Introduction to glutamyltransferase
GGT mainly exists in the liver cell membrane and microsomes, involved in glutathione metabolism. Kidney, liver and pancreas rich in content, but the serum GGT mainly from the liver and gallbladder system. GGT is widely distributed in the liver of the capillary bile duct side of the liver and the entire bile duct system, so when the liver hyperactivity or bile discharge blocked, the serum GGT increased.
The clinical significance of glutamyltransferase
(1) biliary obstructive diseases: primary biliary cirrhosis, sclerosing cholangitis caused by chronic cholestasis, liver cancer due to intrahepatic obstruction, induced liver cells to produce a large number of GGT cancer cells also synthesized GGT So that GGT significantly increased, up to 10 times the upper limit of the reference value. At this time, GGT, ALP, 5-Nucleotide (5-NT), leucine aminopeptidase (LAP) and serum bilirubin were increased in parallel.
(2) acute and chronic viral hepatitis, cirrhosis: acute hepatitis, GGT was moderate; chronic hepatitis, cirrhosis of the non-clean period, the enzyme activity is normal, if GGT continued to rise, suggesting that the disease clean or condition deterioration.
(3) acute and chronic alcoholic hepatitis, drug-induced hepatitis: GGT can be significantly or moderate higher than (300 ~ 1000U / L), ALT and AST only slightly increased, or even normal. Alcoholics can drop GGT when they drink alcohol.
(4) other: fatty liver, pancreatitis, pancreatic cancer, prostate cancer and other GGT can also be slightly increased.
Reason of low glutamyltransferase
Lysyltransferase is mainly found in the kidney, liver and pancreas, the serum glutamyl transferase mainly from the liver and gallbladder system. Clinical low glutamyl transferase phenomenon is not common, the general glutamyl transferase values as long as the reference range is normal. Hepatitis B patients with glutamyl transferase in the case of over-low may have severe hepatitis, in addition, acute hepatitis B outbreak period can also be low glutamyl transferase situation.
Reason of high glutamyltransferase
1, viral hepatitis: acute hepatitis, glutamyl transferase was moderate increase; chronic hepatitis, cirrhosis of the inactive, glutamyl transferase performance is normal, if the glutamyl transferase continued to rise, then said The condition worsens;
2, alcohol, drug-induced hepatitis: glutamyl transferase is generally 300 ~ 1000U / L, alcoholics alcohol diarrhea after glutamyl transferase will decline;
3, biliary obstructive diseases can also cause increased glutamyl transferase, intrahepatic obstruction will induce liver cells to produce large amounts of glutamyl transferase, and even up to the upper limit of the reference value of more than 10 times;
4, fatty liver, pancreatitis, pancreatic cancer, prostate cancer can also make a slight increase in glutamyl transferase;
5, excessive consumption of high protein supplements will increase the burden on the liver, leading to elevated glutamyl transferase.
Glutamyltransferase-induced hepatobiliary disease
Glutamyl transpeptidase is not specific for the diagnosis of hepatobiliary disease. Elevated serum levels not only suggest hepatobiliary disease, but also diseases other than liver, such as acute pancreatitis, congestive heart failure, myocardial infarction and diabetes mellitus.
There are other factors that affect the serum levels of glutamyl transpeptidase, such as alcoholism, barbiturate, phenytoin and male medication may also have glutamyl transpeptidase changes.
However, the activity of glutamyl transpeptidase is in good agreement with the level of transaminase and the degree of liver disease. The elevated glutamyl transpeptidase was positively correlated with transaminase positive. Glutamate transpeptidase abnormalities and the degree of liver tissue lesions were significantly related, so glutamyl transpeptidase can be considered to reflect the degree of liver cell damage index.
Hazards of glutamyltransferase
1, indicates viral hepatitis: acute viral hepatitis, the necrotic area adjacent to the liver cell immortal enzyme synthesis hyperthyroidism, causing serum glutamyl transpeptidase high. The activity of glutamyl transpeptidase in chronic active hepatitis is often higher than that of glutamyl transpeptidase, which is 1 to 2 times higher than that of glutamate transpeptidase.
2, indicates hepatobiliary disease: intrahepatic or extrahepatic bile duct obstruction, glutamyl transpeptidase excretion blocked, with bile reflux into the blood, resulting in high serum glutamyl transpeptidase.
3, indicates that fatty liver: fatty liver patients with glutamyl transpeptidase is also often increased, but the general nutritional fatty liver serum glutamyl transpeptidase activity of the majority did not exceed 2 times the normal value.
4, indicates that alcohol liver: alcoholic hepatitis and alcoholic cirrhosis patients with glutamyl transpeptidase almost all rise, an important feature of alcoholic liver disease.
5, indicates cirrhosis: cirrhosis of serum glutamyl transpeptidase changes depends on whether the liver lesions and its causes. In the inactive are mostly normal, if accompanied by inflammation and progressive fibrosis is often increased. Primary or secondary biliary cirrhosis is often early glutamyl transpeptidase increased. Some people think that liver cirrhosis early glutamyl transpeptidase increased, especially in patients with advanced cases but very low, which may be due to liver cell glutamyl transpeptidase synthesis capacity loss, so that patients with cirrhosis if the glutamylation Peptidase is high, suggesting that the disease is still in its early stages.
6, indicates that liver cancer: primary or metastatic liver cancer patients, glutamyl transpeptidase mostly moderate or increased, can be greater than the normal several times or even several times, while the other system tumors are normal. However, the determination of glutathione transpeptidase in liver cancer and other hepatobiliary diseases, especially with jaundice cases overlap a lot, so the individual determination of glutamyl transpeptidase on liver cancer is not diagnostic value, but if the determination of alpha-fetoprotein, AKP and GGT, the greater the diagnostic value (alpha-fetoprotein negative, and AKP, GGT increased, especially in the absence of jaundice, transaminase normal or only mild increase, should be highly alert to liver cancer may be.
Glutamyltransferase detection method
IFCC and the European conventional Szasz method is the mainly method to detect GGT all over the world now. Both are enzyme motivations based on γ-glutamyl-3-carboxy-4-p-nitroaniline and diglycine as substrates. GOT was applied to γ-glutamyl-3-carboxy-4-p-nitroaniline and diglycine to produce γ-glutamylglycoside and 5-amino-2-nitric acid benzoate at 405 nm , Calculate the concentration of GGT in serum.