Hepatitis b test, what should be considered? & bull; hello healthy

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Definition

What is the hepatitis b test?

Hepatitis B virus test is a blood test that is done to look for substances in the blood that indicate the presence of active hepatitis B virus (HBV) or have had a similar medical history. Tests are performed to find signs of infection (markers). Antigen is a marker made by bacteria or viruses. The presence of HBV antigen in the blood means that the virus is infecting the body. Antibodies are proteins that are produced by the body to fight infection. The presence of HBV antibodies means that you have had contact with the virus or a history of infection in the past. However, you may have been infected in the past and have recovered from the infection, or you may have recently caught an infection.

The genetic material (DNA) of HBV indicates the presence of the virus in the body. The amount of DNA can help determine how severe the infection is and how easily it spreads. It is important to identify the type of hepatitis virus that causes infection to prevent its spread as early as possible and choose the best therapy for you.

Tests used as follow-up after the initial test show HBV:

Anti-hepatitis B core (anti-HBc), IgM

• detects only IgM antibodies to hepatitis B core antigen
• used to detect acute infections; sometimes it is also present in chronic infections

Hepatitis B e-antigen (HBeAG)

• detects proteins that are produced and released into the blood
• often used as a marker of the ability to spread the virus to others (infectivity); Also used to monitor the effectiveness of therapy. However, there are several types (strains) of HBV that do not produce e-antigen; this is common in the Middle East and Asia. In areas where this type of HBV strain is common, HBeAg testing will be of no use to determine whether the virus is susceptible to spreading or not.

Anti-hepatitis B e antibody (Anti-HBe)

• detects antibodies produced by the body in response to the hepatitis B “e” antigen
• used to monitor acute infection in patients who have recovered from acute HBV infection; anti-HBe will coincide with anti-HBc and anti-HBs

Hepatitis B viral DNA

• detect HBV genetic material in the blood
• A positive test result indicates that the virus is multiplying in the body and an infected patient is susceptible to transmitting the infection. This test is often used to monitor the effectiveness of antiviral therapy in people with chronic HBV infection

Hepatitis B virus resistance mutations

• detect mutations in the virus that cause infection in a person that make the virus resistant to drugs (reverse transcriptase inhibitors)
• It helps to choose therapy that is deemed appropriate, especially in people who have previously been on therapy or who do not respond to therapy

When do I need to be tested for the hepatitis B virus?

Hepatitis B Virus test is done when doctors diagnose the appearance of signs and symptoms of acute hepatitis to determine if they are susceptible to infection

Precautions & warnings

What should I know before getting tested for hepatitis b?

Hepatitis D (HDV) is another virus that can cause liver infection, but only when accompanied by the presence of HBV. An individual can be infected with both viruses at the same time (co-infection) or first contract HBV followed by HDV (superinfection). In the US, the incidence of HDV is low. There is no vaccine for HDV, but because infection occurs only when HBV is present, infection can be prevented with the HBV vaccine.

Process

What should I do before getting tested for hepatitis b?

There is no special preparation ahead of the Hepatitis B Virus test, unless consulting your doctor.

How is the hepatitis b test process?

The medical personnel in charge of drawing your blood will take the following steps:

• wrap an elastic belt around your upper arm to stop blood flow. This makes the blood vessel under the bundle enlarge making it easier to insert the needle into the vessel
• clean the area to be injected with alcohol
• inject a needle into a vein. More than one needle may be required.
• Insert the tube into the syringe to fill it with blood
• untie the knot from your arm when enough blood is drawn
• sticking gauze or cotton on the injection site, after the injection is complete
• apply pressure to the area and then apply a bandage

What should I do after taking the hepatitis b test?

You won't feel anything from the injection, or you can feel a light sting like a pinch. You can return home and do normal activities as before after the blood test is over. Your doctor will call or schedule you about taking test results and discussions. Results are acceptable 5 - 7 days.

Explanation of the Test Results

What do my test results mean?

Initial Test	Follow-up	Possible interpretations / Infection Stage
Hep B surface antigen (HBsAg)	Hep B surface antibody (Anti-HBs)	Total Hep B core antibody (Anti-HBc IgG + IgM)	Hep B core antibody (Anti-HBc IgM)	Hep B e antigen (HBeAg) *	Hep B e antibody (Anti-HBe)	HBV DNA
Negative	Negative	Negative	Are not done	Are not done	Are not done	Are not done	Inactivity or a history of infection; not immune — a good candidate for receiving the vaccine; maybe in the incubation stage
Negative	Positive	Negative	Are not done	Are not done	Are not done	Are not done	Immune due to vaccines
Negative	Positive	Positive	Are not done	Are not done	Are not done	Are not done	Invisible infection (recovery stage), the virus has left the body; immunity due to natural infection. However, if immunosuppressed, the virus can reactivate
Positive	Negative	Positive or Negative	Positive or Negative	Positive	Negative	Detected or not detected	Acute infection, usually accompanied by symptoms; possible chronic spread of infection
Negative	Negative	Positive	Positive	Negative*	Positive	Not detected	Acute infection is recovering
Positive	Negative	Positive	Negative	Positive	Negative	Detected	Generally an indication of an active chronic infection (possible liver damage)
Positive	Negative	Positive	Negative	Negative*	Positive	Low levels or undetectable	Chronic infection with low risk of liver damage - carrier stage

* Note: There are several types of HBV strains that do not produce e-antigens. This is common in the Middle East and Asia. In areas where this type of HBV strain is common, HBeAg testing will be of no use to determine whether the virus is susceptible to spread or not. In this case, a negative HBeAg result does not necessarily indicate that the antigen is absent or that the individual is not susceptible to spreading infection; it is possible that the individual is infected with a viral strain that does not produce e-antigen.

Monitor chronic infection therapy

If the results of the initial and follow-up tests indicate that the individual has HBV, then the individual may be treated with drugs and their effectiveness can be monitored using tests for HBe antigen and HBV antibodies and DNA.

If HBeAg becomes negative and anti-HBe becomes positive during therapy, this usually indicates that the test is effective and that therapy can be stopped after an additional 6-12 months.

HBV DNA measurement will measure the amount of virus contained in the blood. A high yield means that the virus is actively reproducing and the therapy is considered ineffective. Low results or those that are reported to fall below the mean (undetectable) mean the virus is neither present in the blood nor present at levels so low that they cannot be detected. Generally this indicates that the therapy is effective.