fast food;
• uncontrolled intake of dietary supplements;
• obesity;
• fetal pressure on the biliary tract, preventing the outflow of bile.

Normalization of nutrition, moderation of physical activity, weight control and choleretic drugs normalize enzyme parameters.

ALT (ALT, Alanine aminotransferase, alanine transaminase)

For research, blood is taken from a vein. Usually, AST (AST, Aspartate aminotransferase) is determined simultaneously and the AST/ALT ratio (de Ritis coefficient) is assessed. You can take a blood test for ALT (ALT, Alanine aminotransferase, alanine transaminase) at the nearest INVITRO medical office. A list of offices where biomaterial is accepted for laboratory research is presented in the “Addresses” section. Interpretation of study results contains information for the attending physician and is not a diagnosis. The information in this section should not be used for self-diagnosis or self-treatment. The doctor makes an accurate diagnosis using both the results of this examination and the necessary information from other sources: medical history, results of other examinations, etc.

Dependence of ALT level on age and other indicators

During a person's life, the level of ALaT changes. You need to know this in order to correctly decipher ALT in a biochemical blood test.

• In healthy full-term newborns, the alanine aminotransferase rate ranges from 10 to 17 U/l.
• If the baby was born prematurely, then this figure can be 13–26 U/l, and the level of this substance in the blood of such babies changes almost daily.
• From the sixth day of life to six months of age, the upper limit of alanine aminotransferase increases slightly and amounts to 30 U/l. This is explained by the fact that in the first six months all biochemical mechanisms are gradually “launched” in the baby’s body, because the child adapts to existence outside the mother’s womb.
• From seven months to a year, this figure fluctuates between 13–29 U/l. At this time, the indicators for boys and girls do not yet differ.
• From one year to 14 years, the concentration of alanine aminotransferase in boys and girls is different. Moreover, in the female body it will be lower than in the male body. For girls of preschool age, the norm will be considered a concentration of 13–18 U/l, and for boys the upper limit is already 22 U/l. This trend will continue throughout your life.

Alanine aminotransferase levels in adults

• Before reaching the age of 60, the normal alanine aminotransferase level in men is 10–45 U/L, while the normal ALT level in women during this period is only 10–31 U/L.
• The level of this substance in the blood can only change during pregnancy, and then not in all women. In some cases it remains unchanged. If the expectant mother's ALT level is slightly elevated and is 35 U/L, this is not a cause for concern. An increase in ALT during pregnancy is caused by the fact that the enlarged uterus may slightly compress the bile ducts or a slight bend has appeared in the bile ducts. There is no need to be afraid of this state of affairs - after childbirth, the uterus will shrink and the indicators will return to normal. However, if the increase in ALaT in the blood during pregnancy continues, and the concentration of this substance reaches high levels, additional examinations should be performed, as this may be associated with impaired functioning of the liver, kidneys and heart.
• When people “step over” the 60-year barrier, the level of alanine aminotransferase in the blood also changes. Normally, ALT in men of this age ranges from 10 to 40 U/l, and for females it will be 10–28 U/l. The concentration of alanine aminotransferase remains at this level until the end of life.

However, a normal blood level of this substance does not always indicate that a person is healthy. In some cases, even with severe pathology of the liver and kidneys, the indicator does not change, especially for the fairer sex. That is why an isolated study of the concentration of this enzyme in the blood is very rarely prescribed. Most often, other biochemical indicators are analyzed in parallel, which allows a much more accurate understanding of the state of the body.

Normal indicators

Units of measurement: U/l.
Reference values

How does the level of alanine aminotransferase in hepatitis depend on gender?

Russian scientists, having examined 320 people, including both sick people and healthy people (control group), found that in women with chronic hepatitis, the ALT indicator in 78.6% of cases does not correspond to the severity of the disease. Some patients even had normal alanine aminotransferase levels.

In men, the number of cases of hepatitis not accompanied by an excess of the concentration of this enzyme was only 21.4%, that is, the difference between the sexes is 3.7 times. Moreover, even with approximately the same severity of the disease, in women this figure was 1.5 times lower.

The female body has great potential to combat liver pathology, so if a representative of the fairer sex has clear signs of “liver problems,” then one test

for alanine aminotransferase is not enough - it may not be informative. At a minimum, you still need to undergo an ultrasound of the liver.

In order to get a real picture of the functioning of the liver, it is necessary to carry out other liver tests, then it is possible to more accurately say whether a woman has this pathology or not. Representatives of the fair sex often experience a latent course of chronic hepatitis, when symptoms of liver damage appear later, in the presence of pronounced, sometimes irreversible, changes. In addition, they are characterized by a more rapid restoration of normal ALT levels after Botkin’s disease, which is also associated with the physiological characteristics of the female body.

All these factors must be taken into account when examining men and women for the presence of liver pathologies.

Dependence of alanine aminotransferase levels on gender in viral hepatitis

ALAT norm

with various types of hepatitis it can increase 20 or even 100 times. In this case, the cause of this pathology (viruses, poisoning, hemolysis of red blood cells) does not play a role.

• In Botkin's disease, an increase in this biochemical indicator can be observed even before the appearance of jaundice and other clinical symptoms. Also, the level of ALT in the blood
  may be increased for some time after recovery, returning to normal (women - 31 U/L; men - 45 U/L) after two to three weeks.
• With “syringe” viral hepatitis , especially those with a chronic and protracted course (CVH), this indicator can constantly fluctuate either down or up. Sometimes it depends on the stage of the infectious process, and in some cases such jumps are difficult to explain.
• Mechanical (obstructive) jaundice also causes sudden changes in ALT concentration. With this pathology, the level
  of alanine aminotransferase in the blood can rise to 600 U/L in one day, and then spontaneously return to normal within about two days.

If obstructive jaundice is due to primary liver cancer, the concentration of alanine aminotransferase remains consistently high.

What do increased indicators mean?

First of all, when ALT increases, liver problems should be suspected: fatty hepatosis, hepatitis of viral or toxic etiology, liver cirrhosis, liver cancer - primary or metastatic.
The degree of increase in ALT is usually associated with the volume or severity of liver damage, but cannot be considered as a determining factor for the prognosis of the disease. Maximum levels of ALT (and AST) - more than a hundred times higher than normal - are observed in patients with acute viral and drug-induced hepatitis.

A significant increase in alanine aminotransferase can be observed in acute cholecystitis, cholelithiasis, and acute destructive pancreatitis. Another reason may be taking hepatotoxic drugs that damage liver cells.

An increase in ALT levels is detected with extensive injuries to skeletal muscles, severe myositis and muscular dystrophy, and frequent intramuscular injections.

A less significant increase in ALT is recorded in acute myocardial infarction and myocarditis.

Why is an ALT test done?

The endogenous enzyme ALT serves as a reliable marker of liver tests - liver pathologies in diagnostic laboratory practice. Alanine aminotransferase is formed due to intracellular synthesis, so it is present in the blood in small doses.

Blood test for ALT

in a healthy person it shows a minimum value. Diseases or damage to the liver cause the death of its cells, and the intracellular liver enzyme ALT is released into the blood, which, along with other indicators, is a fairly informative indicator of disease processes. Any deviation of the enzyme indicator from the standard range, especially upward, is an indisputable sign of an incipient liver disease or an extensive process of its destruction

Elevated ALT levels may also be observed in pregnant women, during a heart attack, and in certain pathological conditions. An increase in the dose of ALT in the blood is observed before the manifestations of jaundice, which allows for early diagnosis of liver diseases.

What is aspartate aminotransferase (AST)

The endogenous enzyme aspartate aminotransferase (AST) is responsible for accelerating the release of ammonia from amino acids for its subsequent processing in the urea cycle. AST is found not only in the liver, but also in the heart muscle and brain, kidneys and spleen, lungs and pancreas. Due to the intracellular nature of synthesis, AST is successfully used in diagnosing the condition of the myocardium and liver. Using a biochemical blood test for AST and ALT, as well as their ratio, doctors are able to predict a heart attack even before the appearance of the main symptoms.

AST is also used as a marker in the differentiated diagnosis of a number of diseases:

• Cirrhosis and hepatitis;
• Metastases in the liver;
• Jaundice of various origins.

If, according to the results of the study, high ALT levels are much greater than the excess of the norm for AST, this is a characteristic sign of liver damage. If AST is increased more than ALT, the possibility of myocardial cell death should be considered. Excessive activity of alanine aminotransferase is also possible during the period of taking certain medications. Reduced values ​​of AST and ALT are possible during pregnancy, renal failure or pyridoxine deficiency.

Rules for preparing and submitting analysis

To obtain objective results, a biochemistry analysis should be done after simple preliminary preparation. The patient must comply with the following conditions:

• for 5–7 days, avoid drinking alcohol-containing drinks, because toxic metabolites of ethanol disrupt the synthesis of proteins and enzymes in the liver.
• Eliminate fatty foods and fried foods from your diet in 2–3 days so as not to create additional stress on the liver and pancreas;
• temporarily stop using medications;
• fast before the procedure for at least 8–12 hours.

Why do you need to take the test on an empty stomach? This is due to the fact that any food changes the composition of the blood, and fats make the plasma cloudy. Test results performed on a full stomach will be inaccurate.

What does ALT show in the blood?

Alanine aminotransferase, or ALT for short, is a special endogenous enzyme. It is included in the group of transferases and the subgroup of aminotransferases. The synthesis of this enzyme occurs intracellularly. A limited amount of it enters the blood. Therefore, when a biochemical analysis shows an increased ALT content, this indicates the presence of a number of abnormalities in the body and the development of serious diseases. They are often associated with the destruction of organs, which leads to a sharp release of the enzyme into the blood. As a result, alanine aminotransferase activity also increases. It is difficult to establish the extent of necrosis or the degree of tissue damage by the disease based on this, since the enzyme is not characterized by organ specificity.

Alanine aminotransferase is found in many human organs: kidneys, heart muscle, liver and even skeletal muscles. The main function of the enzyme is to exchange amino acids. It acts as a catalyst for the reversible transfer of alanine from the amino acid to alpha-ketoglutarate. As a result of the transfer of the amino group, glutamic and pyruvic acids are obtained. Alanine is necessary in the tissues of the human body, as it is an amino acid that can quickly be converted into glucose. In this way, it is possible to obtain energy for the functioning of the brain and central nervous system. In addition, among the important functions of alanine are strengthening the body’s immune system, the production of lymphocytes, and regulating the metabolism of acids and sugars.

The highest activity of alanine aminotransferase was detected in the blood serum of men. In women, processes involving the enzyme proceed more slowly. The highest concentrations are noted in the kidneys and liver, followed by skeletal muscles, spleen, pancreas, red blood cells, lungs, and heart.

What is analysis used for?

The largest amount of transferase was found in the liver. This observation is used to detect diseases of a given organ that do not have external symptoms. ALT, unlike many other components considered in a biochemical blood test, has been studied most fully. Therefore, with its help you can identify even minor problems in the body. In some cases, the amount of ALT is compared with the volume of other elements in the blood. This allows us to draw conclusions about the presence of pathologies.

For example, an enzyme such as aspartate aminotransferase or AST is often used. It is also synthesized intracellularly, and a limited amount enters the blood. Deviation from the norm established in medicine for the content of aspartate aminotransferase, as in the case of alanine aminotransferase, is a manifestation of abnormalities in the functioning of certain organs. The most complete understanding of the nature of the pathology can be obtained by correlating the contained amounts of both enzymes. If there is an excess of alanine aminotransferase over aspartate aminotransferase, this indicates the destruction of liver cells. AST levels rise sharply in late stages of disease of this organ, such as cirrhosis. When the level of aspartate aminotransferase exceeds the level of alanine aminotransferase, problems with the heart muscle are observed.

Additional diagnostic methods can confirm the presence of the disease and the extent of organ damage. However, ALT is an accurate indicator; in some cases, it can even be used to establish the stage of the disease and suggest possible options for its development.

Symptoms

Symptoms of increased alanine transaminase in the blood are varied. The clinical picture is determined by the affected organ and the disease that led to it.

From the liver

A characteristic symptom of liver cirrhosis is “head of the jellyfish”, a combination of ascites and varicose veins of the abdominal wall

If the liver is damaged, pain in the right hypochondrium, nausea, and vomiting are possible. Yellowness of the skin and icterus of the sclera are possible. With a viral etiology, there may be hyperthermia. When cirrhosis has developed, rashes like spider veins appear on the body, and an enlarged abdomen due to ascites (fluid accumulation in the abdominal cavity).

Varicose veins (esophagus, stomach), which can be complicated by bleeding. Multiple organ failure gradually develops.

From the pancreas

Pancreatitis is manifested by severe pain in the abdomen, in the navel, swelling, repeated vomiting, weakness, and subsequent clouding of consciousness.

From the side of the heart

The main symptom of myocardial infarction is severe, burning pain behind the sternum, which can spread to the left arm, jaw, and under the shoulder blade.

A painless form of heart attack is possible, or an atypical one, when the pain is localized in the abdomen, or severe shortness of breath develops. In addition to pain, heart rhythm disturbances and a drop in blood pressure are possible. Concerned about severe weakness, fear of death, chills.

If there is an oncological process in the affected organ, severe weight loss in a short period of time, weakness, and increased fatigue are possible.

Recommendations for correcting indicators

To reduce a high ALT level in the blood, first of all, it is necessary to begin treatment of the underlying disease that affected the test results. Since in most cases, the increased concentration of ALT is due to the development of liver pathologies, drugs of the hepatoprotective group are prescribed:

• Essential phospholipids (complex compounds of alcohols, high molecular weight acids and lipids). Stimulate the regeneration of hepatocytes, stabilize metabolic processes, maintain the balance of proteins, fats and carbohydrates (Essliver, Phosphonciale, Essentiale Forte N, Phosphogliv, etc.).
• Hepatoprotectors-lipotropics. Inhibit or stop fatty infiltration of the liver (Heptral, Betargin, Hepa-Merz).
• Plant hepatoprotectors. Promotes the restoration of liver cells, treatment requires long-term use. The tablets contain natural extracts of medicinal herbs (Liv-52, Silimar, Karsil, Bonjigar, etc.).

Additional therapy is carried out with drugs based on ursodeoxycholic acid (Ursosan, Urdoxa, Ursodez) and lipoic acid, which help neutralize toxins and breakdown products of alcohol. You can lower ALT with diet therapy. A patient with impaired functional abilities of the liver and pancreas is prescribed the “Table No. 5” diet.

A brief table of permitted and prohibited foods for increased ALT in the blood

Important! If ALT levels are elevated, any alcoholic drinks are completely excluded from the menu!

When is an ALT test prescribed?

The amount of alanine aminotransferase is determined as part of a general biochemical blood test. Often only one type of examination is prescribed when there is no need to use additional methods. They get tested for ALT. This is due to the selective tissue specialization that the enzyme has.

The amount of alanine aminotransferase in case of liver problems helps to identify them even before the appearance of the most characteristic symptom - jaundice. Therefore, a doctor most often prescribes an ALT test to check for damage to this important organ as a result of taking medications or any other substances that are toxic to the body. The study is also carried out if hepatitis is suspected. An ALT test is required if the patient has symptoms such as fatigue and weakness. He loses his appetite and often feels nausea, turning into vomiting. Yellow spots on the skin, abdominal pain and discomfort, yellowing of the whites of the eyes, light-colored stool and dark urine can all be signs of liver disease. In such cases, this analysis is required.

ALT can be compared with AST to provide additional information about the causes of liver damage. This is done if the amount of enzymes significantly exceeds the norm. The ratio of AST to ALT is known in medicine as the de Ritis ratio. Its normal value ranges from 0.91 to 1.75. If this indicator becomes more than 2, then damage to the heart muscle is diagnosed, which occurs with the destruction of cardiomycytes. Myocardial infarction is also possible. A de Ritis coefficient not exceeding 1 indicates liver disease. Moreover, the lower the value of the indicator, the greater the risk of an unfavorable outcome.

ALT analysis can be used not only as a diagnostic method, but also during treatment. This allows you to determine the dynamics of the disease and identify improvements or deteriorations in the patient’s condition. ALT testing is necessary if factors contributing to liver disease are present. These include abuse of alcoholic beverages or drugs that destroy organ cells. If the level of alanine aminotransferase in the blood exceeds the normal level, other medications are prescribed. It is imperative to check the amount of ALT if the patient has been in contact with people with hepatitis or has recently had it, has diabetes and is overweight. Some people are predisposed to liver disease. They are also shown an ALT test.

It uses either venous or capillary blood. To obtain reliable results, certain requirements must be met. Firstly, do not eat 12 hours before the test and do not drink alcohol for a week. Even a small amount of food can make a significant difference in your results. Secondly, for half an hour before the analysis, stop smoking, don’t worry, and avoid mental and physical stress. The results are usually ready a day after the test.

Increasing values

Sufficiently high values ​​(5-10 times higher than normal) of ALT in the blood indicate an acute course of the disease or an exacerbation of chronic pathology.

Indulging in fast food also leads to a slight increase in ALT in the blood. However, timely nutritional correction returns the indicators to normal.

Very high values ​​(more than 10 times the normal):

• Destruction (necrosis) of hepatocytes against the background of viral, toxic liver damage (in acute cases, the ALT level exceeds the norm by 10 or more times, in chronic cases - more than 4-5 times);
• Paracetamol overdose;
• Acute fulminant hepatitis;
• Tumor necrosis.

Moderately high values ​​(increase in concentration by 5-10 times):

• Liver cancer, incl. metastatic;
• Cholestasis (stagnation of bile in the bile ducts), cholelithiasis;
• Fatty hepatosis (replacement of healthy hepatocytes with adipose tissue cells, fatty liver);
• Shock due to extensive burns, severe injuries;
• Heatstroke, incl. sunny (the level depends on the degree of tissue damage);
• Chronic or acute heart failure, other heart diseases (myocarditis, myocardial infarction);
• Diseases that slow blood flow to the liver (occlusion of hepatic venules);
• Pathologies of the muscular system: myodystrophy, myositis;
• Chronic alcoholism;
• Acute, exacerbation of chronic pancreatitis (inflammation of the pancreas);
• Kidney damage;
• Excessive intake of vitamin A;
• Deficiency of levocarnitine (a natural substance, an active participant in all metabolic processes in the body);

Small increase (1.5-5 times):

• Taking hepatotoxic (aggressive effects on the liver) drugs: psychotropic drugs;
• anabolics;
• contraceptives;
• salicylates;
• antibiotics;
• sulfonamides;
• immunosuppressants (drugs that suppress the immune system);
• drugs (anesthetics);
• cytostatics (antitumor agents);
• statins.

Transaminases

It is known that in the body there are a huge number of different biologically active substances that take part in certain reactions and have very high selectivity and specificity. These are enzymes, also called enzymes. The presence of enzymes makes it possible to speed up the occurrence of chemical reactions many hundreds and thousands of times.

In biochemistry, there are several groups of enzymes. So, in our body there are oxidoreductases. These enzymes assist biological oxidation such as proton transfer. There are hydrolases that break down intramolecular bonds. For example, these enzymes are involved in the breakdown of esters and fats. The body contains isomerases that catalyze the mutual transformations of different isomers of the same molecule. Finally, enzymes are represented in large quantities by transferases. These enzymes catalyze the transfer of various groups of atoms from one molecule to another. Their common name is built from the name of the donor molecule, then the name of the transferred group is added, and then the ending is added: transferase.

Thus, ALT or alanine aminotransferase transfers the NH2 amino group from the alanine amino acid, and AST, or aspartate aminotransferase, transfers the same NH2 amino group from the aspartate amino acid. Why are these processes needed, and where do these transaminases, that is, transporters of amino groups that carry out transamination, occur?

How to lower ALT in the blood?

It is possible to reduce the level of alanine aminotransferase in the blood by eliminating the cause of this phenomenon. Since the most common factor in increasing ALT is liver and heart disease, it is necessary to start with their treatment. After a course of procedures and taking appropriate medications, a biochemical blood test is repeated. With proper treatment, ALT levels should return to normal.

Sometimes special drugs are used to reduce it, such as hefitol, heptral, duphalac. They must be prescribed by a doctor, and the appointment is carried out under his supervision. Most drugs have contraindications that must be taken into account before starting treatment. However, such remedies do not eliminate the main cause of the increase in ALT. Some time after taking the drugs, the enzyme level may change again. Therefore, it is necessary to contact a qualified specialist who will make the correct diagnosis and prescribe appropriate treatment.

Author of the article:

Mochalov Pavel Alexandrovich |
Doctor of Medical Sciences therapist Education: Moscow Medical Institute named after. I. M. Sechenov, specialty - “General Medicine” in 1991, in 1993 “Occupational diseases”, in 1996 “Therapy”. Our authors

Decrease in values ​​(in dynamics)

It is possible to predict a favorable outcome of the disease against the background of treatment by determining, albeit slowly (over several weeks), but a decrease in ALT levels to normal values. If the ALT concentration decreases too quickly, and at the same time there is still an increase in blood bilirubin (hyperbilirubinemia), then the prognosis for the patient is unfavorable.

In women, alanine aminotransferase activity is slightly lower than in men. During pregnancy, ALT decreases without damaging parenchymal cells - the condition is due to the functional “restructuring” of the body of the expectant mother.

Sources:

• Marc S Orlewicz, MD. Alanine Aminotransferase. — English-language database of current medical data Medscape.
• Data from the independent laboratory Invitro.
• Data from Helix laboratory.
• A.A. Kishkun, Doctor of Medical Sciences, Prof. Guide to laboratory diagnostic methods, - GEOTAR-Media, 2007.