LFTs

Question 1

Liver enzymes

Answer 1

ALT/AST - serum transaminases
Alkaline phosphatase
Gamma Glutamyl Transpeptidase

Question 2

Hepatic enzymes are ___ and released in response to ___

Answer 2

Intracellular

Hepatocellular injury

Question 3

Alanine aminotransferase (ALT) features

Answer 3

More sensitive than AST
Located in cytovsisl
Short half life

Question 4

AST

Answer 4

Cytosol and mitochondria

Longer half life

Question 5

The levels of AST and ALT reflect the amount of damage true/false

Answer 5

False

Can drop when they have no more hepatocytes to burn out

Question 6

What are ALT/AST levels in obstructive jaundice

Answer 6

Les than 500 U/L

Question 7

Alkaline phosphatase role

Answer 7

Enzyme that catalyses the hydrolysis of a number of organic phosphate esters

Question 8

What is bilirubin

Answer 8

Breakdown product of heme 
transported to liver bound in albumin 
Uptake unto hepatocytes 
undergoes conjugation 
excreted via urine/faeces

Question 9

What is isolated hyperbiliruinaemia

Answer 9

High bilirubin either conjugated or uncongugated without jaundice??

Question 10

what is prothrombin time

Answer 10

Liver responsible for synthesis of clotting factors

PT measures the conversion time from prothrombin to thrombin reflecting vital component of liver

Question 11

What does elevated prothrombin time mean

Answer 11

Reduced synthetic functionality

Question 12

What are some there causes of elevated prothrombin time

Answer 12

Drugs (warfarin)
Bile malabsorption causing vitamin K deficiency
Consumptive coagulation properties

Question 13

History taking qs to ask before doing LFTs

Answer 13

Use/exposure to drugs
Accompanying symptoms
Parenteral exposures (snorting drugs) IV med/blood transfusion, tattoos, sexual history
Travel history
Alcohol exposure
Occupational exposure
Temporal variation - itchy at night better in day

Question 14

ALT/AST ratio greater than ALP

Increased bilirubin/normal bilirubin

Answer 14

Hepatocellular injury

Question 15

ALP greater than ALT/AST ration

Increased bilirubin

Answer 15

Cholestasis

Question 16

Raised PT and INR (international normalised ratio)

Answer 16

Prolonged jaundice
Bit K malabsorption
Hepatocellular dysfunction

Question 17

Albumin meaning

Answer 17

Difficult to use in isolation

Question 18

Acute hepatocellular picture

Answer 18

Can use AST:ALT ration (>2 suggests alcohol)

Need acute liver screen

Question 19

How to screen for coeliac disease

Answer 19

tTG-IgA
Gold standard - biopsy
Can present insidiously with biochem reflecting NAFLD

Question 20

What mimic/overlap conditions can caused raised AST/ALT

Answer 20

Coeliac disease
muscle disorders 
adrenal insufficiency 
anorexia nervosa 
thyroid

Question 21

What caused hyperbilirubinaemia - uncongugated

Answer 21

Increased bilirubin production
Impaired hepatic bilirubin update
Impaired bilirubin congugation

Question 22

Conditions associated with impaired bilirubin conjugation

Answer 22

Gilberts
CN type II
Hyperthyroidism

Question 23

Conditions associated with impaired hepatic bilirubin uptake

Answer 23

-Heart failure, portosystemic shunts, drugs- rifampcin, probenecid

Question 24

Conditions associated with increased bilirubin production

Answer 24

• haemolysis, extravasion of blood into tissues

Question 25

What causes hyperbilirubinaemia - conjugated

Answer 25

Extrahepatic cholestasis (biliary obstruction) 
Intra hepatic cholestasis

Question 26

What can cause extra hepatic cholestasis

Answer 26

Cholelithiasis 
PSC 
Cholanhiocarcinoma 
HoP mass 
Acure/chronic pancreatitis

Question 27

What causes intra hepatic cholestasis

Answer 27

Check lecture

Question 28

What is cholestasis

Answer 28

Stoppage of bile flow

Question 29

Symptoms of cholestasis

Answer 29

Itch
dark urine
light faeces
jaundice

Question 30

What does v raised ALP mean

Answer 30

Cholestasis