Liver Function Test (Bilirubin | P)

Question 1

What is bili?

Answer 1

1) It is the end product of hgb metabolism

2) It is the principal pigment of bile

Question 2

Process of bili metabolism?

Answer 2

1) The RBCs (that are already senescent / near to being senescent) are engulfed by macrophages / monocytes (from the spleen; from the reticuloendothelial system)
2) The RBCs will be broken down into hgb
3) Hgb will be broken down into heme
4) Heme will be converted into biliverdin reductase via the enzyme heme oxygenase
5) Biliverdin will be further metabolized into UCB via the enzyme biliverdin reductase
6) UCB will be bounded to albumin for it to be transported to the liver from the spleen
7) In the liver, this is where conjugation from UCB to CB happens. Along w/ conjugation, the albumin is removed for it to become H2O soluble (for it to become excreted in the urine)
8) Since CB is now already H2O soluble, it will combine w/ bile and will be excreted from the liver

Question 3

What are the characteristics of UCB?

Answer 3

1) It is also called as unconjugated / bilirubin 1
2) It is H2O-insoluble
3) It is also called as indirect bili
4) It is also called as hemobilirubin
5) It is also called as pre-hepatic bilirubin

Question 4

What are the characteristics of CB?

Answer 4

1) It is also called as conjugated / bilirubin 2
2) It is H2O-soluble
3) It is also called as direct bilirubin
4) It is also called as cholebilirubin
5) It is also called as post-hepatic bilirubin

Question 5

What is delta bili?

Answer 5

It is a CB w/c is tightly bound to albumin

Question 6

What are the characteristics of delta bili?

Answer 6

1) It has a longer half life compared to other forms of bili

2) It directly reacts w/ diazo rgnt

Question 7

Why is delta bili formed?

Answer 7

It is formed due to prolonged elevation of CB in biliary obstruction (obstructive jaundice)

Question 8

What is the condition present if a pt has jaundice?

Answer 8

The pt is icterus / hyperbilirubinemia

Question 9

What are the characteristics of a pt w/ jaundice?

Answer 9

The pt has yellow discoloration of the:

1) Skin
2) Sclera
3) Mucus membranes

Question 10

What is the bili lvls of a pt w/ jaundice (or possible to have jaundice)?

Answer 10

2 mg/dL >

Question 11

What are the sx considerations for bili lvls determination?

Answer 11

1) The sx must be free from hemolysis
2) The serum should be stored in the dark
3) The sx / serum must be measured ASAP

Question 12

What is the principle used for determination of bili lvls?

Answer 12

Van den Berg

Question 13

What are the 2 procedures for determination of bili lvls (w/c uses the principle of Van den Berg)?

Answer 13

1) Evelyn and Malloy

2) Jendrassik and Grof

Question 14

What is the product for Evelyn and Malloy & Jendrassik and Grof?

Answer 14

Azobilirubin

Question 15

What is the color of the product in Evelyn and Malloy?

Answer 15

Pink to purple azobili

Question 16

What is the color of the product in Jendrassik and Grof?

Answer 16

Pink to blue azobili

Question 17

What is the accelerant used in Evelyn and Malloy?

Answer 17

Methanol

Question 18

What is the accelerant used in Jendrassik and Grof?

Answer 18

Caffeine

Question 19

What is the process (or steps) for determination of bili lvls?

Answer 19

1) Label test tubes: blank, standard, unknown
2) Dispense 1,000 uL of bilirubin working rgnt to all tubes
3) Add 50 uL Na nitrite to all tubes
4) Add 100 uL of each standard, blank, and sx to its respective tube. Mix well
5) Allow all tubes to stand for 5 mins at room temp
6) Set the wavelength of the instrument at 560 nm
7) Read and record the A of all tubes

Question 20

What is the normal reference range of bili for infants (after 1 month) and for adults?

Answer 20

0.2 - 1.0 mg/dL

Question 21

What is the normal reference range of bili for newborns who are 1 day old?

Answer 21

Up to 5.1 mg/dL

Question 22

What is the normal reference range of bili for newborns who are 1 - 2 days old?

Answer 22

Up to 7.2 mg/dL

Question 23

What is the normal reference range of bili for newborns who are 3 - 5 days old?

Answer 23

Up to 10.3 mg/dL