MLAB 1415- Hematology
Keri Brophy-Martinez
Hematopoiesis
Hematopoiesis
 Hematopoiesis
 Process of blood cell production, development and
replacement.
 Formation and development usually occurs in the
bone marrow.

Purpose

Allows hematopoietic system to respond to stimuli such
as infection, bleeding, or hypoxia by increasing
production of cell line needed.
2
3
Hematopoietic Precursor Cells
Stem Cells/
Pluripotential
Progenitor Cells
Maturing Cells
0.5% of total
hematopoietic precursors
3% of total hematopoietic
precursors
>95% of total
hematopoietic precursors
Population size stable
Population amplified by
proliferation
Population amplified by
proliferation
Not morphologically
recognizable
Not morphologically
recognizable
Morphologically recognizable
Multilineage differentiation
Multipotential
Committed cells
Cell Growth Factors
 Cytokines

Growth factors secreted by cells for the purpose of cell-tocell communication

They stimulate the pluripotential stem cells to proliferate
and differentiate.

GF’s must be present to “grow” hematopoietic precursor
cells.
Cytokines
 Cytokines
 Include interleukins, lymphokines, monokines, interferons, chemokines
and colony stimulating factors

Colony Stimulating Factors or CSF
 These regulate blood cell development. CSF’s are being
synthetically manufactured to treat diseases.
 Examples
 G-CSF: Stimulate granulocyte production, Used to treat
cancer and AIDS patients with low WBC. Trade name is
Neupogen
 GM-CSF - Stimulate granulocyte-macrophage production,
Used to treat cancer patients with low WBC. Trade name
is Leukine.
 EPO - Stimulate erythrocyte production, Used to treat
chronic anemia caused by renal failure, increase RBC prior
to surgery which may cause blood loss, illegally by athletes
to boost performance. Trade name is Epogen or Procrit.
Review of Cell Morphology
Cell Morphology
 Cell Membrane




Outer boundary of the cell
Allows passage of nutrients, ions and
information between cytoplasm and the
exterior
Location of surface markers
Phospholipid bilayer
Cell Membrane: Phospholipid Bi-layer
Cellular Components
 Cytoplasm: Location of metabolic activities





Golgi complex: involved in formation of gamma globulins,
lysosomes, specific granules and other cellular components.
Ribosomes: RNA, synthesize proteins
Endoplasmic reticulum: Communication system with the
nucleus, smooth or rough
Mitochrondria: furnish cell with energy
Lysosomes: granules with hydrolytic enzymes.
Cellular Components
 Nucleus:

Chromatin



Nucleolus/Nucleoli


Dark staining chromosomal material composed of DNA and
proteins.
DNA regulates all cellular functions
Pale staining patches rich in RNA, DNA
Nuclear envelope

Double membrane which surrounds the nuclear contents.
General Morphological Changes in
Cell Maturation
 Basophilic
cytoplasm to less
basophilic
 Reduction in cell
size
 Reduction in size of
nucleus
 Condensation of
nuclear chromatin
Term:
Nuclear to Cytoplasmic Ratio
 N/C ratio:

Ratio of the size of the nucleus of a cell to the size
of the cytoplasm

N/C ratio decreases with maturity as the nucleus
decreases in size and the cytoplasm becomes
more abundant

Immature “blast” cell has a large nucleus, small
amount of cytoplasm. N/C ratio is high
Lab Method: Wright’s Stain
 Stain used to identify
cells on blood smear
 Eosin is acid stain stains red
 Methylene is basic stain
- stains shades of blue
Staining
blue
Staining red
Cluster Designation (CD)
 Cluster Designation (CD) nomenclature

Monoclonal antibodies specific to cell surface markers
Allows for the phenotypic characterization of cells in disease states

Applications


Flow cytometry
 Cells labeled with monoclonal antibodies are sorted and
enumerated to identify specific populations of cells.
 Example
 CD4 and CD8
 Markers for helper and cytotoxic T cells
 Monitor progress of HIV infection