Lecture 18 - Testing the Liver

Question 1

Hepatocellular conditions and enzymes present to test?

Answer 1

Viral hepatitis, liver toxins/drugs; ALT & AST

Question 2

Biliary/Cholesattic conditions and enzymes present to test?

Answer 2

Gallstones, some drugs; ALP, GGT, bilirubin

Question 3

Bilirubin source?

Answer 3

Along with Albumin which it is bound in aquepus environment (unconjugated), a product of the metabolism of haem

Question 4

Conjugation of Bilirubin?

Answer 4

Uptake into liver, conjugation w binding to sugar forming bilirubin-glucuronide (conjugated - water soluble),

Question 5

Urobilinogen?

Answer 5

Bilirubin-glucoronide is sent down bile duct nto small intestine where it is converted into urobilinogen which is excretedd in faeces or reabsorbed and excreted in urine

Question 6

Haemolysis?

Answer 6

Bilirubin production in overdrive, higher amounts of urobilinogen in urine to test

Question 7

Hepatitis/Cancer?

Answer 7

Bile duct blockage causing excess bilirubin-gluuronide build up in liver which backs up into circulation causing increased ratio of bilirubin-glucoronide in blood stream and urine

Question 8

Inside liver causes of jaundice?

Answer 8

Haemolysis, Gilbert’s syndrom (slow conjugation), Cholestasis (problem w transfer into duct), obstruction leading to pressure increase and compression/scarring

Question 9

Obstructions outside liver causing jaundice?

Answer 9

gallstones, biliary/pancreatic cancer, pancreatitis

Question 10

Alkaline phosphatase?

Answer 10

Transfers alkaline groups, age variability due to bone growth

Question 11

ALP locations?

Answer 11

Biliary system (obstruction, inflammation), osteoblasts, intestine (inflammation), placenta (pregnancy), Tumors (bone, lung)

Question 12

GGT cause of elevation?

Answer 12

Inflammation/obstruction of biliary system, inducible (alcohol, drugs)

Question 13

GGT and alcohol

Answer 13

A rise in weekend, a persistent rise w ALP in chronic alcohol abuse due to scarring - imperfect marker

Question 14

ALT funcion and location?

Answer 14

Amino acid transfer, alanine converted into pyruvate for gluconeogenesis; primarily liver

Question 15

AST function and location?

Answer 15

Aspartate into oxaloacetate for gluconeogenesis, less liver specific than ALT (heart, muscle, RBC) with shorter halflife

Question 16

ALT and AST in liver diseases?

Answer 16

Early & late hepatits; early and chronic hepatitis

Question 17

Causes of Albumin loss?

Answer 17

decreased snthesis (cirrhosis), increased excretion, illness, redistribution (35-47g/l)

Question 18

Globulin presence?

Answer 18

reflect inflammation (subacute, chronic), v high levles in chr hepatitis and cirrhosis

Question 19

Prothrombin Ratio increase?

Answer 19

Reflects clotting factor synthesis - vi K deficiency or liver failure

Question 20

Compounds decreasing in scarring?

Answer 20

Glucose, albumin

Question 21

Compounds increasing in scarring?

Answer 21

GGT, ALP, AST/ALT ratio, globulins, bilirubin, NH3, prothrombin ratio

Question 22

CEA?

Answer 22

can be indicative of cancer but also benign conditions, more than 20 micg/ml is malignant