Liver function analysis
"Through the study of various substances in the blood, the functioning of the liver can be determined".
DR. JOSÉ IGNACIO MONREAL MARQUIEGUI SPECIALIST. BIOCHEMISTRY DEPARTMENT
The liver is the largest organ in the body and is one of the most important in the body's metabolism. It is located under the diaphragm, towards the right side.
It receives blood from the heart through the hepatic artery and from the intestine through the portal vein. The functional unit is the hepatic lobule.
The functions of the liver are:
- Excretory: through the production of bile which is the vehicle to eliminate cholesterol, bilirubin and other products.
- It promotes digestion and absorption of fats in the intestine with bile salts.
- Detoxifying function of both drugs and other toxins, including ammonia from the protein metabolism that transforms into urea to be eliminated.
- Controls the metabolism of carbohydrates, fats and proteins.
- It is capable of storing vitamins and some metals.
- It participates in the defense of the body against foreign agents.
When is the study of liver function indicated?
They are a set of biochemical tests that allow detecting the state of the different functions of the liver.
The excretion test is performed to assess liver excretory function and to differentiate the possible causes of jaundice. It is mainly used to determine bilirubin in the blood. Bile salts can also be determined, which will be elevated in the blood in cases of poor biliary extraction.
The integrity of the cellular structure associated with this hepatic function can also be assessed through the determination of the enzymes g-glutamyl transpeptidase (GGT), alkaline phosphatase and 5'-nucleotidase, which will be elevated in the blood in cases of biliary obstruction, consumption of alcohol and some drugs such as phenytoin.
Most frequent indications of this test:
Do you have any of these diseases?
It may be necessary to perform a liver function study
Types of liver function tests
The determination of the half-life of galactose in the blood, after being administered intravenously and measuring its concentration in ten-minute intervals, assesses the hepatic metabolic activity of carbohydrates. Its half-life is increased in metabolic problems and not in other hepatic alterations.
In acute hepatocellular disease, the blood levels of high-density lipoproteins (HDL) and the enzyme that esterifies cholesterol for transport, lecithin-cholesterol acyltransferase (LCAT), decrease and the blood levels of triglycerides and LDL-cholesterol increase.
As the liver is the organ that synthesizes most of the plasma proteins, in acute disease it decreases the synthesis of prealbumin, retinol transport protein and transferrin. Prolonged liver disease is required to alter proteins such as albumin and clotting factors. When coagulation factor synthesis is altered, it is manifested in coagulation tests, particularly in prothrombin time, which is increased.
In advanced liver disease, the synthesis of urea from ammonia can be altered, increasing the amount of ammonia in the blood and potentially causing hepatic encephalopathy.
One of the final steps in the synthesis of Vitamin D takes place in the liver. In cases of liver failure, a deficit of Vitamin D can occur and liver osteopathy can develop.
In some liver diseases the destruction of liver cells occurs and these molecules increase in the blood. Within those molecules are several enzymes: lactate dehydrogenase (LDH), which is not specific to the liver and in cases of doubt about its origin, isoenzymes are determined; aspartate transaminase (GOT or AST) and alanine transaminase (GPT or ALT) -transaminase, are also not specific to the liver but are elevated in cases of hepatitis, some intoxications (drugs, mushrooms) and shock; g-glutamyl transpeptidase (g-GT), alkaline phosphatase and 5'-nucleotidase.
These enzymes, once released into the bloodstream, remain in it for a variable time, depending on the half-life of each of them.
The Kuffer cells of the liver have great capacity to destroy agents recognized as foreign by the body. In situations of liver failure, clots can form due to the inability of these cells to eliminate pathological coagulating agents in circulation and disseminated intravascular coagulation (DIC) can develop.
Also in liver failure there is an inability to remove endotoxins from the circulation. When this cellular immune mechanism fails, another humoral immune mechanism is enhanced, causing an elevation in the blood of gamma globulins.
The liver has the capacity to store certain metals, such as copper or iron. When these accumulate in excess, liver cells are altered.
When hemochromatosis with hepatic iron deposits is suspected, it is advisable to determine iron and ferritin in the blood and, depending on the results, to determine the iron in a liver biopsy.
Similarly, when Wilson's disease is suspected with accumulation of copper in the liver, copper is determined in blood and urine after causing its elimination with D-penicillamine, ceruloplasmin in blood and, depending on the results, copper in liver biopsy.
It is highly associated with viral hepatitis and its evolution is quite fast.
The elevation in blood of a tumor marker, the alpha-fetoprotein (AFP), helps in the diagnosis, the follow-up after the application of treatment and even the establishment of the prognosis of patients affected by a hepatocarcinoma, although it is also possible to find increases in other pathologies such as chronic hepatitis or cirrhosis.
Where do we do it?
IN NAVARRE AND MADRID
The Clinical Biochemistry Service
of the Clínica Universidad de Navarra
The Clinical Biochemistry Service of the Clinica Universidad de Navarra is responsible for performing the biochemical analyses requested by the medical specialists of our center.
We carry out technical quality controls to guarantee the proper functioning of the equipment and the highest precision in the results obtained from the samples.
In order to guarantee excellence in patient service, we offer the response with the results of the analyses in the shortest possible time, responding in only 46 minutes in some cases of general analysis.
Organized in care units
- General biochemistry.
- Hormones, urine and proteins.
Why at the Clinica?
- Maximum speed in offering the analytical results.
- We carry out quality controls to guarantee the correct and most precise results obtained.
- We work in a multidisciplinary way with all the departments of the Clinic.