The hepatitis B virus belongs to the hepatotropic DNA virus family, and its genome consists of partially double stranded circular DNA, encoding HBsAg, HBcAg, HBeAg, viral polymerase, and HBx protein. HBV has strong resistance, but it can be inactivated by boiling at 65 ℃ for 10 hours, boiling for 10 minutes, or high-pressure steam. Ethylene oxide, glutaraldehyde, peracetic acid, and iodine also have good inactivation effects on HBV. The high-sensitivity HBsAg ELISA detection kit is a widely used diagnostic tool for quantitative detection of hepatitis B surface antigen (HBsAg) in human serum, plasma, and other biological samples.
Figure 1. Hepatitis B virus.
The hepatitis B virus has at least 9 genotypes (A to I) and 1 undetermined genotype (J). China is mainly characterized by genotype B and genotype C. HBV genotype is associated with disease progression and response to interferon alpha therapy. The mutation rate of HBV is relatively high, and mutations in the reverse transcriptase region are mostly related to NAs resistance. Partial mutations in the pre-S/S region, basic core promoter region, and pre-C/C region may be associated with the occurrence of acute liver failure and HCC. HBV infection is a global public health problem. With the production and investment of genetic engineering vaccine, the prevalence of hepatitis B vaccine is increasing year by year, and the infection rate is declining.
Under the electron microscope, hepatitis B virus can present three kinds of particle structures: large spherical particles with a diameter of about 42nm, small spherical particles with a diameter of about 22nm, and tubular particles. Dane particles are complete viral particles composed of an envelope and nucleocapsid. The envelope contains HBsAg, glycoproteins, and cellular fat, while the core particles contain HBcAg, circular double stranded HBV-DNA, and HBV-DNA polymerase. They are the complete form of the virus and infectious. Both small spherical particles and tubular particles are composed of lipoproteins that are the same as the viral envelope. The former is mainly composed of hollow particles formed by HBsAg and does not contain DNA or DNA polymerase, making it non infectious; The latter is formed by the series polymerization of small spherical particles, with the same composition as the small spherical particles.
The main transmission route of HBV is blood transmission (blood transfusion and blood products). Secondly, there is mother to child transmission, which refers to the infection of newborns by mothers carrying hepatitis B virus before, during, and after childbirth. Breastfeeding can also lead to mother to child transmission, which accounts for a large proportion in China. 40% to 50% of chronic hepatitis B patients are transmitted from mother to child. The third is close contact transmission, such as virus transmission through semen and vaginal secretions. The fourth is iatrogenic transmission, such as incomplete disinfection and unsafe injections.
(1) Transmission through blood, blood products: HBV is widely present in the blood, and a very small amount of blood or blood products containing the virus can enter the human body and cause infection. In addition to blood transfusion, it can also be transmitted through blood dialysis, organ transplantation, etc.
(2) Mother to child vertical transmission: mainly refers to intrauterine infection, perinatal transmission, and postpartum transmission. Mothers carrying HBV can infect their fetuses through blood flow.
(3) Close contact transmission: it has been confirmed that saliva, sweat, vaginal secretions, semen, milk and other body fluids contain hepatitis B virus. Close life contact, especially sexual contact transmission, is the common mode of transmission
Figure 2. Transmission Routes.
HBV adheres to the surface of liver cells through low affinity receptors such as heparan sulfate and proteoglycans, and then binds to virus receptors through the preS1 region of the large envelope protein to mediate cellular endocytosis of the virus. Sodium ion taurocholic acid transporter peptide (NTCP) is an important receptor that mediates the entry of HBV into cells and establishes infection. The fusion of endocytic virus envelope and membrane releases the capsid into the cytoplasm, which is transported to the nuclear pore complex. The viral genome rcDNA inside is released into the cell nucleus. In the nucleus, rcDNA may be transformed into covalently closed circular DNA (cccDNA) through the cell's DNA replication mechanism.
The detection limit of this kit is 0.05 IU/mL, which can recognize HBsAg in patients with early infection, "window period" (before clinical symptoms appear), and low viral load, thereby reducing the risk of false negatives.
The antibodies used in the kit recognize the conserved region of HBsAg and can detect common HBV mutations (such as escape mutants) that may not be recognized by standard kits, making it suitable for areas with high mutation prevalence.
The reagent can be stored stably for 12 months at 2-8 ° C, ensuring long-term usability and reducing waste. Provide calibrators and control devices to maintain consistency between batches and experiments.
Acute hepatitis B B patients, chronic hepatitis B B patients and hepatitis B virus carriers are the main sources of infection. The blood of hepatitis B virus infected people is infectious whether in the incubation period, acute period or chronic period. The highly sensitive HBsAg ELISA detection kit represents an important breakthrough in HBV diagnosis, and its excellent sensitivity, specificity, and user-friendly design can meet the diverse needs of clinical laboratories, blood banks, and public health institutions.
