Blood tests for hepatitis B
Viral hepatitis B is a viral pathology with parenteral transmission.
The causative agent of the disease is highly infectious.
Therefore, for the development of the infectious process, it is enough for a minimum amount of viral particles to enter the human body.
The disease often has a chronic course without the development of severe symptoms.
That is why laboratory research is required for its reliable diagnosis, for more details https://kvd-moskva.ru/analizy-na-infektsii/464/, aimed at detecting the hepatitis B virus or its antibodies - a blood test for hepatitis.
For what purposes is hepatitis diagnosed?
Laboratory tests for suspected hepatitis are performed for several indications, which include:
- Detection and identification of the causative agent of the infectious process (detection of antigens of the viral particle or genotype of the hepatitis B virus) to confirm or exclude infection.
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Determination of viral load is an analysis that determines the amount of the virus.
- Determination of the stage of development of the infectious process.
- Determination of structural changes in the liver in order to predict the further course of the disease (prognosis of the development of cirrhosis of the liver, provoked by viral hepatitis).
Each stage of laboratory diagnostics can include several studies.
At the screening stage, a general analysis is performed for markers of viral hepatitis B.
Before the appointment of treatment (including antiviral etiotropic therapy aimed at suppressing the activity of the viral replication process in liver cells) or to monitor its effectiveness, tests are performed to determine the viral load and the stage of development of the infectious process.
For the comprehensive diagnosis of infections with parenteral and sexual transmission, tests for HIV and hepatitis B, C are performed.
What tests are taken for hepatitis
To achieve all diagnostic goals, laboratory tests for viral hepatitis B include several research methods, which include:
- Tests for markers of viral hepatitis - include the determination of specific antibodies in the blood to certain protein compounds, which are components of various structures of viral particles.
- Research aimed at identifying the genetic material of the hepatitis B virus.
- Quantitative analysis of hepatitis virus - is performed to assess the viral load by determining the number of viral particles in a unit of volume of the analyzed blood.
The combination of these research methods makes it possible to determine the presence of a virus in the body, in more detail https://kvd-moskva.ru/analizy-na-infektsii/257/, to assess the viral load, as well as the stage of the infectious process.
A complete blood count and biochemical profile are also performed for hepatitis.
They make it possible to assess the functional state of the liver and the immune system.
To detect structural changes in the liver, a biopsy is performed.
This is the taking of a small piece of liver tissue for subsequent histological (tissue) examination under a microscope, which is necessary for the early detection of the possible development of liver cirrhosis.
All methods of analysis for hepatitis should be carried out in case of detection of the disease, since they are necessary for the subsequent appointment of adequate treatment by a doctor.
Determination of markers for viral hepatitis B
The viral particle of the causative agent of this infectious disease consists of genetic material (represented by DNA) and also several layers of the capsule (nucleoprotein, capsid and supercapsid).
These structures are complex proteins (they are antigens for the body), to which specific antibodies are produced by the human immune system.
To establish the presence of a virus in the body, as well as the stage of development of the infectious process, the antigens of the hepatitis B virus and specific antibodies to them are determined:
- HBsAg (Australian antigen) is the main marker of viral hepatitis B. Its detection indicates the presence of a disease at the time of the study or a pathology transferred in the past.
- Hepatitis B surface antibodies - antibodies to the HBsAg antigen. Their titer (activity) is used to judge the stage of the infectious process.
- HBeAg is an antigenic marker that indicates active replication (multiplication) of the virus in liver cells.
- Anti-HBeAg antibodies - are determined to monitor the effectiveness of treatment. An elevated hepatitis B antibody titer indicates a favorable prognosis.
- Antibodies to the HBcorAg antigen. The core antigen is not detected in the blood, only in liver cells. In the blood, the total antibodies, immunoglobulins M and G to this antigen are determined, the activity of which is used to judge the stage of the course of infection and the activity of virus replication.
To screen for infection, an HBsAg antigen test is performed.
Usually, hepatitis tests are performed on pregnant women, potential blood donors, and patients before being admitted to a surgical hospital.
In-depth examination for the detection of HBsAg includes the determination of all markers and antibodies to hepatitis B.
To obtain the most reliable results before testing for hepatitis, it is important not to consume fatty fried foods, alcohol, as this can cause false positive results.
Identification of the genetic material of the hepatitis B virus
Hepatitis B virus (HBV) contains DNA (deoxyribonucleic acid) as its genetic material.
During the active course of the infectious process with the replication of the virus in the liver, the pathogen appears in the blood.
The genetic material is determined using PCR (polymerase chain reaction), which has high specificity and sensitivity.
This study can be quantitative. Its implementation involves determining the number of units of the genetic material of the virus in a unit of blood volume.
With the help of PCR, the viral load is determined.
The polymerase chain reaction is carried out in conjunction with research for other markers of viral hepatitis B.
General tests for hepatitis
To determine the functional state of the liver and the immune system, a general and biochemical blood test is performed.
The hepatitis B virus affects the immune system, so a general blood test may include:
- change in the number of leukocytes (cells of the immune system) with a predominant increase in lymphocytes in the leukocyte formula;
- increased ESR (erythrocyte sedimentation rate).
In a biochemical analysis, the activity of the enzymes ALT and AST (hepatic transaminases) is necessarily determined.
An increase in which is evidence of an active course of the infectious process with damage to liver cells.
What if the test showed hepatitis?
If a positive result for HBsAg is obtained, a comprehensive study is required to exclude or confirm an infectious process.
In a dermatovenerologic dispensary, the patient, if desired, can pass an anonymous test for hepatitis
This should be done as early as possible, because the more timely the treatment, the better the prognosis.
Hepatitis B is treated, so you should not start the disease while waiting for the development of liver cirrhosis.
For any suspicion of hepatitis, get tested by a doctor, an appointment for anonymous testing for hepatitis in Moscow 8 (495) 642-30-37.
