Alanine aminotransferase, or ALT, and aspartate aminotransferase, or AST, are enzymes found in body cells that are involved in amino acid metabolism. They are located only in the cells of organ tissues, and enter the bloodstream only when the cell decays due to traumatic injuries or pathologies.
Types of diseases
Excessive content of ALT indicates the development of the pathology of the organ, in the cells of which there is its greatest amount. The causes of an increase in alanine aminotransferase are liver pathologies. A feeling of discomfort and pain in the right hypochondrium, diarrhea, icteric staining of the skin and mucous membranes, flatulence, bitter belching are signs of an increase in ALT. When conducting a blood test, an increase in the level of bilirubin joins the increased ALT and AST when hepatitis develops. More often, an increase in the content of ALT indicates the occurrence of other diseases. ALT concentration has a directdependence on the severity of the pathology.
Necrotic process in the heart muscle causes the release of these enzymes into the blood. Their increased content in serum also indicates the development of other cardiopathologies: insufficiency, inflammation of the heart muscle. In addition, the causes of an increase in the concentration of ALT in the serum may be existing in the body injury, which is associated with damage to muscle tissue, and pancreatitis.
Biochemical blood test for ALT and AST can indicate the pathology of the liver, pancreas, heart. With a cardioinfarction, the concentration of AST increases several times, and ALT - a little.
Indications for conduction
Human body organs contain different amounts of ALT and AST enzymes, so an increase in the concentration of a certain enzyme indicates damage to a specific organ:
• ALT is found primarily in liver, heart, kidney and pancreatic cells. If these organs are destroyed, 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 found mainly in nerve, muscle, liver and heart cells, and in small amounts in pancreatic, lung and kidney tissues. Therefore, in this case, an aspartate aminotransferase test is necessary.
ALT and AST blood test (decoding) indicates the state of the organs. Increasing themindicates damage to the tissues of the organs in which these enzymes are located. And, accordingly, a decrease indicates a cure. A slight increase in ALT in the first trimester of pregnancy is quite acceptable, but it is necessary to re-test the blood for aminotransferases to rule out liver damage.
Biochemical blood test (ALT, AST) is prescribed when a heart attack is suspected, they serve as an early sign in this acute pathology. Deciphering 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 muscles.
Preparation for blood sampling for research
Blood for biochemical analysis is taken in the morning on an empty stomach from a vein. At the time of the analysis, 8 hours should have passed. from the last food intake. For 24 hours. before blood sampling, alcohol and fried and fatty foods are prohibited. It is recommended to reduce physical activity.
Immediately after ultrasound, x-ray, fluorography, colonoscopy or physiotherapy procedures, blood is also not recommended to be taken for analysis, otherwise the decoding of biochemistry will be distorted. For 1-2 weeks. before a biochemical study, you need to stop taking medications. When it is impossible to comply with this condition, a doctor makes a note about taking the drugs and their dose in the direction for analysis. On a biochemical blood test (decoding ALT,AST) can be influenced by heavy exercise, as well as alcohol consumption and hemolysis.
Blood test transcript - ALT, AST: normal
How many of these enzymes should be contained in the blood of a he althy person? Conducting a biochemical blood test (decoding ALT, AST), the norm for women is in the range from 31 to 35 units per liter of blood. For the representatives of the stronger sex, this figure is slightly different. The norm of ALT in the blood in men (decoding of biochemistry) is from 41 to 50 units / l. In newborns (up to 1 month), the normal reading corresponds to up to 75 units, from 2 to 12 months. - no more than 60 units, and from one year to 14 years - less than 45 units. A blood test (ALT, AST) with an increased reading may indicate cirrhotic damage or acute inflammation of the liver, congestive or hemolytic jaundice, other liver pathologies (including neoplasms), angina pectoris in the attack stage, acute rheumatic heart disease, myopathy, bile stasis, pulmonary embolism and acute pancreatitis.
ALT and AST blood test (decoding) with increasing readings is observed in traumatic injuries, cardiac surgery or angiocardiography. An increased AST index by 20–50 times in some cases indicates a hepatic pathology accompanied by necrosis, and hepatitis of viral etiology. An increase in the content of AST by 2-5 times can indicate diseases with hemolysis, muscle injuries, acute pancreatitis and gangrene. With dystrophic phenomenain muscles and dermatomyositis, an 8-fold increase in AST is observed.
Ritis ratio
In order to obtain accurate answers, the ALT and AST blood test (decoding) shows the ratio of transferase indicators. This ratio shows the de Ritis coefficient conducted in one serum study. In the case when the number is above the standard (N=1, 3), this indicates the presence of a cardioinfarction, and when it is below the standard values, it indicates viral hepatitis.
Since aminotransferases have tissue localization, the decoding of the blood test AST shows the pathology of the myocardium, and ALT - the pathology of the liver, that is, the presence of cell decay:
• When there is an excess of 2 or more times, a heart attack is determined in the heart.
• ALT and AST blood test (decoding) shows a significant excess - this is evidence of infectious hepatitis in the incubation period.
• With a decrease in aminotransferase, there is a lack of pyridoxine in the body. Here, differential diagnosis with pregnancy is necessary.
Tactics
Normally, transferases exist in small amounts in blood serum. All options for increasing the level of aminotransferase are subject to mandatory investigation.
To begin with, a repeated biochemical blood test (decoding ALT, AST) should be carried out. Re-examination of some individuals (donors) shows a normal level in about a third of cases.
Next you needcarefully collect anamnesis and conduct a complete examination.
The role of anamnesis in decoding
History includes information about taking medications, blood transfusions, the presence of jaundice or hepatitis syndrome, family diseases of the liver or the presence of cirrhosis in it, abdominal pain, cancer, diabetes, obesity, or, conversely, rapid weight loss.
Family liver diseases are alcohol addiction, Wilson's disease, etc.
If the ALT and AST blood test (decoding) showed less than twice the normal values, it is necessary to organize observation and a 2-fold examination. This tactic is optimal for patients.
ALT and AST blood test - decoding for some diseases
A slight increase in transferases is indicative of non-alcoholic fatty liver damage, including "fatty liver", non-alcoholic steatohepatosis, chronic viral hepatitis.
Moderate increase may exist in viral or alcoholic inflammation of the liver and various chronic liver diseases with or without cirrhotic damage.
Elevated levels are typical of severe acute hepatitis, toxic or drug necrosis, shock, or hepatic ischemia.
Excessively high levels (greater than 2000-3000 U/l) exist with acetaminophen overdose and use in alcohol-dependent patients, in shock and/or hepatic ischemia.
ShouldIt should be noted that since ALT is located in erythrocytes, it is necessary to prevent their decay when preparing serum for analysis. ALT may decrease if serum is stored for several days.
The role of medicines, herbs and other substances
Careful history taking and interpretation of laboratory results are important to detect drug-induced transferase increases. Similar liver damage is detected in 1-2% of cases of liver inflammation in a chronic form. They are associated with the use of antibiotics, antiepileptics, hydroxymethylglutaryl-CoA reductase inhibitors, non-steroidal anti-inflammatory drugs and drugs for the treatment of tuberculosis.
The easiest way to determine the dependence of an increase in aminotransferases with any agent is to cancel it and observe the level of enzymes. Without canceling the remedy, this dependency cannot be determined.
