Alanine aminotransferase, or ALT, andaspartate aminotransferase, or AST, are enzymes that are contained in the cells of the body and which participate in the amino acid exchange. They are located only in the cells of the tissues of organs, and enter the blood only when the cell decays with traumatic injuries or pathologies.
Types of diseases
Excessive content of ALT indicatesthe development of organ pathology, in cells of which there is its largest number. The causes of an increase in alanine aminotransferase are liver pathologies. Feeling of discomfort and painful sensation in the right hypochondrium, diarrhea, icteric staining of the skin and mucous membranes, flatulence, belching bitter - these are signs of an increase in ALT. When carrying out a blood test for increased ALT and AST, an increase in the level of bilirubin is added when there is a development of hepatitis. More often the increase in the content of ALT indicates the occurrence of other diseases. The concentration of ALT is directly dependent on the severity of the pathology.
Necrotic process in the cardiac muscle causesrelease of these enzymes into the blood. Their increased content in the serum also indicates the development of other cardiopathologies: insufficiency, inflammation of the heart muscle. Additionally, the causes of increased ALT concentration in the serum can be the injuries that are present in the body, which involve damage to muscle tissue, and pancreatitis.
Biochemical analysis of blood on ALT and AST can talk about the pathology of the liver, pancreas, heart. With cardioinfarction, the concentration of AST increases several times, and ALT - a little.
Indications for conduction
The organs of the human body contain different amounts of ALT and AST enzymes, so increasing the concentration of a certain enzyme indicates the defeat of a particular organ:
• ALT is mainly found in the hepatic,heart, kidney and pancreatic cells. In case of destruction of these organs, a lot of ALT is released into the blood. Then, to confirm the diagnosis, it is necessary to study specifically for alanine aminotransferase.
• AST is mainly found in the nervous, muscular,hepatic and cardiac cells, and in small numbers in cells of the pancreas, pulmonary and renal tissues. Therefore, in this case, a study on aspartate aminotransferase is necessary.
Analysis of blood ALT and AST (decoding)indicates the condition of organs. Increasing them indicates damage to the tissues of the organs in which these enzymes are located. And, accordingly, the decrease indicates a cure. A small increase in ALT in the first trimester of pregnancy is entirely permissible, but it is necessary to re-examine the blood for aminotransferases to exclude liver damage.
Biochemical blood test (ALT, AST)prescribe, when a cardioinfarct is suspected, they serve as an early sign in this acute pathology. The interpretation of AST in biochemical analysis makes it possible to diagnose and monitor the dynamics of other changes in the heart muscle, liver diseases and diseases of the striated muscle.
Preparation for blood sampling for the study
Blood for biochemical analysis is taken in the morningon an empty stomach from a vein. At the time of the analysis, it should be 8 hours. from the last use of food. For 24 hours. Before taking blood, alcohol and fried and fatty foods are not allowed. It is recommended to reduce the bills.
Explanation of the blood test - ALT, AST: norm
How many of these enzymes shouldcontained in the blood of a healthy person? Carrying out a biochemical blood test (decoding ALT, AST), the norm for women is in the range of 31 to 35 units per liter of blood. For the stronger sex, this indicator is slightly different. The norm of ALT in the blood of men (decoding of biochemistry) - from 41 to 50 units / liter. In newborns (up to 1 month) the normal reading corresponds to 75 units, from 2 to 12 months. - no more than 60 units, and from one year to 14 years - less than 45 units. The analysis of blood (interpretation of ALT, AST) with an increased indication may indicate cirrhotic damage or acute inflammation of the liver, congestive or hemolytic jaundice, other liver pathologies (including neoplasms, etc.), angina at the stage of an attack, acute rheumatic carditis, myopathy, bile stasis , thromboembolic pulmonary artery disease and acute pancreatitis.
Ratis coefficient
In order to obtain accurate answers, a blood test of ALTand AST (decoding) shows the ratio of transferase rates. This ratio shows the de Ritis coefficient, carried out in one serum study. In the case when the number is higher than the norm (N = 1,3), this indicates the presence of cardioinfarction, and when it is below the normative indices - about viral hepatitis.
Since aminotransferases have tissue localization, the interpretation of the AST blood test shows the pathology of the myocardium, and ALT - the pathology of the liver, that is, the presence of cell disintegration:
• When there is an excess of 2 or more times, a heart attack is determined in the heart.
• Blood tests for ALT and AST (transcript) show a significant excess - this is evidence of infectious hepatitis during the incubation period.
• With a decrease in aminotransferase - in the body lack of pyridoxine. Here it is necessary to diagnose with pregnancy.
Tactics
Normally, serum transferase exists in small volumes. All variants of increasing the level of aminotransferase are necessarily investigated.
To begin with, a repeated biochemical blood test should be carried out (deciphering ALT, AST). Re-examination of some individuals (donors) in about a third of cases shows a normal level.
Then you need to carefully collect history and conduct a full examination.
Anamnesis role in decoding
Medical history implies admission information.medications, blood transfusion, the presence of jaundice or hepatitis syndrome, family liver disease or the presence of a cirrhotic process in it, abdominal pain, cancer, diabetes, obesity, or, conversely, rapid weight loss.
Family liver disease is alcohol dependence, Wilson's disease, etc.
If the ALT and AST blood test (transcript) showed less than twice the normal values, it is necessary to organize an observation and a 2-fold examination. This tactic is optimal for patients.
Blood test ALT and AST - transcript for some diseases
A slight increase in transferase is indicative.for non-alcoholic fatty liver damage, including “fatty liver”, non-alcoholic steatohepatosis, chronic hepatitis.
A moderate increase may exist with viral or alcoholic inflammation of the liver and various chronic liver diseases with or without cirrhotic damage.
Elevated levels are typical of acute severe hepatitis, toxic or drug necrosis, shock, or hepatic ischemia.
An excessively high level (more than 2000-3000 U / l) exists when acetaminophen is overdose and when using the drug in alcohol-dependent patients, with shock and / or hepatic ischemia.
It should be noted, since ALT is in red blood cells, it is necessary to prevent their disintegration in the preparation of serum for analysis. ALT may decrease during storage of serum over several days.
The role of medicines, herbs and other substances
Careful history taking and decodingLaboratory results are important for detecting drug-induced increases in transferase. Similar liver damage is detected in 1-2% of cases of liver inflammation in the chronic form. They are associated with antibiotics, antiepileptic drugs, hydroxymethylglutaryl-CoA reductase inhibitors, nonsteroidal anti-inflammatory drugs and medicines for the treatment of tuberculosis.
The easiest method to determine the dependence of an increase in aminotransferases with some means is to cancel it and observe the level of enzymes. Without cancellation of funds, this dependence cannot be determined.
