Viral Hepatitis Flashcards
Most common cause of acute hepatitis?
Hepatitis A virus
Why has Hepatitis A decreased in the US?
Because of vaccination
When is the Hepatitis A virus considered clincally active?
When serum transaminases rise
What are the serious sequelae of Hepatitis B infection?
Acute and Chronic Liver Disease
What morphology is observed on EM of Hepatitis B virus?
HBsAg is observed as rodlike and spherical particles, and Dane particles (the virus)
What gene is likely responsible for the role in the pathogenesis of hepatocellular carcinoma?
X gene
What has contributed to the decreased amount of HBV carriers?
HBV vaccine
What fluids are the infectious HBV particles found in?
Infectious particles are found in blood, saliva, semen
What do the vaccines for HBV contain?
Recombinant HBsAg or immunogenic epitopes of HBsAg
What causes most of the damage that occurs in HBV infections?
CD8 response to HBV epitopes on infected hepatocytes
Three general courses of HBV infection?
- Acute hepatitis
- Fulminant hepatitis
- Chronic hepatitis
First marker that appears in serum of patients with acute hepatitis B?
HBsAg
What is the typical progression of a patient infected with HBV?
Increase in HBs and HBe Ag followed by a brief stint of Syx and then Anti-HBc/Anti-HBs w/o incorporation of viral genome into hepatocytes
What are the typical Syx and lab findings that suggest an active HBV infection?
Increase and persistence of Syx, HBs and HBe Ag and increase in Anti-HBC. The virus persists in the nucleus but is not integrated into the DNA host
What are the typical findings in an asymptomatic HBV carrier?
Few if any Syx, Increase in HBsAg, increase then decrease in HBeAg and Increase and persistence in Anti-HBc; HBV DNA is integrated into the hepatocyte DNA
When in the course of acute hepatitis B does HBcAg circulate?
It doesn’t
What does serum HBeAg correlate with?
Period of intense viral replication and hence, maximal infectivity of the patient
What occurs in fulminant hepatitis B?
Massive liver necrosis, hepatic failure, and high mortality
How is chronic HBV Dx?
Continued necrosis and inflammation in the liver for more than 6 months
What are the three phases of HBV?
- Immune tolerant phase
- Immune active phase
- Inactive phase
What are the characteristics of the immune tolerant phase?
HBeAg positive and very high HBV DNA levels
Characteristics of the immune active phase of HBV?
HBV viremia and liver cell necrosis (ALT and AST increase)
What are the characteristics of the inactive phase of chronic HBV?
Anti-HBe is seen but HBeAg is not; HBV DNA is very low
What vasculitis is associated with HBV?
Polarteritis nodosa
What does HDV require for infection?
HBsAg and therefore HBV infection
What is the progression of hepatitis if HDV is superimposed on HBV?
Typical increase in severity of existing chronic hepatitis
What is the cause of cell death in HCV?
Liver cell injury has been attributed to cytotoxic T-cell responses to virus-infected hepatocytes
What are the levels in a self-resolving and chronic hepatitis C infection of ANTI-HCV?
ANTI-HCV remains high for both types of infection
Describe the clinical course of chronic HCV?
Intial large symptomatic disease followed by cyclic waxing and waning of Syx at a lower level
What is an even worse sequela following cirrhosis?
Hepatocellular carcinoma
Most commonly encountered extrahepatic manifestations of HCV?
Mixed cryoglobulinemia
Of the hepatitis viruses, which has the highest rate of chronic hepatitis?
Hep C
Which of the Hep viruses is orally transmitted?
Hep A - fecal-oral route
Which Hep virus does not evolve into liver cancer?
Hep A
How is HEV transmitted?
Vertical, parenteral, waterborne, zoonotic
