What is the introduction of HBsAg?
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HBsAg, commonly referred to as the Australia antigen, is the surface antigen of the hepatitis B virus (HBV). The detection of HBsAg in the blood signifies the presence of an active hepatitis B infection.
Structure and Function
The outer layer of an enveloped virus contains specific surface proteins that differ from the viral core. These surface proteins serve as antigens recognized by antibodies, which target and bind to these viral proteins.
Immunoassay
Technological advancements now allow for the genetic manufacturing of these antigen proteins, such as using transgenic E. coli, to create tests that can effectively identify HBV presence.
HBsAg is detectable in the serum of patients with viral hepatitis B, including cases without visible clinical symptoms. The seroconversion of antibodies against HBsAg (anti-HBsAg) typically indicates that the individual is no longer infectious. HBsAg immunoassay detection is essential not just for blood screening, but also for diagnosing hepatitis B infections alongside other clinical markers, and for monitoring antiviral treatments.
In histological evaluations, HBsAg is often showcased using the Shikata orcein technique, which employs a natural dye to bind to the antigen in infected hepatic cells.
Note that positive HBsAg test results might arise from recent vaccinations against the hepatitis B virus, although such positivity seldom persists beyond two weeks post-vaccination.
History
This antigen was initially isolated by American researcher Baruch S. Blumberg, a Nobel Prize winner, from the serum of an Australian Aboriginal individual. Further investigation by virologist Alfred Prince revealed HBsAg as part of the virus responsible for serum hepatitis.
The vaccine "Heptavax", developed during the 1980s, utilized HBsAg extracted from blood plasma of hepatitis carriers. Contemporary vaccines, however, are manufactured from recombinant HBsAg cultivated in yeast.
Hepatitis B Surface Antigen
Does this test have other names?
HBsAg
What is this test?
This particular test is designed to detect hepatitis B surface antigens within your blood. It serves to determine whether you are facing a recent or long-term infection caused by the hepatitis B virus (HBV).
For further details, please refer to the hbsag test procedure.
HBV is characterized by the presence of proteins called antigens on its surface, which stimulate your immune system to produce antibodies. Surface antigens of hepatitis B can typically be detected within weeks from the onset of infection, making them one of the earliest indicators of a hepatitis B infection.
HBV belongs to a group of five hepatitis viruses, which includes hepatitis A, C, D, and E. These viruses are the primary causes of hepatitis infections. HBV is primarily transmitted through blood, as well as seminal and vaginal fluids. Symptoms of hepatitis B may take several months to manifest after the initial infection. While the virus often resolves itself within six months, a small percentage of adults and a larger subset of children, particularly newborns, may develop a chronic infection. This chronic infection can lead to severe liver damage, scarring, cirrhosis, or potentially liver cancer.
Hepatitis B surface antigens can be found during both acute infections and chronic illnesses.
Why do I need this test?
Your healthcare provider might recommend this test if there's suspicion of a liver infection caused by HBV, especially if you exhibit symptoms of hepatitis B. These symptoms can initially arise gradually, and many individuals may feel no symptoms or only experience mild flu-like signs. Severe symptoms may only arise in advanced or chronic infections.
Common symptoms include:
- Extreme fatigue
- Nausea
- Loss of appetite
- Muscle aches
- Fever
- Yellowing of skin and eyes (jaundice)
- Dark urine
- Abdominal pain
- Severe cases may exhibit swelling and confusion
Additionally, you may require this test if you possess any risk factors associated with potential exposure to the virus, which may include:
- Engaging in sexual relations with an infected individual
- Living in close proximity to someone with the virus
- Being a man who has sex with men
- Being born to a mother infected with the virus
- Using shared needles for IV drug use
- Working in healthcare where exposure to blood is possible
- Receiving a blood transfusion or organ transplant, although this is rare due to stringent screening processes
This test may also be repeated if you have previously been diagnosed with hepatitis B to monitor your recovery progress.
What other tests might I have along with this test?
Along with the HBsAg test, your healthcare provider may order further blood tests to identify HBV. Tests can explore antigens covering the surface, envelope, and core of the virus, as well as screen for antibodies associated with these antigens. Due to similarities in symptoms among the five hepatitis infections, these blood assessments are typically performed in conjunction with other hepatitis tests to ascertain the specific virus type and stage of your infection.
A hepatitis B monitoring panel may also be ordered by your healthcare provider to evaluate whether your infection is improving.
What do my test results mean?
Your test results can fluctuate based on various factors like age, gender, and your health history. Variations in results may also be influenced by the specific laboratory conducting the test. Always consult your healthcare provider for the specific implications of your results.
A normal result indicates negative or nonreactive findings, suggesting no hepatitis B surface antigen was detected.
If your test comes back as positive or reactive, it likely signifies an active HBV infection. Typically, most individuals recover within six months. Upon recovery, individuals develop immunity against the virus and cannot transmit it to others. Conversely, a positive test result could also indicate a chronic hepatitis B infection. If recovery does not occur within six months, the virus could persist, leading to potential liver complications and transmissibility to others. Your healthcare provider might consider prescribing medication if improvement is not seen within six months.
How is this test done?
The test requires a blood sample drawn from a vein in your arm or hand using a needle.
Does this test pose any risks?
As with any blood drawing procedure, risks exist, including bleeding, infection, bruising, or lightheadedness. You may experience mild pain or a sting when the needle is introduced, and some soreness may occur at the site afterward.
What might affect my test results?
Other external factors are unlikely to influence your results.
How do I get ready for this test?
No specific preparations are needed prior to this test. Ensure that your healthcare provider is informed of all medications, herbs, vitamins, and supplements you are using, including over-the-counter medicines and any illegal substances.
For more information about the urine microalbumin test, please reach out to us for professional guidance.