LFT's Flashcards
What are the cytotoxic blood tests?
AST, ALT, Albumin, PT
What are ALT and AST?
Enzymes within the hepatocytes. When the hepatocyte dies, the enzymes get released.
When would you see raised ALT and AST?
Recent liver cell injury and hepatic inflammation.
What would you see in the LFT results of someone with liver failure?
Low AST and ALT/
What do we use ALT and AST for?
Hepatic inflammation.
What is albumin and where is it made?
A complex protein made in the liver
What does low albumin suggest?
Chronic liver injury.
What is PT?
Prothrombin time.
Which is the most sensitive LFT?
Prothrombin time.
Explain how PT shows evidence of liver damage.
Prothrombin time is a measure of how long clotting takes.
The liver produces many of the enzymes involved in the clotting process, if the liver is damaged, it can’t make these enzymes so clotting takes longer and prothrombin time increases.
What clotting factors does the liver make that effects PT?
Factors II, VII, IX, X
What can increase PT and is unrelated to the liver?
Decreased vitamin K, Anti-Coagulant drugs and haemophilia.
Which is more specific to the liver AST or ALT?
ALT - The L (for Liver) in the middle can help you remember.
In what liver condition would you see AST higher than ALT
Alcoholic fatty liver disease.
What is the half life of Albumin?
20 days.
The breakdown of erythrocytes produces?
Unconjugated bilirubin
What does the liver do to unconjugated bilirubin?
The liver combines bilirubin with glucaronic acid by the action of an enzyme to make it conjugated bilirubin which is soluble in water.
What happens if there is a blockage in the extrahepatic ducts?
The conjugated bilirubin and unconjugated biliruibin builds up in the blood. The conjugated bilirubin is then excreted by the kidney as it is soluble.
What is Bilirubinuria and what does it look like?
The presence of conjugated bilirubin in the urine and is characterised as dark urine.
What causes Bilirubinuria?
Blockage in the intra/extrahepatic duct.
What can increase the level of Alk Phos?
Cholestasis (Blockage in the hepatic ducts)
Pregnancy
Bone disease and growth. (Paget’s disease)
What does GGT stand for?
Gamma-glutamyl transferase
What can cause in an increase in GGT?
Cholestasis.
How is GGT useful?
It can show the origin of high levels of ALP because GGT is not effected by bone disease.
What is Gilbert’s disease?
A lack of an enzyme in the liver that conjugates the bilirubin.
What is bilirubin?
The product of RBC breakdown after conjugation in the liver and secretion
What does AST stand for?
Aspartate aminotransferase
What does ALT stand for?
Alanine aminotransferase
What does GGT stand for?
Gamma-glutamyl transpeptidase
