The anti-hbs exam is requested to check whether the person has immunity against the hepatitis B virus, whether acquired through vaccination or through curing the disease.
This test is done by analyzing a small blood sample in which the amount of antibodies against the hepatitis B virus is checked in the bloodstream. Normally, the anti-hbs test is requested together with the HBsAg test, which is the test where the virus is present in the blood and is therefore used for diagnosis.
What is it for
The anti-hbs test serves to assess the body's production of antibodies against a protein present on the surface of the hepatitis B virus, HBsAg. Thus, through the anti-hbs exam, the doctor can check whether the person has been immunized against hepatitis B or not, through vaccination, in addition to checking whether the treatment is effective or has been cured, when the diagnosis for hepatitis B was confirmed.
HBsAg Exam
While the anti-hbs test is requested in order to verify immunity and response to treatment, the HBsAg test is requested by the doctor to find out if the person is infected or has had contact with the hepatitis B virus. examination is requested to diagnose hepatitis B.
HBsAg is a protein present on the surface of the hepatitis B virus and is useful for diagnosing acute, recent or chronic hepatitis B. Usually the HBsAg test is requested together with the anti-hbs test, as it is possible to check if the virus is circulating in the bloodstream and if the body is acting on it. When the person has hepatitis B, the report contains reagent HBsAg, which is an important result for the doctor, as it is possible to start treatment. Understand how hepatitis B is treated.
How is done
To do the anti-hbs test, no preparation or fasting is required and it is done by collecting a small blood sample, which is sent to the laboratory for analysis.
In the laboratory, the blood undergoes a serological analysis process, in which the presence of specific antibodies against the hepatitis B virus is verified. These antibodies are formed after coming into contact with the virus or due to vaccination, in which the organism is stimulated to produce these antibodies, giving immunity to the person for the rest of his life.
Know when the hepatitis B vaccine should be taken.
Understanding the results
The result of the anti-hbs test varies according to the concentration of antibodies against the hepatitis B virus in the bloodstream, with reference values being:
- Anti-hbs concentration less than 10 mUI / mL - non-reagent. This concentration of antibodies is not enough to protect against the disease, it is important that the person is vaccinated against the virus. In case the diagnosis of hepatitis B has already been made, this concentration indicates that there was no cure and that the treatment is not being effective or is in its initial phase; Concentration of anti-hbs between 10 mUI / mL and 100 mUI / mL - undetermined or satisfactory for vaccination. This concentration may indicate that the person has been vaccinated against the hepatitis B virus or is being treated, and it is not possible to determine whether hepatitis B has been cured. In these cases, it is recommended that the test be repeated after 1 month; hbs greater than 100 mUI / mL - reagent. This concentration indicates that the person has immunity against the hepatitis B virus, either through vaccination or through curing the disease.
In addition to evaluating the result of the anti-hbs test, the doctor also analyzes the result of the HBsAg test. Thus, when monitoring a person already diagnosed with hepatitis B, the HBsAg non-reactive and positive anti-hbs result indicates that the person is cured and that there are no more viruses circulating in the blood. The person who does not have hepatitis B also has the same results and the anti-hbs concentration exceeds 100 mIU / mL.
In the case of HBsAg and positive anti-hbs, it is recommended to repeat the test after 15 to 30 days, as it may indicate a false positive result, formation of immune complexes (immune complexes) or infection by different subtypes of the hepatitis B virus.
