Interpretation of leukocyte responses in disease

Question 1

Leukemia is

Answer 1

neoplastic cells in the blood and/or bone marrow

Question 2

Leukemoid response or reaction is

Answer 2

can easily be mistaken for leukemia

Question 3

Leukemoid response or reaction is characterized by

Answer 3

Marked leukocytosis (>50.0 x 10⁹WBC/L)
Usually due to an inflammatory response

Question 4

Pancytopenia means

Answer 4

refers to a decrease in the number of all blood cell types

Question 5

Left shift means

Answer 5

increased numbers of immature neutrophils in the blood

Question 6

Degenerative left shift means

Answer 6

normal to decreased numbers of mature neutrophils with equal or higher numbers of immature neutrophils BAD

Question 7

Leukopenia looks like

Answer 7

A decrease in white blood cell numbers
Leukopenia may be balanced with a decrease in the number of all cellular elements, or it may be confined to one cellular element
Nursing care and great nutrition are important to prevent secondary infections & for bone marrow function

Question 8

Common causes of leukopenia

Answer 8

Viral infections
Overwhelming bacterial infections
Anaphylactic shock & endotoxic shock
Certain antibiotics
Chemotherapeutic drugs
Some analgesics
Lead, mercury, antihistamines, & cortisone products
A cachectic state (usually due to anorexia)

Question 9

Leukocytosis looks like and is due to

Answer 9

An increase in white blood cells
Usually due to a rise in the number of circulating neutrophils
Commonly occurs due to a physiological cause (as opposed to a pathological one)

Question 10

Physiological causes of leukocytosis

Answer 10

EXERCISE (more common in cats & horses)
STRESS (more common in dogs)
TRAUMA
STEROID THERAPY
CHRONIC ILLNESS
Due to an increase in other cell types

Question 11

Stress response results in WBC

Answer 11

WBC changes that occur in response to stress, chronic illness, exercise or steroid supplementation
The absence of a stress response in an animal that is sick is significant

Question 12

What will you see in a cat and dogs blood smear from a stress response

Answer 12

you will see a mature neutrophilia, monocytosis, lymphopenia, possible eosinopenia

Question 13

What will you see in a cattles blood smear from a stress response

Answer 13

reversal of neutrophil to lymphocyte ratio even if both are still within reference limits

Question 14

What will you see in a horses blood smear from a stress response

Answer 14

mature neutrophilia and lymphopenia*

Question 15

Pathological Causes of Leukocytosis

Answer 15

Systemic or localized infections–can cause marked neutrophilia (in dogs also monocytosis) with a possible left shift
Mastitis, peritonitis & metritis
Inflammation
Acute hemorrhage –especially if it is into a body cavityt
Sudden lyses of erythrocytest
Some toxinst
Neoplasia
Leukemia– may produce an increase in bizarre, atypical cell types and a severe left shift
t These cases usually result in a neutrophilia with NO left shift, may be followed by a monocytosis

Question 16

Leukocytosis is and related to

Answer 16

The total leukocyte response in an individual is directly related to the patient’s susceptibility to an infection, it’s immune status, and it’s general health
Debilitated animals may fail to show the expected response
The bone marrow may be affected by the underlying condition

Question 17

Left shift refers to

Answer 17

Refers to an increased concentration of immature neutrophils in the peripheral blood
Band neutrophils are the first immature cells to appear
Metamyelocytes or earlier immature forms may also be seen
Can accompany either a neutrophilia or neutropenia

Question 18

What does a left shift look like

Answer 18

Orderly classification-there should be fewer immature cells than mature neutrophils

Question 19

Left shifts are described as

Answer 19

Left shifts are usually described as to the degree of the shift
They are termed slight or mild if shifted to the band neutrophil stage
Moderate if shifted to the metamyelocyte stage
Marked or severe if shifted to the myelocyte or promyelocyte stage

Question 20

Regenerative Left Shift looks like

Answer 20

A leukocytosis due to a neutrophilia & the appearance of immature neutrophils that do not out-number the mature neutrophils → the bone marrow is responding to the inflammatory stimulus

Question 21

Degenerative Left Shift looks like

Answer 21

The total WBC count is often normal, but it can also be above or below the normal range
The immature neutrophils out-number the mature ones → the bone marrow is no longer keeping up to the demands of the body
Usually indicates a poor prognosis
A DEGENERATIVE left shift accompanying a low total WBC count calls for a guarded prognosis

Question 22

Regenerative to a Degenerative Left Shift

Answer 22

It will take some time to go from a regenerative to a degenerative shift
At first the body will be able to maintain a leukocytosis
In time, the total WBC count will fall & a leukopenia develops

Question 23

What happens to the bone marrow with a left shift

Answer 23

The bone marrow’s ability to respond is measured by the total leukocyte count
The intensity of the response is measured by the extent of the left shift

Question 24

Leukemoid Response/Reaction

Answer 24

This is a condition that is easily mistaken for a leukemia
The leukemoid response & leukemia can only be differentiated via a bone marrow exam
With both conditions, the peripheral blood shows an increased total count with a severe left shift
A leukemoid response is usually associated with severe inflammation & infection such as a pyometra, hepatic abscesses, etc
A leukemoid response is likely treatable while leukemia has a grave prognosis

Question 25

How to tell its a leukemoid response

Answer 25

Characterized by a severe leukocytosis (more than 50.0–100.0 x 10⁹WBC/L)
Most are mature neutrophils
Marked left shift showing myelocytes and metamyelocytes
Cells show toxic granulation, Döhle bodies and increased vacuoles

Question 26

Bone Marrow Function

Answer 26

In young animals, the bone marrow is very hematopoietically active
As the animal matures the marrow activity decreases & fat cells take up more marrow volume

Question 27

There are two types of marrow, they differ histologically

Answer 27

The active marrow is called RED MARROW
The other is called YELLOW MARROW

Question 28

What happens to bone marrow with blood loss

Answer 28

If there is a sudden massive blood loss or hemolytic destruction of red cells, it takes about 48 hours for the yellow marrow to begin the conversion into red marrow
-It then becomes very active to replace the lost cells
During chronic blood loss, this conversion occurs more slowly

Question 29

Bone marrow evaluation is used for what

Answer 29

Used to diagnose conditions or provide a prognosis for a condition
Findings on a blood smear analysis are used to determine whether or not a bone marrow evaluation is required

Question 30

What in a blood smear will tell you a bone marrow evaluation needs to be done

Answer 30

Persistent unexplained pancytopenia, neutropenia, or thrombocytopenia, and non-regenerative anemia
Abnormal circulating cells
Unexplained presence of immature cells on a smear

Question 31

How to preform a bone marrow evaluation

Answer 31

Contraindicated in patients with clotting disorders
It is a painful procedure–the patient needs to be anesthetized or heavily sedated with a local anesthetic at a minimum
Requires aseptic technique

Question 32

Bone marrow aspiration site for dogs

Answer 32

Dogs: proximal end of the femur at the trochanteric fossa, the iliac crest or the proximal humerus

Question 33

Bone marrow aspiration sites for cats

Answer 33

Cats: trochanteric fossa or proximal humerus

Question 34

Bone marrow aspiration sites for LA

Answer 34

Horses & cattle: sternum, ribs or ilium

Question 35

How to preform a bone marrow evaluation

Answer 35

An RVT should screen the slide to make sure it is of diagnostic quality before it is submitted to the lab
Ensure that cells are present and intact
Bone marrow evaluation must be accompanied with a CBC*
The CBC should be taken at the same time as the bone marrow aspirate
The smear should be evaluated on low-power objective to evaluate the adequacy of the smear and the degree of cellularity

Question 36

What should a bone marrow evaluation look like

Answer 36

Juveniles or Young animals should have 75% nucleated cells to 25% fat
Adults should have a 50% nucleated cells to 50% fat
Geriatric animals should have a 25% ratio of nucleated cells to 75% fat

Question 37

Cells Within the Bone Marrow

Answer 37

mmature RBCs
Mature RBCs
Immature granulocytes
Mature neutrophils, eosinophils and basophils
Immature platelets
Macrophages, lymphocytes, plasma cells, mast cells, osteoblasts and osteoclasts

Question 38

Microorganisms in bone marrow

Answer 38

Occasionally found on bone marrow aspirates
Bacteria are a very rare finding

Question 39

What are you likly to see in bone marrow that is bad

Answer 39

More likely to see:
Histoplasma capsulatum
Toxoplasma gondii
Leishmania donovani
Ehrlichia species
Mycoplasma haemofelis
Babesia species