UW Hepatitis B Flashcards
what two phases HBV goes through?
the proliferative phase and the integrative phase
The entire virion and all related antigens of the episomal HBV DNA are present?
proliferative phase
What happens in proliferative phase?
The entire virion and all related antigens of the episomal HBV DNA are present.
Where are expressed HBsAg and HBcAg?
on the hepatocyte cell surface
HBsAg and HBcAg are in conjunction with what?
with the MHC class I molecules
viral HBsAg and HBcAg + MCH I –> activation of what?
This expression serves to activate the cytotoxic CD8+ T lymphocytes, which respond by destroying the infected hepatocytes.
Note that the virion itself does not have a cytopathic effect.
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The HBV DNA is incorporated into the host genome of those hepatocytes that survived the immune response?
integrative phase
what happens in integrative phase?
The HBV DNA is incorporated into the host genome of those hepatocytes that survived the immune response
When infectivity ceases and liver damage tapers off?
when the antiviral antibodies appear and viral replication stops.
why the risk of hepatocellular carcinoma, however, remains elevated despite antibodies?
The risk of hepatocellular carcinoma, however, remains elevated because of the HBV DNA that has been integrated into the host genome
NOTE THAT THE VIRION ITSELF DOES NOT HAVE A CYTOPATHIC EFFECT.
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HBV cytotoxic effect?
Hepatitis B virus has no direct cytotoxic effect.
How host antibody HBsAb neutralizes HBV infectivity?
by binding to the viral surface antigen HBsAg and preventing the antigen from interacting with hepatocyte receptors.
Host antibody HBsAb neutralizes HBV infectivity. relation of this neutralization to carcinoma?
THIS NEUTRALIZATION OCCURS BEFORE THE VIRUS ENTERS THE HEPATOCYTE, AND THEREFORE WOULD NOT BE ASSOCIATED WITH HEPATOCELLULAR DAMAGE
Antigen-antibody complexes in HBV infection. What manifestation?
Antigen-antibody complexes cause some of the early symptoms of hepatitis B virus infection (eg, arthralgias, arthritis, and urticaria) as well as some of the chronic complications (eg, immune complex glomerulonephritis, cryoglobulinemia, vasculitis).
HBV causes III type hypersensitivity.
Antigen-antibody complexes in HBV infection. Relation to hepatocellular damage?
These complexes are not responsible for hepatocellular damage.
Pathogenesis of autoimmune hepatitis?
The pathogenesis of autoimmune hepatitis (not hepatitis B infection) involves antigen mimicry with generation of self-antigen recognizing CD4+ T lymphocytes that damage hepatocytes.
common causes of hepatic injury in the United States?
HBV infection
reason of HBV infection?
Frequently transmitted sexually or via percutaneous inoculation (eg, intravenous drug use)
A distinct histopathologic manifestation of chronic infection is the accumulation of what?
Accumulation of hepatitis B surface antigen within infected hepatocytes
accumulation of hepatitis B surface antigen results in what appearance?
This results in the appearance of a finely granular, homogeneous, pale eosinophilic cytoplasm (ground-glass hepatocytes).
how called hepatocytes that have accumulation of B surface antigens?
ground-glass hepatocytes.
Other nonspecific morphologic changes in livers infected with HBV?
Other nonspecific morphologic changes include hepatocyte necrosis, apoptosis, steatosis, and mononuclear portal inflammation (lymphocytes, macrophages
HBV hypersensitivity? manifestation?
type III. SERUM SICKNESS-LIKE.
joint pain, lymphadenopathy, and a pruritic urticarial vasculitis rash
transmission of HBV?
sexually, parenterally, or vertically.
type of HBV and incubation time?
Hepatitis B is a DNA virus with an incubation period of 30-180 days.
what is elevated in HBV hepatitis?
aspartate aminotransferase and alanine aminotransferase, often >10 times the upper limit of normal.
Most patients will have nonicteric hepatitis, but icteric hepatitis with jaundice and elevated bilirubin is also common.
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what impaired function of liver defines poor prognosis?
Impaired hepatic synthetic function, as indicated by a prolonged prothrombin time, confers a poor prognosis
The most important early marker of acute infection?
hepatitis B surface antigen (HBsAg),
when hepatitis B surface antigen (HBsAg) can be detected?
May be detectable prior to symptoms or changes in transaminase levels
in accordance to HBaAg what other marker can be detected?
IgM anti-hepatitis B core (anti-HBc) may also be positive.
what 2 markers correlate with infectivity?
Hepatitis B e antigen (HBeAg) and HBV DNA counts correlate with infectivity.
What other clinical manifestation apart from serum sickness symptoms may be present?
Other features may include right upper quadrant pain, hepatomegaly, and elevated hepatic transaminase levels
what apoptosis undergo hepatocytes?
hepatocytes may undergo cytotoxic T-cell-mediated apoptosis due to the presence of viral antigens on the hepatocyte surface.
where present viral antigens?
hepatocytes may undergo cytotoxic T-cell-mediated apoptosis due to the presence of viral antigens on the hepatocyte surface.
appearance of apoptotic cells?
round, acidophilic (pink on hematoxylin and eosin staining) bodies known as Councilman bodies.
what are concilman bodies?
apoptotic cells appear as round, acidophilic (pink on hematoxylin and eosin staining) bodies known as Councilman bodies.
how is defined inflammation in viral hepatocytes?
panlobular lymphocytic inflammation, which may “bridge” into adjacent hepatic lobules due to collapse of the reticulin framework.
how looks areas of hepatocyte injury?
Spotty areas of hepatocyte injury are typically seen.
appearance of necrotic hepatocytes?
Necrotic hepatocytes appear ballooned with pale cytoplasm (ballooning degeneration).
location of chronic viral hepatitis inflammation?
significant inflammation surrounding the portal triad (hepatic artery branch, portal vein branch, bile ductule)
appearance of hepatocytes in chronic B?
Hepatocytes usually have a ground-glass appearance (chronic hepatitis B virus)
