REASON FOR TESTING OF HEPATITIS B

It is ordered in patient who has following symptoms: -

• Fever
• Fatigue
• Loss of appetite
• Nausea, vomiting
• Abdominal 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.

• 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, such as organ transplant recipients
• Pregnant women
• People who are in close contact with someone infected with HBV
• Those infected with HIV
• Healthcare and safety worker

WHAT IS BEING TESTED IN HEPATITIS B

Hepatitis B surface antigen (HBsAg): A protein on the surface of the hepatitis B virus (HBV); it can be detected in high levels in serum during acute or chronic HBV infection. The presence of HBsAg indicates that the person is infectious. The body normally produces antibodies to HBsAg as part of the normal immune response to infection.

Hepatitis B surface antibody (anti-HBs): The presence of anti-HBs is generally interpreted as indicating recovery and immunity from HBV infection. Anti-HBs also develops in a person who has been successfully vaccinated against hepatitis B.

Total hepatitis B core antibody (anti-HBc): Appears at the onset of symptoms in acute hepatitis B infection and persists for life. The presence of anti-HBc indicates previous or ongoing infection with HBV in an undefined time frame.

IgM antibody to hepatitis B core antigen (IgM anti-HBc): Positivity indicates recent infection with HBV (≤6 months). Its presence usually indicates acute infection.

Hepatitis B e antigen (HBeAg): A secreted product of the nucleocapsid gene of the hepatitis B virus that is found in serum during acute and chronic hepatitis B infection. Its presence indicates that the virus is replicating and the infected person has high levels of HBV.

Hepatitis B e antibody (HBeAb or anti-HBe): Produced by the immune system temporarily during acute HBV infection or consistently during or after a burst in viral replication. Spontaneous conversion from e antigen to e antibody (a change known as seroconversion) is a predictor of long-term clearance of HBV in patients undergoing antiviral therapy and indicates lower levels of HBV.

INTERPRETATION OF HEPATITIS B TEST RESULT

Test	Result	Typical interpretation
HBsAg anti- HBc anti- HBs	Negative Negative Negative	SUSCEPTIBLE
HBsAg anti- HBc anti- HBs	Negative Positive Positive	RESOLVED HBV INFECTION
HBsAg	Negative
anti- HBc anti- HBs	Negative Positive	VACCINATED
HBsAg anti- HBc IgM anti- HBc anti- HBs	Positive Positive Positive Negative	ACUTE HBV INFECTION
HBsAg anti- HBc IgM anti- HBc anti- HBs	Positive Positive Negative Negative	CHRONIC HBV INFECTION
HBsAg anti- HBc anti- HBs	Negative Positive negative	Various possibilities including distant resolved infection, recovering from acute HBV, false + or occult HBV

HEPATITIS B TEST REFERENCE INTERVAL

Not Applicable

HEPATITIS B RELATED TEST

HBV DNA VIRAL LOAD (QUANTITATIVE PCR) - provide information how rapidly the virus is multiplying in the Liver.

HBV GENOTYPING - done in chronic patients to plan therapy.