Introduction to Haematology 22.09.2014

Question 1

What would be the indications to look for erythrocytes, leukocytes, platelets and plasma on a haematology test?

Answer 1

• Erythrocytes - anaemia, erythrocytosis (i.e. increased)
• Leukocytes - inflammatory conditions, neoplastic conditiions, chemotheraphy
• Platelets - bleeding disorders, DIC
• Plasma - colour (normally colourless)

Question 2

How do you determine total protein?

Answer 2

Run a PCV, the put plasma into a refractometer to determine plasma protein

Question 3

Why would a stressed animal show a different PCV to normal?

Answer 3

The spleen releases stored RBCs when the animal is stressed.

Question 4

What variables are looked at in relation to RBCs? (7)

Answer 4

RBC concentration, HGB, HCT, MCV, MCH, MCHC, RDW (red cell distribution width)

Question 5

How is anaemia classified? (4) Why is it done these ways?

Answer 5

1. ) Mild, moderate, severe
2. ) MCV - normocytic, microcytic, macrocytic
3. ) MCHC - normochromic, hypochromic, (hyperchromic)
4. ) Regenerative vs. non-regenerative.

Helps narrow cause

Question 6

Examples of when you might see a normocytic anaemia.

Answer 6

Often associated with mild non-regenerative anaemia, acute haemorrhage etc,

Question 7

When might you see microcytic anaemia? (3) Dog breed predisposition? (1)

Answer 7

Iron deficiency (allows an extra RBC division to ensure red cell haemoglobin concentration), PSS, hepatic failures. 
Akitas.

Question 8

When might you see a macrocytic anaemia? Dog breed predisposition (1)

Answer 8

In regeneration.

Some poodles.

Question 9

When might you sees a normo- or hypochromic anaemia?

Answer 9

Decreased iron/poor iron incorporation (with microcytosis)

Question 10

Why isn’t a hyperchromic anaemia not possible?

Answer 10

RBCs are haemolysed.

Question 11

2 reasons for regenerative anaemia

Answer 11

Haemolysis or haemorrhage

Question 12

Most common causes of non-regenerative anaemia (3)

Answer 12

• Anaemia of inflammatory/chronic disease (mild, v. common)
• CRF (severe)
• Decreased production in marrow

Question 13

Differentiate polychromataphils and reticulocytes.

Answer 13

Same cells just different staining:

• Polychromatophils: Diff-quik or giemsa stain, young cells containing rRNA show up as larger, bluer cells
• Reticulocytes: same cells stained with New Methylene Blue and the RNA precipitates from aggregates (reticulum)

Question 14

How are cat reticulocytes different?

Answer 14

They are released as aggregate reticulocytes and mature to punctate retics over time. Retic. counts should record either aggregate or both.

Question 15

How do you differentiate between regenerative and non-regenerative aneamias? What are (ab)normal values?

Answer 15

Using the reticulocyte % (1000 RBCs counted, retics expressed as a percentage of this). Corrected reticulocyte % (same number of reticulocytes willt ake up more of a percentage in a very anaemic animal therefore calculate ritc %*(patient PCV/normal PCV).

NORMAL= 45% in dogs, 35% in cats
If regenerative>1% corrected (dog), >0.4% (cat)

Absolute reticulocyte concentration may be better:
RBC conc*retic%

Question 16

What are the signs of regenerative anaemia on a blood smear? (7)

Answer 16

polychromasia, anisocytosis, macrocytosis, nRBCs, Howell-Jolly bodies, codocytosis, basophilic staining.

Question 17

What are different aspects of RBC morphology? (5)

Answer 17

• Spherocytes, ghost cells
• Hypochromasia/leptocytosis
• Shear products (keratocytes, shistocytes, acanthocytes)
• Oxidative damage (Heinz bodies, eccentrocytes, pyknocytes)
• Organisms

Question 18

Which WBCs are considered in a CBC?

Answer 18

Neutrophils, lymphocytes, monocytes, eosinophils, basophils

Question 19

How can stress affect neutrophils?

Answer 19

Neutrophils normally circulate in the blood for approximately 6 hours but stress can cause neutrophils to move back from the tissue into the blood.

Question 20

What must be considered when looking at neutrophilia or neutropenia?

Answer 20

Ration of ProNP, MatNP and SNP. (i.e. look for left shift and toxicity)

Question 21

How is left shift classified?

Answer 21

REGENERATIVE: neutrophilia, segmented>bands
DEGENERATIVE: neutropenia, bands>segemented
In between?

Question 22

Which two ways can leukaemia be defined?

Answer 22

Acute/chronic or lymphoid/myeloid (i.e. lymphocytes vs neutrophils)

Question 23

How does clumping affect platelets?

Answer 23

It is a very common problem. It causes a decrease in platelet count/concentration as platelets aren’t evenly distributed in the fluid.

Question 24

Describe acute leukaemias

Answer 24

Blast cells in circulation (difficult to ID cell of origin). Much more likely to be lymphoid. ALL (acute lymphoid leukaemia) versus stage 5 lymphoma. If signs of segmentation = myeloid or myelomonocytic. Do immunophenotyping using a flow cytometer.

Question 25

Describe chronic leukaemias.

Answer 25

CLL = chronic lymphoid leukaemia; lymphocytes appear small and mature, persistant high numbers
CML = chronic myeloid leukaemia, neutrophils appear normal, persistant high numbers.

Question 26

How do you do a manual estimate of WBC numbers?

Answer 26

Average platelet number per 10 field, multiply by 15-20*10^9/L. Ensure you have a monolayer!