Liver/Pancreas Pathologies Flashcards
What is produced by the liver ?
Albumin
Glycogen
Coagulation factors
Bile
What is catabolised in the liver ?
Drugs (CYP450) Hormones Haemoglobin Toxins(CYP450) Can take over removal of RBC after splenectomy
How can you test for liver dysfunction (not integrity ) ?
- Plasma Albumin = hypoalbuminaemia
- Coagulation factors = prolonged INR (international normalised ratio) or Prothrombin time
What is the normal lifespan of RBC ?
120 days
What are the products of RBC breakdown and what happens to them ?
- Haemoglobin broken down in globin and heme
- Globin is broken down in aaback to plasma
- Heme gives iron which goes to plasma and Bilirubin which enters bilirubin metabolism
Briefly describe the bilirubin metabolism
Unconjugated bilirubin released from heme > is hydrophobic so binds to Albumin and carried to liver > conjugated to glucoronic acid by UDP glucuronyl transferase > conjugated bilirubin secreted in bile > converted to urobilinogen in gut > 90% to stercobilin in faeces , 10% reabsorbed and converted to urobilin in kidney
How can you test for abnormalities of bilirubin production or secretion ?
Test for plasma bilirubin levels
Urinary urobilinogen (dipstick)
Urinary conjugated bilirubin (dark urine or dipstick)
What is jaundice ? What are the different types ?
Raised plasma bilirubin , deposit in tissue ,give yellow colour (conjunctiva)
Pre-hepatic, intra-hepatic, post-hepatic
What causes pre-hepatic jaundice ?
Excessive haemolysis : Sickle cell disease, autoimmune disease
What signs are seen in pre-hepatic jaundice ? What would be the result of investigations ?
- Mild-jaundice
- Very dark stools
- Normal urine
- Raised plasma bilirubin
- increased urinary urobilinogen
- no urinary conjugated bilirubin
What causes intra-hepatic jaundice ?
Failure of hepatocyte so to conjugate and / or secrete bilirubin (decreased secretion to gut )
Eg: hepatitis , cirrhosis , Cholangitis ,drugs
What are the signs of intra-hepatic jaundice and investigation results ?
- moderate jaundice
- normals stools
- Dark urine
- Raised serum bilirubin
- Presence of conjugated bilirubin in urine
- Normal Urobilinogen in urine
What causes post-hepatic jaundice ?
Failure of the biliary tree to bring bilirubin to gut
Eg: biliary tree obstruction (gallstones) , carcinoma…
How do you call bile stuck in the liver ?
Cholestasis
What signs and investigation are present in post-hepatic jaundice ?
- Severe jaundice (green)
- Pale stools
- Dark urine
- Pruritis (itching)
- Raised plasma bilirubin
- Decreased urine urobilinogen
- Presence of conjugated bilirubin in Urine
What causes Pruritis in post-hepatic jaundice ?
Cholestasis cause deposition of bile salt in skin
Do you expect patient with post-hepatic jaundice to have xanthelasma ? Why ?
Yes , raised plasma cholesterol due to decreased secretion of bile salt in gut
What markers are used to assess liver damage ?
ALT : alanine aminotransferase
Alkaline Phosphatase
Gamma GT
Damage to what causes raised ALT ? In which conditions would you expect to see raised ALT ?
Inflammed or damaged hepatocytes release ALT
Seen in Hepatitis due to Viral infection (A,B,C) , Acute alcohol intake , Fatty liver disease, Drugs/toxins
Where is Alkaline Phosphatase present ?
- Liver canaliculi
- Bile ducts
- Bones
In which conditions would you expect to see raised AlkPhos ?
- Bile duct/liver disease with cholestasis : biliary obstruction , cirrhosis (compression of canaliculi ) , liver metastases, drugs
- Bone disease : bone metastases, fracture, osteomalacia,hyperparathyroidism, Paget’s disease of the bone
What is Paget’s disease of the bone ?
Due to change in balance between activity of bone cells : remodelling
Causes bones to be enlarged , distorted, porous
When is Gamma GT produced ?
- Present in bile duct cells , a little in hepatocytes
- Production is induced by alcohol
When do you expect gamma GT to be increased ?
- Biliary duct obstruction, cholestasis
- Cirrhosis
- Liver metastasis
- Drugs
-Alcoholism
