Hepatitis B virus

Question 1

Genome of Hepatitis B

Answer 1

• circular
• double stranded
• DNA

Question 2

Capsid of Hepatitis B

Answer 2

• icosahedral
• core protein: Hepatitis B core antigen(HBcAg)
• soluble core protein: HBeAg

Question 3

Detection of HBeAg is an indicator of

Answer 3

HBV replication phase

Question 4

Envelope of Hepatitis B

Answer 4

Hepatitis B surface antigen(HBsAg)
S: large HBsAg protein
S2: medium HBsAg protein
S1: small HBsAg protein

Question 5

Unique aspect of replication of Hepatitis B

Answer 5

Even though DNA, encodes a reverse transcriptase and replicates through an RNA intermediate.

Question 6

Replication process of Hepatitis B

Answer 6

1. ds DNA enters into the nucleus
2. transcription to produce 4 mRNAs
3. mRNA moves to cytoplasm
4. core proteins assemble around larger mRNA
5. • sense DNA synthesized by a reverse transcriptase activity in the core
6. RNA degraded as a positive sense DNA
7. Core is enveloped, released by exocytosis.

Question 7

Incubation of acute hepatitis B

Answer 7

• period of 1-6 months

Question 8

Symptoms of acute hepatitis B

Answer 8

• icteric(Jaundice) hepatitis
• anorexia, nausea, vomiting, low grade fever, myalgia
• fatiguability, right upper quadrant and epigastric pain
• jaundice

Question 9

Rare symptoms of acute hepatitis B

Answer 9

• fulminant hepatitis
• risk of developing GI bleeding
• coma, hepatic encephalopathy, ascites, coagulopathy

Question 10

Results following acute hepatitis B

Answer 10

• complete recovery with life immunity

- will not develop “chronic” hepatitis

Question 11

Chronic hepatitis B infection

Answer 11

-individuals who can’t fight off virus will develop “chronic” hepatitis

Question 12

Chronic carriers

Answer 12

-patients with chronic hepatitis B can be healthy carriers

Question 13

Designation to become a chronic carrier

Answer 13

• chronic hepatitis B infection for longer than 6months

Question 14

Symptoms of chronic active hepatitis B

Answer 14

-fatigue, anorexia, nausea, mild upper quadrant pain

Question 15

Hepatitis B and risk to infants

Answer 15

-contract hepatitis B during birth, and turn into chronic

Question 16

Risks of chronic hepatitis B infection

Answer 16

• liver damage
• liver failure
• liver diseases like cirrhosis and cancer

Question 17

Pathogenesis of chronic hepatitis B infection

Answer 17

• HBV infection does not directly cause the issue

- cell mediated immune lysis of infected cells produces symptoms

Question 18

Insufficient immunity of hepatitis B can lead to what

Answer 18

Chronic hepatitis B infection

Question 19

Typical hepatitis B disease progression

Answer 19

Acute infection => chronic infection => liver cancer, cirrhosis, liver failure => death

Question 20

Typical immunology response to Acute hepatitis B

Answer 20

HBsAg : peaks 4-24wks
IgM anti-HBc : peaks 7-32wks
IgG anti-HBs : peaks 32wks and on
Total anti-HBc : begins after 7wks, rises, constant

Question 21

Immunology response that leads to chronic hepatitis B?

Answer 21

• lack of the IgG anti-HBs development

- constant presence of HBsAg

Question 22

Epidemiology of Hepatitis B

Answer 22

• blood, sex, direct contact

- in utero or birth

Question 23

Occurrence of chronic hepatitis B infection

Answer 23

• not prevalent in N. A., western europe

- more common everywhere else

Question 24

Treatment for hepatitis B

Answer 24

• Acute : no treatment

- Chronic: reverse transcriptase inhibitor, polymerase inhibitor ( Lamivudine, Adefovir)

Question 25

Control of hepatitis B

Answer 25

• screening donated blood

- passive or active immunizations