viral hepatitis Flashcards Preview

BII > viral hepatitis > Flashcards

Flashcards in viral hepatitis Deck (16)
Loading flashcards...
1
Q

how does hepatitis cause jaundice

A

pre-hepatic
-haemolysis

hepatic
- failure of conjugation, transport

post-hepatic
- biliary tree

2
Q

how does hepatitis cause oedema

A

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

3
Q

how does hepatitis cause a patient to easily bruise

A

insufficient coagulation protein synthesis by liver

4
Q

Hepatitis A virus

  • nucleic acid
  • route of transmission
  • key notes
A

RNA

faecel-oral

  • common in developing world
  • mostly asymptomatic
  • acute illness
  • testing relies on ABs
5
Q

Hepatitis B virus

  • nucleic acid
  • route of transmission
  • key notes
A

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)
6
Q

Hepatitis C virus

  • nucleic acid
  • route of transmission
  • key notes
A

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
7
Q

Hep B surface antigen (HBSAg)

A
  • 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
8
Q

diagnosis of HAV

A
  • antibody against HAV

- PCR usually not required

9
Q

diagnosis of HBV

A

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

10
Q

diagnosis of HCV

A
  • antibody against HCV

- HCV RNA PCR and genotype

11
Q

diagnosis of chronic hepatitis

A
  • evidence of infection >6 months
  • most often diagnosed because ALT elevated
  • immunotolerance
12
Q

describe these blood test results

  • HAV IgM +
  • HAV IgG -
  • HBSAg -
  • HCV AB -
A
  • IgM means current Hep A infection

IgG + would mean past infection

13
Q

describe these blood test results

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

14
Q

describe these blood test results

  • HBSAg +
  • anti-HBS -
  • anti-HBC +
  • anti-HBC IgM -
  • HBEAg +
A
  • 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)
15
Q

treatment of acute viral hepatitis

A
  • not required
  • supportive care
  • in fulminant cases - transplant
16
Q

treatment of chronic hepatitis

A
  • to prevent cirrhosis and cancer
  • to decrease transmission
HBV = suppress replication
HCV = curative treatment with drugs