Transcript MLAB 1315- Hematology Fall 2007 Keri Brophy

MLAB 1415- Hematology
Keri Brophy-Martinez
Chapter 7: Leukocytes
Part One
Terms

Myelopoiesis


the production and development of
myeloid cells in the bone marrow
Also known as granulocytopoiesis
Leukocytes

Function

Protect the host from infectious agents
or pathogens

Innate=Natural Immune response




1st response to pathogens (nonself)
Always available
Neutrophils, monocytes, and macrophage
main players
Adaptive Immune response




Starts in lymphoid tissue
Slow
Long-lasting immunity (memory)
Lymphocytes become “activated”
Common
Lymphoid
progenito
r= CLP
Common
Myeloid
Progenitor=
CMP
Neutrophils
Neutrophil Lifespan

Three areas

Bone marrow


Peripheral blood


Differentiation, proliferation, maturation
Circulate for a few hours
Tissues

Work in host defense
Regulation

Neutrophil production primarily
regulated by cytokines



Interleukin-3
Granulocyte -monocyte-colony
stimulating factor (GM-CSF)
Granulocyte-colony-stimulating factor
(G-CSF)
Maturation Changes




Nucleoli disappear
Chromatin condenses
Nuclear mass indents and segments
Cytoplasm becomes granular &
pinkens
Seg
Band
Maturation of the granulocytic series
**Least mature to mature**

Myeloblast


Size: 14-20µm
Cytoplasm



Nucleus





Slight
amount/blue
No granules
(possible Auer
rods to be
discussed in
another
section)
Round/Central
or eccentric
Reddish purple
1-3 nucleoli
Fine
meshlike/lacy
chromatin with
no clumping
N:C ratio = 4:1
Maturation of the granulocytic series

Promyelocyte
(progranulocyte)




Size: 15-21 µm
Cytoplasm
 Increased amount/blue
 Fine, azurophilic,
nonspecific granules
present
Nucleus
 Round/Central or
eccentric
 Reddish-purple
 Fine, meshlike/lacy
chromatin beginning to
clump
 1-2 nucleoli
N:C ratio = 3:1
Maturation of the granulocytic series

Myelocyte



Last myeloid cell capable of
division
Size: 12-18µm
Cytoplasm




Nucleus





Increased, bluish-pink
(“dawning of
neutrophilia”)
Fine specific granules
Secretory vesicles
Round or oval/eccentric
Reddish-purple
Chromatin loosely
clumped
No nucleolus
N:C ratio = 2:1 or 1:1
Maturation of the granulocytic series

Metamyelocyte



Also called “meta” or
“juvenile”
Size: 10-18µm
Cytoplasm





Nucleus






Moderate amount
Specific granules
(neutrophilic, eosinophilic or
basophilic)
Tertiary granules
Secretory vesicles
Indented (kidney-bean
shaped)
Central or eccentric
Purple
Clumped chromatin
No nucleolus
N:C ratio = 1:1
Maturation of the granulocytic series

Band



1st stage found in P.B
Size: 9-15µm
Cytoplasm



Moderate amount
Specific granules
(see meta)
Nucleus



Elongated, narrow
band (sausage)
shape with uniform
thickness
Central or eccentric
Clumped, coarsely
granular chromatin
Maturation of the granulocytic series

Segmented neutrophil
 Size: 10-16µm
 Cytoplasm
 Neutrophil - Granules
stain equally with eosin
and methylene blue,
causing a pinkish
appearance
 Normal in circulation
= 40 - 80%

Nucleus
 Neutrophil - purplish-red,
clumped granular
chromatin, 2-5 distinct
nuclear lobes connected
by a filament of chromatin
Eosinophil

Eosinophil - Granules
stain mainly red, due
to reaction with eosin
in stain
 Normal in
circulation = 0-5%

Eosinophil - deep
blue purple,
coarsely granular
chromatin, 2
distinct lobes
Eosinophil
Basophil


Basophil - Granules stain
mainly blue, due to the
reaction with methylene blue
in stain
 Normal in circulation = 01%
 Mast cell is a tissue
basophil
Basophil - deep blue purple,
coarsely granular chromatin,
2 nuclear lobes (sometimes
obscured by cytoplasmic
granules
Basophil
Function of the granulocytic cells

Neutrophils


Eosinophils




Defense against bacterial infections
Regulate inflammation
Respond to antigenic stimulation in chronic
allergies
Interact with larval stages of some helminthic
parasites
Basophils


Histamine in granules plays a role in acute,
systemic allergic reactions (sudden release of
histamine can cause anaphylactic shock)
Granules also contain heparin
Granulocytes: A Final Thought

Why are they called granulocytes?

The granules are lysosomes created by lipids that
contain hydrolytic enzymes such as peroxidase,
acid phosphatase, lysozyme and specific
esterase.
References


Harmening, D. M. (2009). Clinical
Hematology and Fundamentals of
Hemostasis. Philadelphia: F.A Davis.
McKenzie, S. B., & Williams, J. L.
(2010). Clinical Laboratory
Hematology . Upper Saddle River:
Pearson Education, Inc.