ALT norm

Alanine aminotransferase (ALT) is one of the main indicators in the lesion of liver cells and cardiac muscle. The main indicators for the use of ALT are toxic liver damage, preventive examinations and viral hepatitis.

ALT is also an enzyme involved in the cellular metabolism of amino acids. The largest number is in the kidneys, liver, skeletal and cardiac muscles. Since ALT is localized mainly in the cytoplasm of the cell, any damage to it leads to an increase in the content or activity of this enzyme.

In acute or chronic diseases, organic lesions can occur, which will be accompanied by necrosis of the cells of the etiology, which will lead to the release of alanine aminotransferase into the blood from the lesion focus. The initial growth of enzyme activity in acute myocardial infarction occurs approximately 6 to 12 hours and coincides with the peak of ALT activity.

The most characteristic is an increase in the activity of alanine aminotransferase in the blood in diseases of the liver that are accompanied by hepatitis or toxic effects. Also, the ALT enzyme serves as an indicator of the severity of hepatitis A, B and C. Without considering the etiology, in acute hepatitis, ALT activity can increase tens of times and lead to jaundice.

The highest increase in enzyme activity is observed in acute viral hepatitis. With a favorable course of the disease, normalization of activity occurs within a month. In the event that this period is delayed, this may indicate a transition from acute hepatitis to chronic.

In chronic hepatitis, liver metaphase, liver cancer, as well as infectious mononucleosis, a slight increase in ALT activity is observed. Also, the activity of alanine aminotransferase may increase with myocardial infarction, but to a significantly lesser extent, at least in comparison with aspartate aminotransferase (AST). In order to deliver the most accurate diagnosis, the de Ritis coefficient is calculated, which is the ratio of ALT activity to AST.

The AST ALT norm is 1.3 ± 0.4. It is exceeded when the heart muscle is affected. With necrosis of hepatic cells in viral hepatitis, ALT AST is reduced to 0.6-0.8. These figures have become quite widespread in Ukraine and Europe, but based on some reagents, these indicators can vary slightly. It all depends on the set of reagents that determine ALT and AST enzymes, as well as from laboratories that usually apply the norm when determining transaminase rates.

In acute hepatitis, the ALT rate is exceeded more than AST. And with myocardial infarction, the last is exceeded. Since the ALT rate increases with a given ailment, the de Ritis coefficient increases significantly. And with viral hepatitis ALT the norm returns within a few weeks.

In adults and children older than a year for men, it is 10-40 units per liter of blood, and for women - 7-35. From birth to one year ALT norm in children is about 13 to 45 units per liter of blood.

Indications for the purpose of this analysis are usually diagnosis of liver disease, differential diagnosis, donor examination, studies in the focus of viral hepatitis, myocardial pathology, as well as diseases of skeletal muscles.

The ALT level should be measured on an empty stomach in the morning, as during the day the coefficient may change. The indicator can be increased if the body weight exceeds the norm.

The study on ALT is carried out biochemically using serum without traces of hemolysis in a special tube with a red lid, or in a plastic tube with a screw cap. The serum is stored for no more than a day.