Friday, February 10, 2012

Interpretation of Hepatitis B Serologic Test Results

Hepatitis B serologic testing involves measurement of several hepatitis B
virus (HBV)-specifi c antigens and antibodies. Different serologic “markers”
or combinations of markers are used to identify different phases of HBV
infection and to determine whether a patient has acute or chronic HBV
infection, is immune to HBV as a result of prior infection or vaccination, or
is susceptible to infection.
Hepatitis B surface antigen (HBsAg):
A protein on the surface of hepatitis B virus; it can be detected in high levels in serum during acute or chronic hepatitis B virus 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. HBsAg is the antigen used to make hepatitis B vaccine.

Hepatitis B surface antibody (anti-HBs):
The presence of anti-HBs is generally interpreted as indicating recovery and immunity from hepatitis B virus 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 and persists for life. The presence of
anti-HBc indicates previous or ongoing infection with hepatitis B virus in an undefined time frame

IgM antibody to hepatitis B core antigen (IgM anti-HBc):
Positivity indicates recent infection with hepatitis B virus (<6 mos). Its presence indicates acute infection.
Tests Results Interpretation


Susceptible
HBsAg negative
anti-HBc negative
anti-HBs negative

Immune due to natural infection
HBsAg negative
anti-HBc positive
anti-HBs positive

Immune due to hepatitis B vaccination
HBsAg negative
anti-HBc negative
anti-HBs positive

Acutely infected

HBsAg positive
anti-HBc positive
IgM anti-HBc positive
anti-HBs negative

Chronically infected
HBsAg positive
anti-HBc positive
IgM anti-HBc negative
anti-HBs negative

Interpretation unclear; four possibilities:
1. Resolved infection (most common)
2. False-positive anti-HBc, thus susceptible
3. “Low level” chronic infection
4. Resolving acute infection

anti-HBs negative
HBsAg negative
anti-HBc positive
Adapted from: A Comprehensive Immunization Strategy to Eliminate Transmission of Hepatitis B
Virus Infection in the United States: Recommendations of the Advisory Committee on Immunization
Practices. Part I: Immunization of Infants, Children, and Adolescents. MMWR 2005;54(No. RR-16


Courtesy: http://www.cdc.gov/hepatitis/HBV/PDFs/SerologicChartv8.pdf

No comments:

Post a Comment