Cytometry, An Issue of the Clinics in
Laboratory Medicine, 1st Edition
Editor :
Christopher B. Hergott
,Chapter 1: The Immunophenotypic Profile
of Healthy Human Bone Marrow
1. Which of the following cell types is predominantly found in healthy human
bone marrow?
A) Neutrophils
B) Erythrocytes
C) Megakaryocytes
D) Hematopoietic stem cells
Answer: D) Hematopoietic stem cells
Rationale: Hematopoietic stem cells are the foundational cells in the bone
marrow that give rise to all blood cell types.
2. In considering the immunophenotypic profile of bone marrow, which cluster of
differentiation (CD) marker is most commonly associated with hematopoietic
stem cells?
A) CD34
B) CD2
C) CD19
D) CD45
Answer: A) CD34
Rationale: CD34 is a well-known marker for hematopoietic stem cells and is
utilized in the identification of these cells.
3. Select all that apply: Which markers are commonly used to identify myeloid
cells in bone marrow?
A) CD33
B) CD19
C) CD14
D) CD15
Answer: A) CD33, C) CD14, D) CD15
Rationale: CD33, CD14, and CD15 are markers expressed on myeloid lineage
cells, while CD19 is a B-cell marker.
4. A patient’s bone marrow aspirate shows a significant number of immature
cells. Which of the following markers would most likely be elevated?
A) CD34
B) CD56
C) CD61
D) CD127
Answer: A) CD34
, Rationale: CD34 is expressed on immature hematopoietic cells and would be
elevated in conditions with a surplus of immature cells.
5. Which of the following is NOT a characteristic of normal bone marrow?
A) Presence of adipocytes
B) Absence of lymphocyte infiltration
C) High cellularity
D) Presence of abundant megakaryocytes
Answer: B) Absence of lymphocyte infiltration
Rationale: While lymphocytes are less prominent in the bone marrow than in
lymphoid tissues, they are still present in normal bone marrow.
6. In healthy adults, what is the predominant type of cell in the bone marrow?
A) B lymphocytes
B) T lymphocytes
C) Granulocytes
D) Erythrocytes
Answer: C) Granulocytes
Rationale: Granulocytes are generally the predominant cell type found within
the bone marrow of healthy adults.
7. A cytometric analysis indicates the presence of a large percentage of CD38
positive cells in the bone marrow. What does this suggest?
A) Increased proliferation of mature lymphocytes
B) Presence of activated or memory B cells
C) A decline in stem cell population
D) Presence of malignant cells
Answer: B) Presence of activated or memory B cells
Rationale: CD38 is a marker associated with B-cell activation and memory
formation.
8. Which of the following antibodies would you use to confirm the presence of
plasma cells in bone marrow?
A) Anti-CD19
B) Anti-CD45
C) Anti-CD138
D) Anti-CD34
Answer: C) Anti-CD138
Rationale: CD138 is a specific marker for plasma cells, distinguishing them
from other cell types in the bone marrow.
9. What is the significance of the CD45 marker in bone marrow analysis?
A) It is a marker for hematopoietic progenitors.
B) It differentiates between myeloid and lymphoid cells.
C) It indicates differentiation into a specific lineage.
, D) It serves as a pan-leukocyte marker.
Answer: D) It serves as a pan-leukocyte marker.
Rationale: CD45 is a common leukocyte antigen and is expressed on all
leukocytes, used to identify general leukocyte populations.
10. Select all that apply: Which cell types can be identified with the CD19 marker
in the bone marrow?
A) B-cell precursors
B) T-cells
C) Plasmablasts
D) NK cells
Answer: A) B-cell precursors, C) Plasmablasts
Rationale: CD19 is specific to B-lineage cells, including B-cell precursors and
plasmablasts, but not T-cells or NK cells.
11. A patient with suspected hematologic malignancy shows a high percentage of
cells expressing CD2 and CD5. Which type of cell might this indicate?
A) Plasma cells
B) T-cells
C) Monocytes
D) Erythrocytes
Answer: B) T-cells
Rationale: CD2 and CD5 are markers commonly associated with T-
lymphocytes.
12. The presence of which of the following markers might indicate an immature
state in granulocyte development?
A) CD15
B) CD34
C) CD117
D) CD41
Answer: B) CD34
Rationale: CD34 is a marker for progenitor and immature cells, while CD15
and CD117 are more associated with mature granulocytes.
13. A laboratory technician is examining bone marrow samples for evidence of
hematopoietic malignancies. Which assay is likely the most informative?
A) Hemoglobin electrophoresis
B) Flow cytometry
C) Peripheral blood smear
D) Bone marrow trephine biopsy
Answer: B) Flow cytometry
Rationale: Flow cytometry provides detailed immunophenotypic profiles,
which are crucial for diagnosing hematopoietic malignancies.