Hepatitis B Core Ab, IgM

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Hepatitis B tests may be used for a variety of reasons. Some of the tests detect antibodies produced in response to HBV infection; some detect antigens produced by the virus, and others detect viral DNA.
Generally, one set of tests is used to determine the cause of acute symptoms while another set of tests may be used after a diagnosis is made, to monitor possible progression of the disorder, to detect chronic infection and/or carrier status.
The items below list the main uses for HBV tests:
·To detect acute hepatitis B infection: hepatitis B surface antigen (HBsAg), hepatitis B core antibody (anti-HBc), IgM and sometimes hepatitis B e antigen (HBeAg)  
·To diagnose chronic HBV hepatitis: HBsAg, hepatitis B virus (HBV) DNA, and sometimes HBeAg  
·To monitor chronic hepatitis B infection and its treatment: HBsAg, hepatitis B e antigen (HBeAg), hepatitis B surface antibody (anti-HBs) IgG, hepatitis B e antibody (anti-HBe) IgG and HBV DNA  
·To detect previous exposure to hepatitis B, in a person who is immune compromised (when the virus can become reactivated): hepatitis B core antibody (anti-HBc) total and anti-HBs  
Some of the secondary reasons to perform testing include: to screen for hepatitis B infection in at-risk populations or in blood donors, to determine if someone is a carrier, to detect previous infection (with subsequent immunity), and to determine if immunity has developed due to vaccination.
Some of the tests used to screen for infection may be performed as part of an acute viral hepatitis panel in conjunction with tests for other hepatitis viruses, including hepatitis A (HAV) or hepatitis C (HCV).
The following table summarizes the various hepatitis B tests and their uses:
Test
Description
Use

Hepatitis B surface antigen (HBsAG)
Protein that is present on the surface of the virus; will be present in the blood with acute and chronic HBV infections
Often used to screen for and detect HBV infections; earliest indicator of acute hepatitis B and frequently identifies infected people before symptoms appear; undetectable in the blood during the recovery period; it is the primary way of identifying those with chronic infections.

Hepatitis B surface antibody (anti-HBs)
Antibody produced in response to HBV surface antigen; levels in the blood rise during the recovery phase.
Used to detect previous exposure to HBV; can also be acquired from successful vaccination. This test is done to determine the need for vaccination (if anti-HBs is absent) or to determine if a person has recovered from an infections and is immune (cannot get the infection again).

Anti-hepatitis B core (anti-HBc), IgM
IgM antibody to the hepatitis B core antigen (The hepatitis B core antigen is present only in infected liver cells; it cannot be detected in the blood.)
First antibody produced after infection with HBV; used to detect acute infection

Anti-hepatitis B core (anti-HBc), Total
Both IgM and IgG antibodies to hepatitis B core antigen
Can be used to help detect acute and chronic HBV infections; it is produced in response to the core antigen and usually persists for life.

Hepatitis B e-antigen (HBeAG)
Protein produced and released into the blood by actively replicating hepatitis B virus
Unlike the surface antigen, the e-antigen is found in the blood only when the HBV virus is actively replicating. HBeAg is often used as a marker of ability to spread the virus to other people (infectivity). It may also be used to monitor the effectiveness of treatment. However, there are some types (strains) of HBV that do not make e-antigen; these are especially common in the Middle East and Asia. In areas where these strains of HBV are common, testing for HBeAg is not very useful.

Anti-hepatitis Be antibody (Anti-HBe)
Antibody produced in response to the hepatitis Be antigen
In those who have recovered from acute hepatitis B infection, anti-HBe will be present along with anti-HBc and anti-HBs. In those with chronic hepatitis B, anti-HBe can be used to monitor the infection and treatment.

Hepatitis B DNA (HBV DNA)
Detects hepatitis B viral genetic material
Can detect an active HBV infection; its primary use is to monitor antiviral therapy in patients with chronic HBV infections.

   
While the tests described above are specific for HBV, other liver tests such as AST, ALT, and gamma-glutamyl transferase (GGT) may be used to monitor the progress of the disorder. In some cases, a liver biopsy may be performed for confirmation.

Hepatitis B tests may be ordered when someone has signs and symptoms associated with acute hepatitis to determine if they are due to infection with HBV. Some of these include:
·Fever  
·Fatigue  
·Loss of appetite  
·Nausea, vomiting  
·Abdominal pain  
·Dark urine  
·Pale stools  
·Joint pain  
·Jaundice  
Hepatitis B tests may be done as follow up when routine tests results such as ALT and/or AST are elevated. Sometimes acute forms of hepatitis may be detected this way since they may cause only mild symptoms that can be confused with the flu. Chronic hepatitis more often has no symptoms and is more commonly detected when routine test results are abnormal.
A test for hepatitis B surface antigen (HBsAg) may be used for screening when someone falls into one of the high-risk categories for chronic hepatitis B. In September 2008, the CDC revised it guidelines and recommends the following groups be tested for HBsAg:
·People who are possible source of infection through accidental cuts, needlesticks, etc. in health care workers  
·People born in areas of the world that have a greater than 2% prevalence of HbsAg (for example, much of Asia and Africa)  
·People born in the US but were not vaccinated and whose parents are from an area with greater than 8% prevalence of HbsAg  
·Men who have sex with men  
·People who have elevated liver enzymes (ALT and AST) with no known cause  
·People with certain medical conditions that require that their immune system be suppressed  
·Pregnant women  
·People who are in close contact with someone infected with HBV  
·Those infected with HIV  
In addition, some states in the US recommend that people who are in contact with the public and who are a possible source of infection through accidental cuts, scrapes, etc. be screened.
When hepatitis B tests are used to monitor people with chronic hepatitis B infections, they may be performed on a regular basis. Hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) are usually measured about every 6 months to a year, since in some people HBeAg (and, less commonly, HBsAg) will go away on their own. In those who are being treated for chronic HBV, HBeAg and HBV DNA can be used to determine whether the treatment is successful. HBV DNA will fall, usually to undetectable levels, with successful treatment. If HBeAg was positive before treatment and becomes negative, then treatment may sometimes be stopped after a further period of treatment, and both it and HBV DNA may remain undetectable. If HBeAg was negative before treatment or remains positive, then treatment is usually continued.
All donated blood is tested for the presence of the HBsAg before being distributed for transfusion.

Test results
The tests for hepatitis B may be ordered individually, but are often ordered in some combination depending on the reason for testing. Results of the tests are typically evaluated together. Sometimes the meaning of one result depends on the result of another test. However, not all tests are done on all people. Ask you doctor what she expects to find out from the results of your tests. She can help you understand what the results mean.
The table below summarizes possible interpretations of some common patterns of results.
Hep B surface antigen (HBsAg)
Hep B surface antibody (Anti-HBs)
Hep B core antibody (Anti-HBc IgM)
Hep B core antibody Total (Anti-HBc IgG+IgM)
Hep B e antigen (HBeAg)*See note
Hep B e antibody (Anti-HBe)
Interpretation / Stage of Infection

Negative
Negative

Negative


No active or prior infection; not immune — may be good candidate for vaccine; possibly in the incubation stage

Positive
Negative
Negative
Negative
Positive
Negative
Early acute infection

Positive
Negative
Positive or Negative
Positive or Negative
Positive
Negative
Acute infection, usually with symptoms; contagious

Positive
Negative
Positive
Positive
Negative*
Positive
Late in the acute stage of infection (seroconversion)

Negative
Negative
Positive
Positive
Negative*
Positive
Acute infection is resolving (convalescent)

Positive
Negative
Negative
Positive
Positive
Negative
Usually indicates an active chronic infection (liver damage likely)

Positive
Negative
Negative
Positive
Negative*
Positive
Chronic infection but low risk of liver damage — carrier state

Negative
Positive
Negative
Positive
Negative*
Positive
Infection resolved (recovery); immunity due to natural infection

Negative
Positive

Negative


Immunity due to vaccination



Hepatitis B viral (HBV) DNA: This test measures the amount of virus present in the blood, so results are reported as numbers, specifically, as "international units per milliliter." A high result usually means that the virus is actively replicating and that the infection can be passed to others. It also indicates that the person has a high risk of having liver damage.
A low result or one that is reported as below a lower limit (for example, 100 international units/milliliter) means the virus is not present or is present in such low numbers that it cannot be detected. This usually means that the infection cannot be spread to others. If the test is used to monitor treatment, a low result usually indicates the therapy is effective.

Also you should know
Even if you don't have symptoms, an HBV infection can damage your liver and you can spread the infection to others. For this reason, it is important to get tested if you think you have been exposed to HBV.
Hepatitis D (HDV) is another virus that can cause liver infections, but only if hepatits B is also present. A person may become infected with both viruses at the same time (a co-infection) or may first be infected with hepatitis B and then become infected with HDV (a superinfection). In the U.S., the incidence of HDV is low. There is no vaccine for HDV, but since it causes infections only in the presence of HBV, it may be prevented with the HBV vaccine.

Unless there is something in your medical history to the contrary, it is prudent to get the series of vaccinations. Babies, children and adolescents are routinely given the series of shots. The Centers for disorder Control and Prevention recommends that adults in high risk groups get vaccinated. Some of these groups include those in close contact with someone who has hepatitis B, dialysis patients, people with chronic liver or kidney disorder, people with HIV or who seek treatment for other sexually transmitted disorders or drug treatment, and those who travel to countries where hepatitis B is common.

There is no specific treatment for acute hepatitis B infections. Symptoms are usually treated with supportive care. This usually involves making sure that you are getting plenty of rest and enough fluids and nutrition by eating and drinking small amounts several times a day.
Chronic forms of hepatitis B may be treated with antiviral medications such as interferon, entecavir, tenofovir, lamivudine, and adefovir. However, some antiviral drugs can have serious side effects and not all people need to be treated. Often, people with chronic hepatitis will be closely monitored to see if they develop cirrhosis or liver cancer. It is important to talk to your doctor about your treatment options and the risks and benefits of those currently available.



 
 
 
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All information on this page is intended for your general knowledge only and does not provide medical advice, diagnosis or treatment.