What are the basic items of liver function test?

There are many ways to test liver function, and accurate results can be obtained through blood tests. Before doing a liver function test, you should be aware that you cannot eat or drink water before the test, and you cannot drink alcohol the day before. Do not eat spicy and greasy food, and the fasting time must be more than eight hours.

(1) Indicators reflecting liver parenchymal damage

It mainly includes alanine aminotransferase (ALT), aspartate aminotransferase (AST), etc. Among them, ALT is the most commonly used sensitive indicator. When 1% of liver cells are necrotic, the serum ALT level can increase by 1 times. Continuous increase in AST and values ​​exceeding ALT often indicate severe liver parenchymal damage and is a sign of increasing chronicity.

(2) Indicators reflecting bilirubin metabolism and cholestasis

It mainly includes total bilirubin (TBil), direct and indirect bilirubin, urinary bilirubin, urobilinogen, blood bile acid (TBA), γ-glutamyl transpeptidase (γ-GT) and alkaline phosphatase (ALP). The above indicators may increase when there is hepatocyte degeneration and necrosis, bilirubin metabolism disorder or intrahepatic cholestasis. In hemolytic jaundice, elevated indirect bilirubin may occur.

(3) Indicators reflecting liver synthesis function

It mainly includes albumin, prealbumin, cholesterol lipase, prothrombin time and activity, etc. When albumin and cholesterol lipase are reduced for a long time and prothrombin activity decreases, and vitamin K supplementation cannot correct the situation, it means that normal liver cells are gradually decreasing, the liver cells have poor function in synthesizing proteins and coagulation factors, the liver reserve function is reduced, and the prognosis is poor.

(4) Indicators reflecting liver fibrosis

It mainly includes type III procollagen (PⅢP), type IV collagen hyaluronic acid (HA), laminin (LN), etc. These indicators can assist in the diagnosis of liver fibrosis and early cirrhosis.

(5) Detection indicators of liver coagulation function

The liver can synthesize all coagulation factors except factor III and factor a chain, and plays an important role in maintaining normal coagulation function. Patients with liver disease have reduced synthesis of coagulation factors, and clinically they may experience bleeding from the gums and nasal mucosa, ecchymosis of the skin, and in severe cases,

Gastrointestinal bleeding is present. Generally, factor VII appears first and decreases the most, followed by factors II and X, and factor V appears last and decreases the least.

A. Prothrombin time (PT)

The normal value is 11 to 15 seconds, and an extension of more than 3 seconds compared to the normal control is significant. The PT of patients with acute hepatitis and mild chronic hepatitis is normal, while that of patients with severe hepatocellular necrosis and cirrhosis is significantly prolonged. PT is a sensitive indicator for reflecting the degree of liver cell damage and judging prognosis.

B. Prothrombin activity (PTA)

The normal value is 80%~100%. Its clinical significance is the same as PT

C. Hepatic thromboplastin test (HPT)

It is one of the methods to measure the liver's reserve function, and can sensitively and reliably reflect the synthesis disorder of coagulation factors II, VII, and X caused by liver damage. Clinical tests show that the HPT of patients with acute hepatitis, chronic active hepatitis, cirrhosis and subacute severe hepatitis is reduced at various stages of the disease. The more severe the condition, the lower the HPT. When liver disease develops to hepatocellular failure, the HPT decreases significantly, usually below 0.5. If the HPT gradually recovers, the prognosis is good.