Hematopoiesis and normal WBC

Question 1

White Cell: the word is derived from?

Answer 1

visual appearance of “buffy coat”

Question 2

Leukemia:

Answer 2

Term coined by Virchow to indicate a malignancy which greatly increases the “Leuko” fraction of the blood, but now also includes aleukemic leukemias (increase in neoplastic wbcs in bone marrow, but not in circulation)

Question 3

Lymphoma:

Answer 3

Solid tumors derived from lymphoid tissue that primarily involve lymph nodes and peripheral organs

Question 4

“Myeloid” has two meanings!

Answer 4

Myeloid Disorders (leukemias): precursors of erythroid, granulocytic, monocytic and megakaryocytic series
	Granulocytes include neutrophils, eosinophils  and basophils
	Myeloid Cells (Myeloid:Erythroid ratio): Granulocytes and monocytes only

Question 5

Nodes with low grade non-Hodgkin lymphoma : trends

Answer 5

Tends to involve multiple lymph nodes (“matted” nodes)

Nodes involved with lymphoma usually appear fleshy tan and are rubbery firm

Question 6

High grade Non-Hodgkin’s lymphoma (NHL): trends

Answer 6

tends to involve a single node, localized group of nodes or extranodal site

Question 7

What kind of tube do we use for CBC? What should we find in the plasma?

Answer 7

Normally use EDTA tube for CBC

Plasma – 
  91% water 
  7% blood proteins (including coag. factors)
  2% other solutes
  No Ca++ due to use of EDTA

Question 8

Most common stains for peripheral blood white cells

Answer 8

Wright

Giemsa (better for parasites)

Question 9

-“Romanovsky stains”

Answer 9

Dimitri Romanovsky, M.D. 1891 reported use of eosin and methylene blue to identify malaria parasites in red cells -

Question 10

The WBC Differential

Answer 10

Use “Romanovsky” stains on air-dried thin smears of blood.
The “Manual WBC differential” is performed by examining via light microscopy a “Wright stained” peripheral blood smear and counting 100 white cells.
The relative number of each type of WBC is expressed as % of the total white cell population.
WBC, RBC and platelet morphology is also accessed.

Question 11

Relative Versus Absolute ValuesChanges in WBCs in Peripheral Blood

Answer 11

Relative change in one type of white blood cell WBC expressed as a % of overall number WBCs usually doesn’t mean much
What matters for each WBC type is the “absolute’ count or % of total multiplied by the total WBC count; e.g.,

Absolute Neutrophil Count = % Neutrophils X total WBC count

Absolute neutrophils = 46% X 10,000 cell/microliter 
		= 4,600 neutrophils/uL

Question 12

Performing a Bone Marrow Biopsy: Aspirate and core biopsy

Answer 12

A bone marrow aspirate best illustrates cytology and allows enumeration of cells. The core is used to assess “cellularity” and architecture.

Question 13

In adults, myelopoiesis occurs

Answer 13

almost exclusively in the bone marrow

Question 14

Immunophenotyping: Immature B-cells

Answer 14

• TdT, CD10,
• sIg- (usually CD20-)

(CD19)

Question 15

Immunophenotyping: Mature B-cell

Answer 15

• CD20

CD19, CD22, sig+

Question 16

Immunophenotyping: Immature T-cells

Answer 16

• TdT, CD1a, CD4/CD8 (usually surface CD3-)

CD2, CD5, CD7

Question 17

Immunophenotyping: Mature T-cells

Answer 17

• TdT-, CD1a-

CD2, sCD3, CD4, CD5, CD7, CD8

Question 18

EDTA does what?

Answer 18

chelates calcium, acts as an anticoagulant

Question 19

elevated sed rate means what?

Answer 19

too many proteins, probably from inflammation of any kind.

Question 20

serum haptoglobin means what?

Answer 20

if it’s low, RBCs have probably been lysing (hemolytic anemia);
haptoglobin carries the heme