LFT Interpretation

Question 1

What is ALT?

Answer 1

alanine transminase
- more specific for hepatocellular injury than AST

Question 2

Normal range of ALT?

Answer 2

Based on population and disease state
- men = 30 U/L
- women = 20 U/L

Question 3

What is AST?

Answer 3

aspartate transferase
- less specific for liver since also present in cardiac muscle, skeletal muscle, kidney, and brain

Question 4

What is alk phos?

Answer 4

Marker of cholestasis, can be non-specific since also present in bone

Question 5

What is GGT?

Answer 5

Gamma-glutamyl transpeptidase (GGT)
- marker of cholestasis, also non-specific (found in intestine, brain, blood vessels)

Question 6

What is LDH?

Answer 6

Lactate dehydrogenase (LDH)
- can be a liver marker but more useful in hemolytic conditions

Question 7

Name synthetic liver function tests?

Answer 7

1. serum albumin
2. Prothrombin time / INR (international normalized ratio)

Question 8

What is prothrombin time?

Answer 8

a blood test that measures the time it takes for the plasma of your blood to clot

Question 9

What is INR?

Answer 9

international normalized ratio
- how long it takes your blood to clot
= 1.0

Question 10

Determining LFT patterns?

Answer 10

1. acute <6 weeks
2. subacute - 6 weeks to 6 months
3. chronic >6 months

Question 11

Hepatocellular pattern?

Answer 11

Elevated ALT, AST, with normal Alk Phos, elevation in serum bili, tests of synthetic function are normal or abnormal

Question 12

Cholestatic pattern?

Answer 12

Elevated Alk Phos, with normal ALT, AST, elevation in serum bili, tests of synthetic function are normal or abnormal

Question 13

Isolated hyperbilirubinemia?

Answer 13

normal AST, ALT, Alk Phos, but raised bili

Question 14

Acute viral hepatitis?

Answer 14

AST, AST are >25 times upper limit

Question 15

Chronic viral hepatitis?

Answer 15

ALT normal or raised but usually less than 10 times upper limit normal

Question 16

Alcohol liver disease?

Answer 16

ALT <5 times ULN, AST: ALT ratio >2