PCR analysis for hepatitis B

A DNA-containing virus of the Hepadnaviridae family is the direct causative agent of hepatitis B (HBV). Analysis of PCR for hepatitis B, allows you to determine the presence of virus DNA in the patient’s blood. A positive result for HBV DNA demonstrates the presence of an infection in the patient’s blood. It should be noted that diagnostics using PCR analysis allows not only to determine the presence of the pathogen, but also its quantitative load and activity. This method is reliable, accurate and reproducible. Quantification of HBV DNA by real-time PCR (qPCR) can be used to monitor the effectiveness of HBV therapy and be useful in understanding the etiology of HBV.

The process of infection with hepatitis B occurs through domestic or sexual contact, or through direct contact with infected blood. After infection, the virus enters the liver cells, in which it continues its active reproduction. Through the bloodstream, pathogenic cells spread throughout the body. It is known that the hepatitis B virus is highly resistant to acid and high temperatures and is able to maintain its damaging properties for six months.

Types of PCR for hepatitis B

To date, there are two types of diagnostics that are prescribed if you suspect the presence of the hepatitis B virus: high-quality PCR (allows you to determine with absolute accuracy the presence of the virus in the blood) and quantitative PCR (determines the degree of activity of the virus).

Qualitative PCR is prescribed if there is a suspicion of infection with the hepatitis B virus, or if other diagnostic methods have not shown a positive result. It is extremely simple to decipher this type of PCR analysis: negative (the virus is not detected in the blood), positive (the virus is present in the blood). The main task of qualitative analysis is to determine the presence of infected cells in the early stages of the disease. If the virus was diagnosed two weeks after the alleged infection, the effectiveness of treatment will be an order of magnitude higher. If the virus is in the blood for about two months, the disease becomes chronic, therefore, it cannot be completely cured.

If a qualitative diagnosis has confirmed the presence of HBV in the blood, a quantitative analysis is prescribed.

Quantitative analysis allows you to determine the activity of the development of the virus in the patient’s body. This type of PCR analysis is assigned:

• to determine the stage of the disease;
• to monitor the effectiveness of the therapy used;
• to determine the level of resistance of the virus to a particular drug;
• for drug selection.

Quantitative indicators of the virus in the blood are measured in IU per milliliter or DNA per milliliter.

In the event that a quantitative diagnosis is immediately assigned without a qualitative one, then the rate of 75 IU per milliliter is taken as the norm. If a smaller number of international units is detected, the result is that HBV is not detected; when the values ​​​​exceed the norm, the presence of viral hepatitis B is diagnosed.

Deciphering quantitative analysis

The following indicators (number of copies/milliliter) are considered normal for OCP in hepatitis B: less than 10³ – the virus is inactive; from 10⁴ to 10⁵ – the virus is usually inactive; ten⁶ – the virus is active; ten⁷ – the virus is in a high stage of activity (1 IU = 4,5 copies of hepatitis B DNA).

Based on quantitative indicators, it is possible to accurately determine the form of the disease (carriage, acute or chronic), the response of the virus to treatment, and the need for additional diagnostics.

The chronic form of hepatitis B is established if the activity of the virus is 10⁵ copies per milliliter. Carrier is diagnosed if the counts are below 10⁵ copies per milliliter.

During the treatment period, it is necessary to regularly (every three months) undergo repeated quantitative diagnostics in order to determine in time the moment when the virus develops resistance to the drugs used and change the treatment regimen. In the event that all studies were carried out correctly and an effective treatment was selected, on re-analysis (after three days of treatment) a decrease in the activity of viral particles by at least eighty-five percent will be observed.

A liver biopsy is performed if, within six months of treatment, ALT values ​​exceed the norm twice, and PCR diagnostics show values ​​below 10⁵ copies per milliliter of blood.

Preparation for the survey

The analysis requires venous blood. To obtain the most accurate results, it is necessary to prepare for the procedure: refuse to eat at least eight hours before blood sampling; stop drug treatment in two days (it is mandatory to warn the doctor about taking the drugs); before donating blood, you need to spend twenty minutes in rest mode; Twelve hours before the procedure, stop exercising, drinking alcohol, smoking and eating fatty foods.

Important: if a diagnosis is necessary for a child under the age of five months, then he needs to give a tablespoon of boiled water every ten minutes an hour before the blood sampling procedure.

Summing up

PCR analysis for hepatitis B today is the most accurate method for diagnosing the virus. The method makes it possible to identify mutated and latent forms of the disease, to diagnose the disease in the first days of infection, and therefore to select the most effective treatment. Based on a comparison of the results of the analysis with the norm, a conclusion is issued. The data is processed within a few days. In order to get a referral for a PCR test, you need to contact a hepatologist, infectious disease specialist or virologist. It is important to remember that the sooner you get to the doctor, the sooner the results will be obtained, therefore, the more effective the treatment will be.

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