Patterns of Liver Injury - Acute Hepatitis

Question 1

The clinical definition of acute hepatitis is

Answer 1

significant elevation of ALT of less than 6 months duration with no previous hx of liver disease

Question 2

ALT (alanine aminotransferase) comes from

Answer 2

cytosol of damaged hepatocytes

Question 3

What inflammatory cells predominate in acute viral hepatitis?

Answer 3

T lymphocytes, not neutrophils

Question 4

Bile ducts are lined by

Answer 4

epithelial cells

Question 5

Sinusoids are lined by

Answer 5

vascular epithelial cells

Question 6

Which zone of the hepatic acinus is most susceptable to damage by toxins and hypoxia?

Answer 6

Zone 3 (furthest from portal triad)

Question 7

What are the 3 patterns of acute hepatitis?

Answer 7

• lobular disarray and apoptosis (eg acute viral hepatitis A & B)
• zonal coagulative necrosis (eg paracetamol toxicity)
• acute hepatitis with Mallory bodies (acute alcoholic hepatitis)

Question 8

What are the histological features of acute viral hepatitis?

Answer 8

• lobular disarray
• T lymphocyte infiltrate
• compression of sinusoids (hard to see)
• enlarged kupffer cells containing lipofuschin and breakdown products
• NO NEUTROPHILS
• councilman bodies (cells undergoing apoptosis)

Question 9

What is the mode of cell death in acute viral hepatitis?

Answer 9

• apoptosis (councilman bodies) via intrinsic pathway induced by cytotoxic T cells

Question 10

What is the mechanism of paracetamol liver toxicity?

Answer 10

depletes glutathione (anti-oxidant) leading to oxidative damage

Question 11

What are the histological features of liver toxicity?

Answer 11

• zonal coagulative necrosis from oxidative injury
  
  • most severe in Zone 3; 1 usually spared, 2 involved sometimes
• no acute inflammation; macrophages later on

Question 12

What are the histoligcal features of alcoholic hepatitis?

Answer 12

• acute hepatitis with Mallory bodies
• fat vacuoles
• neutrophils (gather around Mallory bodies) tf possibly fever
• hepatocellular ballooning degeneration
• fiborous scarring around central vein; can cause complete obliteration
• often more severe in Zone 3

Question 13

What is a Mallory body?

Answer 13

• severe form of liver injury
• cytoskeleton (keratin 18 and ubiquitin) collapses
• forms pink, ropey material in a C shape around the nucleus
• feature of alcoholic hepatitis

Question 14

What are the histological features of cholestasis?

Answer 14

• marker of impaired bile excretion
• dilated canaliculi filled with bile