White Blood Cells: Normal and Malignant

Question 1

What does a FBC (full blood count) give information on?

Answer 1

kinds and number of cells in blood

- red, white platelets

Question 2

What does a WBC differential tell us?

Answer 2

percentage of each type of WBC in blood

Question 3

Why is a WBC differential useful?

Answer 3

• evidence of and response to infection
• allergic response
• leukemia
• abnormal cells within bone marrow

Question 4

What additional tests can be carried out on WBC?

Answer 4

> flow cytometry - lymphoid and myeloid populations - and degree of cell maturity
cytogenics (is there a clone) - metaphase analysis and fluorescent in-situ hybridisation (FISH) - shows finer detail within chromosome - malignancy
gene sequencing to look for specific mutations

Question 5

Where is bone marrow found?

Answer 5

medullary bone - centre of long bones - marrow within spaces of trabeculae

• ribs sternum, vertebral bodies, pelvis
• (in red marrow)

Question 6

What type of cells in marrow produce blood cells?

Answer 6

hemopoietic

- differentiates stem cells into blood cells

Question 7

Progenitor cells?

Answer 7

can differentiate into a specific type of cell - but more specific than stem cell

Question 8

What does bone marrow consist of?

Answer 8

• hamatopoietic cells
• marrow adipose tissue
• supportive stromal cells

Question 9

Granulocytes?

Answer 9

white blood cell with secretory granules in cytoplasm - 3 types (neutrophils, eosinophils, basophils)

Question 10

Neutrophils?

Answer 10

• commonest WBC
• short lifespan 8-10 hours
• chemotaxis - migrate in response to eg. bacterial wall antigens
• non-specific
• bacteria ingested and killed by enzymes in granules - lysozyme peroxidase
• acute response to bacterial infection, inflammation, malignancy

Question 11

Eosinophils?

Answer 11

• 1-6% of WBC
• Eosin stains granules orange/pink
• life span in blood 4-5 hours (longer in tissues)
• response to helminth infection
• chemokine attract them to site of infection
• growth promoted by interleukin-5
• granules contain major basic protein (MBP) and reactive O2 species
• raised numbers in allergies and some malignancy

Question 12

Basophils?

Answer 12

• less than 1% of WBC
• dark granules
• granules contain histamine, leukotrienes, proteases, heparin
• role in phagocytosis also
• cells have surface receptors for IgE binding - degranulation following chemotaxis
• role in hypersensitivity

Question 13

Lymphocytes?

Answer 13

• 20%-40% of WBC
• differentiate early from other marrow derived cells
• divide into T and B (thymus, bone marrow)
• long life span
• T and B malignancy - leukaemia

Question 14

Monocytes/macrophages?

Answer 14

• 5-10% of blood cells
• granules containing hydrolases and myeloperoxidase
• 8-12 hours in blood (longer in tissues)
• ingest material and present peptides to T cells - antigen presenting cells
• kill mycobacteria, fungi and intracellular organisms

Question 15

white blood cell name?

Answer 15

leukocytes

Question 16

Chronic myeloid leukemia?

Answer 16

• any age groups
• symptoms - anaemia, large spleen, bone pain
• anaemia, high WB~C and platelet count
• typically a chronic phase then accelerated and blast phase
• 95% of cases have identical cryogenic and molecular mutation - Philadelphia chromosome - translocation of gene
• imatinib used to treat

Question 17

Drug used to treat CML?

Answer 17

Imatinib - tyrosine kinase inhibitor - blocking tyrosine kinase stop cancer cels growing

• most cases have same mutation so same drug can be used
• frug resistance unusual

Question 18

Acute myeloid leukaemia?

Answer 18

• more common in older people
• symptoms - marrow failure
• anaemia, bleeding (purpura, bruises), infections (sepsis) , pneumonia
• diverse cryogenic mutations
• more likely to survive if younger

Question 19

Acute myeloid leukaemia treatment?

Answer 19

diverse cryogenic mutations - so no single target for chemotherapy

• chemotherapy used to produce marrow aplasia (failure)
• marrow regenerates from residual stem cells
• blood transfusion or stem cell transplant - toxic but effective

Question 20

What problems can chemotherapy cause?

Answer 20

• infections
• bleeding
• phycological
• venous access