Path Notes: Viral Hepatitis **

Question 1

What is the general frequency of each Hep virus (a-e) progressing to chronic hepatitis?

Answer 1

Hep A = Never
Hep B = 10%
Hep C = 80%
Hep D = 5% in co-infection (with B), up to 70% if super-infection (with B)
Hep E = Never

Question 2

What are some general features of the clinical course/presentation of Hep B?

Answer 2

1. Always check for vaccination status
2. Usually subclinical with recovery: 70%
3. Symptomatic Acute Hepatitis occurs in 30%. Of these, 99% will fully recover and <2% will recover, 30+% will be in carrier state, and 12-20% will develop cirrhosis
4. Of those who develop cirrhosis, 6-15% will develop hepatocellular carcinoma
5. Hep B is a backdrop for Hep D. If co-infected (at same time) with Hep D, the infection is virtually indistinguishable from HepB infection. If super-infected (e.g. from HepB carrier state), then severe acute hepatitis with progression to chronic hepatitis is more likely

Question 3

What are the general features of the clinical course/presentation of Hep C?

Answer 3

1. NO VACCINATION
2. Acute infection - generally asymptomatic with recovery - in 15%
3. Progression to chronic hepatitis in 85%. 20-30% of those will develop cirrhosis
4. Fulminant Hepatitis is rare

Question 4

Aside from the Hep viruses, what are some common causes of viral hepatitis?

Answer 4

1. Epstein Barr Virus (note, this causes 90% of Infectious mononucleosis aka glandular fever)
2. Cytomegalovirus (which is usually more prominent in immunosuppressed and newborns)
3. Yellow Fever (a flavivirus, endemic to tropical parts of Africa and South America, transmitted via mosquitoes)

Question 5

What are some typical characteristics of Acute VIral Hepatitis due to Hep B and Hep C?

Answer 5

Hep B = Ground Glass Hepatocytes

Hep B & Hep C = Lymphoid Aggregates within the Portal Tracts

Question 6

What are the general pathological Features associated with Acute Hepatitis (largely microscopic level)

Answer 6

1. Ballooning Degradation of hepatocytes - empty-looking hepatocyte cytoplasm, with only eosinophilic remnants of organelles
2. Cholestasis (bile duct obstruction) can sometimes occur
3. Macrophage Aggregates
4. Hepatocyte Necrosis or Apoptosis
5. Bridging Necrosis in severe cases
6. Kupffer cell hypertrophy and hyperplasia
7. Interface Hepatitis. Usually, there is mixed inflammatory cell infiltrate within the portal tracts. Interface Hepatitis when this infiltrate spills out into the surrounding parenchyma and causes damage to the hepatocytes

Question 7

What is the definition of Chronic Viral Hepatitis? (**)

Answer 7

Symptomatic, biochemical or serological evidence of infection that continues or relapses over a period >6 months

Question 8

What are the clinical signs/symptoms of Chronic Viral Hepatitis? (**)

Answer 8

1. Fatigue
2. Signs of liver disease
3. In some people, vasculitis and cryoglobulinaemia may occur due to HBV and HCV immune complex deposition

Question 9

What are the microscopic features of Chronic Viral Hepatitis? (**)

Answer 9

1. Significant (though mild-mod in spread) inflammation of portal tracts, with: lymphocytes, macrophages, occasional plasma cells, neutrophils or eosinophils
2. Lymphoid Aggregates
3. Bile Duct Damage
4. Mild-Moderate Steatosis
5. Bridging Necrosis
6. Progressive Liver Damage
7. Fibrosis (hallmark of irreversible damage). Starts off within portal tracts, then becomes peri-portal, then bridging fibrosis
8. *Continued loss of hepatocytes and increasing fibrosis = cirrhosis