Lecture 5: White Blood Cells and their Disorders

Question 1

Name the stages in the lifecycle of a neutrophil.

Answer 1

• Myelocyte
• Promyelocyte
• Myelocyte
• Metamyelocyte
• Band
• Segment

Question 2

What is left shifting?

Answer 2

An blood abnormality in which more immature neutrophils are present in blood. Usually caused by an ongoing infection.

Question 3

How long do mature neutrophils typically spend in the peripheral blood?

Answer 3

Usually only around 8-10 hours.

Question 4

What usually happens after neutrophils have circulated for 10 hours?

Answer 4

Diapedesis. This is the movement of neutrophils from the circulatory system into peripheral tissues.

Question 5

How are neutrophils attracted to sites of infection?

Question 6

How do neutrophils bind to pathogens?

Question 7

How do neutrophils destroy pathogens once engulfed?

Answer 7

Respiratory Burst. This is

Question 8

What is neutrophilia?

Answer 8

A high neutrophil presence in blood. There can be many pathological and non-pathological reasons for neutrophilia.

Question 9

What is the reference range for neutrophils?

Answer 9

7x10^9 cells/L

Question 10

What is pseudo-neutrophilia?

Answer 10

Neutrophilia caused by non-pathological reasons such as pregnancy, diurnal variation. exercise, etc.

Question 11

How can true neutrophilia be distinguished?

Answer 11

A left shift is often associated with true neutrophilia, as well as toxic granulation. Dohle bodies are often found.

Question 12

What are Dohle bodies?

Answer 12

Aggregates of degraded ribosomes,

Question 13

What is toxic granulation?

Question 14

What is sepsis?

Answer 14

A syndrome of multi-organ dysfunction due to abnormal immune response to infection. Caused by many errors in immune response, associated with

Question 15

What are the three most common infection sites of sepsis?

Question 16

Name some risk factors that can lead to sepsis?

Question 17

What are the most common pathogens associated with sepsis?

Question 18

What is neutropenia?

Question 19

How is chronic granulomatous disease caused?

Question 20

What are eosinophils?

Answer 20

Leukocytes that deal with parasites. They are weakly phagocytic but will secrete toxic granule contents when near parasites. Eosinophils are also able to modulate immune response by secreting histaminase and arylsulfatase (destroy histamine and leukotrienes respectively). Can also phagocytose antibody-antigen complexes.

Question 21

How long will eosinophils circulate before migrating into peripheral tissue.

Answer 21

Only around 5 hours.

Question 22

How long will eosinophils live in tissue after migrating?

Answer 22

~14 days. Eosinophils are numerous under epithelial tissue.

Question 23

What is eosinophilia?

Answer 23

An abnormally high level of eosinophils in blood. Non-malignant eosinophilia can be classed as idiopathic, reactive or as part of organ-eosinophilic syndromes.

Question 24

What is reactive eosinophilia be classed as?

Question 25

In what way are T-cells and eosinophils linked in eosinophilia?

Question 26

What are some organ associated eosinophilic syndromes?

Question 27

What are lymphocytes?

Question 28

What do B cells do in health?

Question 29

What do T cells do in health?

Question 30

What does a cluster of differentiation mean?

Answer 30

A nomenclature system in immunology, for identifying markers on a cell’s surface. A cell can be positive or negative for specific CDs.

Question 31

What are some common CDs?

Answer 31

• CD3
• CD4
• CD8
• CD25
• CD34

Question 32

How can CD markers be identified and quantified?

Answer 32

By using monoclonal antibodies. Two techniques employing antibodies are immunohistochemistry and flow cytometry.

Question 33

What is lymphocytosis?

Question 34

What is the Epstein-Barr virus?