Evaluation of Liver Function

Question 0

Hepatocyte system functions

Answer 0

1 Metabolic reactions
2 Macromolecular synthesis
3 Macromolecular degradation
4 Metabolism of xenobiotics

Question 1

Three systems in the liver

Answer 1

1 Hepatocyte
2 Biliary system
3 Reticuloendothelial system (RES)

Question 2

Biliary system functions

Answer 2

1 Metabolism of bilirubin and bile salts
2 Involves transport of bilirubin into the hepatocyte, its conjugation to glucoronic acid, its secretion into bile canaliculi and the enterohepatic system

Question 3

Reticuloendothelial system (RES) functions

Answer 3

1 Immune system function

2 Production of heme and globin metabolites

Question 4

Synthesis of hormones (angiotensinogen, insulin like growth factor 1)

Answer 4

Biochemical hepatocytic system

Question 5

Site of clearance of insulin, parathyroid hormone, estrogen, cortisol

Answer 5

Biochemical hepatocytic system

Question 6

Site of metabolism of ammonia to urea

Answer 6

Biochemical hepatocytic system

Question 7

Site of synthesis of albumin and coagulation factors (except von Willebrand factor)

Answer 7

Biochemical hepatocytic system

Question 8

Hepatic metabolism

Answer 8

Bilirubin is transported into the hepatocyte, where it is converted into the diglucoronide form and secreted into canaliculi

Question 9

Reticuloendothelial system

Answer 9

Kuppfer cells

Question 10

Kuppfer cells

Answer 10

1 Major site of defense against intestinal bacteria
2 Primary location for removal of antigen-antibody complexes from the circulation
3 Breakdown of hemoglobin from dead erythrocytes, giving rise to bilirubin, which, together with bilirubin from the spleen, enters the hepatocyte

Question 11

Normal hemoglobin variants

Answer 11

HbF (infant)

HbA (adult)

Question 12

Pathway of bilirubin

Answer 12

(Review)

Question 13

Urobilinogen and urobilin may be

Answer 13

1 Reabsorbed from the gut
2 Reexcreted in the liver
3 Excreted in the urine

Question 14

Bilirubin metabolism

Answer 14

After canalicular excretion, it is further metabolized by intestinal bacteria in the intestine forming urobilinogen and urobilin

Question 15

Neonatal bilirubin reference ranges

Answer 15

Full term 0-24 hr: 2.0-6.0 mg/dL
Full term 24-48 hr: 6:0-10.0 mg/dL
Full term 3-5 days: 4.0-8.0 mg/dL
Premature 0-24 hr: 1.0-8.0 mg/dL
Premature 24-48 hr: 6.0-12.0 mg/dL
Premature 3-5 days: 10.0-14.0 mg/dL

Question 16

Causes of elevated serum levels of unconjugated bilirubin

Answer 16

1 Hemolysis (e.g. Sickle cell anemia)
2 Gilbert's syndrome
3 Crigler Najjar Syndrome
4 Cirrhosis
5 Toxic substances

Question 17

Affected infants develop severe unconjugated hyperbilirubinemia leading to kernicterus causing severe motor dysfunction and retardation

Answer 17

Crigler Najjar Syndrome Type 1

Question 18

Treatment of Crigler Najjar Syndrome Type 1

Answer 18

Phototherapy

Question 19

Interferences in neonatal bilirubin test

Answer 19

1 Dietary pigments

2 Light

Question 20

Specimen in neonatal bilirubin test

Answer 20

Serum

Plasma

Question 21

Neonatal bilirubin reaction principle

Answer 21

1 Serum is diluted with phosphate buffer at pH 7.4
2 Absorbance is determined at 454 and 540 nm (oxyhemoglobin)
3 Concentration is determined from a standardized curve using adjusted (subtracted) absorbance from the sample (dual-wavelength narrow bandpass spectrophotometer)

Question 22

Fibrosis leading to decrease in cellular mass and alteration in blood flow

Answer 22

Cirrhosis

Question 23

Causes of elevated serum levels of conjugated bilirubin

Answer 23

1 Dubin-Johnson Syndrome
2 Rotor syndrome
3 Biliary obstruction
4 Ascending cholangitis
5 Gram negative sepsis

Question 24

Dubin-Johnson Syndrome clinical manifestations

Answer 24

1 Mild jaundice
2 Total bilirubin, 2-5 mg/dL
3 Intense dark pigmentation of the liver due to accumulation of lipofuscin pigment

Question 25

Blockade of the excretion of bilirubin into the canaliculi

Answer 25

Dubin-Johnson Syndrome

Question 26

Causes Dubin-Johnson Syndrome

Answer 26

Defects in the adenosine triphosphate (ATP)-binding cassette (ABC) canalicular multispecific organic anion transporter, MRP2/cMOAT/ABCC2

Question 27

Suppress neonatal conjugation of bilirubin

Answer 27

1 Progesterone
2 Other hormones in breast milk
3 Betaglucoronidase

Question 28

T or F. Hyperbilirubinemia may be more pronounced due to blood group differences of mother and child (group O mothers)

Answer 28

T

Question 29

Causes an increase in supply of heme for degradation to bilirubin

Answer 29

Higher turnover of neonatal erythrocytes shortly after birth in order to replace fetal hemoglobin (HbF) with hemoglobin A

Question 30

Causes of physiological jaundice of the newborn

Answer 30

1 Short-term or transient immaturity of the liver

2 Short-term delay in ability to produce UDPG-transferase for conjugation

Question 31

Physiological jaundice of the newborn tests

Answer 31

1 Slight increase in bilirubin in the first few days of life when compared to the normal adult bilirubin level. Peaks at around 2-4 days but may remain elevated for up to 2 weeks.
2 Associated with increased total and unconjugated bilirubin but near-normal conjugated bilirubin
3 Serum hepatic enzyme levels are typically normal since there is no associated cell inflammation

Question 32

Hemolytic disease of newborns

Answer 32

1 Fetal cells entering mother’s blood stream at birth
2 Maternal memory cells generate IgG antibodies directed against Rh factor expressed on fetal RBCs
3 Results in mild to severe anemia in second fetus

Question 33

Rotor syndrome

Answer 33

1 Viral in etiology

2 Does not cause liver hyperpigmentation

Question 34

Most common cause of hyperbilirubinemia in adults

Answer 34

Cholelithiasis