lecture 5 - leucocytes & pathology

Question 1

What is the most common type of granulocyte?

Answer 1

Neutrophils

Question 2

What is the name for the process of granulocyte production?

Answer 2

granulopoiesis

Question 3

What is the most immature form of a granulocyte?

Answer 3

Myeloblast

Question 4

Where does granulopoiesis occur?

Answer 4

Bone marrow

Question 5

How long does it take for neutrophils to mature in the bone marrow?

Answer 5

~10 days

Question 6

How long will neutrophils spend in the blood before tissue migration?

Answer 6

~5 days

Question 7

What are the 2 key cytokines that stimulate neutrophil growth?

Answer 7

GM-CSF (granulocyte (monocyte) colony stimulating factor), G-CSF (Granulocyte colony stimulating factor)

Question 8

What cytokine is used to stimulate neutrophil production following chemotherapy?

Answer 8

G-CSF (granulocyte colony stimulating factor)

Question 9

What are the 5 key stages of neutrophil adhesion & migration into tissues?

Answer 9

Rolling, slow rolling, arrest, crawling, transmigration

Question 10

What proteins aid in the adhesion and rolling of neutrophils to the endothelium?

Answer 10

adhesion molecules - selectin, integrin

Question 11

What molecules are involved in the arrest of neutrophils during adhesion and migration?

Answer 11

chemokines

Question 12

What are the 2 major mechanisms that neutrophils respond to bacteria with?

Answer 12

Apoptosis, NETosis

Question 13

What are the stimuli for neutrophil response to bacteria?

Answer 13

inflammatory cytokines, opsonized bacteria, immune complexes, fungi/ECM components

Question 14

What is opsonization?

Answer 14

The process where a pathogen is made susceptible to phagocytosis

Question 15

What is NETosis?

Answer 15

The process where neutrophils die and spill out their DNA as decondensed chromatin covered in antimicrobial compunds, forming a Neutrophil Extracellular Trap (NET) that traps bacteria and yeast.

Question 16

What are the pro-inflammatory effects of neutrophils?

Answer 16

release of self—antigen, stimulation of interferon-a/B, forming chromatin lattice (NET), presentation of antimicrobial peptidees

Question 17

What are the anti-inflammatory effects of neutrophils?

Answer 17

uptake by macrophages, stimulation of anti-inflammatory cytokines, removal of cellular debris

Question 18

What is neutrophilia?

Answer 18

An elevated neutrophil count in the blood.

Question 19

What are the 3 main causes of neutrophilia?

Answer 19

Infection, steroids, chronic illness (smoking, obesity, etc)

Question 20

What is a ‘left shift’ in neutrophil count?

Answer 20

An increase in immature neutrophils, typically due to an acute infection

Question 21

What are the features of severe infection-induced neutrophilia?

Answer 21

‘left shift’ with high immature neutrophil count, toxic granulation (increased number of prominent granules in cells), vacuolation (autophagocytosis where cells make holes in themselves)

Question 22

Why do steroids cause neutrophilia?

Answer 22

Steroids cause demmargination of neutrophils, meaning more remain in the blood and the count appears higher

Question 23

What are the causes of neutropenia?

Answer 23

pancytopenia related causes (bone marrow disease, chemotherapy, etc.), drug side effect, viral infection, genetic mutation, blood group (duffy-null), fulminant bacterial infections

Question 24

What are fulminant bacterial infections?

Answer 24

A severe, sudden bacterial infection

Question 25

Why do fulminant bacterial infections cause neutropenia?

Answer 25

At the very beginning of a rapid, severe infection all of the available neutrophils can be used up/migrate to tissue, meaning the count in the blood is low until the immune system kicks in to produce more.

Question 26

What is neutropenia?

Answer 26

Low neutrophil count in the blood

Question 27

What are the treatments for severe neutropenia?

Answer 27

intravenous antibiotics if febrile, protective isolation, G-CSF treatment

Question 28

What are the 3 key mechanisms of functional defect of neutrophils?

Answer 28

Acquired, steroid medication, genetic defect

Question 29

What are the 3 key acquired causes of functional defect in neutrophils?

Answer 29

diabetes, alcoholism and renal failure

Question 30

What is eosinophilia?

Answer 30

Elevated eosinophil count in blood

Question 31

What are the 2 major causes of eosinophilia?

Answer 31

parasitic infection, allergic/drug reactions

Question 32

What do monocytes go on to become when tissue resident?

Answer 32

macrophages

Question 33

What is monocytosis?

Answer 33

High level of monocytes in the blood

Question 34

What are the 2 main causes of monocytosis?

Answer 34

reactive chronic inflammatory states (infection), myelodysplastic syndrome

Question 35

What are the 2 likely roles of basophils?

Answer 35

immunity against worms, regulation of chronic allergic inflammation

Question 36

If immature white and red cells are found in the blood, what is this usually a sign of?

Answer 36

Severe bone marrow disease

Question 37

What is leukoerythroblastic anaemia?

Answer 37

When immature blood cells are pushed out of ‘full marrow’

Question 38

What are the key causes of leukerythtoblastic anaemia (caused by ‘full marrow’ pushing out immature cells)?

Answer 38

marrow replacement from leukaemia or lymphoma, marrow infiltration by metastatic cancer, myelofibrosis, severe hypoxia, infection

Question 39

What are the 3 main types of lymphocytes in the blood?

Answer 39

T cells, B cells, NK (natural killer) cells

Question 40

What is lymphocytosis?

Answer 40

Elevated levels of lymphocytes in the vlood

Question 41

What are the key causes of lymphocytosis in children?

Answer 41

viral infections, pertussis, acute lymphoblastic leukaemia

Question 42

What is the major cause of lymphocytosis in adolescents/young adults?

Answer 42

EBV (epstein barr virus) and subsequent glandular fever

Question 43

What does the Epstein Barr virus infect in the blood?

Answer 43

B cells

Question 44

What type of large, atypical lymphocyte are found in the blood during an acute epstein barr infection?

Answer 44

Reactive T cells

Question 45

What are the most common causes of lymphocytosis in the elderly?

Answer 45

chronic lymphocytic leukaemia, lymphoma