Liver Path 1 - Nelson Flashcards
Rapid fire definition of cholectasis?
Impaired secretion of bile
Summarize the steps of bilirubin metabolism:
1) Reticuloendothelial cells convert heme to bilirubin
2) Bilirubin transported to liver and complexed to albumin (unconjugated)
3) Bilirubin is conjugated by UDP glucuronyl transferase in liver cells
4) Conjugated bilirubin is excreted in bile
5) CB is then converted to urobiliogen by gut flora, makes feces brown and urine yellow
Which form of bilirubin is toxic to tissues?
Unconjugated bilirubin is toxic to tissues
It is not excreted int he urine because ti is bound to albumin
What are some causes of unconjugated hyperbilirubinemia?
1) Impaired bilirubin production
- caused by hemolysis
- dyserythropoesis
2) Impaired uptake of bilirubin
- heart failure, portosystemic shunts, Glibert’s Syndrome, drugs
3) Impaired conjugation of Bilirubin
- Crigler-Naiiar syndrome, Gilbert’s, neonatal jaundice, hyperthyroid, ethinyl estradiol, liver disease(cirrhosis, chronic hepatitis)
Causes of Coonjugated hyperbilirubinemia?
1) Extrahepatic cholectasis (biliary obstruction)
- cholelithiasis, pancreatic cancer, primary sclerosing cholangitis, pancreatitis, parasites
2) Intrahepatic cholestasis
- viral hepatitis, alcoholic heptatitis, primary biliary cirrhosis, drugs/toxins, sepsis, etc
A couple is a little worried because their first child seems a little yellow. Why do they probably not need to be worried?
Pretty normal to have jaundice with neonates. Why?
- Increased bilirubin because they have more RBCs with shorter life spans
- More difficult to clear bilirubin because their UGT1A1 enzymes are not super active yet
- They have more enteroheptic circulation
After you see this couple’s child you realize this probably isn’t normal neonate jaundice. Their child has severe hyperbilirubinemia.
What do you have to worry about in this situation?
Any treatments available?
They are at risk for bilirubin-indiced neuro dysfunction (BIND). Can present as bilirubin encephalopthy.
Could lead to long term neuro problems or kernicterus
Tx: Phototherapy can convert bilirubin into water-soluble isomers
Gilbert’s syndrome is caused by decreased action of what enzyme?
UGTA1A - Causes an increase in unconjugated bilirubin because UGT is usually what does the conjugation step
What disorder causes the pathological finding of nutmeg liver?
centrilobular hemorrhagic necrosis
periportal areas are spared
Right/Left-sided heart failure, hepatic vein thrombosis, or shock can cause hepatic problems. Which part of the liver is most prone to ischemic injury (or drug toxicity for that matter)?
The centrilobular portion
(ex. cardiac sclerosis caused by long-standing chronic passive congestion/centrilobular hemorrhagic necrosis)
Basically it’s centrilobular fibrosis
It’s your first time on the wards in your 3rd year. Your patient has hepatomegaly, ascites, and abdominal pain. You also know this patient has a history of polycythemia vera.
What is your suspicion?
Budd-Chiari!
Hepatic vein thrombosis. He has the classic triad, and PV should make you think he could be prone to thrombus
What is the disorder characterized by obstrutive NONTHROMBOTIC lesions of the small hepatic veins?
Causes?
Sinusoidal Obstruction Syndrome!
Caused by radiation or hepatotoxins
How does portal vein thrombosis differ from other causes of portal hypertension?
The obstruction os before the liver, which means it is just like portal hypertension, but there is no ascites present.
How do you know if a patient has recovered from viral hepatitis?
NO more surface antigen!
How is Hep A transmitted?
Fecal oral
