Hep B Test

The Hep B Test test contains 1 test with 2 biomarkers .

Brief Description: The Hep B test is a blood test used to detect the presence of the hepatitis B surface antigen (HBsAg) in the bloodstream. HBsAg is a protein found on the surface of the hepatitis B virus (HBV), and its presence indicates an active HBV infection. If the initial test for HBsAg is positive, the test automatically reflexes to a confirmatory test to rule out false positives and ensure accurate results. This two-step process is critical for diagnosing hepatitis B infection and determining the appropriate course of action.

Also Known As: Hep B Test, HBsAg Test, Hepatitis B Antigen Test, HBV Test, HBV Surface Antigen Test

Testing Method: Immunoassay

Collection Method: Blood Draw 
Specimen: 1 mL Serum 

Test Preparation: No preparation required

When is a Hepatitis B Surface Antigen test ordered?

The Hep B test is typically ordered when a healthcare provider suspects a patient may have been exposed to the hepatitis B virus. This suspicion may arise due to risk factors such as unprotected sex, sharing needles, or exposure to contaminated blood. The test is also commonly ordered as part of routine screening for individuals at higher risk of HBV infection, including healthcare workers, people with multiple sexual partners, and those born in regions where hepatitis B is prevalent. Additionally, the test may be ordered for pregnant individuals to prevent mother-to-child transmission of the virus. It is also used to monitor individuals with chronic hepatitis B or those undergoing treatment for the infection.

What does a Hepatitis B Surface Antigen blood test check for?

The Hep B test checks for the presence of the hepatitis B surface antigen (HBsAg) in the blood. HBsAg is the earliest marker of an active HBV infection and can be detected as early as 1 to 9 weeks after exposure to the virus. If the initial HBsAg test is positive, the reflex confirmation step is performed to validate the result and rule out false positives. This confirmatory step is essential for ensuring the accuracy of the diagnosis, as false positives can occur due to laboratory errors or other medical conditions.

Sample Ulta Lab Tests View of Hep B Test Results

Sample Quest Result Report View of Hep B Test Results

Lab tests often ordered with a a Hepatitis B Surface Antigen test:

When an HBsAg test is ordered, it's typically part of a broader evaluation for hepatitis B infection and liver health. Here are some tests commonly ordered alongside it:

1. Hepatitis B Core Antibody (Anti-HBc):

   • Purpose: To detect antibodies produced in response to a component of the HBV core.
   • Why Is It Ordered: Anti-HBc helps distinguish between acute and chronic HBV infection and can indicate previous exposure to the virus.

2. Hepatitis B Surface Antibody (Anti-HBs):

   • Purpose: To check for immunity to HBV, either from vaccination or past infection.
   • Why Is It Ordered: To determine if an individual is immune to HBV, either through recovery from past infection or successful vaccination.

3. Hepatitis Be Antigen (HBeAg) and Hepatitis Be Antibody (Anti-HBe):

   • Purpose: To assess the infectivity and stage of HBV infection.
   • Why Is It Ordered: HBeAg generally indicates high levels of viral replication and infectivity, while Anti-HBe can indicate lower levels of virus and reduced infectivity.

4. Liver Function Test:

   • Purpose: To assess liver health and function.
   • Why Is It Ordered: HBV can cause liver inflammation and damage. These tests help evaluate the extent of liver damage.

5. Complete Blood Count (CBC):

   • Purpose: Provides a broad picture of overall blood health.
   • Why Is It Ordered: To detect signs of anemia, infection, or other blood cell abnormalities, which can occur in chronic liver disease.

6. Prothrombin Time (PT/INR):

   • Purpose: To assess blood clotting function.
   • Why Is It Ordered: Liver damage can affect the production of clotting factors, making this test important for evaluating liver function.

7. Alpha-Fetoprotein (AFP):

   • Purpose: To screen for liver cancer.
   • Why Is It Ordered: Chronic HBV infection increases the risk of developing liver cancer, and AFP is a tumor marker used in screening.

These tests, when ordered alongside a Hepatitis B Surface Antigen with Reflex Confirmation test, provide a comprehensive view of hepatitis B infection status and liver health. They are crucial for confirming the diagnosis, assessing the severity of liver disease, evaluating the risk of transmission, and planning appropriate treatment. The specific combination of tests will depend on the individual’s risk factors, symptoms, and the results of initial screenings.

Conditions where a Hepatitis B Surface Antigen test is recommended:

The Hep B test may be recommended in several situations. For individuals with symptoms of hepatitis B, such as fatigue, jaundice, dark urine, or abdominal pain, the test can help confirm the diagnosis. It is also recommended for people with known risk factors, such as a history of intravenous drug use, unprotected sex, or exposure to contaminated blood or needles. Pregnant individuals are often screened for hepatitis B to prevent transmission to the baby during childbirth. Additionally, the test is used to monitor individuals with chronic hepatitis B or those undergoing treatment to assess the effectiveness of therapy and detect any changes in their condition.

How does my health care provider use a Hepatitis B Antigen test?

A healthcare provider uses the results of the Hep B test to diagnose hepatitis B infection, determine the need for treatment, and monitor the progression of the disease. A positive HBsAg result, confirmed by the reflex test, indicates an active HBV infection. In this case, the provider may order additional tests, such as hepatitis B e antigen (HBeAg) or HBV DNA, to assess the severity of the infection and guide treatment decisions. For pregnant individuals, a positive result prompts interventions to prevent mother-to-child transmission, such as administering the hepatitis B vaccine and hepatitis B immune globulin (HBIG) to the newborn. A negative HBsAg result indicates no active infection, though further testing may be needed to rule out past exposure or immunity.

What do my Hepatitis B Surface antigen test results mean?

The results of the Hep B test can have several interpretations. A positive HBsAg result, confirmed by the reflex test, indicates an active hepatitis B infection. This result requires further evaluation to determine whether the infection is acute or chronic and to assess the need for treatment. A negative HBsAg result suggests no active infection, though it does not rule out past exposure or immunity. In some cases, individuals may have resolved a past infection and developed antibodies, which can be detected through additional testing. For individuals undergoing treatment, a negative HBsAg result after therapy may indicate successful clearance of the virus, though ongoing monitoring is necessary to ensure the infection does not recur.