15.9 Pathology: Patterns of liver injury 3 Flashcards
What is autoimmune hepatitits?
An aggressive form of chronic hepatitis that can progress rapidly to cirrhosis (85% of untreated patients over 5 years)
What are the two types of autoimmune heptatitis?
Type 1 (most common): adult women, associated with ASMA (anti-smooth muscle antibodies)
Type 2: children/teenages, associated with LKM-1 (anti-liver kidney hormone)
How does AIH present and progress?
Presents as acute hepatitis (severe early phase destruction of liver cells)
Fibrosis develops rapidly in area of collapes
What is the definition of cirrhosis?
Conversion of liver into nodules of regenerating hepatocytes surrounded by bands of fibrous tissue
(diffuse-whole liver)
What is end stage chronic liver failure associated with?
Most often cirrhosis (not always)
What are some causes of cirrhosis in adults? (7)
ALD NASH HBV, HCV AIH Chronic biliary disease Metabolic Drugs
What is a very common complication in cirrhosis?
Thromobis of vessels, especially portal veins
Can we tell the cause of cirrhosis by looking at a section?
No, different patterns provide little information about the cause. Need clinical history etc.
Is hepatocellular death directly resulting from cirrhosis important?
Hepatocellular death due to direct effect of insult is unimportant (cells can be replaced by mitotic division of hepatocytes)
Why does fibrous septa and scarring develop in cirrhosis?
Develop where hepatocytes have dropped out as a result of inflammatory injury to the portal veins
What is progression to cirrhosis driven by?
Parenchymal extinction (caused by vascular inflammation and thrombosis)
Who do hepatocellular carcinomas often develop in?
What is the greatest risk?
Patients with cirrhosis (esp. cirrhosis due to alcohol, HBV/HCV, haemochromatosis)
How much hepatic blood flow does the portal vein account for?
How much of total liver oxygen supply
2/3rds of hepatic blood flow
Wehre does the portal vein carry blood from and to?
GI tract, pancreas and spleen to the sinusoids of the liver
What is the definition of portal hypertension (2)?
Absolute increase in blood pressure within portal vein (>8mm Hg)
OR
Increase in pressure gradient (between portal vein/hepatic vein) of 5mmHg+
What is the most common cause of portal hypertension in our community?
Cirrhosis
What is this referring to?
- Splanchnic circulation: hyperdynamic
- Vascular SM/stellate cells contract
- Hepatic vein directly compressed
- Small portal vein branches trapped by scar tissue
- Hepatic arterial blood shunts into portal vein via arterovenous anasomoses in fibrous septa
Pathogenesis of portal hypertension in liver cirrhosis
What are 4 symptoms of portal hypertension (due to cirrhosis)
Ascites
Formation of porto-systemic anastamoses
Congestive splenomegaly
Hepatic encephalopathy
Where are the main sites of porto systemic anastomoses? (3)
Oesophagus, rectum and around umbilicus
What are oesophageal varacies?
Collateral veins that have dilated when portal blood flow is re-routed
Bleed EASILY (50% mortality if ruptured)
