Viral hepatitis I

Question 1

What is hepatitis and what causes it?

Answer 1

hepatitis = inflammation of the liver

causes:
- toxins and chemicals (e.g. alcohol)
- autoimmune diseases
- fat
- viruses

Question 2

What is the main laboratory test for hepatitis?

Answer 2

looking for elevated liver enzymes - ALT

Question 3

why is chronic hepatitis a problem?

Answer 3

• very common
• often without symptoms until late in the disease when the patient is developing cirrhosis or liver cancer

Question 4

Describe the morphology of HAV

Answer 4

• +ssRNA
• picornaviridae; hepatovirus
• nonenveloped

Question 5

What is HAV route of transmisson?

Answer 5

• fecal-oral
• contamination of food
• poor hygiene
• inadequate sewer treatment

Question 6

What is the clinical course of HAV?

Answer 6

• subclinical or acute
• short duration
• elevated ALT
• rarely causes chronic disease

Question 7

What are some HAV prevention techniques?

Answer 7

• good hygiene
• passive immunity
• vaccine
• no antiviral agents

Question 8

Describe the morpholgy of HBV

Answer 8

• partially dsDNA
• hepadnavirus family
• subviral particles –> sausage shaped
• dane particles -> donut shaped

Question 9

Describe HBV genes

Answer 9

• HBsAg (S, M, L) - surface
• HBcAg - capsid
• viral pol
• x protein

Question 10

Describe HBV lifecycle

Answer 10

entry –> uncoating –> repair DNA –> cccDNA (responsible for persistance) –> integration –> ts –> tl –> assembly –> exit

Question 11

What is the mortality rate trend of hepatitis?

Answer 11

deaths are continuing to rise!

Question 12

What is HBV’s route of transmisson?

Answer 12

1. horizontal
   - blood
   - IV drug use
   - sexual transmisson
2. vertical

Question 13

Are females or males more at risk of developing liver death from HBV?

Answer 13

males

Question 14

When are you most susceptible to becoming an HBV chronic carrier, how does this change with age?

Answer 14

• most susceptible at birth
• as you age youre less likely to become chronic carrier after being infected

Question 15

What are the consequences of HBV for chronic carriers

Answer 15

1. asymptomatic
2. cirrhosis
3. hepatoma

Question 16

What are the top two leading causes of liver disease?

Answer 16

1. smoking
2. HBV

Question 17

What is the major cause of HCC worldwide?

Answer 17

HBV

Question 18

What is the serological response to infection with HBV: acute and chronic?

Answer 18

acute:
- HBsAg appears
- peaks over several weeks
- disappears with the appearnace of HBsAb

chronic:
- HBsAg appears and remains
- do not have detectable HBsAb in serum

Question 19

What are the vaccine strategies for HBV

Answer 19

1. pre-exposure - select high risk groups
2. post-exposre - needle accidnts, sexual exposure, babies born to HBV
3. universal immunization - best

Question 20

How does HBV vaccination affect the incidience of HCC?

Answer 20

universal HBV vaccination significantly decreases HCC incidence

Question 21

What’s a big problem for the development of antiviral therapy for HBV?

Answer 21

development of an animal model - duck model was eventually used

Question 22

What nuceloside analog works well for HBV, which one doesn’t work? How does it work?

Answer 22

works = ddG –> prevents proofreading
doesn’t work = ddC

Question 23

What was the first oral antivrial for HBV, what did it cause?

Answer 23

first antiviral = Lamivudine

• decreases HBV load in serum
• regresses HBV cirrhosis
• re-opened the possibility of liver transplants
• developed antiviral resistance

Question 24

What antivirals are used for HBV today? Why?

Answer 24

tenofovir and entecavir - potent and have very low rates of resistance

Question 25

Are antivirals for HBV a cure? Why or why not?

Answer 25

no - they do not target cccDNA