Leukogram

Question 1

What are the parts of this blood test?

Answer 1

Red - Erython

Blue/white - Leukon

Blue - Thrombon

Green - Morphology

Question 2

Where and what are the steps in neutrophil production?

Answer 2

• Bone Marrow
• Occasional EMH (spleen, liver, other)
• Myeloblast →Progranulocyte → Myelocyte →
• Proliferate and mature
• Metamyelocyte →Band →segmented neutrophil
• Maturation only

Question 3

What are the 3 main steps in cells leaving blood vessels?

Answer 3

• Marginalisation
• Adhesion
• Migration

Question 4

What may produce a shift from marginal to circulating pool?

Answer 4

• Epinephrine
• Infection
• Stress

Question 5

What does a normal neutrophil count mean?

Answer 5

• Inflammatory disease is ruled out
• Inflammatory disease could be present

Question 6

Name causes of neutrophilia

Answer 6

• Inflammation
• Infections (bacterial, viral, fungal, protozoal)
• Immune mediated anaemia
• Necrosis (including haemolysis, sterile inflam. and FB’s)

(Inflammatory mediators must be able to get from lesion to circulation to reach marrow – think about superficial skin, LUTD, CNS)

• Steroid
• Stress
• Steroid therapy (occ. ACTH)
• Hyperadrenocorticism
• Physiological
• Fight or flight (excitement, fear, pain, exercise)
• Chronic neutrophil leukaemia
• Paraneoplastic (rectal polyp, renal tubular carcinoma, metastatic fibrosarcoma)
• Other
• E.g. LAD

Question 7

Name regenerative and degenerative causes of left shift neutrophilia

Answer 7

Regenerative left shift: mature neutrophils Hematology: neutrophil outnumber bands and are elevated or normal.

Degenerative left shift: excessive neutophil consumption → bands and/or less mature leukocytes outnumber mature neutrophils.

Question 8

What causes a right shift of neutrophils?

Answer 8

•Glucocoticoids down-regulate adhesion molecules, less neutrophils leave the circulation to die, aged cells remain in circulation

Question 9

What would be signs of toxic change in neutrophils?

Answer 9

• Foamy cytoplasm
• Dispersed organelles (not discrete –EDTA)
• Diffuse cytoplasmic basophilia
• Persistent of cytoplasmic RNA
• Incl segmented neutrophils
• Döhle bodies
• Focal blue-grey cytoplasmic structures (RER/RNA)
• Isolated finding in some healthy cats
• Asynchronus nuclear maturation
• Finely granular nuclear chromatin but in “segments”

Question 10

Label

Answer 10

A.Normal mature Neutrophil

B.Toxic neutrophil

C.Normal Band Neutrophil

D.Toxic Band Neutrophil

Question 11

Name the different types of neutrophil inclusions and what can cause these

Answer 11

• Bacterial
• Ehrlichia, Anaplasma
• Viral
• Canine distemper
• Protozoa
• Toxoplasma
• Hepatozoon
• Fungi
• Histoplasma
• Hereditary/metabolic
• Chediak-Higashi, Birman cat anomaly, mucopolysidosis,

Question 12

What is this?

Answer 12

Rabbit heterophil

Question 13

What is this?

Answer 13

Reptile heterophil

Question 14

What is this?

Answer 14

Avian Heterophil

Question 15

Define heterophil

Answer 15

Functionally equivalent to neutrophils, but granules stain red

Question 16

Name inflammatory causes of neutropenia

Answer 16

• Peracute/overwhelming bacterial infections
• Canine and feline parvo-virus

Question 17

Name causes for decreased production neutropaenia

Answer 17

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

Question 18

Name rare causes for neutropenia (4)

Answer 18

•Immune mediated neutropenia, Chediak-Higashi, ayclic haematopoiesis in grey collies, canine hereditary neutropenia

Question 19

What does it mean to have neutropenia in:

A) Dogs/cats?

B) Horses?

C) Cows?

Answer 19

A) Very severe lesion

B) Probable severe lesion

C)Neutropenia typical in inflammation regardless of severity

Question 20

What animal are these WBC types?

Answer 20

A) Canine

B) Feline

C) Equine

D) Bovine

D) Reactive

E) Granular

Question 21

What are the categories of lymphocyte inclusions and what can cause these?

Answer 21

• Functional
• Large granular lymphocytes
• Infectious
• Ehrlichia
• Distemper
• Metabolic
• Lysosomal storage diseases

Question 22

What are causes of lymphocytosis?

Answer 22

• Physiological
• Catecholamine mediated via splenic contraction (especially cats)
• Chronic Inflammation
• Chronic antigenic stimulation
• May include reactive lymphocytes
• Usu with neutrophilia and/or monocytosis (±eosinophilia)
• Young animals and recent vaccination
• Lymphoproliferative disorder (incl FeLV, BLV)
• May be lymphopenia in lymphoma
• Hypoadrenocorticism

Question 23

What can case lymphopenia?

Answer 23

• Stress/steroid
• Endogenous or exogenous glucocorticoid
• shifts lymphocytes out of circulation & lymphocytolysis
• Acute inflammation
• Bacterial, viral or endotoxaemia
• Migration to inflamed tissue and homing to LN’s
• Often with neutrophilia or neutropenia
• Correction of lymphopenia → better prognosis
• Loss of lymph
• Chylothorax (drainage) or lymphangiectasia
• Cytotoxic drugs, radiation
• Immunodeficiency syndrome
• Lymphoma
• LN pathology and disrupted circulation

Question 24

What is seen with reactive lymphocytes?

Answer 24

• ↑ cytoplasm
• ↑ cytoplasmic basophilia
• Perinuclear halo
• Prominent Golgi zone
• ↑, eccentric, cleaved nucleus
• More medium and large (i.e., vs peripheral blood “small”)

Question 25

What causes reactive lymphocytes?

Answer 25

* Aka immunocytes, plasmacytoid lymphocytes * Stimulated T or B * Inflammation (esp chronic) * Young animals

Question 26

What are these?

Answer 26

Reactive lymphocytes

Question 27

Monocyte/macrophage: A) Which are blood resident? B) How does differentiation happen? What changes?

Answer 27

A) Monocytes B) Differentiation into macrophages occurs when they enter tissues – take on a more spindle like appearance

Question 28

What speciesare these and what are they?

Answer 28

A) Canine B) Feline monocytes

Question 29

What can cause monocytosis?

Answer 29

* Inflammation * Bacterial, fungal, protozoal * Necrosis: haemolysis, haemorrhage, neoplasia, infarction, trauma * Inconsistent finding (chronic but also acute inflammation) * Steroid/Stress * Stress * Glucocorticoids (occ ACTH) * Hyperadrenocorticism * Monocytic/myelomonocytic leukaemia * Monocytopenia not recognised a clinically significant entity

Question 30

What causes eosinophilia?

Answer 30

* Hypersensitivity * Parasitism * Hypoadrenocorticism * Paraneoplastic (esp Mast cell but also others) * Idiopathic eosinophilic syndromes * E.g., canine eosinophilic bronchopneumopathy, myositis, feline eosinophilic granuloma etc * Eosinophilic leukaemia (v rare)

Question 31

What causes eosinopenia?

Answer 31

•Glucocorticoids, stress, inflammation

Question 32

Which cell is rare to be found on a blood smear?

Answer 32

Basophil

Question 33

When might nucleated red cells be seen?

Answer 33

* Can be present in moderate numbers in regenerative anaemias, lead toxicity * EMH and splenic contraction, damaged marrow * Present in inappropriately high numbers in erythroleukaemia (erythemic myelosis; cats)

Question 34

What must hapen to calculate nuclated red cells?

Answer 34

•Manual and automated counting methods for total WBCC that count nuclei in lysed samples, will need WBCC correcting for nRBC’s

Question 35

What is this?

Answer 35

Big, unclassified, neoplastic cells

Question 36

What do we use WBC absolutes for?

Answer 36

Comparison against reference intervals

Question 37

What is the effect of excitement on bloods?

Answer 37

* Catecholamine * Travel, capture, chutes * Handling * Mature neutrophilia * 2x dogs, horses and cows, \>2x cats * Lymphocytosis * esp. cats * Resolves within hours or less

Question 38

What is the effect of steroid/stress on bloods?

Answer 38

* Glucocorticoid * Endogenous * Exogenous * Mature neutrophilia * 2x dogs, horses and cows, \>2x cats * Lymphopenia * Eosinopenia\* * ± Monocytosis

Question 39

How might we measure total leucocyte count?

Answer 39

* Manual –haemocytometer * Machine (also attempts differentiation) * Impedance * SCIL ABC+ * Laser * E.g. IDEXX Lasercyte * Combined laser, impedance * Simultaneous: OSI Genesis * Non-simultaneous: IDEXX Procyte * Multichannel laser * Reference lab: Siemens ADVIA

Question 40

What is the best technology for counting and sizing WBC?

Answer 40

Impedance

Question 41

What is the best technology for inttracellular complexity and lobularity?

Answer 41

Laser

Question 42

What are common errors with automated leukograms?

Answer 42

* Varying degrees of accuracy – none perfect * None count bands, other WBC precursors or nRBC’s * None report toxic change * None report WBC inclusions * None specifically report atypical or reactive morphology * Impedance * Neutrophil count most reliable * May confuse lymphocytes and monocytes * All * Bands and metamyelocytes may be miscounted as monocytes * Sick animals with “neutropenia” and unrealistic “monocytosis” * Differential counts in normal animals usually correct * But we are doing the test to know if abnormal

Question 43

Your analyser says Granulocytes 27 (ref: 3.3 – 12 x 10^9) Is this more likely to be stress or inflammation?

Answer 43

Inflammation

Question 44

* Waxing and waning illness 1-month * Intermittent diarrhoea * Presented weak, difficulty standing * Pale tacky MM’s, HR 120 Can we justify a haematology?

Answer 44

Yes the dog is pale

Question 45

A) Are the findings expected in a sick dog? B) Can you suggest a condition for further rule out?

Answer 45

A) High neutrophil, high esionophl, no bands. Expect low lymphocytes Stress leucogram would expect low eosinophils B) Addisons E are expecting stress leuogram so may not be glucocorticoids!

Question 46

* Weakness, frequent attempts at urination and dribbling urine * Empty scrotum but not definitive history of castration * Palor, prostatomegaly, ?cryptorchid Can you justify a haematology examination?

Answer 46

Pale - yes

Question 47

Which is most likely: inflammation, neoplasia, other? Can you suggest a condition for further rule out?

Answer 47

Neurtopaenia – suggests bone marrow suppression. Sertoli cell tumour

Question 48

What should we investiagate for?

Answer 48

Leukaemia

Question 49

What type of disease does this dog have?

Answer 49

Travel disease

Question 50

What leukogram pattern is seen with adrealine?

Answer 50

An increased WBC where neutrophil is high, no bands, lymphocyte is high

Question 51

What is seen on leukogram with steroids?

Answer 51

High neutrophils, segments, little band and low lymphocyte

Question 52

What is seen on a leukogram with acute inflammation?

Answer 52

Lymphocytes down and bands up

Question 53

What does it mean with neutropaenia: A) Which a left shift? B) No left shift?

Answer 53

A) Demand B) Marrow injury

Question 54

What does it mean if there is neutrophilia and: A) Left shift? B) No left shift and low lymphocyte? C) Lymphocytes normal or slightly up?

Answer 54

A) Inflammation B) Steroids C) Fear

Question 55

What causes a right shift?

Answer 55

•These are very aged cells. Hypermature. When they get old the nucleus divides further. They become hypersegmented. If there are steroids which stops them getting out and keeps them in circulation. They get older and older.

Question 56

What causes a netrophilia left shift?

Answer 56

We aren’t making many more than normal. Taking the out of storage before they are ready

Question 57

What is Physiological (fear/excitement) Neutrophilia?

Answer 57

Think of adrenaline as a fear response. Adrenaline based. Demarginalisation. Not effecting migration. Just means stickiness is reduced so they fall off.

Question 58

What is Steroid Neutrophilia?

Answer 58

Measured neutrophil goes up as we have held some in circulation which would have normally escaped. Moved some from marginal to circulatory

Question 59

What is neutrophilia?

Answer 59

When we have glucocorticoid we stop neutrophil migration across vessel wall to keep them in. Adrenaline and corticosteroids can do this demarginalisation Infection – increased production, storage and output pool

Question 60

How can we have a low high or normal WBC with inflammation?

Answer 60

High WBC in inflammation – lots in circulation Low WBC in inflammation – being sucked up by demand Normal neutrophil count does NOT mean there is no inflammation! Depends on balance of use and production

Question 61

Outline approach to neutrophilia?

Answer 61

Question 62

Outline approach to neutropaenia?

Answer 62