2. Biochemistry And Liver Disease

Front 1

What protein is metabolized in the liver?

Back 1

Bilirubin

Front 2

How is bilirubin formed?

Back 2

By metabolizing haemoglobin from destroyed RBCs

Front 3

Why is jaundice a symptom of a malfunctioning liver?

Back 3

Because it is caused by the buildup of bilirubin in the liver or bile ducts which is then deposited into the blood and skin

Front 4

How does bilirubin leave the body?

Back 4

It travels to the liver, binds with bile, and then enters the digestive tract to be removed in stool and (to a lesser extent) urine

Front 5

What are the primary functions of the liver? (7)

Back 5

--Catabolism and excretion of bilirubin

--Maintenance of glucose homeostasis

--Metabolism of cholesterol and triglycerides

--Production of some clotting factors

--Detoxification of drugs

--Catabolism of ‘amino’ (NH3) groups of amino acids to urea

--Protein synthesis: albumin & globulins (except immunoglobulins)

Front 6

What products are catabolised in the liver? (4)

Back 6

Bilirubin, cholesterol, triglycerides, and amino groups

Front 7

What is produced by the liver? (4)

Back 7

Urea, albumin, globulins, some clotting factors

Front 8

What is tested in an LFT?

Back 8

ALT, AST, ALP, GGT, bilirubin, albumin

Front 9

What is incorrect about the name "Liver Function Test" with regards to the substances measured?

Back 9

They are often produced by other parts of the body and are therefore not direct indicators of liver function

Front 10

What are ALT and AST?

Back 10

Aminotransferases-- enzymes involved in the transfer of amino groups

Front 11

Amino acid metabolism is influenced by what enzymes?

Back 11

ALT and AST

Front 12

Where is ALT abundant?

Back 12

Hepatocytes

Front 13

Where is AST abundant?

Back 13

Hepatocytes, muscle cells, RBCs

Front 14

What would cause elevated ALT and AST levels?

Back 14

Damage to hepatocytes

Front 15

What is ALP?

Back 15

Alkaline phosphatase

Front 16

Where is ALP found?

Back 16

The membranes of hepatocytes near biliary ducts

Front 17

What would cause elevated ALP levels?

Back 17

When biliary duct pressure rises

Front 18

What is GGT?

Back 18

Gamma glutlymyl-transpeptidase-- an enzyme which transfers gamma-glutamyl groups between peptides

Front 19

Where is GGT found?

Back 19

The membranes of hepatocytes near biliary ducts

Front 20

What would cause elevated GGT levels?

Back 20

When biliary duct pressure rises or when enzyme synthesis is induced

Front 21

What induces enzyme synthesis?

Back 21

Alcohol and certain drugs

Front 22

What is albumin?

Back 22

A protein synthesized in the liver which carries proteins, peptides, and drugs in the blood

Front 23

What is the function of albumin?

Back 23

Carries proteins, peptides, and drugs in the blood, and maintains oncotic pressure in blood vessels

Front 24

To what extent do albumin levels indicate liver malfunction?

Back 24

Not greatly-- low albumin concentration is usually a result of general illness, and liver disease must be severe to cause it

Front 25

What is bilirubin?

Back 25

A waste product of haemoglobin metabolism

Front 26

What is the difference between bilirubin in the blood and in the liver?

Back 26

It is unconjugated in the blood, and conjugated in the liver

Front 27

What is the normal balance of conjugated to unconjugated bilirubin?

Back 27

98% unconjugated, 2% conjugated

Front 28

What non-concentration test measures liver function?

Back 28

Prothrombin time

Front 29

How do PT tests measure liver function?

Back 29

By measuring clotting time which is directly correlated to clotting factors, some of which are produced by the liver

Front 30

What effect would liver disease have on a PT test?

Back 30

Increased (prolonged clotting time)

Front 31

What does an increased PT time indicate?

Back 31

Deficiency of clotting factors, possible liver disease

Front 32

When is ammonia measured?

Back 32

In neonates with severe illnesses

Front 33

Why are ammonia levels not measured in adults?

Back 33

Ammonia levels do not correlate with disease severity

Front 34

What is hepatitis?

Back 34

Damage to hepatocytes involving inflammation or infection

Front 35

What is cholestasis?

Back 35

The impairment of bile flow

Front 36

What causes hepatitis?

Back 36

Viruses, drugs, alcohol, autoimmune disease, ischaemia

Front 37

What occurs in hepatitis?

Back 37

Destruction of hepatocytes and release of cell enzymes into the blood

Front 38

What becomes elevated in moderate hepatitis?

Back 38

ALT and AST (serum aminotransferases)

Front 39

What makes hepatitis particularly dangerous?

Back 39

It is caused by contagious viruses

Front 40

What are the symptoms of hepatitis?

Back 40

Exhaustion, dark urine, pale feces, jaundice, itchy skin

Front 41

What are the signs of moderate hepatitis?

Back 41

Increased ALT & AST, increased ALP, increased bilirubin, prolonged clotting time

Front 42

What are the symptoms of severe hepatitis?

Back 42

Increased ALT, AST, ALP, bilirubin, glucose, albumin, and ammonia, severe clotting impairment

Front 43

Where does cholestasis occur?

Back 43

Anywhere from the bile ducts to the duodenum

Front 44

What can cause partial or complete cholestasis?

Back 44

Gallstones, pancreatic cancer, and diseases affecting the biliary tree

Front 45

What is a hepatic pattern?

Back 45

When a condition leads to inflammation or damage to the liver

Front 46

What is a cholestatic pattern?

Back 46

When a condition leads to obstruction of bile flow

Front 47

What causes damage to hepatocytes in cholestasis?

Back 47

The buildup of pressure on cells in the bile duct and then eventually the hepatocytes

Front 48

What are the signs of cholestasis?

Back 48

Severely elevated ALP and bilirubin, slightly elevated ALT & AST

Front 49

What are the symptoms of cholestasis?

Back 49

Bilirubin in urine (brown color), pale stool

Front 50

Why does stool become pale?

Back 50

Because bile pigments are not reaching the gut due to cholestasis

Front 51

What drugs can cause mixed hepatitis & cholestasis?

Back 51

Immunosupressants

Front 52

What does it mean for a tumor to be infiltrative?

Back 52

It is mixed amongst normal tissue and cannot be removed without significant disruption to the organ it affects-- 'sand in the grass' effect

Front 53

Are infiltrative (diffuse) or focal tumors more dangerous?

Back 53

Infiltrative-- cannot be removed without significant disruption to the affected organs

Front 54

How are liver tumors generally classified?

Back 54

Infiltrative

Front 55

What makes liver tumors difficult to detect?

Back 55

They do not affect LFT values until very advanced stages

Front 56

Hepatocarcinomas are usually accompanied by an increase in what?

Back 56

AFP

Front 57

What molecule is produced by liver tumors?

Back 57

AFP

Front 58

What are the signs of alcohol liver disease?

Back 58

Increased GGT, macrocytosis

Front 59

What is macrocytosis?

Back 59

Increased red cell volume

Front 60

Why is alcohol liver disease difficult to test for?

Back 60

Because its primary sign is elevated GGT, which can occur in many types of liver disease

Front 61

Is alcohol liver disease reversible?

Back 61

To an extent-- 3-4 weeks without alcohol will restore normal GGT levels

Front 62

What are the consequences of chronic alcohol intake?

Back 62

Cirrhosis, deposition of fat in liver, elevated urate, elevated GGT, elevated triglycerides, acute hepatitis, macrocytosis

Front 63

What is cirrhosis?

Back 63

Fibrosis / scarring of the liver which occurs in heavy drinkers. Not inherently dangerous but progresses to malignancy

Front 64

What three molecules are elevated in alcohol liver disease?

Back 64

GGT, urate, triglycerides

Front 65

A patient presents with high ALT and AST values, along with INR (prolonged clotting times). What is the most likely cause?

Back 65

Hepatitis

Front 66

A patient presents with jaundice, pale stool, elevated ALT and AST, and severely elevated ALP and bilirubin levels. What is the most likely cause?

Back 66

Cholestasis

Front 67

A patient presents with fatigue, hepatomegaly, slightly raised ALP levels, and severely raised ALT and AST levels. What is the most likely cause?

Back 67

A mixed hepatitic and cholestatic pattern

Front 68

A parient presents with raised urate, tryglyceride, and GGT, as well as a high MCV. Four weeks later, these values have reduced to normal or ULN. What is the most likely cause?

Back 68

Excessive alcohol consumption

Front 69

Why does the MCV of a patient with alcohol liver disease take longer to normalise than their GGT levels?

Back 69

Because red blood cells have a long half life

Front 70

What is fibrosis?

Back 70

The thickening and scarring of tissue

Front 71

What LFT value becomes severely elevated in late-stage hepatic cancer?

Back 71

ALP

Front 72

Why are GGT levels measured as part of LFTs?

Back 72

Primarily to determine if raised ALT, AST, or ALP values are due to liver issues (raised GGT) or bone issues (normal GGT)