viral hepatitis

Question 1

how does hepatitis cause jaundice

Answer 1

pre-hepatic
-haemolysis

hepatic
- failure of conjugation, transport

post-hepatic
- biliary tree

Question 2

how does hepatitis cause oedema

Answer 2

decreased albumin production from the liver, causing a decrease in oncotic pressure. As a result, fluid leaks from vessels

Question 3

how does hepatitis cause a patient to easily bruise

Answer 3

insufficient coagulation protein synthesis by liver

Question 4

Hepatitis A virus

• nucleic acid
• route of transmission
• key notes

Answer 4

RNA

faecel-oral

• common in developing world
• mostly asymptomatic
• acute illness
• testing relies on ABs

Question 5

Hepatitis B virus

• nucleic acid
• route of transmission
• key notes

Answer 5

DNA

blood

• worldwide, extremely contagious (esp vertical transmission)
• most cases asymptomatic
• acute illness
• can cause chronic e.g. cirrhosis and cancer
• long incubation (3-4 months)

Question 6

Hepatitis C virus

• nucleic acid
• route of transmission
• key notes

Answer 6

RNA

blood

• more common in developing world, less contagious
• generally infection of adults (IV drug users, sex)
• usually doesn’t cause acute hepatitis
• curative treatment

Question 7

Hep B surface antigen (HBSAg)

Answer 7

• as virus replicates in liver, excess HBSAg is produced and spills into blood
• HBSAg in blood is measured to confirm active Hep B
• HBSAg surface antigen used in vaccines

Question 8

diagnosis of HAV

Answer 8

• antibody against HAV

- PCR usually not required

Question 9

diagnosis of HBV

Answer 9

3 antigens

• surface antigen (vaccine is recombinant HBSAg)
• early antigen (surrogate for replication)
• core antigen (never found in serum)

Anti- HBS
Anti- HBE
Anti-HBC

HBV DNA PCR

Question 10

diagnosis of HCV

Answer 10

• antibody against HCV

- HCV RNA PCR and genotype

Question 11

diagnosis of chronic hepatitis

Answer 11

• evidence of infection >6 months
• most often diagnosed because ALT elevated
• immunotolerance

Question 12

describe these blood test results

• HAV IgM +
• HAV IgG -
• HBSAg -
• HCV AB -

Answer 12

• IgM means current Hep A infection

IgG + would mean past infection

Question 13

describe these blood test results

• HBSAg -
• Anti-HBS +
• Anti- HBC -
• HBEAg -

Answer 13

• no surface antigen (HBSAg -) means no current Hep B

- presence of antibodies to surface antigens (Anti-HBS +) but none to core antigens (anti-HBC-) indicates vaccination

Question 14

describe these blood test results

• HBSAg +
• anti-HBS -
• anti-HBC +
• anti-HBC IgM -
• HBEAg +

Answer 14

• HBSAg + shows current Hep B infection
• HBEAg + means lots of viral replication
• unsure if acute of chronic
• Anti-HBC IgM - may indicate chronic (tests over 6 months needed to confirm)

Question 15

treatment of acute viral hepatitis

Answer 15

• not required
• supportive care
• in fulminant cases - transplant

Question 16

treatment of chronic hepatitis

Answer 16

• to prevent cirrhosis and cancer
• to decrease transmission

HBV = suppress replication
HCV = curative treatment with drugs