21.
Considering HBV immunological assays, the first marker to appear during an
acute HBV infection is hepatitis B s___e antigen (HBsAg). It can be detected in
the s___m of infected patients during the incubation period. The presence of
HBsAg in serum indicates the possible presence of ___ and the potential i_____s
state of that person. The presence of HBsAg beyond six months and the failure of
seroconversion to anti-HBs implies progression to the chronic c___r s___e.
The HBeAg marker appears shortly after HB__ and acts as an early indicator of
(acute) (chronic) infection. It indicates that the virus is actively r_____g and that
the individual is highly i_____s.
Seroconversion from HBeAg to anti-HBe should occur during the acute phase and
is prognostic for r_____n of the infection. The presence of anti-HBe is an indicator
of the patient's (increased) (reduced) infectious state. The failure to seroconvert to
anti-HBe and the continued presence of HBeAg beyond six months implies
progression to c____c c____r state.
Anti-HBc IgM is an IgM antibody produced in the i____l response to hepatitis B
core antigen. It is an early m____r of acute infection and is used to distinguish an
a_e HBV infection from a chronic c_r state. Anti-HBc IgM is also used to
distinguish hepatitis B from non-_, non-_ hepatitis.
Anti-HBc measures total antibody (IgM and IgG) to hepatitis B c__e antigen. It is a
l___g marker and acts as an indicator of current or p__s hepatitis B infection. It
does not appear to be associated with r___ry from or i____y to hepatitis B.
The immunological marker anti-HBs does not appear during the acute phase of
the disease but rather during c___ce. Ant-HBs is not detectable in the serum until
HBsAg has disappeared and therefore acts as an indicator of r__y and i___y. The
"window period" is the gap of time between the disappearance of the s____e
antigen and the appearance of anti-HBs. This antibody is the major pr___ve
antibody against the virus and results from either past exposure to the virus or as
the result of successful va_____n.
MD0838
7-18