Hepatitis B

Question 1

Is Hep B the most common cause of hepatitis?

Answer 1

Yes, Hep B is the most common cause of hepatitis.

Question 2

Who is affected?

Answer 2

· Nearly half of all infections are in endemic areas of Southeast Asia, China and Africa.

· More common in men.

Question 3

What is the pathophysiology of Hep B?

Answer 3

· Virus doesn’t directly kill hepatocytes.

· The host’s immune response to viral antigens is the cause of the liver injury.

Question 4

What is the prognosis for Hep B?

Answer 4

Patients with HBeAg-positive chronic HBV infection:
- True cure occurs in a very low percentage of patients.

Patients with HBeAg-negative chronic HBV infection:

• Treatment is prolonged and probably needs to be lifelong.
• Relapse is frequent.

Question 5

What is the aetiology of Hep B?

Answer 5

· Highly infectious DNA virus.
· Hepadnavirus family.
· The outer envelope contains 3 related surface antigens (HBsAg), the most abundant being the S protein.
· Inside the envelope is the viral core, which contains DNA (HBcAg).
· HBcAg peptides induce a crucial host cellular immune response against HBV.
· HBeAg serves as a marker for active replication.

Question 6

How is Hep B transmitted?

Answer 6

· By percutaneous and permucosal routes. Also sexually transmitted.

· Transmission via infectious blood or bodily fluids containing blood.

Question 7

What are the risk factors for Hep B?

Answer 7

· Peri-natal exposure to an infant born to an HBV-infected mother.
· Multiple sexual partners (sexual promiscuity).
· Men who have sex with men.
· IVDU.
· Born in a highly endemic region.
· FHx of HBV and/or chronic liver disease.

Question 8

What are the common signs and symptoms of Hep B?

Answer 8

· 70% of patients with acute HBV infection are asymptomatic. 
· Jaundice.
· Hepatomegaly.
· Ascites.
· Fever. 
· Malaise. 
· RUQ pain.

Question 9

What investigations should be done if Hep B is suspected?

Answer 9

· LFTs
· FBC.
· U&Es. 
· Coagulation profile. 
· Serum HBsAg.
· Serum anti-HBs.
· Serum anti-HBc (IgM).
· Serum HBeAg.

Question 10

If a patient was Hep B positive, what would their LFT results show?

Answer 10

· Elevated ALT/AST.
· Elevated alkaline phosphatase.
· Elevated bilirubin.
· Low albumin.

Question 11

In regards to serum HBsAg, when does it appear and when does it disappear?

Answer 11

· Appears 2-10 weeks after HBV exposure.
· Becomes undetectable after 4-6 months.
· Persistence after 6 months implies chronic HBV infection.

Question 12

In regards to serum anti-HBs, when does it appear and when does it disappear?

Answer 12

· Appears several weeks after HBsAg has disappeared.
· Provides life-long immunity, suggesting resolved infection.
· Also detectable in those immunised with HBV vaccine.

Question 13

In regards to serum anti-HBc (IgM), when does it appear and when does it disappear?

Answer 13

Appears within weeks of acute infection and remains detectable for 4-8 months.

Question 14

In regards to serum HBeAg (IgM), when does it appear and when does it disappear?

Answer 14

· Found in the early part of acute infection.

· Presence >3 months indicates high likelihood of development of chronic infection.

Question 15

Suggest some differential diagnoses.

Answer 15

· Acute hepatitis A infection.
· Acute hepatitis C infection. 
· Chronic hepatitis C infection. 
· Acute hepatitis E infection. 
· EBV, CMV or HSV infection.
· Budd-Chiari syndrome.

Question 16

What is the treatment for Hep B?

Answer 16

Acute HBV infection:

• 1st line - supportive care.
• With hepatic failure - antiviral therapy +/- liver transplant.

Chronic HBV infection:

• 1st line - antiviral therapy or peginterferon.
• Decompensated cirrhosis - Evaluation for liver transplant.

Question 17

At what ages are Hep B vaccinations given?

Answer 17

3 injections (8, 12 and 16 weeks of age)

Question 18

What complications can arise in regards to Hep B?

Answer 18

· Cirrhosis.

· Hepatocellular carcinoma.