Introduction to Haematology Part 1

Question 1

What is haemopoeisis?

Answer 1

The physiological development process that gives rise to the cellular components of blood.
Via a multipotent haemopoietic stem cell.

Question 2

Stem cell division can be…

Answer 2

Symmetric Self Renewal - Increases stem cell pool; no differentiated progeny.
Asymmetric Self Renewal - Maintains stem cell pool; generates single differentiated progeny.
Lack of self renewal -
Depletes stem cell pool; generation of only differentiated progeny.

Question 3

Haematopoietic Lineages

Answer 3

Multipotent stem cells give rise to pluripotent stem cells… these can be myeloid or lymphoid.
Myeloid - Granulocytes, Erythrocytes, Platelets.
Lymphocytes - B/T lymphocytes.

Question 4

Origins of Haemopoiesis

Answer 4

Trophoblast at 9 days… check lecture video as slides are not clear
Aorto-Gonado-Mesonephros:
Day 27 - appearance
Day 35 - population expansion
Day 40 - disappearance/migration of haematopoietic stem cells to the liver.

Question 5

Red blood cell levels -

Answer 5

Anaemia - reduced count
Polycythaemia - raised count (normally Polycythaemia Vera - due to mutation in JAK2 gene increasing RBC production)
Relative polycythaemia - reduced plasma volume (dehydration and burns).

Question 6

White Blood Cell - types

Answer 6

Granulocytes
Monocytes
Lymphocytes

Question 7

Neutrophils

Answer 7

Granulocyte
Phagocyte
Neutrophilia - increased numbers (bacterial infection/inflammation)
Neutropenia - decreased numbers (can be drug side effect).

Question 8

Eosinophils

Answer 8

Granulocyte
Eosinophilia - increased numbers (parasitic infection/allergy).
Production is regulated by T-cell activity…

Question 9

Basophils

Answer 9

Granulocyte
Part of the primitive immune system.
Basophilia - increased numbers (can be indicative of Chronic Myeloid Leukaemia); associated with pruritus due to increase in histamine levels.

Question 10

Monocytes

Answer 10

Phagocytic and Antigen presenting cells.
Migrate to tissues - then named as macrophages/histocytes.
i.e. Kupffer cells in the liver & Langerhans cells in the skin.
Monocytosis - increased numbers (TB); ineffective clearance of monocytes facilitates disease (i.e. atherosclerosis - encourages progression of lipoproteins into foam cells)>

Question 11

Lymphocytes
Lymphocytosis - 2 examples
Lymphopenia - 1 example

Answer 11

Lymphocytosis - increased numbers.
Atypical lymphocytes of glandular fever (Herpes - Epstein Barr virus; infectious mononucleosis).
Chronic Myeloid Leukaemia.
Lymphopenia - decreased numbers.
Post bone marrow transplant.

Question 12

Natural Killer Cells

Answer 12

Large granular lymphocytes

Innate immune system; ‘recognition of non-self’.

Question 13

T-lymphocytes

Answer 13

Adaptive Immune System
CD4 - Helper - MHC2
CD8 - Cytotoxic - MHC1
Cell mediated immunityˑ regulates the immune response.

Question 14

B-lymphocytes

Plasmacytosis

Answer 14

Adaptive Immune System
Rearrange immunoglobulin genes for antigen specific antibody production.
Humoral immunity.
Plasmacytosis - increased numbers of plasma cells (infection/myeloma).