Reticulocyte Count (F)

Question 1

What is a reticulocyte?

Answer 1

It is the last immature RBC stage

Question 2

How are reticulocytes formed?

Answer 2

These are formed when the nucleus of the late normoblasts are lost through extrusion

Question 3

What are the components of reticulocytes?

Answer 3

1) Remnants of cytoplasmic RNA
2) Remnants of organelles
3) Reticulum

Question 4

What are the organelles which are one of the component of reticulocytes?

Answer 4

1) Mitochondria

2) Ribosomes

Question 5

True or False

The more mature the reticulocyte is, the greater is the ribosomal content

Answer 5

True

Question 6

What are the purposes of reticulocyte ct?

Answer 6

1) It is used to assess erythropoietic activity of the bone marrow
2) It is also used to monitor therapeutic measures for anemia

Question 7

What is the principle of reticulocyte ct?

Answer 7

Whole blood, anticoagulated w/ EDTA, is stained w/ a supravital stain. Any non-nucleated RBC that contains 2 or more particles of blue-stained granulofilamentous mat after new methylene blue staining is defined as reticulocyte

Question 8

What are the mats needed for reticulocyte ct?

Answer 8

1) Anticoagulated blood
2) BCB
3) Glass slide
4) Microscope
5) Cedarwood oil
6) Tissue paper
7) Test tube

Question 9

What is the method (or steps) of reticulocyte ct?

Answer 9

1) Mix equal volumes of blood and freshly filtered BCB in a tube
2) Allow the mixture to stand at room temp for 15 - 30 mins
3) Remix the preparation and prepare smears
4) Allow the smears to dry
5) Examine under OIO
6) In an area w/c cells are close together but not touching, ct 1,000 RBCs (include reticulocytes in the RBC ct)
7) Calculate the % reticulocyte ct

Question 10

What is the formula for reticulocyte ct?

Answer 10

Reticulocyte % = number of reticulocytes X 100 / total RBC counted

Question 11

Provide an ex of computing reticulocyte ct

Answer 11

R% = 15 X 100 / 1,000
R% = 1.5%

Question 12

What are the normal values of reticulocyte ct for adults and infants?

Answer 12

1) Adults: 0.5 - 1.5%

2) Infants: 2.0 - 6.0%

Question 13

What is the meaning of ARC?

Answer 13

Absolute Reticulocyte Count

Question 14

What is ARC?

Answer 14

It is the actual # of reticulocytes in 1 L or uL of blood

Question 15

What is the formula for computing ARC?

Answer 15

ARC = retic % X RBC count (X 10^12/L) / 100

Question 16

Provide an ex of computing ARC

Answer 16

ARC = 2% X (2.20 X 10^12 / L) / 100 
ARC = 44 X 10^9/L

Question 17

What is the normal value for ARC?

Answer 17

20 - 115 X 10^9/L

Question 18

What is the meaning of CRC?

Answer 18

Corrected Reticulocyte Count

Question 19

What is the formula for CRC?

Answer 19

CRC % = reticulocyte % X patient Hct (%) / 45

Question 20

What are the normal values for CRC?

Answer 20

1) Hct = 35% ; CRC = 2 - 3% (mild anemia)

2) Hct = <25% ; CRC = 3 - 5% (moderate anemia)

Question 21

What are the causes of high reticulocyte ct?

Answer 21

More RBCs are being made in the bone marrow after:

1) Bleeding
2) A move to high altitude or
3) After treatment for anemia

Question 22

What are the causes of low reticulocyte ct?

Answer 22

Fewer RBCs are being made in the bone marrow due to:

1) Anemia
2) Exposure to radiation
3) Long-term infection
4) Certain medicines that damage the bone marrow