L8-9 - Liver Disease Flashcards
What are the two types of liver disease?
Acute and chronic
Give 3 causes of acute liver disease
Acute viral hepatitis, drugs/toxins (e.g. paracetamol), inadequate blood supply
Give 3 possible consequences of acute liver disease
Decreased Na and Ca, acidosis, renal failure (toxin exposure), hypoglycaemia, increased ammonia, oedema or ascites (fluid retention)
What are the causes of chronic liver disease?
Prolonged acute liver disease, chronic viral hepatitis, chronic toxin exposure, cholestatic disease (biliary blockage)
What is cirrhosis?
How does this occur?
Terminal stage of chronic liver disease
Prolonged damage leads to liver fibrosis; this destroys hepatocytes, reducing liver function
Give 3 things that can cause cirrhosis
Excessive drinking (alcoholic fatty liver can progress to cirrhosis), viral hep B or C, autoimmune (e.g. Primary biliary cirrhosis)
What are the main liver function tests?
AST/ALT, ALP, bilirubin, albumin
What occurs to AST/ALT levels after liver damage has occurred? Why is this?
Initial damage - both increase at same rate as the cytoplasmic forms are released from hepatocytes
After further damage - AST>ALT as the membrane bound form of AST is released
What does a slight AST/ALT elevation usually indicate?
Chronic conditions - viral hep, autoimmune hepatitis, drugs/chemicals, hepatic steatosis (fat deposits)
What does a severely elevated AST/ALT level usually indicate?
Acute - viral hep, passing gallstones, drugs/toxins, ischaemic hepatitis (shock liver, decreased blood flow)
What does AST>ALT indicate?
Alcohol based condition - alcoholic steatosis, hepatitis or cirrhosis
What can a raised ALP indicate?
What test can be carried out to confirm this?
Cholestatic liver disease
Gamma-glutamyl transferase (GGT)
What happens to albumin levels in chronic liver disease?
Decrease
What can an increased bilirubin level indicate?
Jaundice, cholestatic liver disease
What immunological tests can be carried out for liver disease? Why/when would these be used?
Test for viral antigen/antibodies in viral hepatitis
Test for autoantibodies in autoimmune hepatitis and primary biliary cirrhosis
What is jaundice?
Hyperbilirubinaemia (high bilirubin)
What results in increased bilirubin synthesis? Why is this?
Haemolysis - bilirubin is made using haem groups from broken down RBCs
What are the 2 forms of bilirubin? where does the transition between the two take place?
Conjugated and unconjugated
Hepatocytes take in unconjugated and secrete conjugated into biliary tract
What are the 3 general types of jaundice? Describe the circumstances that results in these
Pre-hepatic - increased bilirubin synthesis (more than the liver can conjugate)
Hepatic - decrease in uptake by/delivery to hepatocytes
Post-hepatic - blockages causes reabsorption of conjugated bilirubin
What are the bilirubin levels/types seen in pre-hepatic jaundice?
Increased unconjugated bilirubin
Give 3 causes of pre-hepatic jaundice
Haemolytic anaemia, rhabdomyolysis, haemolytic disease of the newborn
What are the 3 types of congenital jaundice?
Gilbert’s disease, Crigler-Najjar syndrome and Dubin Johnson syndrome
What is involved in Gilbert’s disease?
What are the levels/type of bilirubin?
Hepatocytes cant take up bilirubin
Increased unconjugated bilirubin
What is involved in Crigler-Najjar syndrome?
What are the levels/type of bilirubin?
Hepatocytes cant conjugate bilirubin
Increased unconjugated bilirubin
What is involved in Dubin Johnson syndrome?
What are the levels/type of bilirubin?
Hepatocytes cant secrete the conjugated bilirubin
Increased conjugated bilirubin
What are the two types of obstructions seen in post-hepatic jaundice? Give an example of each
Intrahepatic - intrahepatic carcinoma, primary biliary cirrhosis, hepatocellular damage
Extrahepatic - gallstones, extrahepatic carcinoma
What types of jaundice results in an increased conjugated bilirubin?
Post-hepatic (obstructive jaundice) and Dubin Johnson syndrome
