My Clinical Notes

• In adult life, haematopoietic marrow is limited to the central skeleton, and the proximal ends of the femur and humerus
• A common stem cell gives rise to;
  • Erythroid cell lineage
  • Granulocytic and monocytic lineage
  • Megakaryocytic lineage
  • Lymphoid cell lineage
• The earliest separation of the CSC is common lymphoid progenitor (CLP) and common myeloid progenitor (CMP)
• CLP gives rise to T cells, B cells and NK cells
• The CMP gives rise to at least three types of committed stem cells called CFU;
• Erythroid/megakaryocytic
• Eosinophilic
• Granulocyte/macrophage

 

• T lymphocytes, monocytes (and macrophages), endothelial cells and fibroblasts are the major sources of EPO – 90% of which is produced in the kidney

 

• IL-1 and TNF from macrophages and T cells during inflammation, stimulate other cells including endothelial cells, fibroblasts and other macrophages and T cells to produce the growth factors;
  • GM-CSF
  • G-CSF
  • M-CSF
  • IL-6

 

Haematopoietic growth factors

• Acting on stromal cells to produce GM-CSF, G-CSF, M-CSF, IL-6
  • IL-1
  • TNF
• Acting on the common stem cell
  • SCF
  • Flt3 ligand
• Acting on early multipotential cells
  • IL-3
  • IL-6
  • GM-CSF
• Acting on late cells committed to one or two lineages
  • G-CSF
  • M-CSF
  • IL-5
  • EPO
  • TPO

Bone marrow morphology

• The ratio of fat cells to haematopoietic cells should be 1:1 in the adult. The proportion of fat cells increases with BM hypoplasia and decreased with increased haematopoiesis
• The normal proportion of haematopoietic precursors should be 65% granulocytes and their precursors, 25% erythroid precursors and 10% lymphocytes and monocyes and their precursors

 

This entry was posted on Monday, January 21st, 2008 at 5:14 pm and is filed under Haematology. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.