Don't worry about the "liver"｜Interpretation of the "liver function" of the laboratory test report

Since ancient times, people in China have put the most emphasis on health preservation.

In the traditional Chinese medicine theory of viscera, the liver belongs to the five elements of the wood, and the main role is to "remove venting" and "storage blood"

In the system of western medicine, various important functions of the liver have been studied in depth

liver function

As far as the human body is concerned, the liver is called a "model worker", responsible for the synthesis and metabolism of a variety of nutrients, and it is a constantly running "factory"

① "Energy responsibility" of the human body : sugar metabolism 

When you eat a piece of chocolate or drink a cup of sugar water, simple sugars are absorbed through the mucosa of the small intestine, and then reach the liver through the portal vein, where they are converted into glycogen and stored in the liver, just like stored "energy bars"

② "Nutrition responsibility" of the human body : protein synthesis and metabolism 

When you eat a fish, it is rich in high-quality protein.

③Fat metabolism 

The liver is the hub of fat transport

④ Store and metabolize vitamins 

The liver can store fat-soluble vitamins.

Under normal circumstances, various hormones in the blood maintain a certain level, and the excess is inactivated by the liver

02

Bilirubin metabolism

As the saying goes, "the liver and gallbladder are in the same light".

Friends who have their gallbladder removed, because the bile excreted in the liver cannot be stored, they may not be blessed with greasy food, and may even become a vegetarian

In short, if liver disease involves the bile ducts in the liver or the function of liver cells, there may be symptoms such as elevated blood bilirubin, yellow urine, yellow skin, and eyes.

03

Detoxification function

In the process of body metabolism, the portal vein collects blood from the abdominal cavity, and harmful substances and microbial antigenic substances in the blood will be detoxified and eliminated in the liver

04

Defense and immune function

The liver is also the body's largest immune organ and has the largest phagocytic system of reticuloendothelial cells

05

other

In addition to the above functions, the liver can also regulate circulating blood volume, synthesize a variety of coagulation factors (coagulation factors II, VII, IX, X) and participate in the body's heat production, water, and electrolyte balance

Let's take a look at the "liver function" test sheet

Liver function test is to detect various indicators related to liver function and metabolism through various biochemical tests, and comprehensively reflect liver cell damage, bilirubin metabolism, cholestasis, liver synthesis function, and liver fibrosis degree
.

1

Indicators reflecting liver cell damage

Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) are the most widely used clinical biochemical indicators to reflect liver cell damage
.

ALT is mainly distributed in the cytoplasm of liver cells, and its intrahepatic concentration is 3000 times higher than that of serum.
It is a sensitive indicator of liver cell damage
.

AST is mainly distributed in the mitochondria of liver cells, and a few in the cytoplasm.
If the concentration of AST is found to be elevated in liver function, it may indicate severe liver cell damage, or mitochondrial damage of liver cells, such as alcohol
.

The determination of serum AST and ALT levels and the AST/ALT ratio are conducive to the diagnosis and identification of abnormal liver function
.

2

Reflecting the index of bilirubin metabolism

Bilirubin is produced by the liver and is excreted through the biliary tract.
The liver has the functions of uptake, binding and excretion in the metabolism of bilirubin
.
Bilirubin determination includes total bilirubin (TBIL), direct bilirubin (DBIL) and indirect bilirubin (IBIL).
A variety of pathogenic factors can cause serum bilirubin to rise, leading to jaundice
.
The total bilirubin in the blood is significantly increased, which needs to be paid attention to
.
What is the reason for the need to go to the hospital for examination .

3

An indicator of cholestasis

If there is a problem with the liver cells or the biliary system, cholestasis may occur, and the bile cannot be discharged normally and enters the blood
.

Elevated serum alkaline phosphatase (ALP) and GGT are the most characteristic early manifestations of cholestasis, and elevated levels of both indicate cholestasis
.

There are many factors that can cause a significant increase in blood ALP in normal people
.
After 3 months of pregnancy, placental ALP enters the bloodstream up to 2-3 times the normal level, and can continue for several weeks after delivery; in children and adolescents after the age of 10, the bones are in the developmental stage, and the ALP level is up to 3 times higher than that of adults.
In addition, after a high-fat diet and certain bone diseases, ALP levels will also increase
.

4

An indicator reflecting the liver's synthetic function

The main indicators reflecting liver synthesis function include: albumin (Alb), prealbumin (PA), prothrombin time (PT) and cholinesterase (CHE)
.

Albumin (Alb)

The liver is the only organ for the body to synthesize Alb.
After synthesis, it is needed by the body and is hardly excreted.
It is also a "nutrition" often referred to by the people
.
Its half-life in plasma is about 21 days.
Therefore, the level of Alb reflects the anabolic function and reserve function of the liver, and is also an indicator for evaluating the severity of liver cirrhosis and judging the prognosis
.
If Alb continues to decrease, it indicates that hepatocyte necrosis is getting worse and the prognosis is poor
.

When liver function is severely damaged, such as chronic moderate or higher hepatitis, liver cirrhosis, primary liver cancer, etc.
, Alb synthesis decreases, while globulin synthesis increases, causing the A/G ratio to be inverted
.

Prealbumin (PA)

Prealbumin has a small molecular weight and is synthesized by hepatocytes.
Electrophoresis separation is often displayed in front of albumin.
Its half-life is about 1.
9 days short.
Therefore, the concentration of prealbumin in serum is more important for understanding liver synthesis function and nutritional status than albumin.
High sensitivity
.

Prothrombin time (PT)

Serum PT is another index for evaluating liver synthesis function.
This index detects blood clotting time.
It requires the participation of liver synthesis of coagulation factors (II, V, VII, X)
.

When liver cells are extensively damaged, the ability of the liver to synthesize coagulation factors decreases, leading to prolonged PT.
When PT exceeds the normal reference value for more than 3s, it is abnormal; 4-6s, indicating severe liver damage and poor prognosis
.

Cholinesterase (CHE)

Serum CHE mainly reflects the degree of liver protein synthesis and liver parenchymal cell damage
.

In liver disease, CHE often decreases, and its decrease is roughly parallel to serum albumin
.
Since the half-life of CHE is shorter than that of albumin, CHE can more sensitively reflect changes in the condition, which is often detected in patients with liver failure, reflecting the liver's real-time synthesis function
.

The common symptoms of liver disease are fatigue, poor appetite, oiliness, etc.
Each index of liver function has its corresponding role in the diagnosis of liver disease, but it is inevitable that there are limitations
.
In actual clinical work, there are many causes of abnormal liver function, such as viral hepatitis, drug-induced hepatitis, fatty liver, etc.
Therefore, when abnormal liver function is found, it is necessary to seek medical treatment in time, clarify the cause, and treat the cause
.

Case analysis

Patient, female, 56 years old
.
Main complaint: Repeated abnormal liver function for more than 1 year, and found HCV positive for 2 months
.
Follow-up medical history, the patient's history of infusion in the local clinic, many people have abnormal liver function, HCV positive
.
Liver function and kidney function results on admission:

Interpretation of the report: The patient’s liver function showed a significant increase in ALT and AST, suggesting hepatocyte damage; total bile acid, alkaline phosphatase, and γ-GT increased, suggesting bile duct cell damage
.
At present, total bilirubin and direct bilirubin are normal, indicating that the current injury has not significantly affected the metabolism and excretion of bilirubin
.
The albumin level is normal, indicating that the liver synthesis function is acceptable
.
Changes in liver function of this patient are related to hepatitis C virus infection
.
After 1 month of treatment, the patient's liver function improved significantly, and after nearly 2 months of treatment, the liver function completely returned to normal
.

references:

[1] Zhu Danian, chief interrogator; Wang Tinghuai, chief editor; Luo Ziqiang, Shen Linlin, Guan Youfei, Wu Yuming deputy chief editor.
Physiology 9th edition [M].
Beijing: People's Medical Publishing House, 2018.
08.

[2] Chinese Medical Association Hepatology Branch.
Digestive Diseases Branch of Chinese Medical Association.
Infectious Diseases Branch of Chinese Medical Association.
Consensus on the diagnosis and treatment of cholestatic liver disease (2015)[J].
Journal of Clinical Hepatobiliary Diseases, 2015, 31(12): 924-933.

[3] Wang Xiaolin, Yang Jing, the relationship between prealbumin, cholinesterase, prothrombin time and fibrinogen and the pathological grade of chronic hepatitis B [J].
Journal of Clinical Hepatobiliary Diseases, 2007.
23(5):377-378.

[4] Zhang Shuyan, Xiong Huishun, Examination and clinical significance of serum prealbumin and albumin in patients with liver disease [J] Journal of Clinical Medicine, 2010, 38(2): 279-280.

[5] Li Fei, Lu Lungen, Evaluation and clinical significance of abnormal liver function [J], Journal of Clinical Hepatobiliary Diseases.
2015, 31(09), 1543-1546

[6] Li Yonggang, Yang Daguo.
Re-discussion of "enzyme and gallbladder separation" as an index for judging severe liver damage[J].
Journal of Integrated Traditional Chinese and Western Medicine, 1995(01): 15-17.

[7]Botros M, Sikaris K A .
The deritis ratio: the test of time[J].
Clin Biochem Rev,2013,34(3):117-130.

Since ancient times, people in China have put the most emphasis on health preservation.
"Thinking about hurting the spleen and anger hurting the liver" is an important basis for emotional health preservation in TCM theory
.

In the traditional Chinese medicine theory of viscera, the liver belongs to the five elements of the wood, and the main role is to "remove venting" and "storage blood"
.
Dredging includes mental emotions, digestion, and the circulation of qi, blood, and water; while blood storage includes the storage and regulation of blood
.

In the system of western medicine, various important functions of the liver have been studied in depth
.
The liver is the largest physical organ in the human body, located in the upper right abdomen and deep in the right rib cage
.
The liver has multiple functions such as synthesis and metabolism of various nutrients, secretion of bile, phagocytosis and defense
.
The liver also has hematopoietic function during the embryonic period
.

liver function

As far as the human body is concerned, the liver is called a "model worker", responsible for the synthesis and metabolism of a variety of nutrients, and it is a constantly running "factory"
.

① "Energy responsibility" of the human body : sugar metabolism 

When you eat a piece of chocolate or drink a cup of sugar water, simple sugars are absorbed through the mucosa of the small intestine, and then reach the liver through the portal vein, where they are converted into glycogen and stored in the liver, just like stored "energy bars"
.
When labor, hunger, fever, liver cells can break down liver glycogen into glucose into the circulating blood, supply energy for the human body
.
If the liver is not good, the endurance of exercise or fatigue is relatively low, and feel flustered and dizzy when hungry, while people with strong liver function have vigor and lasting energy
.

② "Nutrition responsibility" of the human body : protein synthesis and metabolism 

When you eat a fish, it is rich in high-quality protein.
It is digested and decomposed into amino acid molecules in the digestive tract, and then absorbed and transported by the digestive tract to the liver for protein synthesis, deamination and transamination.
The synthesized protein enters the circulating blood.
For the needs of organs and tissues throughout the body
.
The liver is the main place for the synthesis of plasma proteins, which can be used for the renewal of various tissue proteins in the body and maintain the normal operation of various organs
.
At the same time, the liver synthesizes the ammonia produced by amino acid metabolism into urea, which is excreted from the body through the kidneys
.

③Fat metabolism 

The liver is the hub of fat transport
.
Part of the fat after digestion and absorption enters the liver, and then is converted into body fat and stored
.
When you are hungry, the stored body fat can be transported to the liver and decomposed into glycerol and fatty acids.
Glycerol can produce energy through the sugar metabolism pathway, and the fatty acids can be completely oxidized to CO₂ and water
.
The liver is also one of the main organs for the synthesis of fatty acids, cholesterol, and phospholipids in the body.
It is involved in regulating the proportion of various components of blood lipids, and excess cholesterol is excreted with bile
.
If a large amount of high-fat food is consumed for a long time, it may cause excessive accumulation of fat in liver cells, leading to fatty liver
.

④ Store and metabolize vitamins 

The liver can store fat-soluble vitamins.
95% of the body's vitamin A is stored in the liver.
The liver is also a place where vitamins C, D, E, K, B₁, B6, B₁₂, niacin, folic acid and other vitamins are stored and metabolized
.

⑤Inactivation hormone

Under normal circumstances, various hormones in the blood maintain a certain level, and the excess is inactivated by the liver
.
When liver dysfunction occurs, estrogen inactivation disorder may occur, causing gynecomastia, menstrual irregularities, and changes in sexual characteristics
.
If aldosterone and antidiuretic hormone inactivation disorder occurs, it can cause sodium and water retention and edema
.
It can also be seen clinically that some patients with liver cirrhosis have breast development
.

02

Bilirubin metabolism

As the saying goes, "the liver and gallbladder are in the same light".
There is a gallbladder fossa under the liver, which hides the "gallbladder".
Inside the liver, there are also bile ducts used to excrete bile acid and bile produced by hepatocytes
.
Every day, 800-1000 ml of bile is transported to the gallbladder through the bile duct
.
Bile can promote the digestion and absorption of fat in the small intestine.
It is especially important for "meat" lovers.
Otherwise, if you eat greasy food, you may experience diarrhea caused by indigestion
.

Friends who have their gallbladder removed, because the bile excreted in the liver cannot be stored, they may not be blessed with greasy food, and may even become a vegetarian
.
For some friends who don't like breakfast or breakfast is too light, because there is no greasy signal, bile can not be output from the gallbladder, resulting in bile concentration and easy formation of gallstones
.

In short, if liver disease involves the bile ducts in the liver or the function of liver cells, there may be symptoms such as elevated blood bilirubin, yellow urine, yellow skin, and eyes.
You need to see a doctor in time
.

03

Detoxification function

In the process of body metabolism, the portal vein collects blood from the abdominal cavity, and harmful substances and microbial antigenic substances in the blood will be detoxified and eliminated in the liver
.
The liver is the main detoxification organ of the human body, which makes the toxicity of poisons disappear, weaken or combine, and convert them into soluble substances, which are excreted with bile or urine to protect the body from damage
.
If you take in excessive amounts or highly toxic and harmful substances, the liver will also bear the brunt, and liver damage of varying severity may occur, and in severe cases, fulminant liver failure may occur
.
Many drugs are also metabolized by the liver.
The so-called "three-part drug", many drugs themselves cause damage to the liver, such as excessive antipyretic drugs, inferior health care products, and improperly handled Chinese herbal medicines.
Not taking them will not affect your health.
Later, it increases the burden on the liver and causes liver damage
.

04

Defense and immune function

The liver is also the body's largest immune organ and has the largest phagocytic system of reticuloendothelial cells
.
The endothelium of the hepatic sinusoids contains a large number of Kupffer cells like scavengers, patrolling the liver to remove foreign bodies, bacteria and other particulate matter from the blood
.
The mononuclear-macrophages in the liver can also swallow antigens, and then stimulate the body's immune response to eliminate them
.

05

other

In addition to the above functions, the liver can also regulate circulating blood volume, synthesize a variety of coagulation factors (coagulation factors II, VII, IX, X) and participate in the body's heat production, water, and electrolyte balance
.

Let's take a look at the "liver function" test sheet

Liver function test is to detect various indicators related to liver function and metabolism through various biochemical tests, and comprehensively reflect liver cell damage, bilirubin metabolism, cholestasis, liver synthesis function, and liver fibrosis degree
.

1

Indicators reflecting liver cell damage

Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) are the most widely used clinical biochemical indicators to reflect liver cell damage
.

ALT is mainly distributed in the cytoplasm of liver cells, and its intrahepatic concentration is 3000 times higher than that of serum.
It is a sensitive indicator of liver cell damage
.

AST is mainly distributed in the mitochondria of liver cells, and a few in the cytoplasm.
If the concentration of AST is found to be elevated in liver function, it may indicate severe liver cell damage, or mitochondrial damage of liver cells, such as alcohol
.

The determination of serum AST and ALT levels and the AST/ALT ratio are conducive to the diagnosis and identification of abnormal liver function
.

2

Reflecting the index of bilirubin metabolism

Bilirubin is produced by the liver and is excreted through the biliary tract.
The liver has the functions of uptake, binding and excretion in the metabolism of bilirubin
.
Bilirubin determination includes total bilirubin (TBIL), direct bilirubin (DBIL) and indirect bilirubin (IBIL).
A variety of pathogenic factors can cause serum bilirubin to rise, leading to jaundice
.
The total bilirubin in the blood is significantly increased, which needs to be paid attention to
.
What is the reason for the need to go to the hospital for examination .

3

An indicator of cholestasis

If there is a problem with the liver cells or the biliary system, cholestasis may occur, and the bile cannot be discharged normally and enters the blood
.

Elevated serum alkaline phosphatase (ALP) and GGT are the most characteristic early manifestations of cholestasis, and elevated levels of both indicate cholestasis
.

There are many factors that can cause a significant increase in blood ALP in normal people
.
After 3 months of pregnancy, placental ALP enters the bloodstream up to 2-3 times the normal level, and can continue for several weeks after delivery; in children and adolescents after the age of 10, the bones are in the developmental stage, and the ALP level is up to 3 times higher than that of adults.
In addition, after a high-fat diet and certain bone diseases, ALP levels will also increase
.

4

An indicator reflecting the liver's synthetic function

The main indicators reflecting liver synthesis function include: albumin (Alb), prealbumin (PA), prothrombin time (PT) and cholinesterase (CHE)
.

Albumin (Alb)

The liver is the only organ for the body to synthesize Alb.
After synthesis, it is needed by the body and is hardly excreted.
It is also a "nutrition" often referred to by the people
.
Its half-life in plasma is about 21 days.
Therefore, the level of Alb reflects the anabolic function and reserve function of the liver, and is also an indicator for evaluating the severity of liver cirrhosis and judging the prognosis
.
If Alb continues to decrease, it indicates that hepatocyte necrosis is getting worse and the prognosis is poor
.

When liver function is severely damaged, such as chronic moderate or higher hepatitis, liver cirrhosis, primary liver cancer, etc.
, Alb synthesis decreases, while globulin synthesis increases, causing the A/G ratio to be inverted
.

Prealbumin (PA)

Prealbumin has a small molecular weight and is synthesized by hepatocytes.
Electrophoresis separation is often displayed in front of albumin.
Its half-life is about 1.
9 days short.
Therefore, the concentration of prealbumin in serum is more important for understanding liver synthesis function and nutritional status than albumin.
High sensitivity
.

Prothrombin time (PT)

Serum PT is another index for evaluating liver synthesis function.
This index detects blood clotting time.
It requires the participation of liver synthesis of coagulation factors (II, V, VII, X)
.

When liver cells are extensively damaged, the ability of the liver to synthesize coagulation factors decreases, leading to prolonged PT.
When PT exceeds the normal reference value for more than 3s, it is abnormal; 4-6s, indicating severe liver damage and poor prognosis
.

Cholinesterase (CHE)

Serum CHE mainly reflects the degree of liver protein synthesis and liver parenchymal cell damage
.

In liver disease, CHE often decreases, and its decrease is roughly parallel to serum albumin
.
Since the half-life of CHE is shorter than that of albumin, CHE can more sensitively reflect changes in the condition, which is often detected in patients with liver failure, reflecting the liver's real-time synthesis function
.

The common symptoms of liver disease are fatigue, poor appetite, oiliness, etc.
Each index of liver function has its corresponding role in the diagnosis of liver disease, but it is inevitable that there are limitations
.
In actual clinical work, there are many causes of abnormal liver function, such as viral hepatitis, drug-induced hepatitis, fatty liver, etc.
Therefore, when abnormal liver function is found, it is necessary to seek medical treatment in time, clarify the cause, and treat the cause
.

Case analysis

Patient, female, 56 years old
.
Main complaint: Repeated abnormal liver function for more than 1 year, and found HCV positive for 2 months
.
Follow-up medical history, the patient's history of infusion in the local clinic, many people have abnormal liver function, HCV positive
.
Liver function and kidney function results on admission:

Interpretation of the report: The patient’s liver function showed a significant increase in ALT and AST, suggesting hepatocyte damage; total bile acid, alkaline phosphatase, and γ-GT increased, suggesting bile duct cell damage
.
At present, total bilirubin and direct bilirubin are normal, indicating that the current injury has not significantly affected the metabolism and excretion of bilirubin
.
The albumin level is normal, indicating that the liver synthesis function is acceptable
.
Changes in liver function of this patient are related to hepatitis C virus infection
.
After 1 month of treatment, the patient's liver function improved significantly, and after nearly 2 months of treatment, the liver function completely returned to normal
.

references:

[1] Zhu Danian, chief interrogator; Wang Tinghuai, chief editor; Luo Ziqiang, Shen Linlin, Guan Youfei, Wu Yuming deputy chief editor.
Physiology 9th edition [M].
Beijing: People's Medical Publishing House, 2018.
08.

[2] Chinese Medical Association Hepatology Branch.
Digestive Diseases Branch of Chinese Medical Association.
Infectious Diseases Branch of Chinese Medical Association.
Consensus on the diagnosis and treatment of cholestatic liver disease (2015)[J].
Journal of Clinical Hepatobiliary Diseases, 2015, 31(12): 924-933.

[3] Wang Xiaolin, Yang Jing, the relationship between prealbumin, cholinesterase, prothrombin time and fibrinogen and the pathological grade of chronic hepatitis B [J].
Journal of Clinical Hepatobiliary Diseases, 2007.
23(5):377-378.

[4] Zhang Shuyan, Xiong Huishun, Examination and clinical significance of serum prealbumin and albumin in patients with liver disease [J] Journal of Clinical Medicine, 2010, 38(2): 279-280.

[5] Li Fei, Lu Lungen, Evaluation and clinical significance of abnormal liver function [J], Journal of Clinical Hepatobiliary Diseases.
2015, 31(09), 1543-1546

[6] Li Yonggang, Yang Daguo.
Re-discussion of "enzyme and gallbladder separation" as an index for judging severe liver damage[J].
Journal of Integrated Traditional Chinese and Western Medicine, 1995(01): 15-17.

[7]Botros M, Sikaris K A .
The deritis ratio: the test of time[J].
Clin Biochem Rev,2013,34(3):117-130.