Jaundice and LFTs Flashcards
What vitamin does the liver activate?
D- helps absorption of calcium
Why would someone with liver disease bruise more easily?
Reduced production of clotting factors
Why do we use LFTs?
To confirm liver disease/damage
Allows to differentiate between hepatocellular injury (direct injury to the liver) and cholestasis (decrease in bile secretion - normally due to bile obstruction)
What are the “true” LFTs?
Albumin
Bilirubin
PT (prothrombin time)
Measure of protein synthesis
What are the other (non-true) LFTs?
ALT - alanine aminotransferase
AST - aspartate aminortransferase
ALP - alkaline phosphate
GGT - gamma - glutamyltransferase
Measure of enzyme activity
You diagnose someone purely on AST and ALT levels. True/false?
False
What LFTs increase due to hepatocellular damage?
ALT
AST
What LFTs increase due to cholestasis?
ALP
GGT - (used to show that increase ALP is due to biliary obstruction and not to do with bones)
What LFT increases due to large alcohol intake/drugs?
GGT
What is the only LFT enzyme to be found solely in the liver?
ALT
If experiencing v.high levels of aminotransferase (>1000 U/l) what is this almost always caused by?
Hepatitis
How would you expect increase in ALT and ALP to be to confirm more hepatocellular injury/ cholestasis (remember it can be a mixed cause)
> 10x increase in ALT and <3x increase in ALP = hepatocellular injury
<10x in ALT and >3x increase in ALP = cholestasis
Will a patient has higher AST or ALT levels if they have acute damage?
AST > ALT
AST is a marker of acute damage - acute alcoholic hepatitis/ cirrhosis
ALT> AST levels is indicative of what?
Chronic liver disease
Chronic liver disease will never cause AST levels to be higher than what?
1000 U/l
What would LFTs look like in chronic hepatocellular damage?
Raised or normal
What is the role of albumin? What effect does cirrhosis have on its production?
Maintain intravascular osmotic pressure (opposes filtration)
Decrease (acute phase of inflammation also causes albumin to temporarily drop)
What is prothrombin time?
A measure of the time taken for blood to clot
will sometimes increase due to decrease in clotting factor production
What is bilirubin?
What happens to it in the liver?
A breakdown product of Hb
It becomes conjugated
What are the 3 causes of jaundice and what kind of Hyperbilirubinemia is associated with each
Pre-hepatic - UCB
Hepatocellular - CB and UCB
Post-Hepatic - CB
Describe the stool changes assoc. with each kind of jaundice and briefly explain why this happens?
Pre-hepatic - normal urine and normal stools
Hepatic - dark urine and normal stools
Post-hepatic - dark urine and light stools (Steatorrhea)
UCB is insoluble in water and hence increase has no effect on urine
CB is soluble and makes urine darker
CB is released with bile and lipases into small intestine - these all help stool to form normally. If problem with obstruction of biliary tree we get steatorrhea
Give 2 examples of causes of each type of jaundice
Pre-hepatic
- Gilbert’s syndrome
- Haemolytic anaemia
Hepatocellular
- Cirrohsis
- Alcoholic liver disease
- Viral hepatitis
Post-hepatic
- Gallstones
- Cancer
- Drug-induced cholestasis
If a patient presents with high UCB and normal LFTs what should be suspected?
Under what circumstances may the patient be presented with jaundice?
Gilbert’s syndrome (a genetic condition which causes a decrease in function of enzyme which conjugates bilirubin)
Stress
Alcohol binge
Infection/illness
At what level of bilirubin would you begin to see jaundice?
When hits excess of 35 u/mol
