Haemopoiesis

Question 1

A 50-year-old individual is being investigated for a suspected bone marrow malignancy. Which of the following anatomical sites is most appropriate for bone marrow examination?

A. Anterior tibia
B. Posterior iliac crest
C. Proximal femur
D. Sacrum
E.  Any long bone, that is easily palpable

Answer 1

B. Posterior iliac crest

Question 2

What is the most appropriate technique to assign cell lineage? 
A. Morphology
B. Cytogenetic (chromosome) analysis
C. Next generation sequencing (NGS)
D. Immunophenotyping
E.  Polymerase chain reaction (PCR)

Answer 2

D. Immunophenotyping

Question 3

Which of the following tissues has the least proportion of blood cells with self renewal potential?
A. Bone marrow
B. Peripheral blood
C. Umbilical cord blood
D. Peripheral blood following G-CSF treatment

Answer 3

B. Peripheral blood

Question 4

What names are given to the formation of different blood cells?

Answer 4

erythropoiesis - RBC formation
lymphopoiesis - lymphocyte formation
myelo/granulopoieis - formation of granulocytes and monocytes
thrombopoiesis - formation of platelets

Question 5

Compare the lifespan on RBCs to neutrophils and platelets

Answer 5

RBCs - 120 days
Neutrophils - 7-8 hours
Platelets - 7-10 days

Question 6

What does the suffix “blast” mean in haematology?

Answer 6

nucleated precursor cell
e.g. Megakaryocyte (platelet precursor)
reticulocyte (immediate red cell precursor)
myelocyte (nucleated neutrophil precursor)

Question 7

What is meant by stem cell “self-renewal”?

Answer 7

Can divide and preserve one cell as a stem cell whilst the other matures further

Question 8

What happens when blood cells “mature”?

Answer 8

• acquire more functions
• these are specific to whatever lineage they are following
• they may stop proliferating

Question 9

Most stem cells are dormant during steady state haematopoiesis. TRUE/FALSE?

Answer 9

TRUE

Question 10

Where does haemopoiesis take place in the embryo and how does this change over time?

Answer 10

• Stem cells originate in the mesoderm

Yolk sac is the main site of erythroid activity
- this stops at week 10

Liver starts in week 6 of life

Bone Marrow starts at week 16 of life

Question 11

Name the main sights of extramedullary haematopoiesis

Answer 11

Liver
Spleen
Thymus

Question 12

Where does haematopoiesis take place in an adult?

Answer 12

Axial skeleton

=> pelvis and proximal long bones

Question 13

Where is a bone marrow sample taken in an adult vs in a child?

Answer 13

Adult - posterior iliac crest

Child - Tibia

Question 14

What non-haematological cells are found in the bone marrow?

Answer 14

• adipocytes
• fibrocytes
• osteoblasts/clasts
• connective tissue

Question 15

Describe how the bone marrow is supplied?

Answer 15

• supplied by neurovascular bundle

- venous sinuses drain marrow rather than capillaries

Question 16

What colour does the marrow appear when it is active vs when it is inactive?

Answer 16

Active - RED

Inactive - YELLOW/ fatty

Question 17

There are usually more myeloid precursors in the bone marrow than erythroid precursors. TRUE/FALSE?

Answer 17

TRUE

Question 18

How is haematopoiesis regulated?

Answer 18

• intrinsic cell properties
• signals from surrounding microenvironment
• specific anatomical area has “niche” for making certain cell type

Question 19

What regulates neutrophil precursor maturation?

Answer 19

Granulocyte Colony Stimulating Factor

G-CSF

Question 20

What hormones regulate erythrocyte production and megakaryocyte production?

Answer 20

Erythropoietin

Thrombopoietin

Question 21

How can haematopoiesis be assessed?

Answer 21

Blood count (for cell indices)
blood film (for morphology)
Bone marrow biopsy

Question 22

What is required to differentiate between B and T cells?

Answer 22

Immunophenotyping

- analyses antigen expression on surface of lymphocytes by directing antibodies to them