Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) are enzymes that are active participants in the exchange of amino acids. They are able to be in the cells of the kidneys, liver, heart muscles and other organs.
If they enter the blood, it indicates the presence of any disruption of the organs due to the destruction of cells.
When ALT levels are elevated, this most often indicates the development of a specific disease affecting the liver. The deciphering blood test can show in more detail which organ is damaged, it will significantly increase the level of ALT or AST.
What is ALT in a blood test?
Why is ALT elevated in blood tests, and what does this mean? Alanine aminotransferase (ALT) is an endogenous enzyme belonging to the transferase group, a subgroup of transaminases, or aminotransferases. Determining its level in the blood is widely used in medical practice in order to identify pathologies of the liver and some other organs. Blood tests for ALT are almost always carried out in conjunction with determining the level of AST.
Evaluation of these two laboratory parameters allows the physician to assume the localization of the pathological process and determine the likely severity of the disease. For evaluation, the Ritis coefficient is applied (AST / ALT ratio), which is normally 1.33. In acute viral hepatitis, this coefficient decreases, while in myocardial infarction and alcoholic liver damage it increases.
Where is the ALT:
- Liver (most);
- A heart.
The main function of alanine aminotransferase is associated with the exchange of amino acids. This substance acts as a catalyst in the transfer of certain molecules. In case of violation of energy metabolism, an increase in the permeability of cell membranes occurs, which leads to cell destruction and the release of the enzyme into the blood serum.
The standards in which alanine aminotransferase must fit in the blood are:
- children under 1 year: 13 – 45 U / l;
- men under 1 – 60 years: 10 – 40 U / l;
- women 1 – 60 years: 7 – 35 U / l.
In analytical studies on this enzyme, high accuracy is necessary, and it is directly related to the intake of certain drugs that can distort the analytical picture. Therefore, before checking the level of ALT, you should consult with your doctor, who will either temporarily cancel the medication, or will take into account deviations in the results of the analysis associated with drug therapy.
Increased ALT in the blood: causes
In simple terms, alanine aminotransferase is an enzyme that, in addition to the liver, where its concentration is particularly high, is found in virtually all parenchymal organs, occupying mainly the cytoplasm of tissue cells. It is not for nothing that ALAT is considered a kind of marker of liver pathology and is regarded as a reliable sign of damage to its parenchyma, because the enzyme activity in the blood plasma is directly dependent on the degree of tissue involvement of this important organ in the pathological process.
Given the high sensitivity of ALT, it can be expected that alanine aminotransferase will be enhanced in cases of the slightest suffering of the hepatic parenchyma.
Thus, the increase in ALT occurs in the following cases:
- Hepatitis. This inflammatory liver disease can be represented in several forms. For chronic or viral hepatitis, alanine aminotransferase levels in the blood are insignificant.
- Rarely, an increase in ALT can be observed in cases of obstructive jaundice, however, high values of this indicator are extremely rare.
- Cirrhosis. This disease is dangerous because for a long time it may not have pronounced symptoms. Patients get tired quickly, feel tired.
- Liver cancer. This malignant tumor is often formed in patients with hepatitis. Analysis of ALT in this case is necessary both for the diagnosis of the disease, and for making decisions about the operational decision.
- Non-alcoholic fatty liver disease (steatosis): the level of ALT increases slightly – by 2-3 times. When the disease passes into the steatohepatitis phase, there is a marked increase in ALT, a high level of total and direct bilirubin, as well as indicators of inflammatory blood activity.
- Pancreatitis. The presence of this disease also indicates the level of ALT. Its increased amount indicates an exacerbation of pancreatitis.
- Myocarditis. It manifests itself in lesions of the heart muscle. Its main symptoms are shortness of breath, fatigue of the patient and elevated levels of ALT in the blood.
- Myocardial infarction. This disease is a consequence of impaired blood flow, resulting in necrosis of the heart muscle.
- Analyzes can show an increase in ALT levels in alcoholism and immediately after ingestion of alcoholic beverages.
With an increase in the level of ALT 5 times, myocardial infarction can be assumed, if it reaches 10-15 times, we can talk about the deterioration of the patient’s condition after the attack. The value of the de Ritis coefficient also changes upwards.
Acute hepatitis provokes an increase in the enzyme content in the blood by 20-50 times, muscular dystrophy and dermatomyasitis – by 8. About the gangrene, acute pancreatitis, says the upper limit of the index is 3-5 times.
Causes of ALT is not associated with diseases
To increase the level of ALT in the blood can drgua and causes, for example, some drugs, such as estrogens, oral contraceptives, holestatiki, steroids, iron salts, nicotinic acid, sulfonamide, methyldopa, azithromycin, aminoglycosides, cephalosporins, fluoroquinolones, clofibrate, clindamycin.
In some cases, physiological causes can cause an increase in the level of alanine aminotransferase:
- Increased physical activity;
- Reception of dietary supplements containing components that adversely affect the liver cells;
- The use of alcoholic beverages a week before the deadline for blood testing for ALT;
- Emotional stress that can lead to disruptions in the nervous system, and as a result, the body’s reaction to it;
- Improper nutrition – in particular, the use of products with harmful food additives: convenience foods, “fast food”, sugary carbonated drinks and
Of course, generally the level of the enzyme increases due to other health problems, but it is for the reasons listed above that the indicator can be increased, but only slightly.
What to do when ALT is elevated in the blood?
If the blood test of ALT is increased, then a more complete examination is necessary to identify the cause of this change. And the sooner this is done, the better the outcome will be.
Most often, hepatoprotectors are prescribed to reduce ALT:
These drugs have numerous effects. First of all, they protect liver cells from further damage, as well as restore already damaged, but not yet dead cells.