Liver Enzymes Flashcards
As a rule of thumb, ALT over 10,000 means what?
DEATH
What level is ALT in a severe hepatitis?
5000
According to the newer model of cell injury, what is the cell’s response to mild injury?
Bleb formation - blistering off of the cell membrane releasing packets of cytoplasm into the blood stream
Which liver enzymes are cytoplasmic?
ALT - alanine transanimase
AST - asparate transanimase
LD - lactate dehydrogenase
What does elevated ALT and AST mean when ALT is higher?
Chronic/resolving liver injury
eg chronic viral,
What is the function of AST?
Shift malate in and out of the mitochondria
What is one of the most important events in the lead up to cell death?
Destruction of cell cytoskeleton
Which liver enzyme is most correlated with BMI?
ALT
Which liver enzymes are located on the membrane?
ALP
GGT
(one the biliary membrane in particularly)
How high do you expect GGT and ALP when there is an extrahepatic obstruction?
10x normal
Which results in LFTs truely reflect the liver’s function?
Albumin
Bilirubin
Which has the shorter half life, ALT or AST?
AST
Which enzymes are released in liver cell necrosis?
AST, ALT and LD
What are ALT in acute viral hepatitis?
2500-5000
Which liver enzymes are released with biliary disease?
GGT
ALP
What liver enzyme profile do a intrahepatic obstruction produce?
Mildly elevated GGT and ALP
What is the most common cause of liver enzyme elevation in Australia?
Obesity
What is the liver GGT involved in?
Production of glutathione
Why are ALP and GGT released with biliary disease?
Bile salts that accumulate dissolve cell membranes
What other viruses can cause hepatitis?
Q fever
Rubella
CMV
EBV
Which enzyme does the liver possess two of?
AST
Why does alcohol upregulate GGT?
Alcohol depletes the amount of NAD > glutathione is required > GGT is upregulated for glutathione producton
What does elevated ALT and AST mean when AST is higher?
Acute injury affecting mitochondria - eg acute viral or alcohol
Why isn’t fructose converted into glucose most of the time?
Because it is consumed with glucose therefore no more glucose is required
What are ALT levels in chronic hep B and C
50-250
Which liver enzymes are elevated with alcohol/drug induction?
ALP and GGT
Which organs can fructose enter?
Liver only
Do liver cells have more AST or ALT?
AST because it’s in the cytoplasm and mitochondria
How high is ALT for hepatitis symptoms to appear?
500-1000
What is the relationship between alcohol and GGT levels?
There isn’t one
Which is more specific for the liver ALT or AST?
AL(liver)T
