Hepatitis B virus (HBV) five serological markers refer to HBV surface antigen (HBsAg), HBV surface antibody (HBsAb), HBV e antigen (HBeAg), HBV e antibody (HBeAb), HBV core antibody (HBcAb), which is also known as the “Hepatitis B two halves”. Its qualitative detection began in the mid-1980s, and currently the enzyme-linked immunosorbent assay (ELISA) is more commonly used in China. Although the qualitative test of hepatitis B two halves has played a certain role in the diagnosis of hepatitis B, disease monitoring and observation of therapeutic effect, but due to the results of the qualitative test are either positive or negative, and it is not possible to dynamically observe the changes of patients’ conditions and therapeutic effect, so the information provided by the qualitative test for the clinic is limited, and along with the rapid development of the clinical medicine, the qualitative test is not able to satisfy the requirements of the clinic and the patients gradually. With the rapid development of clinical medicine, qualitative testing gradually fails to meet the requirements of clinics and patients. Under the development of laboratory medicine, the quantitative testing of hepatitis B 2:1 has become a feasible technology, which greatly makes up for the shortcomings of the qualitative testing of ELISA; at the same time, the quantitative testing of hepatitis B 2:1 can be supplemented with the detection of serum HBV DNA fluorescence quantitative polymerase chain reaction (PCR) to comprehensively assess the condition of the patient and the effect of treatment. Improved sensitivity of quantitative detection Chemiflex chemiluminescence immunoquantitative detection technology for HBsAg sensitivity of up to 0.1ng/ml, while ELISA qualitative test will only be positive when the content of HBsAg reaches 2ng/ml. 1.Early stage of acute hepatitis B: Chemiflex chemiluminescence immunoquantitative detection technology can detect HBsAg early and confirm HBV infection; the application of Chemiflex chemiluminescence immunoquantitative detection technology enables HBsAg to be detected almost at the same time with HBV PreS1 protein, which greatly shortens the ” window period” time of disease observation; while ELISA qualitative detection must be positive only when HBsAg reaches 2ng/ml. Window period” time; and in the early stage of hepatitis B ELISA qualitative detection, HBsAg is often negative. 2.Chronic hepatitis B: some patients lack the immune response to HBV envelope protein, HBsAg expression is low, therefore, ELISA qualitative test can appear HBsAg and HBsAb are negative, and Chemiflex chemiluminescent immunoquantitative test can avoid these situations, and provide the basis for the correct judgment of the disease. 3, HBV mutation: HBV mutation, the expression is often low, conventional ELISA may not be able to detect the antigen, and Chemiflex chemiluminescence immunoquantitative testing has a higher sensitivity, can find and detect HBsAg and HBsAb. domestic and foreign studies have shown that the immune response of HBsAg has a certain relationship with hepatocyte injury; the level of serum HBsAg and HBsAg level in serum and the patient’s cellular immunity to HBsAg are negatively correlated, while changes in liver function are positively correlated with such cellular immunity; therefore, quantitative detection of HBsAg is also a means of reflecting this relationship. 4, low concentration carriers: for some special groups such as health care workers, patients’ family members, etc., they have close contact with hepatitis B patients for a long time, but only a few of them will be infected with acute hepatitis B directly, and most of them are infected with HBV for a long time in a small amount, and they have a certain degree of immunity to HBV, which may be a low concentration of infection. Infectious diseases doctors should pay enough attention to them, pay close attention and take measures to prevent them from developing into hepatitis B patients or chronic HBV carriers. Dynamic observation of therapeutic efficacy and monitoring of disease The occurrence, development and prognosis of disease is a process of dynamic change, the application of Chemiflex chemiluminescence immunoquantitative assay to detect the concentration change of serum markers in hepatitis B two half, can play a role of whole process dynamic monitoring of the disease development, treatment and prognosis of hepatitis B, and provide a basis for the doctors to make a reasonable explanation of the development of the disease and guide the treatment. 1.Quantitatively analyze the changes in the concentration of HBsAg and HBsAb to foresee whether acute hepatitis B is in the recovery period. If the concentration of HBsAg decreases and the concentration of HBsAb gradually increases, it means that the condition is developing in the recovery stage. And if the concentration of HBsAg is at a high level or rising trend, while HBsAb is always at a low level, it means that it is easy to develop into chronic hepatitis B patients or HBV carriers. 2.Quantitatively analyze the changes in the concentration of HBeAg and HBeAb, reflecting the changes in the condition and the effect of treatment. Quantitative testing can clearly determine the period of conversion of HBeAg to HBeAb, that is, the process of decreasing HBeAg concentration and increasing HBeAb concentration. High concentration of HBeAg can also indirectly indicate that HBV is in high replication state and highly infectious; in most cases, high concentration of HBeAb suggests that the condition is getting better, while in some cases (such as poor liver function indicators) may be related to liver necrosis, cirrhosis, liver cancer. 3. The level of HBcAb concentration can reflect the status of HBV infection. High concentration of HBcAb suggests acute HBV infection, and low concentration of HBcAb is generally recovery or previous infection. Chronic hepatitis B is a persistent high concentration of HBcAb. 4, conducive to the determination of chronic hepatitis B active and inactive. Inactive chronic hepatitis B patients have relatively stable serologic indicators, while active chronic hepatitis B patients tend to show progressive changes. 5.Classification of chronic hepatitis B can be carried out. According to the study of HBV DNA pre-C gene mutation, chronic hepatitis B can be categorized into two major groups according to HBeAg and HBeAb status. One is HBeAg-positive chronic hepatitis B caused by wild-type HBV infection, whose natural history of the disease can be categorized into HBeAg-positive and HBeAb-positive periods. The other type is HBeAb-positive chronic hepatitis B, which is mainly caused by infection with the pre-C gene mutation strain of HBV, also known as heterozygous chronic hepatitis B. During the course of the disease, HBeAg is never detected, but the HBV DNA has been replicating, and the HBsAg has been changing in high concentrations.Comparison of the transformation periods of HBeAb-positive chronic hepatitis B and HBeAg-positive chronic hepatitis B. HBeAb-positive chronic hepatitis B and HBeAg-positive chronic hepatitis B are characterized by the two-pair test results. The results of both tests are small triple positive, but the latter is mainly characterized by high levels of HBsAg, fluctuating high and low alanine aminotransferase (ALT) and consistently positive HBV DNA; this group of patients tends to be ineffective on interferon and lamivudine treatment. Serum HBV DNA fluorescence quantitative PCR measurement HBV DNA negative does not completely mean that the patient’s body has been cleared of HBV, the serum HBV DNA fluorescence quantitative PCR measurement results combined with the serological indicators in the two halves of hepatitis B, can more objectively reflect the patient’s body status of HBV, and correctly determine the prognosis and formulate a treatment plan. If the test result shows that HBV DNA is negative but the concentration of HBsAg, HBeAg or HBeAb and HBcAb are still high, it suggests that the patient is not completely cured, and HBV may replicate again, so it should be closely monitored. If HBV DNA is negative and HBsAg, HBeAg, HBeAb and HBcAb concentrations are very low or negative for a certain period of time, it suggests that the patient may be completely cured and has a good prognosis. Quantitative determination of HBsAb guides the prevention of hepatitis B. Patients with HBsAb concentration of more than 10mIU/ml can be positive for HbsAb in ELISA test, but it does not mean that the body must have immunity; patients with HBsAb concentration of 10-100mIU/ml are positive in ELISA qualitative test, but at this time the immunity of the body against HBV is weak, and cannot prevent HBV infection; only patients with concentration of 10-100mIU/ml are positive for HBsAb, but at this time the immunity against HBV is weaker, and cannot prevent HBV infection. cannot prevent HBV infection; only when the concentration of HBsAb reaches more than 100mIU/ml can it be determined that the organism has the ability to resist HBV infection. The higher the level of HBsAb, the stronger the body’s ability to resist HBV infection and the longer it lasts. By doing quantitative test, according to the concentration of HBsAb, we can judge the immune status of the body against HBV and the immunization effect of hepatitis B vaccine; if the concentration of HBsAb is low, we should strengthen the injection of hepatitis B vaccine, so that the concentration of HBsAb in the body can be increased, which can play a protective role. At the same time, after receiving hepatitis B vaccine, the immunity produced by the body may vary according to individual differences, some people can produce high concentration of HBsAb and last for decades; while some people produce not very high concentration of HBsAb, and the duration is not long, and it will disappear gradually after a few years, and this part of the people should pay attention to the changes of the concentration of HBsAb in the body in time, and must be reinforced with one injection of hepatitis B vaccine when necessary (※And some people think that the concentration of hepatitis B vaccine after receiving hepatitis B vaccine is low. However, it is also believed that after the injection of hepatitis B vaccine, although the concentration of HBsAb in this group of people is not high, when the body is infected by HBV, it will produce a memory response and rapidly improve immunity). In conclusion, quantitative detection of hepatitis B vaccine immunity is of great significance for preventive immunization of high-risk groups, especially in the prevention of hepatitis B in children and adolescents. During the treatment of chronic hepatitis B, patients are most concerned about the changes in their condition. Quantitative detection of the concentration of serological markers in hepatitis B two halves can enable patients to have a clearer understanding of their own condition and improve their confidence in treatment, as well as strengthen the trust in doctors, improve the doctor-patient relationship, improve treatment compliance, and facilitate the treatment of the disease.