Haemopoiesis Flashcards
What is haemopoiesis?
A tightly regulated process that forms blood cells
What are the processes of haemopoiesis?
- Erythropoiesis- red cell production (erythrocytes). Transport 02 from lungs to tissues
- Leucopoiesis- white cell production (leucocytes) defend body against infection
- Thrombopoiesis- platelet production (thrombocytes) prevent blood loss at site of injury
Label this diagram
What is haemopoiesis regulated by?
- Growth factors
- Cytokines
- Environmental factors
- Apoptosis
Ontogeny of Haemopoiesis in adults, infants and foetus
Adults
•Bone marrow of Vertebrae, ribs, sternum, skull, sacrum and pelvis, proximal ends of femurv
Infants
•Bone marrow (practically all bones)
Foetus
- 0–2 months (yolk sac of embryo)
- 2–7 months (liver, spleen)
- 5–9 months (bone marrow)- at birth sole site
Haemopoietic stem and progenitor cells
Haemostasis begins with pluripotent stem cell also called haemopoetic stem cell there are about 11000-22000 per individual
Bone marrow stroma
One single cell can secrete many different growth factors in response to various stimuli, each can impact on:
- Different cell types
- Have a different effect when they are acting lone or in combination with other growth factors
- Sequence of a growth factors activity
Give some examples of growth factors
Summary: role of growth factors in haemopoiesis
Apoptosis is programmed cell death
Morphologically it is characterised by:
- Cell shrinkage
- Condensation of nuclear chromatin
- Fragmentation of the nucleus
- Cleavage of DNA at internucleosomal sites
What is erythropoesis?
Formation of RBC
What is the normal concentration of RBC in the blood?
Normal concentration in the blood 3.9-6.5 X 1012/L
Key steps involved in red cell development from a blast cell involve:
- slow reduction in size
- loss of the nucleus to become a reticulocyte
Process occurs in parallel with development of Haemoglobin
Draw the process of erythropoiesis
Reticulocytes
Erythropoiesis is regulated by
EPO
What things stimulate EPO
- Atmosphere 02 is low
- Defective cardiac/pulmonary function
- Damage to the renal circulation
EPO levels
What is thrombopoiesis?
Platelet production
Draw thrombopoiesis
Draw granulopoiesis
•IL-1, IL3, GM-CSF and M-CSF control proliferation and differentiation.
Show the mature granulocytes (Neutrophils and Eosinophils)
Show the mature granulocytes (Basophils and monocytes)
Lymphocyte production
- B and T cells – both arise from the Haemopoietic
- stem cell (IL-7)
Describe B-cells and the BCR
B cell receptor is membrane bound, after activation secreted as immunoglobulin proteins
IgA, IgG,IgM,IgD,IgE
T cells develop in the
Thymus
Helper T cells express
CD4
Cytotoxic T cells express
CD8
What is marrow analysis?
- Status of and capability for blood cell production.
- Measure blood cell production, to help diagnose:
leukaemia
bone marrow disease
spread of cancer
severe anaemia
Cultured for the presence of microorganisms
Obtaining bone marrow
- Hip bone (pelvic bone), but it also can be done from the breastbone, lower leg bone or backbone
- Cleaned with iodine solution or alcohol. Local aesthetic injected
- Bone marrow needle is then placed through the skin and into the bone.
- Bone marrow aspiration
- Bone marrow biopsy
Once aspirated bone marrow is smeared onto a slide and stained for examination:
1.Romanowsky stain
2. Pearls Stain
Describe the bone marrow
- Cellularity alters throughout life
- Normal adult will have 50:50 haemopoetic cells to fat
- In a healthy individual myeloid WBC precursors exceed number of RBC precursors 3:1- varies with disease- M/E ratio
M/E Ratio is increased, normal and reduced in these conditions
What can fluorescence flow cytometry be used for?
To identify blood and bone marrow cells according to the presence of CD molecules (glycoprotein’s) on the cells surface or in the cytoplasm.
What are the uses of fluorescence flow cytometry?
–Panels of markers to confirm diagnosis of malignancies (AML/CLL)
–CD34 counts before marrow harvest
–Minimal residual disease detection.
