White Blood Cells

Question 1

Leukon

Answer 1

White blood cells and their precursors

Question 2

What is Leucocytosis

Answer 2

High levels of white blood cells

Question 3

What is leucopenia

Answer 3

Low levels of white blood cells

Question 4

3 steps in cells leaving blood vessels

Answer 4

Marginalisation
Adhesion
Migration

Question 5

Roughly what proportion of white blood cells are in the circulating pool

Answer 5

dogs- 50%
cat- 25-50%

Question 6

What factor produce a shift of white blood cells from marginal to circulating pool (4)

Answer 6

Epinephrine!
Glucocorticoids!
Infection
Stress

Question 7

How to white blood cells bind to blood vessels walls

Answer 7

binding selectin receptors on blood vessels binds to ligands on cell walls

Question 8

What happens when delivery of neutrophils from marrow exceeds inflammatory site consumption

Answer 8

Blood neutrophilia develops

Question 9

What happens when tissue consumption fo neutrophils exceeds delivery from bone marrow

Answer 9

neutropenia with left shift develops

Question 10

Causes of neutrophilia (6)

Answer 10

High neutrophils
Inflammation- infections, immune mediated anaemia, necrosis
Steroids- Stress, Steroid therapy, hyperadrenocorticism
Physiological- Epinephrine, fight or flight (excitement, fear, pain exercise)
Chronic neutrophil leukaemia
Paraneoplastic- lymphoma, MCT, haemangiosarcoma, adenocarcinoma

Question 11

White blood cell shift seen in regenerative anaemia

Answer 11

Left shift
Segmented>immature
Neutrophils INCREASE

Question 12

White blood cell shift seen in degenerative anaemia

Answer 12

Right shift
immature -> segmented
Neutrophils stay the same or decrease

Question 13

Why does right shift occur

Answer 13

Decreased extravasion -Cells are held in circulation for longer than they should be
Due to Glucocorticoids

Question 14

How to glucocorticoids lead to right shift

Answer 14

down-regulate adhesion molecules,
less neutrophils leave the circulation
aged cells remain in circulation

Question 15

What is neutrophil toxic change

Answer 15

Rapid neutropoesis- release of neutrophils that have not fully matured
Poor prognostic indicator

Question 16

Cause of neutrophil toxic change

Answer 16

usually severe bacterial infection
or injection of G-CSF (type of growth factor that makes the bone marrow produce more white blood cells)
Can be associated with parvo, IMHA, ARF, DIC, neoplasmia

Question 17

What is seen in neutrophil toxic change

Answer 17

Foamy cytoplasm
Diffuse cytoplasmic basophillia
Dohle bodies
Asynchonous nuclear maturation

Question 18

What is a dohle body

Answer 18

grey/white inclusion in nucleus

Question 19

What are heterophils

Answer 19

Present in rabbits, reptiles etc.
Functionally equivalent to neutrophils but granules stain red

Question 20

Causes of neutropenia

Answer 20

Inflammation- Pre-acute/overwhelming bacterial infections
Canine and feline parvo-virus

Decreased production (less common)
Rare- immune mediated, Chediak-Higashi, ayclic haematopoiesis in grey collies, canine hereditary neutropenia

Question 21

Causes of decreased production on neutrophils (4)

Answer 21

Infections: parvovirus, FeLV, toxoplasma
Toxicity: chemotherapy, oestrogen, chloramphenicol (cats)
Neoplasia: leukaemia, myelodysplastic, metastatic
Marrow necrosis
Myelofibrosis

Question 22

Interpretation of neutropenia in acute inflammation (dog or cat, horse, cow)

Answer 22

Dog/cat- very severe lesion
Horse- Probable severe lesion
Cow- Neutropenia typical in inflammation regardless of severity

Question 23

When there is a bone marrow disruption, what order do blood cells decrease in -> pan cytopenia

Answer 23

Neutrophils (hours)
Platelets (days)
RBCs (months)

Question 24

What are reactive lymphocytes

Answer 24

Immune stimulated T or B cells
Present in inflammation (esp. chronic)
Can be seen in young animals

Question 25

What is lymphocytosis

Answer 25

High lymphocytes

Question 26

Causes of lymphocytosis (5)

Answer 26

Physiological- catecholamine mediated via. splenic contraction (esp. cats) Chronic Inflammation Young animals and recent vaccination Lymphoproliferative disorder (FeLV, BLV) Hypoadrenocorticism - loss of normal level of lymphocyte inhibition by glucocorticoids

Question 27

How does chronic inflammation lead to lymphocytosis

Answer 27

Chronic antigenic stimulation of lymphocytes May include reactive lymphocytes usually seen with neutrophilia and/or monocytosis

Question 28

What is lymphopenia

Answer 28

Low lymphocytes

Question 29

Causes of lymphopenia (6)

Answer 29

Stress/Steroids- glucocorticoids, shifts lymphocytes out of circulation and lymphocytolysis Acute Inflammation- lymphocytes move to site of inflammation Loss of lymph-Chylothorax (drainage) or lymphangiectasia Cytotoxic drugs, radiation Immunodeficiency syndrome Lymphoma

Question 30

What do monocytes differentiate to and when

Answer 30

Macrophages Occurs when they enter tissues-> they take on a more spindle like appearance

Question 31

what are monocytes/macrophages responsible for and what does this process releasr

Answer 31

Phagocytosis Immune mediators e.g. cytokines

Question 32

What is monocytosis

Answer 32

high monocytes

Question 33

Causes of monocytosis (3)

Answer 33

Inflammation- may imply chronic Steroid/stress Monocytic/myelomonocytic leukaemia

Question 34

What is eosinophillia

Answer 34

High eosinophils

Question 35

Causes of eosinophilia (6)

Answer 35

Hypersensitivity Parasitism Hypoadrenocorticism Paraneoplastic Idiopathic eosinophilic syndromes Eosinophilic leukaemia (v rare)

Question 36

Why and how do epinephrine and glucocorticoids affect white blood cell concentrations in blood

Answer 36

They produce a shift of cells from marginal (bound to cell walls) pool to circulating pool (free in blood) They increase number of blood cells in blood/ circulating to be used by inflamed tissues

Question 37

Causes of eosinopenia (3)

Answer 37

Glucocorticoids Stress Inflammation

Question 38

Effect of stress on lymphocytes

Answer 38

Stress can have a significant impact on the levels and function of lymphocytes, which are a type of white blood cell involved in the body's immune response. In the short term, stress can cause a temporary increase in the number of circulating lymphocytes, as part of the body's initial response to a perceived threat. This is mediated by the release of catecholamines, which stimulate the release of lymphocytes from the spleen and other lymphoid tissues into the bloodstream. This effect is part of the body's "fight or flight" response, which prepares the body to respond to a physical threat. However, chronic or prolonged stress can have the opposite effect, leading to a decrease in the number and function of lymphocytes. This is due to the release of glucocorticoids, which suppress the immune system and can inhibit the production and function of lymphocytes. Chronic stress can also lead to inflammation and oxidative stress, which can further impair the immune system and lead to immune dysfunction. In summary, acute stress can temporarily increase lymphocyte levels, while chronic stress can lead to a decrease in lymphocyte levels and function, and increase the risk of immune dysfunction and disease.

Question 39

Lymphangiectasia

Answer 39

ilation or enlargement of lymphatic vessels They leak lymphatic fluid into surrounding tissues, leading to swelling, inflammation,

Question 40

monocytes

Answer 40

differentiate into macrophages or dendritic cells- dendritic cells act as APCs and memory cells and produce cytokines Produced in the bone marrow Circulate in the bloodstream Help fight infections and other foreign invaders Engulf and destroy bacteria, viruses, and other foreign substances Produce cytokines to coordinate the immune response and recruit other immune cells Involved in tissue repair and wound healing