Leukogram Flashcards
What are the parts of this blood test?
Red - Erython
Blue/white - Leukon
Blue - Thrombon
Green - Morphology
Where and what are the steps in neutrophil production?
- Bone Marrow
- Occasional EMH (spleen, liver, other)
- Myeloblast →Progranulocyte → Myelocyte →
- Proliferate and mature
- Metamyelocyte →Band →segmented neutrophil
- Maturation only
What are the 3 main steps in cells leaving blood vessels?
- Marginalisation
- Adhesion
- Migration
What may produce a shift from marginal to circulating pool?
- Epinephrine
- Infection
- Stress
What does a normal neutrophil count mean?
- Inflammatory disease is ruled out
- Inflammatory disease could be present
Name causes of neutrophilia
- 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
Name regenerative and degenerative causes of left shift neutrophilia
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.
What causes a right shift of neutrophils?
•Glucocoticoids down-regulate adhesion molecules, less neutrophils leave the circulation to die, aged cells remain in circulation
What would be signs of toxic change in neutrophils?
- 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”
Label
A.Normal mature Neutrophil
B.Toxic neutrophil
C.Normal Band Neutrophil
D.Toxic Band Neutrophil
Name the different types of neutrophil inclusions and what can cause these
- Bacterial
- Ehrlichia, Anaplasma
- Viral
- Canine distemper
- Protozoa
- Toxoplasma
- Hepatozoon
- Fungi
- Histoplasma
- Hereditary/metabolic
- Chediak-Higashi, Birman cat anomaly, mucopolysidosis,
What is this?
Rabbit heterophil
What is this?
Reptile heterophil
What is this?
Avian Heterophil
Define heterophil
Functionally equivalent to neutrophils, but granules stain red
Name inflammatory causes of neutropenia
- Peracute/overwhelming bacterial infections
- Canine and feline parvo-virus
Name causes for decreased production neutropaenia
- Infections: parvovirus, FeLV, toxoplasma
- Toxicity: chemotherapy, oestrogen, chloramphenicol (cats)
- Neoplasia: leukaemia, myelodysplastic, metastatic
- Marrow necrosis
- Myelofibrosis
Name rare causes for neutropenia (4)
•Immune mediated neutropenia, Chediak-Higashi, ayclic haematopoiesis in grey collies, canine hereditary neutropenia
What does it mean to have neutropenia in:
A) Dogs/cats?
B) Horses?
C) Cows?
A) Very severe lesion
B) Probable severe lesion
C)Neutropenia typical in inflammation regardless of severity
What animal are these WBC types?
A) Canine
B) Feline
C) Equine
D) Bovine
D) Reactive
E) Granular
What are the categories of lymphocyte inclusions and what can cause these?
- Functional
- Large granular lymphocytes
- Infectious
- Ehrlichia
- Distemper
- Metabolic
- Lysosomal storage diseases
What are causes of lymphocytosis?
- 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
What can case lymphopenia?
- 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
What is seen with reactive lymphocytes?
- ↑ cytoplasm
- ↑ cytoplasmic basophilia
- Perinuclear halo
- Prominent Golgi zone
- ↑, eccentric, cleaved nucleus
- More medium and large (i.e., vs peripheral blood “small”)
What causes reactive lymphocytes?
- Aka immunocytes, plasmacytoid lymphocytes
- Stimulated T or B
- Inflammation (esp chronic)
- Young animals
What are these?
Reactive lymphocytes
Monocyte/macrophage:
A) Which are blood resident?
B) How does differentiation happen? What changes?
A) Monocytes
B) Differentiation into macrophages occurs when they enter tissues – take on a more spindle like appearance
What speciesare these and what are they?
A) Canine
B) Feline
monocytes
What can cause monocytosis?
- 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
What causes eosinophilia?
- 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)
What causes eosinopenia?
•Glucocorticoids, stress, inflammation
Which cell is rare to be found on a blood smear?
Basophil
When might nucleated red cells be seen?
- 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)
What must hapen to calculate nuclated red cells?
•Manual and automated counting methods for total WBCC that count nuclei in lysed samples, will need WBCC correcting for nRBC’s
What is this?
Big, unclassified, neoplastic cells
What do we use WBC absolutes for?
Comparison against reference intervals
What is the effect of excitement on bloods?
- Catecholamine
- Travel, capture, chutes
- Handling
- Mature neutrophilia
- 2x dogs, horses and cows, >2x cats
- Lymphocytosis
- esp. cats
- Resolves within hours or less
What is the effect of steroid/stress on bloods?
- Glucocorticoid
- Endogenous
- Exogenous
- Mature neutrophilia
- 2x dogs, horses and cows, >2x cats
- Lymphopenia
- Eosinopenia*
- ± Monocytosis
How might we measure total leucocyte count?
- 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
What is the best technology for counting and sizing WBC?
Impedance
What is the best technology for inttracellular complexity and lobularity?
Laser
What are common errors with automated leukograms?
- 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
Your analyser says Granulocytes 27 (ref: 3.3 – 12 x 10^9)
Is this more likely to be stress or inflammation?
Inflammation
- Waxing and waning illness 1-month
- Intermittent diarrhoea
- Presented weak, difficulty standing
- Pale tacky MM’s, HR 120
Can we justify a haematology?
Yes the dog is pale
A) Are the findings expected in a sick dog?
B) Can you suggest a condition for further rule out?
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!
- 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?
Pale - yes
Which is most likely: inflammation, neoplasia, other?
Can you suggest a condition for further rule out?
Neurtopaenia – suggests bone marrow suppression. Sertoli cell tumour
What should we investiagate for?
Leukaemia
What type of disease does this dog have?
Travel disease
What leukogram pattern is seen with adrealine?
An increased WBC where neutrophil is high, no bands, lymphocyte is high
What is seen on leukogram with steroids?
High neutrophils, segments, little band and low lymphocyte
What is seen on a leukogram with acute inflammation?
Lymphocytes down and bands up
What does it mean with neutropaenia:
A) Which a left shift?
B) No left shift?
A) Demand
B) Marrow injury
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?
A) Inflammation
B) Steroids
C) Fear
What causes a right shift?
•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.
What causes a netrophilia left shift?
We aren’t making many more than normal. Taking the out of storage before they are ready
What is Physiological (fear/excitement) Neutrophilia?
Think of adrenaline as a fear response. Adrenaline based. Demarginalisation. Not effecting migration. Just means stickiness is reduced so they fall off.
What is Steroid Neutrophilia?
Measured neutrophil goes up as we have held some in circulation which would have normally escaped. Moved some from marginal to circulatory
What is neutrophilia?
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
How can we have a low high or normal WBC with inflammation?
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
Outline approach to neutrophilia?
Outline approach to neutropaenia?
