Intro to Hematology

Question 1

What conditions may altered erythrocyte numbers show?

Answer 1

^ = erthyrocytosis v = aneamia

Question 2

When may leukocytes be analysed/what can they show?

Answer 2

Inflammatory conditions Neoplastic conditions Chemotherapy (check for leukopenia)

Question 3

What can platelets show?

Answer 3

Bleeding disorders DIC (Disseminated Intravascular Coagulopathy)

Question 4

How is plasma assessed?

Answer 4

Colour - should be clear/straw - if pink = heamolysis - if yellow = icterus

Question 5

What two aspects of blood cells are assessed?

Answer 5

Number (often by machine) Morphology in blood smears (should still be checked if only briefly to confirm machine findings)

Question 6

What can PCV show?

Answer 6

Aneamia/Dehydration Buffy coat assessmnet Plasma colour Total protein measurement from plasma once layers have been measured [check these values against machine]

Question 7

What form of RBCs may be released into the circulation if the BM is struggling to keep up with the demand for cells?

Answer 7

Reticulocytes/polychromatophils Still un-nucleated (pre-cursor to these has nucleus and is rarely released into bloodstream)

Question 8

What is RBCC?

Answer 8

Red blood cell concentration

Question 9

What is HGB?

Answer 9

Total heamoglobin - if RBCs are being lysed this Hgb is released and value ^ (?)

Question 10

What is HCT?

Answer 10

Heamatocrit Equivalent to spun PCV but calculated differently - machine calculates by measuring size and number of RBCs.

Question 11

What is MCV?

Answer 11

Mean Cell Volume Will be increased if blood cells are being produced at a rapid rate and immature cells released into circulation. Will be decreased if Hbg is low/being lost

Question 12

What is MCH?

Answer 12

Mean Cell Heamoglobin Hbg per cell

Question 13

What is MCHC?

Answer 13

Mean Cell Heamoglobin CONCENTRATION Amount of Hbg per unit VOLUME of blood - dependent on size of cell (larger cells will require more Hbg for same concentration per unit volume) This is associated with RBC maturation - will keep dividing until have sufficient Hbg concentration

Question 14

What is RDW?

Answer 14

Redcell Distribution Width Shows uniformity/variability of cell sizes Will be greater if ^ demand for cells is meaning immature cells are released into the circulation

Question 15

How is ameamia classified (3 stages) ?

Answer 15

1. Mild / Moderate / Severe [different differentials] 2. MCV - Normocytic / Microcytic / Macrocytic 3. MCHC - Normochromic / Hypochromic [Hyperchromia does not exist as a pathology as RBCs are released when sufficient Hbg has been added. Thus only an artifact of RBC lysing etc.]

Question 16

What is the ultimate Q we try to answer when investigating aneamia?

Answer 16

Regenerative or non regenerative?

Question 17

When are normocytic cells seen associated with aneamia? What will be noted about normocytic cells in anemic animals?

Answer 17

Mild, NON-regenerative - acute heamorrhage etc > will be ^ spacing between cells

Question 18

When are microcytic cells seen?

Answer 18

Iron deficiency, PSS, Hepatic failure, AKITAS [congenital breed difference] - MCHC determines when division of immature RBCs stops - Fe deficiency allows more division -> smaller cells to maintain same concentration

Question 19

When are macrocytic cells seen?

Answer 19

Regeneration - immature RBCs have not condensed, released as polychromatophils POODLES [congenital breed predisposition - still pathological]

Question 20

When are hypochromic cells sen?

Answer 20

v Hbg concentration due to Fe deficiency or poor Fe incorporation (with microcytosis) Associated with MCHC/MCH on blood panel

Question 21

Why may RBCs appear see through or just have an outline?

Answer 21

v thickness / v volume (not necessarily v diameter)

Question 22

What are the 2 differentials for regenerative anaemia?

Answer 22

Heamolysis (eg. immune mediated) Heamorrhage

Question 23

What are the most common differentials for non-regenerative?

Answer 23

Anaemia of chronic/inflammatory disease (mild) Chronic renal failure (severe) Decreased production in BM If acute stages of anaemia will appear non-regenerative as marrow still catching up

Question 24

How can regenerative anaemia be distinguished?

Answer 24

^ no reticulocytes

Question 25

How do reticulocytes and polychromatophils differ?

Answer 25

They are the same cell when prepared in different ways. IDed due to the cell still containing “machinery” that enables them to make Hbg. Should lose this before being released as fully mature cells. - Polychromatophil = Diff-Quick/Giemsa stain, immature cells show as LARGER and BLUER cells. - Reticulocytes = New Methylene Blue stain, which causes RNA to precipitate and form aggregates/reticulum.

Question 26

Do polycromatophils continue to mature once released into the blood stream?

Answer 26

Yes

Question 27

Which species have different reticulocytes? How do they differ? How does this affect analysis?

Answer 27

Cats Cat retics released as “aggregate retics” then mature to “punctate retics” over time When counting retics only these populations separately and not lumped together. If only one is counted this should be aggregate.

Question 28

How is reticulocyte % calculated?

Answer 28

1000 red cells counted, retics expressed as a percentage Must be CORRECTED for PCV of the patient Retic % x patient’s PCV/normal PCV (Otherwise same no. reticulocytes will give greater % in an anaemic animal)

Question 29

What is the normal reticulocyte % in healthy dog/cats?

Answer 29

~45% dog ~35% cat

Question 30

What difference in reticulocyte % is clinically significant?

Answer 30

>1% dogs >0.4% cats

Question 31

What form of reticulocyte measurment may be better than corrected %? What is the rough range of values for this measurement?

Answer 31

Absolute reticulocyte concentration - [RBC] x retic % - can only be carried out by machine >60-80,000/microL = regenerative *correction NOT neccesary as absolute conc calculated*

Question 32

Give some signs of regeneration visable on a blood smear

Answer 32

Polychromasia Anisocytosis (different shapes and sizes) Macrocytosis nRBCs (nucleated) Howell-Joly bodies (remnant of nucleus) Codocytosis Basophilic stippling (purple/blue dots in cell)

Question 33

What differences in RBC morphology may be noted?

Answer 33

Spherocytes, ghost cells Hypochromasia/leptocytosis [Fe deficiency] Shear products - spiky! (keratocytes, schistocytes, acanthocytes) Oxidative damage (Heinz bodies, eccentrocytes, pyknocytes) Organisms (Babesia)

Question 34

What does CBC stand for?

Answer 34

Complete blood count

Question 35

How are leukocytes analysed on a blood smear?

Answer 35

Count 100 cells, mark no. of leukocytes Expressed as %

Question 36

How may neutrophil morphology show pathologies?

Answer 36

Left shift (band neutrophils) show acute infection Toxicity (intra celluluar granules “Dohle bodies” present) show inflammation, or may be normal if in small numbers.

Question 37

In which species are toxic neutrophils more abundant?

Answer 37

Horses and cats

Question 38

What is the average lifespan of a RBC?

Answer 38

120 d

Question 39

Which neutrophil pool does a blood sample represent? How may this be affected?

Answer 39

Circulating neutrophil pool Many will be adhered to vessel wall - if stressed, ^BP frees many of these.

Question 40

Where may neutrophils be stored to v cNP?

Answer 40

Enter tissues or adhere to vessel walls

Question 41

What are the 3 main questions to be asked regarding neutrophil levels?

Answer 41

1. How much is leaving -> tissues? 2. How much is coming from Marrow? 3. How much is adhered to walls?

Question 42

What are the two forms of left shift classification?

Answer 42

Regenerative left shift - Neutrophilia - More segmented than band neutrophils Degenerative left shift - Neutropenia - More bands than segmented > can be in between the two.

Question 43

What are the common changes in various leukocyte parameters associated with different diseases referred to as?

Answer 43

Leukogram patterns

Question 44

What are the forms of leukaemia?

Answer 44

• Acute (quick death) v chronic (slow progression)
• Lymphoid (lymphocytes) v myeloid (neutrophils) All involve circulation of neoplastic cells
• ALL/AML/CLL/CML abbreviations

Question 45

What may be seen in acute leukaemias? How can lymphoid be differentiated from myeloid?

Answer 45

Many blast cells - difficult to identify cells of origin but MORE likely to be lymphoid.

• ALL v stage 5 lymphoma? [not sure what this means, maybe hard to differentiate the 2 diseases?]
• If signs of segmentation are seen then = myloid/myelomonocytic

Question 46

What may be seen in chronic leukaemia?

Answer 46

Normal looking cells, just ^ numbers

• CLL: lymphoid cells are small and mature
• CML: neutrophils appear normal

Question 47

What is a common problem associated with measuring platelet numbers?

Answer 47

Clumping due to initiation of an inflammatory response v platelet count and abnormal distribution of cells within the sample