LIVER
Fred Maate MD
• Wide variety of metabolic, toxic, microbial,
circulatory, and neoplastic insults.
• The major primary diseases of the liver are
– viral hepatitis,
– nonalcoholic fatty liver disease (NAFLD)
– alcoholic liver disease, and
– hepatocellular carcinoma (HCC).
• May be secondary to heart failure,
extrahepatic infections or disseminated ca
Injury and repair
• Reversible changes– Accumulation of fat (steatosis)
– Accumulation of bilirubin (cholestasis)
Irreversible injury
Regeneration
• From adjacent hepatocytes
• Stem cells- ductular reaction- canals of Hering
Scar formation and Regression
• Hepatic stellate cell.
– In quiescent form, is a lipid (vitamin A) storing
cell.
– In several forms of acute and chronic injury, the
stellate cells become activated & are converted
into highly fibrogenic myofibroblasts.
• In persistent injury, scar deposition begins in
the space of Disse.
• This is particularly important in alcoholic and
nonalcoholic fatty liver diseases,
– but is also a generalized mechanism of scar formation in other forms
of chronic liver injury.
Cirrhosis
• Diffuse scarring surrounding regenerating
hepatocytes
Inflammation and Immunity
• Innate and adaptive immune systems
areinvolved in all manner of liver injury and
repair
– Innert mechanisms- APCs, T- lymphocytesproinflammatory cytokines- various effects
– Adaptive immunity- viral hepatitis- CD8
eradication of HepB & C
Liver failure
• Acute vs chronic
• 80% to 90% of hepatic functional capacity
must be lost before hepatic failure ensues
Acute liver failure
• An acute liver illness associated with
encephalopathy and coagulopathy that occurs
within 26 weeks of the initial liver injury in the
absence of pre-existing liver disease.
Acute liver failure
• caused by massive hepatic necrosis, most
often induced by drugs or toxins
• Nausea, vomiting, and jaundice
• Life threatening encephalopathy, and
coagulation defects
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Alteration of bile flow- jaundice and icterus
Hepatic encephalopathy
Coagulopathy
Portal hypertenstion
Hepatorenal syndrome