White blood cells

Question 1

Normal leukocyte count

Answer 1

4.5-11x10^9

Question 2

Normal neutrophil %

Answer 2

40-70%

Question 3

Normal lymphocytes %

Answer 3

20-40%

Question 4

Normal monocytes %

Answer 4

2-8%

Question 5

Normal eosinophils %

Answer 5

1-4%

Question 6

Normal basophils %

Answer 6

0.5-1%

Question 7

Total WBC count: 7 x 10^9 cells/L 
 Neutrophils: 65%
 Lymphocytes 25%
 Monocytes: 7%
 Eosinophils 2%
 Basophils: 1%

Answer 7

Normal

Question 8

Total WBC count: 7 x 10^9 cells/L 
 Neutrophils: 60%
 Lymphocytes 25%
 Monocytes: 7%
 Eosinophils 7%
 Basophils: 1%

Answer 8

High eosinophils, allergies, asthma, parasitic infection

Question 9

Total WBC count: 25 x 10^9 cells/L  (v high)
 Neutrophils: 20% (low)
 Lymphocytes 76% (very high)
 Monocytes: 3% (low)
 Eosinophils 1% (low)
 Basophils: 0%

Answer 9

Acute viral infection

Question 10

Total WBC count: 11 x 10^9 cells/L  (higher than normal)
 Neutrophils: 85% (High)
 Lymphocytes 11% (Low)
 Monocytes: 3% (low)
 Eosinophils 1% (low)
 Basophils: 0%

Answer 10

Acute bacterial infection

Question 11

Total WBC count: 3 x 10^9 cells/L (low)
 Neutrophils: 9% (very low)
 Lymphocytes 83% (very high)
 Monocytes: 7%
 Eosinophils 2%
 Basophils: 1%

Answer 11

Chronic viral infection

Question 12

What are granulocytes?

Answer 12

Polymorphonuclear leukocytes (PMNs or polymorphs), eosinophils and basophils

Question 13

What are mononuclear leukocytes?

Answer 13

Monocytes, B and T lymphocytes and NK cells

Question 14

How can T lymphocytes be differentiated/ told apart?

Answer 14

Expression of molecules on their cell surfaces.

Question 15

What antibodies are used to recognise B cells?

Answer 15

CD19

Question 16

What antibodies are used to recognise both T cells?

Answer 16

CD3

Question 17

What is flow cytometry?

Answer 17

Flow cytometry uses a machine termed a flow cytometer to detect fluorescently labelled antibodies bound to cell surfaces.

Question 18

What does CD4 give rise to?

Answer 18

T cell co-receptor – defines T helper/Treg subsets, also monocytes

Question 19

What does CD5 give rise to?

Answer 19

T cells and a subset of B cells

Question 20

What does CD8 give rise to?

Answer 20

T cell co-receptor – defines cytotoxic T subset CD3+, also NK cells -CD3-

Question 21

What are NK cell surface markers?

Answer 21

CD3- CD8+

Question 22

What does CD14 show?

Answer 22

Co receptor for LPS expressed on human monocytes

Question 23

What surface marker is CD20

Answer 23

B cell surface marker

Question 24

What does CD25 show?

Answer 24

Lymphocyte activation marker - shows T cell is active

Question 25

What is CD28?

Answer 25

Important T cell co-stimulatory molecule

Question 26

What is CD45?

Answer 26

Leucocyte common antigen, expressed on all hematopoietic cells

Question 27

How does the flow cytometer show relative size?

Answer 27

Forward light scatter (FSC channel)

Question 28

How does the flow cytometer show relative granularity?

Answer 28

Side light scatter (SSC channel)

Question 29

How is flow cytometry done?

Answer 29

1. A sample containing cells or particles is suspended in a fluid and injected into the flow cytometer instrument. 2. The sample is focused to ideally flow one cell at a time through a laser beam, where the light scattered is characteristic to the cells and their components. 3. Cells are often labelled with fluorescent markers so light is absorbed and then emitted in a band of wavelengths.

Question 30

What does forward scatter depend on?

Answer 30

Proportional to the diameter of the cell, and is primarily due to light diffraction around the cell

Question 31

What does side scatter depend on?

Answer 31

Light refracted or reflected at the interface between the laser and intracellular structures, such as granules and nucleus

Question 32

How are RBCs removed from being confounders?

Answer 32

Treated with an agent to lyse them

Question 33

Where do neutrophils lie on a flow cytometry graph?

Answer 33

Top right (large forward scatter and large side scatter)

Question 34

Where do lymphocytes lie on a flow cytometry graph?

Answer 34

Middle bottom (low side scatter, medium forward scatter)

Question 35

Where do monocytes lie on a flow cytometry graph?

Answer 35

Medium to low side scatter and medium to large forward scatter

Question 36

When blood is fractionated what are the layers?

Answer 36

Red blood cells (RBCs) pelleted to the bottom of the centrifuge tube. Polymorphonuclear cells (PMNs) are found above the RBCs whereas peripheral blood mononuclear cells (PBMCs) are found at the plasma/histopaque interphase.

Question 37

Name two of the white blood cell types found in the upper right of this graph i.e. high forward scatter and high side scatter

Answer 37

Granulocytes Neutrophils, Eosinophils, Basophils, Mast cells

Question 38

Name two of the white blood cell types found in the lower left of this graph i.e. low forward scatter and low side scatter

Answer 38

Lymphocytes T cells, B cells + NK cells

Question 39

CD31

Answer 39

Mediates interactions between leukocyte and endothelial cell diapedesis