Alanine transaminase (ALT) blood test

Medical Tests 

Definition

The alanine transaminase (ALT) blood test measures the level of the enzyme ALT in the blood.

Alternative Names

SGPT; Serum glutamate pyruvate transaminase; Alanine transaminase; Alanine aminotransferase

How the Test is Performed

A blood sample is needed.

How to Prepare for the Test

No special preparation is needed.

How the Test will Feel

When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or a slight bruise. This soon goes away.

Why the Test is Performed

ALT is an enzyme found in a high level in the liver. An enzyme is a protein that causes a specific chemical change in the body.

Injury to the liver results in release of ALT into the blood.

This test is mainly done along with other tests (such as AST, ALP, and bilirubin) to diagnose and monitor liver disease.

Normal Results

The normal range is 4 to 36 U/L.

Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or may test different samples. Talk to your health care provider about the meaning of your specific test results.

What Abnormal Results Mean

An increased ALT level is often a sign of liver disease. Liver disease is even more likely when the levels of substances checked by other liver blood tests have also increased.

An increased ALT level may be due to any of the following:

• Scarring of the liver (cirrhosis)
• Death of liver tissue
• Swollen and inflamed liver (hepatitis)
• Too much iron in the body (hemochromatosis)
• Too much fat in the liver (fatty liver)
• Lack of blood flow to the liver (liver ischemia)
• Liver tumor or cancer
• Use of drugs that are toxic to the liver
• Mononucleosis (“mono”)
• Swollen and inflamed pancreas (pancreatitis)

Risks

adam.com”>There is little risk involved with having your blood taken. Veins and arteries vary in size from one person to another and from one side of the body to the other. Taking blood from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight, but may include:

• Excessive bleeding
• Fainting or feeling lightheaded
• Multiple punctures to locate veins
• Hematoma (blood collecting under the skin)
• Infection (a slight risk any time the skin is broken)

References

Chernecky CC, Berger BJ. Alanine aminotransferase (ALT, alanine transaminase, SGPT) – serum. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures. 6th ed. St Louis, MO: Elsevier Saunders; 2013:109-110.

Pincus MR, Tierno PM, Gleeson E, Bowne WB, Bluth MH. Evaluation of liver function. In: McPherson RA, Pincus MR, eds. Henry’s Clinical Diagnosis and Management by Laboratory Methods. 23rd ed. St Louis, MO: Elsevier; 2017:chap 21.

Pratt DS. Liver chemistry and function tests. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran’s Gastrointestinal and Liver Disease. 10th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 73.

Review Date: 01/26/2019

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Information developed by A.D.A.M., Inc. regarding tests and test results may not directly correspond with information provided by UCSF Health. Please discuss with your doctor any questions or concerns you may have.

High vs. Low Levels, Direct vs. Indirect

Written by WebMD Editorial Contributors

• Why Do You Get This Test?
• What Happens During the Test?
• Who Should Get It? Who Shouldn’t?
• What Do the Results Mean?

A bilirubin test measures the amount of bilirubin in your blood. It’s used to help find the cause of health conditions like jaundice, anemia, and liver disease.

Bilirubin is an orange-yellow pigment that occurs normally when part of your red blood cells break down. Your liver takes the bilirubin from your blood and changes its chemical make-up so that most of it is passed through your poop as bile.

If your bilirubin levels are higher than normal, it’s a sign that either your red blood cells are breaking down at an unusual rate or that your liver isn’t breaking down waste properly and clearing the bilirubin from your blood.

Another option is that there’s a problem somewhere along the pathway that gets the bilirubin out of your liver and into your stool.

In children and adults, doctors use it to diagnose and monitor liver and bile duct diseases. These include cirrhosis, hepatitis, and gallstones.

It’ll also help determine if you have sickle cell disease or other conditions that cause hemolytic anemia. That’s a disorder where red blood cells are destroyed faster than they’re made.

High levels of bilirubin can cause a yellowing of your skin and eyes, a condition doctors call jaundice.

High bilirubin levels are common in newborns. Doctors use the age of the newborn and the bilirubin type and levels to determine if treatment is necessary.

A nurse or lab technician will draw blood through a small needle inserted into a vein in your arm. The blood is collected in a tube.

With newborns, blood is usually drawn by using a needle to break the skin of the heel.

Your doctor will send the blood to a lab for analysis.

Before the test, tell your doctor about how active you’ve been and what food and medicines you’ve taken. Certain medications may alter your results.

After the test, you’ll be able to continue with your normal activities right away.

Your doctor may order a bilirubin test if you:

• Show signs of jaundice
• Have anemia, or low red blood cells
• Might be having a toxic reaction to drugs
• Have a history of heavy drinking
• Have been exposed to hepatitis viruses
• Have cirrhosis

You might also have your bilirubin tested if you have symptoms like:

• Dark urine
• Nausea and vomiting
• Abdominal pain or abdominal swelling
• Clay-colored stools
• Fatigue

A bilirubin test measures total bilirubin. It can also give levels of two different types of bilirubin: unconjugated and conjugated.

Unconjugated (“indirect”) bilirubin. This is the bilirubin created from red blood cell breakdown. It travels in the blood to the liver.

Conjugated (“direct”) bilirubin. This is the bilirubin once it reaches the liver and undergoes a chemical change. It moves to the intestines before being removed through your stool.

For adults over 18, normal total bilirubin can be up to 1.2 milligrams per deciliter (mg/dl) of blood. For those under 18, the normal level will be will be 1 mg/dl. Normal results for conjugated (direct) bilirubin should be less than 0.3 mg/dl.

Men tend to have slightly higher bilirubin levels than women. African-Americans tend to have lower bilirubin levels than people of other races.

High total bilirubin may be caused by:

• Anemia
• Cirrhosis
• A reaction to a blood transfusion
• Gilbert syndrome — a common, inherited condition in which there is a deficiency of an enzyme that helps to break down bilirubin.
• Viral hepatitis
• A reaction to drugs
• Alcoholic liver disease
• Gallstones

Very strenuous exercise, such as marathon running, can increase your bilirubin levels.

Caffeine, penicillin, barbiturates, and nonsteroidal anti-inflammatory drugs (NSAIDs) called salicylates all lower your bilirubin levels.

Lower-than-normal levels of bilirubin aren’t a problem.

In newborns, high bilirubin levels that don’t level out in a few days to 2 weeks may be a sign of:

• Blood type incompatibility between mother and child
• Lack of oxygen
• An inherited infection
• A disease affecting the liver

Top Picks

Liver tests.

Checking the main “filter” of the body: why and what indicators should be monitored

The human liver is not only an indispensable main “filter” of the body, but also its main “laboratory”. With the help of its working cells (hepatocytes), this organ performs hundreds of different functions. The liver constantly supplies many different substances into the blood, so even the slightest violation of the liver function entails a change in the composition of the blood. And if you do a blood test for certain markers, you can get a clear picture of the state of the liver. We now describe these analyzes in more detail.

The numbers describing the composition of the blood are biochemical indicators. Among these indicators, there are those in which certain changes always indicate changes in liver function – namely, functions, and not structures (structural changes are monitored in other ways, such as ultrasound). Therefore, these tests are called “liver function tests” (LFTs) or simply “liver tests”.

When should liver tests be done?

If nothing bothers you, you can donate blood for this test every year during a routine medical examination. Also, liver function tests must be examined during pregnancy, before surgical interventions, before and during courses of treatment for certain diseases that involve the use of potent drugs.

Mandatory liver test is required in the presence of one or more of the following symptoms: These sensations usually manifest as a slight pulling pain and/or tingling. Especially noticeable when laughing, sneezing, coughing, screaming, tilting to the side, lifting heavy objects. They can also affect after eating fatty, fried, spicy or smoked foods;

bad taste in the mouth , coppery bitterness, dryness, astringent sensation. This can dull the taste, and the usual food can cause rejection up to vomiting;

The last set of symptoms indicates the presence of serious liver disease, including hepatitis.

Where can I have a liver test?

Donate blood for liver function tests in the departments of the all-Ukrainian network of laboratories “MedLab”. The laboratory offers the following “liver” packages:

• Package No. 970 “Liver tests No. 2” – alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase, g-glutamyl transpeptidase, total protein, total bilirubin.
• Package No. 10 “Liver tests” – bilirubin (total, direct, indirect), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase, total protein, g-glutamyl transpeptidase;
• Package No. 54 “Assessment of the state of the liver”, which includes analyzes for protein fractions (albumin, α-1-globulins, α-2-globulins, β-1-globulins, γ-globulins, A / G coefficient), thymol test , total protein, lactate dehydrogenase (LDH), alkaline phosphatase, gamma-glutamyl transpeptidase (GGT), alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin, direct, indirect.

Test results will be ready:

• Package #10 Oven Samples and Package #970 Oven Samples #2 — within 1 working day.
• Package No. 54 “Assessment of the state of the liver” – within 2 working days.

How do I prepare for a liver test?

To achieve the most reliable liver test results, follow these guidelines:

1. Test strictly on an empty stomach. The liver is involved in the processes of digestion, and the food itself also affects liver performance. Therefore, you should not eat at least 8 hours before taking liver tests (during this time, you should also not drink anything but pure water). In addition, 3 days before delivery, you need to give up spicy and fatty foods.
2. Do not drink alcohol for 3 days prior to testing. Even a minimal dose of alcohol puts a heavy strain on the liver, changes the composition of the blood and its properties (including coagulation and some “liver” indicators).
3. Do not smoke for 12 hours before testing. Substances that enter the blood from cigarette smoke can also change the composition of the blood and affect the results of the study.
4. Avoid strenuous activities , including “serious” sports, for 3 days prior to analysis. By the way, during this period it is recommended to protect yourself not only from physical, but also from psycho-emotional overstrain, stress factors, and also observe the correct sleep pattern.
5. If you are taking any medications, stop taking them if possible. Even harmless vitamins can distort the result of a biochemical “liver” analysis. Therefore, any medications should ideally be discontinued at least a week before the FPP is taken. If this is not possible, then it is necessary to warn the doctor in advance about the medicines that you are taking.

IMPORTANT! Liver tests, like any other analysis, can be performed in different laboratories using different methods, equipment and using different units of measurement. Therefore, when a doctor prescribes a second study to evaluate the effectiveness of treatment, it is necessary to conduct it in the same lab as where liver tests were taken earlier.

Laboratory examination of liver function

Comprehensive laboratory examination of the liver to assess its main functions and indicators of protein, carbohydrate, fat and pigment metabolism.

Examination results are issued with the doctor’s interpretation .

Synonyms Russian

• Liver function tests
• Liver disease screening

Synonyms English

• Laboratory liver panel
• Liver function tests
• Liver check-up

Test Method

• Coagulogram No. 1 (Prothrombin (according to Quick), INR) – side scatter detection method, end point percentage determination
• Alanine aminotransferase (ALT) – UV kinetic test
• Serum albumin – BCG method (bromocresol green)
• Aspartate aminotransferase (AST) – UV kinetic test
• Gamma-Glutamyl Transpeptidase (Gamma-GT) – Kinetic Colorimetric Method
• Bilirubin total – colorimetric photometric method
• Bilirubin direct – colorimetric photometric method
• Alkaline Phosphatase Total – Colorimetric Photometric Method
• Total cholesterol – colorimetric photometric method
• Bilirubin indirect – colorimetric photometric method
• Bilirubin and its fractions (total, direct and indirect) – colorimetric photometric method

Units of measurement

• Coagulogram No. 1 (prothrombin (according to Quick), INR) -% (percentage), sec. (seconds)
• Alanine aminotransferase (ALT) – U/L (unit per liter)
• Serum Albumin – g/l (grams per litre)
• Aspartate aminotransferase (AST) – U/l (unit per liter)
• Gamma-glutamyl transpeptidase (gamma-GT) – U/l (unit per liter)
• Total bilirubin – µmol/l (micromoles per litre)
• Bilirubin direct – µmol/l (micromoles per litre)
• Alkaline phosphatase, total – U/l (unit per liter)
• Cholesterol, total – mmol/l (millimoles per litre)
• Bilirubin indirect – µmol/l (micromoles per litre)
• Bilirubin and its fractions (total, direct and indirect) – µmol/l (micromoles per liter)

Which biomaterial can be used for research?

Venous blood.

How to properly prepare for an examination?

General information about the study

The liver is the largest gland in the human body. This body performs about 5,000 different functions. The main functions of the liver can be assessed using a comprehensive laboratory study.

1. Synthetic function of the liver

• Albumin is the main blood protein that performs a transport function and ensures the maintenance of oncotic pressure. In violation of the synthetic function of the liver, the concentration of this protein, as a rule, decreases. It should be noted that this decrease is observed in severe liver diseases, such as fulminant hepatitis and severe liver failure. On the contrary, with torpid or latent liver diseases (hepatitis C, alcoholic hepatitis), the level of total protein may remain within the normal range. In addition, changes in albumin concentration can be observed in many other diseases and conditions, such as starvation, malabsorption, nephrotic syndrome, infectious diseases, etc.
• Quick prothrombin (another name is prothrombin time) and the international normalized ratio (INR, INR) are the main indicators used to assess the external pathway of blood coagulation (fibrinogen, prothrombin, factor V, VII and X). The liver is the main source of synthesis of these factors, and diseases of this organ can be accompanied by a violation of the coagulation mechanism and lead to increased bleeding. However, it should be noted that clinically significant disorders of blood coagulation are observed in the late stages of liver disease.
• Cholesterol can be synthesized in almost any cell of the body, however, most of it (up to 25%) is synthesized in the liver, from where this compound enters the systemic circulation as part of very low density lipoproteins (VLDL) or into the gastrointestinal tract as part of bile acids . Hypercholesterolemia is a characteristic feature of hepatic cholestasis observed in cholelithiasis, primary sclerosing cholangitis, viral hepatitis, primary biliary cirrhosis, and some other diseases. Hypocholesterolemia has less clinical significance. Different fractions of cholesterol are associated with different effects on human health. Thus, low-density lipoprotein cholesterol (LDL-C) is a well-known risk factor for heart disease, while HDL-C is considered one of the protective factors.

2. Metabolic function of the liver

• ALT and AST are enzymes necessary for the metabolism of amino acids. Although these enzymes can also be found in many other tissues and organs (heart, skeletal muscle, kidneys, brain, erythrocytes), changes in their concentration in the blood are more often associated with liver diseases, which leads to their name – hepatic transaminases. ALT is a more specific marker of liver disease than AST. With viral hepatitis and toxic liver damage, as a rule, the same increase in the level of ALT and AST is observed. In alcoholic hepatitis, liver metastases, and liver cirrhosis, there is a more pronounced increase in AST than ALT.
• Alkaline phosphatase, AP, is another key liver enzyme that catalyzes the transfer of phosphate groups between different molecules. The level of alkaline phosphatase is determined when cholestasis is suspected: the concentration of total alkaline phosphatase is increased in almost 100% of cases of extrahepatic obstruction of the biliary tract. In addition to hepatocytes, alkaline phosphatase is present in bone tissue and intestinal cells, and an increase in total alkaline phosphatase can be observed not only with liver damage, but also with other diseases (bone tissue diseases, myocardial infarction, sarcoidosis).
• Gamma-glutamyltranspeptidase, gamma-GT, is a liver enzyme that catalyzes the transfer of the gamma-glutamyl group of glutathione to other molecules. Gamma-HT is currently the most sensitive marker of liver disease. An increase in the concentration of gamma-HT can be observed in all liver diseases, but the greatest value of this marker is in the diagnosis of biliary tract obstruction. With obstruction of the biliary tract, the concentration of gamma-HT increases by 5-30 times. The study of the level of gamma-HT allows you to make sure that the increase in total alkaline phosphatase is caused precisely by liver disease, and not by other causes, primarily diseases of the skeletal system. As a rule, with obstruction of the biliary tract, there is a parallel increase in the level of gamma-HT and total alkaline phosphatase. High levels of gamma-HT are characteristic of metastatic lesions and alcoholic cirrhosis of the liver. In viral hepatitis, there is a moderate increase in the level of gamma-HT (2-5 times).

3. Excretory function of the liver

• Bilirubin is a pigment formed during the breakdown of hemoglobin and some other heme-containing proteins in the liver, spleen and bone marrow. It exhibits toxicity to the nervous system and must be eliminated from the body in the bile or urine. Excretion of bilirubin is a multi-step process in which the liver plays a major role. There are two main fractions of bilirubin: direct and indirect bilirubin. When bilirubin binds to glucuronic acid, conjugated bilirubin is formed in the liver. Since this type of bilirubin can be determined directly using a direct laboratory test, it is also called direct bilirubin. Bilirubin that has not been conjugated with glucuronic acid is said to be unbound. In laboratory conditions, it is not possible to determine the level of unbound bilirubin: its concentration is calculated based on the concentrations of total and bound bilirubin. For this reason, this type of bilirubin is also called indirect. Total bilirubin consists of both fractions. An increase in the level of bilirubin can be observed in many liver diseases, but the greatest value of this marker lies in the differential diagnosis of jaundice. Hemolytic (prehepatic) jaundice is characterized by an increase in total and indirect bilirubin. For hepatic jaundice, an increase in both fractions (direct and indirect bilirubin) and total bilirubin is typical. Obstructive (subhepatic) jaundice is characterized by an increase in total and direct bilirubin.

This comprehensive study includes indicators to assess the main functions of the liver. In some situations, however, additional tests may be required. Repeated analyzes are recommended to be performed using the same test systems.

What is research used for?

• For the evaluation of liver function and the early diagnosis of diseases affecting it.

When is the test scheduled?

• At a preventive examination;
• in the presence of symptoms of diseases of the liver, gallbladder and bile ducts: with pain or discomfort in the right hypochondrium, nausea, impaired stool, darkening of urine color, jaundice, edema, increased bleeding, fatigue;
• when observing a patient receiving hepatotoxic drugs for any disease (methotrexate, tetracyclines, amiodarone, valproic acid, salicylates).

What do the results mean?

Reference values ​​ *

Coagulogram No. 1

1. Quick prothrombin: 70.0 – 120.0%.
2. INR: 0.8 – 1.2.
3. Prothrombin time: 9.4 – 12.5 sec.

*Reference values ​​vary for some regions due to the use of different test systems for the study.

Alanine aminotransferase (ALT)

Serum albumin

Aspartate aminotransferase (AST)

Gamma-glutamyl transpeptidase (gamma-GT)

Total bilirubin

Direct bilirubin: 0 – 5 µmol/l.

Alkaline phosphatase total

Total cholesterol:

Indirect bilirubin: calculated indicator.

Reasons for increase/decrease depending on the determined indicator:

• Coagulogram No. 1 (prothrombin (according to Quick), INR)
• Alanine aminotransferase (ALT)
• Serum albumin
• Aspartate aminotransferase (AST)
• Gamma-glutamyl transpeptidase (gamma-GT)
• Bilirubin total
• Bilirubin direct
• Alkaline phosphatase, total
• Cholesterol, total
• Bilirubin indirect
• Bilirubin and its fractions (total, direct and indirect)

What can influence the result?

Causes depending on the determined indicator:

• Coagulogram No. 1 (prothrombin (according to Quick), INR)
• Alanine aminotransferase (ALT)
• Serum albumin
• Aspartate aminotransferase (AST)
• Gamma-glutamyl transpeptidase (gamma-GT)
• Bilirubin total
• Bilirubin direct
• Alkaline phosphatase, total
• Cholesterol, total
• Bilirubin indirect
• Bilirubin and its fractions (total, direct and indirect)

Also recommended

• Screening for autoimmune liver disease
• FibroMax
• SteatoScreen
• Extensive laboratory examination of the liver
• Liver and pancreas screening
• Vitamins and trace elements involved in the regulation of the liver detoxification system (Fe, Mg, Mo, Zn, S, vitamins A, C, B1, B3, B5, B6, B9, B12)

Who orders the examination?

Therapist, general practitioner, gastroenterologist, hepatologist.