Traditional liver function tests include ALT, AST, TP, ALB, TBIL, DBIL, GGT, ALP, etc., but the liver secretes α1-acid glycoprotein (AAG), α-1 antitrypsin (α1-AT), and haptoglobin (HAP) but few people know their clinical significance. Today we will take a look at these three proteins.
Data prove that 50% of new and dead liver cancers occur in China worldwide. Combined with China's national conditions, hepatitis B is the biggest cause of liver cancer "hepatitis - cirrhosis - liver cancer" is known as the liver cancer trilogy, hepatitis virus infection is the most important cause of liver cancer.
In order to help patients better understand their physical condition, detect changes in liver function early, and increase the detection rate of primary liver cancer, these three serum proteins are undoubtedly a very good supplement to routine liver function testing.
Alpha1-Acid glycoprotein (AAG)
AAG is a non-specific acute phase reactive protein, and it is also the most sugary content (about 45% sugar content) and the strongest acidic (PI is 2.7 to 3. 5) Glycoprotein. Produced mainly by liver macrophages and granulocytes, cancer cells can also be synthesized. Together with C-reactive protein, it is considered a sensitive indicator of the acute state of inflammatory activity.
Compared with normal people, the concentration of serum AAG decreased to varying degrees in all stages of chronic liver disease, and the more severe the disease, the more obvious the decrease in AAG value. As the condition improves, the serum AAG concentration gradually increases.
AAG can be a good indicator of changes in chronic liver disease, particularly in the decompensated phase of cirrhosis, severe chronic hepatitis, and severe hepatitis.
Compared with PIVKAII, AAG has a higher positive rate at low AFP values for liver cancer, and the detection rate of AAG and AFP complementary in primary liver cancer can reach more than 96%. AAG acts as a protein marker to detect primary liver cancers with low levels of AFP, and the combined AAG and AFP tests improve the detection rate (accuracy and sensitivity) of primary liver cancers.
Clinical application
1. It can be used as a monitoring index for the progression of patients with liver disease;
2. Especially in patients with cirrhosis, joint monitoring with alpha-fetoprotein to distinguish cirrhosis and liver cancer;
3. The indicator of the severity of the condition of patients with acute pancreatitis.
α-1 antitrypsin (alpha1-AT)
Alpha-1 antitrypsin is a glycoprotein that is synthesized primarily by the liver. It is also an acute phase reactive protein, in inflammatory diseases, alpha 1-antitrypsin can enter the tissue fluid through the capillaries, often in high concentrations in the local inflammation, has a certain restrictive effect on acute inflammatory diseases.
The detection rate of primary liver cancer detected by α1-antitrypsin and α1-acid glycoprotein combined with alpha-fetoprotein can reach 98.3%. The American Thoracic Society and the European Respiratory Society have jointly published guidelines for the diagnosis and treatment of alpha-1 antitrypsin (AAT) deficiency, which provide guidance on some diseases that require alpha-1 antitrypsin testing.
Elevated: mainly seen in tissue damage, infectious diseases (bacterial, viral), malignant tumors, viral hepatitis, collagen disease, pregnancy, surgery, drugs (estrogen, oral contraceptives, adrenal steroids, prostaglandins, etc.), typhus, etc.;
Decreased: mainly seen in hereditary alpha 1-AT deficiency, cirrhosis due to alpha 1-AT deficiency, neonatal respiratory distress syndrome, severe hepatitis, nephrotic syndrome, protein-loss gastrointestinal disease, malnutrition, immature infants, and early rejection of kidney transplantation.
In patients with unexplained cirrhosis, alpha 1-AT testing can assist in diagnosis.
Haptoglobin (HAP)
Haptoglobin, also known as globin binding, is widely found in serum and other body fluids in humans and many mammals. Binding globin is mainly synthesized in the liver, its degradation is also in the liver, is a combination of free hemoglobin in the blood and a2-macroglobulin in the liver, anemia, liver disease or malnutrition will often be significantly reduced.
Globin binding is an acute phase phase reactive protein. When the body is in a state of stress, the binding globin in the blood is significantly increased, such as myocardial infarction, tumors, inflammation, trauma, infection and other pathological conditions, and after the application of certain hormones, such as corticosteroids and male hormones, its serum content is often significantly increased, and is related to severity and prognosis.
The sensitivity of tactilein is high, and it decreases significantly in liver disease or anemia, and often even very low concentrations. The conclusions of the study show that the changes in serum globin and ferritin content have certain diagnostic value in patients with acute pulmonary embolism and deep venous thrombosis.
When do I need to test for haptoglobin?
Testing for globin is required in people with the following clinical indications: fatigue, weakness, pallor, syncope, increased heart rhythm, tachypnea, jaundice, hemo/hemoglobinuria, increased bilirubin concentrations, decreased red blood cell count, reticulocyte count, and increased lactate dehydrogenase levels.
Initial screening: decreased when hepatitis, anemia, and immunocompromise are low; increased in infection, inflammation, tumors, myocardial infarction, and other diseases.
Diagnosis: It can be used as a diagnostic indicator of hemolytic anemia, and it is recommended for physical examination, maternal and child and hematological testing; it can be used as a screening index for liver disease and immune function status assessment, and it is recommended for internal medicine, hepatobiliary, infection, and surgical patients.
The significance of the combinatorial detection
Alpha1-acidic glycoprotein (AAG), α-1 antitrypsin (alpha1-AT), haptoglobin (HAP).
Primary liver cancer: AFP +AAG+α1-AT
Hemolytic anemia: HAP + AAG
Acute phase reactive proteins such as inflammation: CRP + AAG + HAP
Source: Clinical Laboratory Medicine
Edited by: Yeah Reviewer: Xiao Ran