WBC Counts

Question 1

Machine count

Answer 1

1. Expensive
2. Rapid
3. Precise (+/- 2%)
4. Repeatable
5. Anyone can run a machine

Question 2

Hemocytometer

Answer 2

Special grid slide
1. Cheap
2. Slow
3. Laborious
4. Moderately precise (+/- 10%)
5. Math
6. Learning curve

Question 3

Manual Count

Answer 3

Regular glass slide
1. Slow
2. Moderately precise (+/- 5-15%)
3. Repeatable if consistent operator
4. Learning curve
5. Average WBC on 10x/4

Question 4

What is a ‘gate’ in a machine count?

Answer 4

A ‘normal range’ for a cell, each machine has a slightly different gate depending on the person programming.

Clouds inside a gate should be ‘clean’

Question 5

Should you examine scatterplot or smear first?

Answer 5

Scatterplot

Question 6

Do you need to do a smear evaluation even if the clouds are clean?

Answer 6

Yes, machines can’t see clumping and rbc morphologies (ie. acanthocytes, schiztocytes, keratocytes)

Question 7

Steps when performing a smear evaluation

Answer 7

1. 20x: rapid scan of smear from top to bottom
2. 50x
3. 100x: go to monolayer

Question 8

Why should you look at a blood smear at 20x?

Answer 8

1. Assess for WBC clumping
2. Estimate WBC count to compare to machine
3. Easier to find leukocytes present in low numbers

Question 9

Left shift

Answer 9

the shifting of a population of cells towards immaturity

Question 10

The circulating pool is called to tissues via ___________

Answer 10

chemotaxis

Question 11

The marginating pool can de-marginate in ______________

Answer 11

seconds to minutes

Question 12

The storage pool can be called in ____________

Answer 12

minutes to hours

Question 13

The three types of left shifts

Answer 13

1. Regenerative
2. Transitional
3. Degenerative

Question 14

Regenerative left shift

Answer 14

1. increased seg neutrophils in blood (neutrophilia)
2. bone marrow expanded to meet demand
3. active inflammation
4. Prognosis: good

Question 15

Transitional left shift

Answer 15

1. segmented neutrophils WRI
2. active inflammation
3. Prognosis: monitor

Question 16

Degenerative left shift

Answer 16

1. segmented neutrophils decreased (neutropenia)
2. inflammation overwhelming BM
3. Prognosis: guarded to critical

Question 17

Toxicity

Answer 17

results of rapid maturation of neutrophil that leads to morphologic defects (ie. lacy cytoplasm, foamy cytoplasm, dohle bodies)

Question 18

How long does it take for neutrophils to be produced?

Answer 18

Normally 3-5 days. Can be sped up to 2-4 days in need.

Question 19

dohle bodies

Answer 19

chucks of rough ER that has a bunch of polysomes (blue appearance)

Question 20

Two important leukograms

Answer 20

1. Stress/Glucocorticoid Leukogram
2. Physiologic/Excitement Leukogram

Question 21

Stress Leukogram

Answer 21

Due to an increase in glucocorticoid. It causes
1. Neutrophilia (demargination of NEU)
2. Monocytosis (demargination of monocytes)
3. Eosinopenia (marrow sequestration of EOS)
4. Lymphopenia* (lympholysis/apoptosis)
5. Hyperglycemia that is still below 200 mg/dL*

Question 22

Difference between marginating pool size of dogs and cats

Answer 22

Dogs: Marginating pool is the same size as circulating pool
Cats: Marginating pool is twice the size as circulating pool

Question 23

Excitement Leukogram

Answer 23

Due to epinephrine/catecholamines. It causes:
1. Neutrophilia (demargination)
2. Monocytosis (demargination)
3. Eosinopenia (marrow sequestration)
4. Lymphocytosis* (redistribution from lymphoid tissues)
5. Hyperglycemia that is >200 mg/dL +/- glucosuria

Question 24

Acute inflammation

Answer 24

1. Usage of circulating, marginating, and storage pool
2. Expansion of granulopoiesis
3. Mobilization of monocytes

Question 25

Chronic Inflammatoin

Answer 25

1. BM expands to meet demand 2. Monocyte pool expands