Pathology of Hepatitis Flashcards
Two structural/functional units of the liver:
Acinus
Lobule
Where are bile canaliculi found?
Between adjacent hepatocytes
What is the space of Disse?
Space between sinusoid and hepatocyte
Bile canaliculi are found where?
Between adjacent hepatocytes
What is the path of movement of bile from hepatocyte?
Canals of Hering to bile ductules to terminal bile ducts
What cytokines causes proliferation of stellate cells?
Platelet-derived growth factor (PDGF)
Tumor necrosis factor (TNF)
What stimulates contraction of stellate cells?
Endothelin-1 (ET-1)
What stimulates fibrosis in the liver?
Transforming growth factor beta (TGF-B)
What signals for chemotaxis of activated stellate cells?
PDGF
Monocyte chemotactic protein-1 (MCP-1)
Four disease categories of liver abnormality:
Viral hepatitis
Alcoholic liver disease (ALD)
Nonalcoholic fatty liver disease (NALD)
Hepatocellular carcinoma (HCC)
What can cause viral hepatitis?
Microbes
Autoimmune
Drug-toxin induced
What occurs in chronic hepatitis that doesn’t in acute hepatitis?
Bridging necrosis and fibrosis between central vein and portal triad
Chronic has mononuclear infiltration acute has little
What bacteria can form bacterial hepatitis?
S. aureus
S. typhi
T. pallidum
How does bacteria cause hepatitis?
Obstruction allowing them to ascend from the gut (ascending cholangitis)
What can fungi and mycobacterium cause?
Granulomatous inflammation
What parasites can affect the liver?
Schistomsomiasis
Echiococcus (hydatid cysts)
Three overlapping forms of ALD?
Hepatocellular steatosis
Steatohepatitis
Steatofibrosis
What is true of hepatocellular steatosis?
It is reversible cell injury that reverses with complete abstinence
What is Steatohepatitis?
Inflammation and recurrent fat deposition
Difference between hepatocellular steatosis and steatohepatits?
Hepatocellular steatosis: fatty deposition
Steatohepatitis: fatty deposition with inflammation
What is reversible liver damage?
Steatosis
Hepatitis
What does early fibrosis affect first?
Space of Disse with collagen
Are males or females affected more by cirrhosis?
Females
How does steatosis occur?
Shunting of substrates to lipid biosynthesis due to increased NADH from alcohol dehydrogenase and acetaldehyde dehydrogenase; increased use of NADH leads to fatty acid synthesis
In hepatitis what does acetaldehyde induce?
Lipid peroxidation
What produces ROS’s?
Cytochrome P-450
What can cause oxidative injury?
impaired glutathione
What does induced cytochrome P-450 enzymes cause?
Increased production of toxic metabolites
What does hepatitis cause?
Release of bacterial endotoxin from gut into circulation inducing inflammation of liver; also release of endothelins causing vasoconstriction leading to hypoxia and ischemia
In acute alcoholic hepatitis what lab findings are present?
Aminotransferase enzymes elevated with a 2:1 ratio of AST>ALT
How many grams of alcohol must be consumed daily for ALD?
80 grams
