L41 Viral Hepatitis

Question 1

Describe the symptoms/ presentation of acute/chronic hepatitis and why those symptoms show up

Answer 1

1. Jaundice: liver doesn’t remove enough bilirubin from the blood
2. Malaise, tender and swollen liver: inflammation, liver damage

Chronic liver disease
3. Easy bruising: failure to synthesise adequate clotting factors

4.Peripheral swelling: reduced liver production of oncotic proteins : oedema

Question 2

Why are they called hepatitis viruses, what are the modes of transmission for Hep A, B, C and the risk factors.

All worldwide

Answer 2

Hepatitis viruses because their main site of replication is the liver. They are not structurally similar.

A: faecal-oral route
- travellers

B: blood borne: most common
-Mother w chronic disease-> child at birth , MSM, sex worker,

C: blood borne, low in NZ
- IV drug use

Question 3

Compare the rates of
assymptomatic infection , acute illness,
fulminant hepatitis (going to kill),
and chronic infection + vaccine availability

between Hep A, B, C

Answer 3

All cause Acute illness. Only Hep C doesn’t have a vaccine.

A: 
assymp infection 
- 90% <5yrs
-60% 5-10yrs
-30% adults 

<1% fulminant disease.
- Never chronic disease

B:
assymp infection
- definitely <1yr, 90% 1-5yrs
-20-70% adults.

0.5% fulminant

Chronic disease:

• 90% in <1yrs - tolerance to hep B
• 10-25% in 1-5yrs
• <5% in adults

C:
Assymp infection: adults >80%

Fulminant disease rare outside of japan

-Chronic disease: yes 50-85%.

Question 4

How is Hep A diagnosed and why

Answer 4

1. Detected of acute anti-HAV IgM (antibodies in blood formed against the excess HBSAg produced by host cell ribosome vs other viral proteins in the cytoplasm)
   - in kids they will likely be assymptomatic
2. To confirm PCR of whole blood for HAV RNA (usually not required)

Question 5

How is acute Hep B diagnosed- what tests (3,3)

Answer 5

Tests detecting antigens in serum

1. Surface Ag: vaccine is recombinant HBSAg : will not have if vaccinated
2. Early Ag: surrogate for replication -
3. Core Ag: never found in serum

Tests detected antibodies in serum
1. Anti-HB-S: cured from past infection/vaccinated:

2. Anti-HB-E: not usually measured
3. Anti HB-C: cured or acute infection

Question 6

What causes the inflammation in Hep B,

why is clearance uncommon for newborns infected

Answer 6

Illness occurs 3 months

Inflammation is caused by cytotoxic T cell removal of infected hepatocytes. If not a lot= assymptomatic

In neonates, immune system ends up tolerating liver infection. Thus causing chronic illness.

Question 7

How is Hep C diagnosed - what is a cancer

Answer 7

1. Detection of IgG antibody against HCV -but doesn’t tell you the time they had it, whether they cleared it enough
2. followed by PCR detected of HCV RNA in blood - more expensive test

Question 8

Define chronic hepatitis

Answer 8

Evidence of infection >6 months.

eg. HBSAg + for 6 months
eg. HCV RNA + for 6 months

Most are diagnosed because ALT is elevated and immunotolerance ?

Question 9

What is the timeline of chronic Hep B vs Hep C and compare cancer rates

Answer 9

1. HBEAg is often cleared by 20-30yrold - can result in flare of acute hep
2. HBSAg clearance is uncommon

3.Adults after 5 yrs:
12-20% will develop cirrhosis

4. 20-25% with cirrhosis will decompensate–>symptomatic ascites, encephalopathy

6-15% with cirrhosis will develop hepatocellular carcinoma - fatal.

This is similar for HCV except there is a smaller proportion at all stages and no decompensated cirrhosis stage

Cancer is less common. only promoted by high cell turnover whereas Hep B viral DNA contains oncogenic genes which is incorporated into host cell

Question 10

What is the treatment/focus for acute hepatitis vs chronic hepatitis

Answer 10

Acute: Treatment is not required, just supportive care.
- in fulminant case: transplant

Chronic: treatment is to prevent cirrhosis and cancer, and reduce transmission.
HBV : suppress, HBC: cure

Question 11

Describe the treatment for HBV- who is it given - suppression

Answer 11

Treatment for

• ppl w complications
• high ALT (2xnormal)

Treatment : Reverse transcriptase inhibitor eg. Entecavir, Tenofovir

Question 12

Describe the treatment for HCV- how has changed, for how long - good or not
-cure

Answer 12

Previously nonspecific toxic antivirals ribavirin, interferon. Virus genotype and host immunity impacted chance of cure.

Now: specific antivirals available with 95% cure rate, no interferon.

eg. Sofoshuvir: NS5B polymerase inhibitor in combination with other specific antivirals.

For 4-6wks, expensive

Question 13

How is chronic HBV prevented

Answer 13

1. Screen pregnant women for chronic hep B
2. Treat mother to lower viral load
3. Immediately after birth give HBV Ig to mop up virus
4. Start vaccination at birth (4 doses)
5. Test after last vaccine to check anti-HBS is >100UVml