Liver function test

What’s measured

Which parameters to focus on

The Liver function test includes 11 interrelated parameters (liver tests) that can be used to determine the severity of liver cell damage (ALT, AST), impaired bile production and outflow (total bilirubin, GGT, ALP) and possible drug or alcohol toxicity (GGT).

The liver is the main organ of metabolism (metabolism) and is the organ that produces bile. It has a good regenerative capacity, but it also has its limits. The frequency and intensity of exposure of the liver to harmful substances affect its function. Hand in hand with impaired liver function goes impaired gallbladder and bile duct function.

In addition to assessing the current state of health, the results can also be viewed prognostically.

ALT

Alanine aminotransferase is an enzyme also present in the cytoplasm of cells of some tissues. It is important for the formation and breakdown of amino acids and also plays a role in the metabolism of nitrogen as well as glucose. Increased ALT activity occurs when the integrity of cells, especially the liver, is compromised. As a laboratory marker, it is used to diagnose liver failure, to estimate the functional reserve of the liver, and in liver transplantation or resection.

AST

Aspartate aminotransferase is another liver enzyme that is elevated in severe damage (necrosis) of hepatocytes. The most common causes of liver damage are ethanol (alcohol), liver calcification, or viral hepatitis.

Total bilirubin

Total bilirubin is a yellow-orange dye and a product of heme metabolism (contains iron). Heme is found in red blood cells but also in many proteins (e.g. myoglobin, peroxidase, cytochromes). Bilirubin and its metabolites are produced daily in the spleen, liver and bone marrow and cause the typical colouration of bile, faeces and urine.

Conjugated bilirubin

Conjugated bilirubin is produced in the liver, referred to as direct bilirubin when measured in the blood, converted to direct bilirubin and then excreted in the bile into the intestines and finally out of the body.

Elevated levels of direct bilirubin may indicate problems with the liver or gallbladder.

GGT

Gamma-glutamyltransferase is an enzyme localized on the cell membrane with the highest concentration in the liver. It is very sensitive to changes in the bile ducts (e.g. due to damage from drugs or alcohol).

ALP

Is an enzyme called alkaline phosphatase that is found in high concentrations in liver and bone cells. It is an important parameter in the diagnosis of liver and bone diseases.

Total protein

This is the determination of the concentration of all proteins in the blood plasma. Proteins are the basic building blocks of all cells and tissues. They are not only important for bodily growth, but also fulfil a number of functions, e.g. transport of all water insoluble substances, maintenance of oncotic pressure in cells and pH of blood, defence against infections, etc.

Serum protein electrophoresis

It is recommended for pathological result of total proteins when more detailed information about serum proteins is needed, as evidence of dysproteinemia (change in concentration and qualitative composition of individual proteins in serum), as evidence of paraproteinemia (presence of monoclonal immunoglobulins).

Albumen

Albumin is a small protein that makes up about 60% of blood proteins and is formed in the liver.

The role of albumin in the blood is to transport various substances and maintain the balance of the internal environment. It is excreted from the body to a small extent by the kidneys and the digestive system, and most of it is broken down in the endothelial cells of blood capillaries. In the case of hypoalbuminemia, swelling may occur. Albumin deficiency also affects the biological effect of many substances carried in the body, e.g. drugs, hormones.

Globulin

Globulin is a group of proteins found in your blood. It plays an essential role in various functions in your body, such as immune system support, blood clotting, and transport of hormones and vitamins. Abnormal globulin levels can indicate certain medical conditions, such as liver disease, immune disorders, or malnutrition."

The albumin/globulin ratio

The albumin/globulin ratio compares the levels of two types of proteins in your blood: albumin and globulins. Albumin is a specific protein, while globulins are a group of proteins that include antibodies and other important proteins for various functions in the body. An abnormal albumin/globulin ratio may indicate certain health conditions or imbalances in your body.

Instructions before collection

We do not recommend entry of patients/clients with clinical signs of disease (temperature, cough, signs of respiratory tract infection, etc.) to undergo this test.
We recommend hand disinfection prior to entry to the clinics/collection points.

It is advised to fast for a minimum of 8 hours by refraining from eating or drinking anything expect water. Faiing to fast before the test may affect result quality. If you are currently on medications, consult your healtcare provider to determine whether you should continue taking them prior to the test.

PREPARATION FOR BLOOD COLLECTION
The recommended time to collect blood is between 7 a.m. and 9 a.m., to obtain comparable results from different blood draws. To assess the numerical test result, so-called reference intervals are used, which are based on morning fasting collections and are used for population comparison. This time interval is also recommended in light of the biological cycles that naturally take place in the body.

GENERAL PRE-SAMPLING INSTRUCTIONS
• It is necessary to come to the testing site earlier, so that you can rest in the waiting room for approximately 20 minutes to have a relatively relaxed body and mind.
• It is necessary to arrive on an empty stomach for the collection itself, in the case of collections at a later time in the day, at least three hours on an empty stomach. At home, it is desirable to drink a sufficient amount of pure water (at least up to half a liter) - this is important for a successful blood collection. Mineral water, juice, coffee and tea are not recommended.
Herbs included in tea may contain substances affecting the blood count. Coffee and black tea increase gastric acid production and release insulin from the pancreas, thereby affecting glucose metabolism. Since everything in the body is interrelated, they can impact other tests. Another extreme is when your body is running out of fluids. In this case, the number of red blood cells, the level of protein and lipids bound to the protein increase and the level of urea in the blood can also increase. It is therefore advisable to drink pure water when you wake up.


Generally, it is recommended to:
• around 6 p.m. eat only light meals, do not eat fatty food (cheese, butter, cream, meat, smoked meat, bacon) and sweet meals,
• fast for 10-12 hours (Attention: it is not advisable to starve for more than 16 hours!), in the case of later collection (after 9:30 a.m.), a lighter breakfast is allowed, no later than 3 hours before collection,
• drink non-alcoholic beverages and drinks without sugar in the usual quantity, in the case of adult clients 24 hours before blood collection (Alcohol in the blood changes lipid levels, the level of glucose is reduced, uric acid levels increase and liver enzymes are released into the blood),
• take only prescribed medicines in the evening,
• avoid increased physical activity, and strength and endurance exercise the day before blood collection (Lipid, glucose, some enzyme levels in the blood and other parameters may change during physical activity. The recovery of normal values to maintain the accuracy of laboratory results may take a longer time, depending on the duration of the exercise, your physical fitness in general and other factors. We recommend maintaining normal daily physical activity such as light stretching, short cycling to work, gardening, etc.),
• avoid psychological stress, which raises blood glucose levels and causes the release of stress hormones in particular,
• avoid smoking for at least 6 hours prior to blood collection because it increases the level of carbonylhemoglobin produced by the reaction of the blood dye with carbon monoxide and alters the permeability and elasticity of the vessels, affecting the ratios of blood analytes,
• do not chew gum for at least 6 hours before blood collection, as this may affect glucose and enzyme levels,
• do not undergo stressful diagnostic or therapeutic interventions for at least 24 hours prior to blood collection.
If any of the tests you have selected require special preparation, you will be informed of the fact by email with the order and blood collection instructions attached. These specific instructions have priority over the general recommendations for preparation.


MEDICINES
It is recommended to have blood collected before the planned doses of medicines. If it is not possible to take the medicine later, you should inform the nurse during blood collection and specify what medication you have taken.
Take the medicines prescribed by your doctor in the morning or bring them with you to take them after blood collection (thyroid medicines, antihypertensive medicines, blood thinners, contraceptives, etc.) In the case of later collection (after 9:30 a.m.), you can take the prescribed medication in the morning.
Do not take iron, vitamin, nutritional supplements or other supplements, including homeopathics, for at least three (3) days prior to blood collection.


SPECIFIC SITUATIONS
In order to obtain the appropriate answers to your questions with regard to the laboratory tests, it is important to accurately notify the nurse at the healthcare provider about the following facts prior to your blood test:
• regularly used medicines and supplements (ideally come with a written list to the blood collection site),
• infectious diseases you suffer from (e.g., HIV, hepatitis, mononucleosis...),
• contact with an infected person or presence in an infectious environment,
• if you have received an infusion within the last 5 days, specify into which limb,
• intramuscular injections within 3 days prior to the blood collection date,
• long-term immobilisation, lost ability to move,
• activities at higher altitudes,
• allergy to common band-aids,
• if you feel unwell when looking at blood or needles, please also notify our blood collection staff of the fact.


OTHER FACTORS
Please note that prolonged use of medication or other important factors may affect the values measured by the tests you have selected. For more information, please see the description of the specific test. To obtain objective test results, take the time to properly prepare for your blood collection.