Flashcards in JAUNDICE Deck (42)
What is the normal range of total bilirubin in the blood?
Where does bilirubin come from?
Haemoglobin which is unconjugated to bilirubin by splenic macrophages
How is bilirubin carried in the blood?
Bound to albumin
Where is bilirubin conjugated and by what enzyme?
In the liver by glucuronyltransferase
How is conjugated bilirubin secreted from the liver?
What happens to conjugated bilirubin that is secreted in the bile?
It is turned into urobilinogen.
What happens to urobilinogen?
Either reabsorbed or excrete with faeces as stercobilin. If it is reabsorbed it either returned to liver and re-secreted into bile or excreted with urine.
What causes jaundice?
Increased levels of bilirubin over about 50 micromol/L due to break down of red blood cells. Both unconjugated and conjugated.
What are the features of jaundice?
What are the causes of pre-hepatic jaundice?
Congenital unconjugated hyperbilirubinaemia (sometimes considered a hepatic cause but causes a pre-hepatic picture)
What is the most common form of congenital unconjugated hyperbilirubinaemia?
What is Gilbert's syndrome?
A defect in UDP glucuronyltransferase enzyme which conjugates bilirubin. This leads to less conjugation and therefore increased levels of unconjugated bilirubin. Unconjugated bilirubin cannot be excreted as it is water soluble so there is a build up leading to jaundice.
What is the inheritance of Gilbert's syndrome?
Autosomal recessive (although some dominance has been reported)
Are people with Gilbert's syndrome affected by jaundice all of the time?
No. Only during intercurrent illness eg flu like symptoms or after a fast.
What investigations would you in someone to confirm a diagnosis of Gilbert's syndrome?
Look for a bilirubin rise following a prolonged fasting.
What is the treatment for Gilbert's syndrome?
No treatment is necessary, only reassurance. Carbamazepine and Phenobarbital can reduce unconjugated bilirubin levels. Diet changes are useful as well.
What are the hepatic causes of jaundice?
Drug induced hepatitis
What are the viruses that can cause jaundice?
Hepatitis A, B, C or E
What is Wilson's disease?
Autosomal recessive genetic disorder in which copper accumulates in tissues; this manifests as neurological or psychiatric symptoms and liver disease.
What is the main medication used to treat Wilson's disease?
What is Dubin-Johnson syndrome?
A defect in the ability of hepatocytes to secrete conjugated bilirubin into the bile, and is similar to Rotor syndrome. Leads to conjugated bilirubinaemia but no changes in LFTs.
What are the drugs that can induce jaundice of hepatic cause?
What are the post-hepatic causes of jaundice?
Primary biliary cirrhosis
Primary sclerosing cholangitis
Carcinoma of head of pancreas
Enlarged lymph nodes at porta hepatis
Drug causing cholestasis:
Oral contraceptive pill
Flucloxacillin or co-amoxiclav
What is primary biliary cirrhosis?
Slowly progressive autoimmune disease of the biliary system with a chronic course which may extend over many decades. It involves destruction of the small interlobular bile ducts (canals of Hering) via the formation of portal granulomas. This causes intrahepatic cholestasis which damages cells, leading to scarring, fibrosis and eventually cirrhosis.
What do we look for in the blood in order to make a diagnosis of primary biliary cirrhosis?
Other than anti-mitochondrial antibodies, what else might be abnormal in blood tests of someone with primary biliary cirrhosis?
In someone suffering from primary biliary cirrhosis, what will liver function tests reveal?
Increased bilirubin (but later in the disease)
What is the classic history of a patient with primary biliary cirrhosis?
Young female with jaundice and itching
What is primary sclerosing cholangitis?
A chronic cholestatic liver disease with obliterative inflammatory fibrosis of the bile ducts. The term 'primary' is used to distinguish this condition from bile duct strictures that are secondary to bile duct injury, cholelithiasis or ischaemia.