e. Anti-HBc. Measures total antibody (IgM and IgG) to hepatitis B core antigen.
It is a lifelong marker and acts as an indicator of current or previous hepatitis B
infection. It does not appear to be associated with recovery from or immunity to
f. Anti-HBs. This immunological marker does not appear during the acute
phase of the disease, but rather during convalescence. Anti-HBs is not detectable in
the serum until HBsAg has disappeared and therefore acts as an indicator of recovery
and immunity. The "window period" is the gap of time between the disappearance of
the surface antigen and the appearance of anti-HBs. This antibody is the major
protective antibody against the virus and results from either past exposure to the virus
or as the result of successful vaccination.
7-22. TYPES OF HEPATITIS B VIRUS INFECTIONS
Hepatitis B infections may present themselves in a number of ways. The severity
and course of the infection depends upon several factors to include initial dose of virus,
immunocompetency of the host, and overall health of the individual prior to infection.
a. Asymptomatic Infection. The asymptomatic infection is the most frequent
response. In this case, the patient's symptoms are so mild that the patient is unaware
of the infection or considers the illness as minor. Anti-HBs and anti-HBc levels are
detectable and lasting immunity results.
b. Acute Infection. The period of acute infection usually lasts one to six
months. The symptoms may be mild to quite severe. The infection is considered
resolved with the production of anti-HBs.
c. Chronic Carrier Infection. The classic definition of chronic hepatitis is a
person who exhibits HBsAg positivity and/or elevated liver enzymes for more than six
months. It can last as little as one year or as long as several decades. Chronic HBV
can be mild or quite severe. Two classifications of chronic hepatitis B exist: chronic
persistent hepatitis (CPH) and chronic active hepatitis (CAH). Chronic persistent
hepatitis is a nonprogressive benign condition that is characterized by fluctuating low
enzyme levels, mild liver changes, and occasional mild symptoms and physical findings.
Chronic active hepatitis usually results in liver degeneration that can progress to
cirrhosis and possible liver cancer.
d. Fulminant Infection. One to three percent of acute HBV infections progress
to this stage. The diagnosis of fulminant hepatitis is reserved for patients with signs and
symptoms of liver failure during the course of acute hepatitis. Serum bilirubin and liver
enzymes are extremely high and immunological markers are similar to those in typical
acute hepatitis. Death usually results from the destruction of at least 90 percent of the body's