Viral Hepatitis

Question 1

What characterises Cirrhosis

What is a common complication?

Answer 1

Fibrosis (collagenous scars) and regenerative nodules (attempts at repair)
Ascites (fluid retention in abdominal cavity)

Question 2

Which are enveloped and naked and what difference does this make?

Answer 2

Naked - A&E - acute

enveloped - BCD,G - chronic and persistent

Question 3

What type of genome does each type of hepatitis have?

Answer 3

A - ss+RNA (4)
B - dsDNA (7)
C - ss+RNA (4)
D - ss-RNA (5)
E - ss+RNA (4)

Question 4

Hepatitis A

1) What can it result in?
2) How is it spread
3) Relevance of HAV infection?

Answer 4

1) Fulminant hepatitis and death
2) oral-foetal route, poor hygiene
3) induces lifelong protection, don’t get it twice

Question 5

Hepatitis B

1) How long is it in the body?
2) What can it cause?
3) How is it transmitted?

Answer 5

1) 1-3 months
2) liver disease, cirrhosis, liver cancer
3) STI, blood-to-blood contact, perinatal transmission

Question 6

Hepatitis C

1) How is it transmitted?
2) What shape is it?
3) How man genotypes is there?
4) What is the current treatment?
5) How do boceprevir and telaprevir work
6) How does sofosbuvir

Answer 6

1) Blood-to-blood contact or other bodily fluids
2) two virus-encoded membrane proteins (E1/E2) in addition to capsid protein
3) 11 different genotypes
4) Ribavirin, oral nucleoside analogue and pegylated IFN alpha. Teratogenic. HCV genotype affects treatment, 2/3 3X times more likely to respond
5) Target HCV protease (genotype 1)
6) HCV polymerase, genotypes 2/3 with ribavirin

Question 7

Hepatitis D

1) What is it?
2) What is the role of the delta antigen

Answer 7

1) Defective satellite virus, requires co-infection with HBV, provides antigens needed for cell attachment and infection.
2) stabilises RNA genome, uses hepatitis B surface antigen as its own virion coat

Question 8

What is the difference between passive and active immunisation?

Answer 8

Passive - injection of pathogen-specific pooled human immunoglobulins
Active - post-exposure prophylaxis

Question 9

What are live attenuated vaccines?

Answer 9

grown in culture, viruses with low virulence selected and then reproduced in large quantities.
Immune response similar to natural but doesn’t cause full illness.

Question 10

What are inactivated vaccines?

Answer 10

Cultured and inactivated with formaldehyde, fewer side effects than live but immune response is less vigorous

Question 11

What are subunit vaccines?

Answer 11

surface antigens produced by recombinant DNA technologies, can be given as a single protein by itself but may contain 20+. Pathogen not present so safest approach, no risk to immunocompromised patients but weaker protection.

Question 12

HepA vaccine

1) What does it protect against
2) What does it consist of

Answer 12

1) protects against all 7 strains

2) inactivated whole virus propagated in MRC-5 human lung fibroblast cell line

Question 13

Name the 3 types of HAV vaccine

Answer 13

Monovalent - protects against HepA
Combined A&B
Combine A&Typhoid

Question 14

1) What is the HBV vaccine made of?

2) How many doses?

Answer 14

1) subunit vaccine consisting of surface antigen absorbed into aluminium hydroxide, made from yeast cells
2) 3 doses with or without 4th booster