Lecture 41: Viral Heptatitis

Question 1

What sort of features of presentation can chronic hepatitis lead to?

Answer 1

Ascites, coagulation issues etc are features of chronic hepatitis, unusual for acute to do this.

Question 2

What can lead to hepatitis?

Answer 2

Drugs
Viral
Bacteria
Autoimmune
Ischeamic

Question 3

Describe the nature of different hepatitis virus:

Answer 3

HAV: Fecal-oral, Acute hepatitis (can become fulminant)
HBV: Blood, Acute, Chronic, Cirrhosis, Cancer
HCV: Blood, Acute, Chronic, Cirrhosis, Cancer

NB HAV, HBV, HCV are unrelated!!

Question 4

What proportion of hepatitis virus are asympatomatic?

Answer 4

HAV: 30%
HBV: 20-70% (newborns dont respond to it, assured chronic infection)
HCV: 80%

Question 5

Who likely get HCV?

Answer 5

IV drug users, (needs high viral load to infect)

Also fulminant hepatitis is rare outside of japan, unsure why.

Question 6

Whats the treatments for hepatitis virus?

Answer 6

HAV: None *but vaccine
HBV: Suppressive (vaccine too)
HCV: Curative, no vaccine

Question 7

Describe the Hep A virus:

Answer 7

Picornavirus

• Positive sense RNA, icosahedral caspid, non-envoloped

Question 8

Describe the Hep B virus:

Answer 8

• Partially double stranded
• DNA virus
• Enveloped

Importantly
- HEPAtotropic DNA virus
- Utilised reverse transcriptase (Drug target), also means its oncogenic b/c it puts its DNA into host.
- HepBsAG

Question 9

Whats useful with the HBSAG:

Answer 9

It is made int he ribosomes in large quantities and spills over into the blood (other proteins less so) therefore can be used to diagnose

Question 10

Write some notes on hepatitis C:

Answer 10

Flavivirus
- Positive sense RNA virus
- Spherical
- Enveloped

Question 11

How long does it take for Hep B to become symptomatic?

Answer 11

• 3 months to become symptomatic
• Does not directly damage liver cells, CD8 do this post inf.
• If CD8 response is relaxed then can be asymptomatic infection and individual can be vaccinate which helps

Question 12

How is Hep ABC detected in blood?

Answer 12

Hep A: IgM AB
Hep B: HBSAG
Hep C: IgG AB AND viral RNA

Question 13

Write some notes on detecting Hep A:

Answer 13

IgM AB high post acute infection after 7 weeks IgG AB becomes predominant

HAV RNA PCR usually not required

Question 14

Write some more notes on detecting Hep B:

Answer 14

Three antigen markers:

• HBsAG
• Early Ag (surrogate for replication)
• Core Ag (never found in serum)

Three AB markers:
- anti-HBS: Cured or vaccinated
- anti-HBE: Not usually measured
- anti-HBC: Cured or acute infection

Question 15

How does the Hep B antigen profile change between acute and chronic?

Answer 15

Acute:
- HBsAG rises and falls = highly infectious
- Anti-HBe = less infectious
- Anti-HBs rises and falls

Chronic
- HBsAG is sustained
- Total anti-HBe rises and is sustained

Question 16

What must be done to detect HCV?

Answer 16

AB against HCV AND HCV RNA PCR + gentotype

Question 17

Define chronic hepatitis:

Answer 17

Evidence of infection lasting more than six months
i.e HBsAG for 6+ months
i.e HCV RNA for 6 months

Most often diagnosed because ALT is elevated immunotolerance

Question 18

Incorperate the slides on antibody results

Answer 18

now

Question 19

Write some note son chronic hep B infection:

Answer 19

In chronic Hep B
- HBE antigen often cleared by 20-30 years age (assuming this is vaccine)(can result in a flare of active hepatitis)
- HBSag clearance is uncommon
- In adults after 5 years:
-> 20% develop cirrhosis
-> 20-25% cirrhosis will decompensate
-> 15% with cirrhosis will develop heptaocellular carcinoma which is lethal

Question 20

What is the treatment of acute viral hepatitis?

Answer 20

• Not required
• Supportive care
• Fulminant cases = transplant

Question 21

Whats the treatment of chronic hepatitis?

Answer 21

• To prevent cirrhosis and cancer
• To reduce transmission
• HBV = suppress, HCV = cure

Question 22

What are the medications of HBV chronic hepatitis?

Answer 22

Those with complications or high ALT (x2 normal) then reverse transcriptase inhibitors i.e

Entecavir or tenofovir

Question 23

What does HCV treatment depend on?

Answer 23

Virus genotype, host immunity

Previously treatment was non specific i.e ribavirin, interferon

now very specific treatments available i.e Sofosbuvir inhibitor in combination with other specific antivirals.

Question 24

How can HBV be prevented?

Answer 24

Vaccinate at risk to prevent vertical transmission

Screen pregnant women -> Give IgG at birth and vaccinate baby (checking B response)

Question 25

How is HCV prevented?

Answer 25

Clean needle exchange