6. Intro to White Blood Cells

Question 1

neutrophilia

Answer 1

too many white blood cells

Question 2

neutropenia

Answer 2

too few WBCs

Question 3

Leukocytosis

Answer 3

total WBCs elevated above normal range.

Question 4

general causes of leukocytosis?

Answer 4

infections!!
cancer
leukemia
stress
meds (steroids)

Question 5

if we have leukocytosis, how can we better characterize the problem?

Answer 5

WBC differential

Question 6

what is the difference between absolute count and relative count? which is physiologically impt?

Answer 6

absolute: total WBC * %cells
relative count: just the %
ABSOLUTE is most impt.

Question 7

how do I calculate the absolute neutrophil count?

Answer 7

ANC = WBC * (%Neut + %Bands)

Question 8

why are Neutrophils and Bands part of the ANC but not other cells in that lineage?

Answer 8

because Neutrophils and Bands are functionally active. Other precursor cells aren’t active, unable to fight infection

Question 9

when presented with an abnormal total WBC count, what’s the next step?

Answer 9

calculate the Differential: percentage of each type of WBC cell

Question 10

an increase in neutrophils and bands is called what?

Answer 10

neutrophilia.

Question 11

neutrophil: definition, military analogy?

Answer 11

mature, infection fighting cell. AKA PMN. The Infantry

Question 12

Band: definition, military analogy

Answer 12

immature neutrophil, “young” cell. The Marines.

Question 13

Granulocyte includes what?

Answer 13

PMNs, eosinophils, basophils

Question 14

Neutrophil function, highly simplified?

Answer 14

rolls along vessel, gets slowed down by selectins, adhesion, diapedesis into tissue, follows cytokine trail, eventually phagocytoses C3b-coated bacteria

Question 15

what are the precursors to neutrophils called?

Answer 15

-myelocytes in general. (or myeloid cells)

Question 16

what are the precursors to RBCs called?

Answer 16

-blasts in general

Question 17

what is myelopoiesis? what controls it?

Answer 17

maturation of WBCs from myeloblast to PMN.

G-CSF stimulates it.

Question 18

what % of WBCs are in the proliferative compartment? differentiation compartment (bone marrow)? vasculature?

Answer 18

25%
65%
10%

Question 19

of the 10% in the vasculature, what are WBCs doing?

Answer 19

5% are in circulation

5% are in marginal pool, somewhat trapped

Question 20

5 patterns of leukocytosis/Neutrophilia?

Answer 20

Shift Neutrophilia
Left Shift
Leukemoid Reaction
Leukoerythroblastic Reaction
Leukemia

Question 21

definition of shift neutrophilia

Answer 21

demargination of marginal pool without proliferation. generally no young forms seen (ie, no bands)

Question 22

when is shift neutrophilia seen?

Answer 22

steroids, EPO, exercise, seizures

Question 23

define Left Shift. what do we see in blood?

Answer 23

Bands, metemyelocytes (young PMNs) seen in blood. Bone marrow is now involved, expelling immature forms into circulation.

Question 24

when do we see Left Shift?

Answer 24

severe infection.

Question 25

define Leukomoid reaction

Answer 25

BOTH demargination and marrow proliferation, increase in both mature PMNs and immature forms. both demargination and Left Shift.

Question 26

when do we see Leukomoid reaction?

Answer 26

infection, inflammation, metastatic cancer, administration of G-CSF

Question 27

define Leukoerythroblastic reaction

Answer 27

damaged bone marrow causing premature release of precursor cells. squeezing all forms of WBCs out of marrow. see teardrop-shapes, early forms.

Question 28

when do we see Leukoerythroblastic reaction?

Answer 28

damaged bone marrow (infiltrative state)

Question 29

define leukemia

Answer 29

cancer of blood or bone marrow

Question 30

what cell types do we see in the peripheral blood with leukemia?

Answer 30

BLASTS!

with chronic leukemia there is an increase of all forms and a profound left shift.

Question 31

generally, what do we need in order for Neutrophils to work?

Answer 31

adequate number, adequate function

Question 32

why is neutropenia a problem?

Answer 32

increased risk of infection

Question 33

types of neutropenia?

Answer 33

congenital, acquired (either extrinsic or intrinsic to the bone marrow)

Question 34

acquired causes of neutropenia?

Answer 34

infection, drug/toxin, nutritional deficiencies, cancer, hypersplenism (due to increased sequestration)

Question 35

should you worry about a patient who is neutropenic?

Answer 35

YES, if a pt is neutropenic he is at heightened risk for a severe infection

Question 36

what is a general rule for risk when neutropenic?

Answer 36

at certain ANC levels, at sig higher risk for infection. remember 500 as a cutoff for starting IV antibiotics if any fever is present (even if you don’t yet know what the agent is: use broad spectrum). above that ANC, a fever can be managed as an outpatient.

Question 37

with prolonged duration of a neutropenic infection, what are worrisome risks?

Answer 37

with prolonged duration (>7d), increased risk of fungal infections

Question 38

what will an infection look like in the setting of neutropenia?

Answer 38

without neutrophils, there may be no signs/symptoms of an infection. no pain, swelling, redness, pus. fever response may be blunted.

Question 39

58 yo man with bruising and fever x1 week.
WBC 0.5, Hgb 7.0, Plts 15,000, 53% blasts, ANC 200.
what kind of neutropenia?

Answer 39

acute leukemia. marrow based problem (blasts are clue)

Question 40

35 yo man with schizophrenia on clozapine with fever, tooth abscess.
WBC 1.2, Hgb 14, Plts 400,000, ANC 200.
what kind of neutropenia?

Answer 40

drug induced. clozapine is associated with severe isolated neutropenia.

Question 41

46 yo woman with severe rheumatoid arthritis, spleen tip found on exam.
WBC 1.2, Hgb 13, Plts 200,000, ANC 200
what kind of neutropenia?

Answer 41

autoimmune. if you have one autoimmune do, you are likely to have another

Question 42

15 y/o woman with intermittent mouth ulcers and rare fever.
WBC 1.2, Hgb 12, Plts 200,000, ANC 200
what kind of neutropenia?

Answer 42

cyclic neutropenia

Question 43

75 y/o man with pleuritic pain, cough, fever admitted to the ICU with hypotension and sputum growing Pneumococcus.
WBC 1.6, Hgb 15, Plts 150,000, ANC 200
what kind of neutropenia?

Answer 43

sepsis induced. probable pneumonia.