Unit 1: Review of Normal Blood Cell Maturation Flashcards
Leukopoiesis
is the production and proliferation of white blood cells,
with the exception of lymphocytes, in the bone marrow, lymph
nodes, & thymus.
Myelopoiesis (granulocytopoiesis)
refers to the production of
neutrophils, eosinophils, and basophils
Lymphopoiesis
refers to the production of lymphocytes
There are 5 main types of WBCs (in order of their predominance in
the N. adult)
-Neutrophils (Segs) 50-70%
* Lymphocytes (Lymphs) 18-42%
* Monocytes (Monos) 2-11%
* Eosinophils (Eos) 1-3%
* Basophils (Basos) 0-2%
Granulocytes
(develop only in bone marrow)
Includes: Segs, Eos, Basos, and Monos
Lymphocytes or Mononuclears
(develop in the bone marrow
and lymphoid tissue)
Includes: Lymphs, and NK cells
Mononuclears
Mononuclears can have very fine granules; it’s just that they are not
granulocytes, which all have large, noticeable granules & segmented
nuclei.
As defense against foreign (“non-self”) invaders via
- Ab production by immunocytes (i.e., lymphs.)
- Cytokine production by lymphocytes (aka.
lymphokines.) - Inflammatory mediator production by segs &
monos. - Phagocytosis (i.e., granulocytes and mononuclear
cells)
As a normal cell matures
* Overall:
- cell size decreases
- nuclear chromatin pattern becomes denser
- nucleoli disappear
- amount and color of cytoplasm changes
- size of nucleus decreases greater than the size of the cell (N:C ratio)
Cytoplasmic Maturation
- deep blue color (high RNA content) pales
- granules may appear
- amount increases
Nuclear Maturation:
-nucleus decreases in size (exits entirely in RBCs!)
* chromatin becomes more condensed or clumped
* color changes from reddish to bluish-purple
* nucleoli may decrease in # or become absent
Erythron
the collection of all stages of erythrocytes throughout the body
Hypoxia
diminished availability of oxygen to the body tissues
* Occurs when the oxygen tension in the cells is decreased
The role of RBCs is to
Carry oxygen
Erythropoietin Production and Regulation
EPO is produced primarily in the kidney in response to - Degree of blood oxygenation
it functions to maintain normal RBC mass
Erythropoietin
Initiates a cascade of events that lead to increased RBCs in circulation
- Allows early release of reticulocytes
- Increases number of mature erythrocytes
- Reduces marrow transit time
Pronormoblast (Rubriblast or Proerythroblast) - “Blast”
Cell size
N:C ratio
nucleus shape
Note
- Cell size: 12-20 μm
- Nucleus: contains nucleoli & fine chromatin;
round to slightly oval shape.
High N:C ratio (8:1) - Cytoplasm: very basophilic (high RNA content, lots of organelles),
with the lighter-staining perinuclear area around Golgi (not always visible)
Note: BFU-E for 1 week » CFU-E for 1 week » Pronormoblast for ~24 hrs.
Basophilic Normoblast
Cell size
Nucleus:
N:C ratio
Cytoplasm-
(Prorubricyte /Erythroblast)
- Cell size: 10-15 μm
- Nucleus: round, coarser chromatin; no visible
nucleoli
N:C ratio decreasing to 6:1
- Cytoplasm: temporarily even more basophilic (royal
blue); Golgi may be visible as light area near nucleus.
Polychromatic normoblast
(Rubricyte/Polychromatic
erythroblast)
- Cell size: 10-12 μm
- Nucleus: round, sometimes eccentric, smaller, with
coarser chromatin
N:C ratio of 4:1 - Cytoplasm: opaque, violet-blue or grayish color (due to
Hgb synthesis) polychromasia - (NOTE: Last stage capable of mitosis.)
Orthochromic normoblast
- (Metarubricyte/Orthochromic
erythroblast) - Cell size: 8-10 μm
- Nucleus: pyknotic (degenerated nuclear chromatin);
eventually extruded
N: C ratio of 1:2 - Cytoplasm: polychromasia
- NOTE: This stage is typically called a “nucleated red”, & the WBC count must be corrected if 5 or
more of these are present on a 100 cell WBC differential, because automated analyzers mistake
them for white blood cells!
Erythroblasts (NRBC) stain
Wright-Giemsa Stain
- Reticulocyte - “Retic“
- Cell size: 7-9 μm (nearly normal!)
- Nucleus: none present
- Cytoplasm: varying degrees of polychromasia
(variation in cytoplasmic color, usually a
bluish tinge; may still have basophilic stippling.
Reticulocyte - “Retic
Resides in marrow for
1 day, then peripheral blood for 1 day, then retained in the spleen for
pitting and polishing for a few days, then released as a mature cell
RETICULOCYTE
(Retic)
Normal ranges:
Adults 0.5 - 2.0 %
Children 1.0 - 3.0 %
Newborns 2.0 - 6.0 %
New Methylene Blue
Retic Stain
Erythrocyte
- Cell size: 7 - 8 μm
- Nucleus: none present
- Cytoplasm: has distinctive central pallor; no protein
or Hgb made; no mitochondria present
Erythrocyte
Lifespan ? = __________
Travels how far in that time? = __________120 day
120 days
300 miles
Neutrophilic Maturation
CFU-S, or hematopoietic stem cell (HSC)
-Cluster of Differentiation (CD) 34 antigen
* Undergoes stimulation, mitosis, and maturation in a stem cell (CFU-GEMM)
that’s specific for myeloid cells
Neutrophilic Maturation
CFU-GEMM
- CD34 and CD33 antigens
- Matures into CFU-GM
Neutrophilic Maturation
CFU-GM
- ILs and CSFs control the stability of cell numbers and their functions
- Matures into a myeloblast
Colony Stimulating Factors
Multi-CSF
Sources and functions
(i.e., IL-3) production is stimulated by
endotoxin released from infection
* Source – secreted by marrow fibroblasts, T-lymphs,
macrophages, and monocytes
* Function – stimulates regeneration, maturation, and
differentiation of multipotential and unipotential stem cells
Colony Stimulating Factors
GM-CSF
Sources and functions
is important for myeloid maturation in the
marrow
* Source – secreted by T-lymphs, marrow fibroblasts,
marrow endothelial cells and monocytes
* Function – stimulates neutrophils, eosinophils, and
monocyte growth
Colony Stimulating Factors (cont.)
G-CSF
Sources and functions
is a more specific granulocyte growth factor
* Source – monocytes, marrow fibroblasts and endothelial
cells
* Function – stimulates neutrophils, and enhances functional
response of neutrophils
Colony Stimulating Factors (cont.)
M-CSF
Sources and functions
(i.e., CSF-1) is the primary monocytic growth
factor
* Source – secreted by mature monocytes, marrow
fibroblasts, and marrow endothelial cells
* Function – stimulates macrophages and the release of G-
CSF from monocytes. Stimulates the release of tumor
necrosis factor (TNF), interferon, and IL-1 from
macrophages
Myeloblast: “-blast”
cytoplasm
dark blue to blue cytoplasm
Myeloblast: “-blast”
what may begin to appear
Primary granules may begin to appear
Myeloblast: “-blast”
Chromatin
lacy, smooth, delicate, & uniformly distributed chromatin
Myeloblast: “-blast”
_____ distinct nucleoli
1-2 distinct nucleoli
Myeloblast: “-blast”
Cell size
A large cell (15-20 μm)
Myeloblast: “-blast”
N:C ratio
- high N:C ratio of 4:1 (so not much cytoplasm)
Myeloblast: “-blast”
_________ normal in bone marrow (none are normal in peripheral blood
(p.b.)
1-2% normal in bone marrow (none are normal in peripheral blood
(p.b.)
Myeloblast: “-blast”
Express antigens
CD13 and CD33
Myeloblast: “-blast”
Using light microscopy, it’s hard for
non-experts to differentiate myeloblasts/monoblasts / lymphoblasts
Promyelocyte: “Pro-”
large, prominent, reddish-purple _______
primary granules (described as
azurophilic)*
Promyelocyte: “Pro-”
dark blue to blue _______
cytoplasm
Promyelocyte: “Pro-”
uniformly distributed
chromatin
Promyelocyte: “Pro-”
N:C ratio of
3:1
Promyelocyte: “Pro-”
less distinct __________
nucleoli, but still may be present
Promyelocyte: “Pro-”
It may be larger than ________
blast form (approx. 20 μm)
Promyelocyte: “Pro-”
_________ % normal in bone marrow, none normal in p.b
Primary =
2-5%
Thus used to help distinguish blasts from pros.
(Primary = pro = red-purple)
- Myelocyte: “Myelo-”
Pinkish _________
pinkish secondary/specific granules now visible*; 1o granules less visible
“Specific = Secondary
- Myelocyte: “Myelo-”
Dawn of neutrophilia”
occurs: specific granules tend to form in Golgi area causing pink arc
- Myelocyte: “Myelo-
__________ losing blue color due to decreased RNA synthesis
cytoplasm losing blue color due to decreased RNA synthesis
- Myelocyte: “Myelo-”
nucleus more
condensed, with chromatin clumped; nucleus starting to “round up”
with one flatter side
- Myelocyte: “Myelo-”
N:C ratio of
2:1
- Myelocyte: “Myelo-”
_________ % normal in bone marrow, none normal in p.b.
<10% normal in bone marrow, none normal in p.b.
- Myelocyte: “Myelo-”
Myelocytes have greatest morphological variation of all the ______________
Neutrophils
Thus used to help tell pros from myelocytes!
Primary/Nonspecific or Azurophilic
Red-purple color= Become light blue as cell mature
mostly visible in (blast &) Start at myelocyte stage Appear very late stages
promyelocyte stages
Lysosomes; contains lysozyme, acid hydrolases, myeloperoxidase (MPO)*, proteases, & superoxide
Stain pos. for peroxidase
Secondary/Specific or Neutrophilic
Color: Pale lavender-pink
Start at myelocyte stage Cause “dawn of neutrophilia
Lysosomes; contain lysozyme, Lactoferrin**, collagenases, & complement activators
But no peroxidase
Tertiary granules
Color- Invisible on Wright’s stain)
blue-purple with
special LAP*** stain
Appear very late stages
Lysosomes; contain lysozyme, DAF, gelatinase, & LAP
NO peroxidase
Metamyelocyte: “Meta-”
kidney-bean or peanut-shaped ________
nucleus
Metamyelocyte: “Meta-”
nuclear chromatin
more coarsely clumped
Metamyelocyte: “Meta-”
cytoplasm uniformly
Metamyelocyte: “Meta-”
pink with pinky-purple 20 granules (aka. ?
_____Specific___)
(1o granules still present but don’t stain as intensely)
Metamyelocyte: “Meta-”
N:C ratio of
1.5: 1
Metamyelocyte: “Meta-”
_______ % normal in bone marrow, none normal in p.b.
12-25 %
Metamyelocyte: “Meta-”
_________ becomes indented
Nucleus
Band: “band”
% present
Constitutes ____ % of BM
Shape
Possess full _______
Shift to the ______
- normal in small %’s in p.b., at about 5-10% in normal adults
- Constitutes 40% normal in bone marrow
- curved, band-like nucleus (C or S shape) with no segmentation
- Possess full motility, active adhesion properties, and some phagocytic ability
- A maturation “shift to the left” occurs when neutrophil bands are increased
in p.b., in comparison to the number of segs
Segmented (polymorphonuclear) Neutrophil (PMN): “Poly-”or
“Seg-”
Comprises
Nucleus is
Shift to the right
- comprise 50-70% of total WBC population in normal adult p.b.
- Nucleus continues indentation to form segments, a lobed nucleus
- Cell is completely functional
- should have _2-5_____ lobes
- A maturation “shift to the right” occurs w/ increased number of segs, or
hypersegmentation (>5 lobes)
]
Neutrophil time of maturation
For a neutrophil, about 10 days from myeloblast to maturation.
Granulocytes reside in
3 main areas of the body, moving from
1) bone marrow to
2) p.b. to
3) tissues (& movement from endothelium to tissues does not
reverse itself.)
In the bone marrow, granulocytes have three functions:
- Proliferation (i.e. myeloblasts, promyelocytes, and myelocytes)
- Mitotic pool – 2 to 3 days
- Maturation (i.e. metamyelocytes and bands)
- Storage (bands and polymorphonuclear leukocytes)
- Storage pool – 5 to 7 days
Bone marrow holds 4-10 day supply of WBCs – about 25x amount in circulation!
Granulocyte “Functional Pools”
Process of moving from bone marrow to tissues can speed up under
stress (physical or emotional), causing “shift to the left”: an accelerated release
of immature forms into the p.b.
- In the bloodstream, granulocytes enter & then divide up
equally between two other functional pools:
- Circulating Pool (CP) – These are counted in a WBC count
- Marginating Pool (MP) - Lies against the endothelial lining of
blood vessels
Granulocyte Pools (cont.)
There’s constant exchange between these
2 pools.
There’s constant exchange between these
2 pools.
Marginating cells can be mobilized
into p.b. circulating pool during stress or
exercise
Granulocyte Pools (cont.)
- Movement from MP to CP accounts for the elevated
WBC count seen in crying children or highly stressed-
out adults, due to the effects of hormone?
epinephrine
Granulocyte Pools (cont.)
Granulocytes stay in p.b. about
6-10 hrs., then move
randomly into tissues via? __diapedesis_______, perform their
job (1-5 days), & die.
Granulocyte Pools (cont.)
process in which they squeeze through tight
junctions between
Endothelial cells of the blood
vessel walls, & exit into the tissues. Once in the
tissues, they do not return!
Phagocytosis
Primary phagocyte
are monocytes & neutrophils, but eos &
Basos ARE capable of limited phagocytosis!
Phagocytosis
Five steps:
- Directed Motility (Migration) M
- Recognition & Attachment R
- Ingestion & Phagocytosis I
- Degranulation/Digestion & Killing D (K)
- Exocytosis E
Phagocytosis
Step One: Directed Motility (Migration)
Chemotaxis =
process of phagocytic movement along
gradient of increasing [chemotaxin] (molecules generated
by infection &/or inflammation.)
Phagocytosis
Step One: Directed Motility (Migration)
Phagocytes have p.m. receptors to detect _______
chemotaxins/chemotactic factors, Abs, & fixed
complement. Thus they migrate through p.b. & diapedese
into tissues to reach site of infection/ inflammation
Phagocytosis
* Step One: Directed Motility (Migration)
Who gets there first ________
Segs do
Phagocytosis
Step Two: Recognition & Attachment
Opsonization facilitates recognition & attachment by
marking microorganisms for ingestion
Phagocytosis
Step Three: Ingestion & Phagocytosis
- In an amoeboid motion, phagocyte uses rapid
microfilament rearrangement to extend pseudopodia &
surround foreign particle . . . - Endocytose it,
- And then form vacuole around it (called a phagosome).
- Step Four: Degranulation/Digestion (Killing)
WBC granules = tiny lysosomes containing lysozyme & acid hydrolases
such as myeloperoxidase (MPO); these fuse with phagosome membrane
to form a phagolysosome (functions as a ? _____Garbage disposal ________________)
* Bacterial killing occurs in the phagosome by processes that are either
oxygen-dependent or oxygen-independent
Phagocytosis
* Step Four: Degranulation/Digestion (Killing)
Oxygen dependent
- The burst is triggered by superoxide (generated from MPO) in primary
granules (which are still present in a mature seg, just not visible.) - Segs’ 1 o granules color is? ___________
- Segs’ 1 o granules specific or nonspecific? __________
Phagocytosis
* Step Four: Degranulation/Digestion (Killing)
Oxygen-independent killing
- Accomplished by hydrogen ions (alters the pH), lysozymes , and
bactericidal proteins (cleave segments of bacterial cell wall).
garbage disposal
Phagocytosis
- Step Five: Exocytosis
- Essentially consists of dumping trash left over from the battle!
FYI: Degranulation can also be triggered when seg (or to a lesser
extent, a mono) gets “hung up” on an atherosclerotic plaque inside a
blood vessel, causing release of MPO & localized inflammatory
reaction. Thus MPO & other markers of inflammation are gaining
interest as possible CVD markers.
Eosinophils
similar to
Structurally similar to neutrophils, but differ in their unique cytoplasmic
granules
Eosinophils
Granule contents
2o granules = large red-orange lysosomes containing very
small [peroxidase] & some acid phosphatase. These granules contain mostly
crystalloid form of Major Basic Protein (MBP), which is lysine & arginine-rich (&
cytotoxic to Schisto-soma.) Granules may overlie nucleus, but usually don’t
Eosinophils
cytoplasm is
Colorless
Eosinophils
Nucleus stains
less blue than neutrophils, and can be segmented (mature) or
band-like (immature)
Eosinophils move
Move very slowly, have less intracellular killing ability than segs
Eosinophils function
- Control parasitic infections (damage larval stages of parasitic
helminthic worms: flukes, tapeworms, & roundworms). - Dampen hypersensitivity reactions (allergies).
Eosinophils
Lifespan:
Eos remain < 1 week in p.b
Basophil
Phagocytic ability much <
egs & eos. Classified only into immature or mature forms
(based upon degree of nuclear segmentation.)
Basophil functions
- Mediate inflammatory responses via IgE receptors on their plasma membrane
(including allergies)
Basophil
Granule contents
Large bluish-black lysosomes containing histamine and
heparin(released in allergic reactions). These are water-soluble, so may
disintegrate during staining (& so may appear as empty areas)
BasophilGranules usually DO
overlie nucleus
Monocytes
First function
The first major function is phagocytosis - even
though a monocyte’s speed of mobility is slow
compared to that of segs
* Even though the speed of mobility is slower,
phagocytosis is much quicker
* Require less opsonization, and phagocytosis can be
initiated by contact
Monocytes minor role
Play a minor role in processing specific antigens
for lymphocyte recognition
Monocytes
A mono in the tissues is no longer a mono, but
called a _________
macrophage, either free or fixed
Monocytes Monos stay in p.b for
~ 3 d., then move into
tissues & stay several months or more.
Monocytes maturation
Monoblast
Same ___________ factors active for maturation, are involved in ___________
activity, suggesting link in certain malignant marrow diseases (i.e. __________)
Same stimulating factors active for maturation, are involved in osteoclast
activity, suggesting link in certain malignant marrow diseases (i.e. Multiple
Myeloma)
Monocytes maturation
Monoblast
Usually seen with a single large
nucleolus
Monocytes maturation
Monoblast
Strongly positive for
CD33
Monocytes maturation
Monoblast
Weakly pos for
CD34
Monocytes maturation
Monoblast
Also positive for
Also pos. for CD4 (seen in T-lymphs)
Promonocyte
Capable of some phagocytosis, but lack range of activity
Monocytes
- Granule Contents
- Monos contain MANY lysosomal enzymes: includes lysozyme (released
continuously), acid phosphatase (where was alk. phosphatase?
______in 3 degree granules of segs___________), & a small amount of peroxidase (< «_space;< seg contains!) - Monos also stain + for nonspecific esterases (NSEs.)
Thus so far, where have we seen peroxidase in?
4+ in early segs , 2+ in later segs, 1+ in monos
Monocytes description
- Nucleus is indented or curved
- Chromatin is lacy w/ small clumps
- Largest-sized cell in p.b.
- Phagocytic vacuoles are common
- Regarded as a transitional cell
Monocyte
variant / atypical lymphs or large bands. (Always look at
nuclear chromatin pattern: is it frilly or chunky?)
Macrophage
As a mono leaves the circulation and enters the tissue, it evolves into
lysozyme-filled macrophage
Macrophage
Undergo a sudden increase in
metabolic energy, phagocytic activity, lysosomes, IgG
surface receptors, and mobility
Macrophage cytoplasm is
highly vacuolated and has foamy appearance
Macrophage
Two categories
free and fixed
* Free macrophages are found in various sites of inflammation and repair, and body fluids
* Fixed macrophages are fund in specific sites of concentration (i.e., Kupffer cells, bone marrow, and
lymph nodes)
* Develop different minor characteristics depending upon the organ they occupy
Monocytes and Macrophages function
Some macrophages are motile and respond to ________
Monocytes become immobilized by _______
Become activated to _______
as a
secondary line of defense to clean-up and remove
microbial organisms or cellular debris, and to remove
the bodies own aged and damaged cells
* Some macrophages are motile and respond to
chemotactic factors such as complement and factors from
activated lymphs
* Monocytes become immobilized by migration-inhibition
factor (MIF) released from activated lymphs
* Become activated to phagocytize by complement,
prostaglandins, or in response to previously phagocytized
material
Monocytes and Macrophages perform many vital
functions
A defense against _______
Monocytes present and deliver _______
Have a role in the daily destruction of _______
Macrophages possess ______ activity.
Serve as important effector cells by secreting ________
- A defense against microorganisms
- Monocytes present and deliver IL-1 (a T-lymphocyte
activating factor) to specific membrane surface receptor
sites - Have a role in the daily destruction of aged blood cells,
denatured plasma proteins, and lipids - Macrophages possess heme oxidase activity, which
enables them to break down hemoglobin, and store iron - Serve as important effector cells by secreting IL-1, and
regulators and complement, coagulation, and Kinin
cascades
Lymphoid Maturation
- The 2 Primary Lymphoid Organs:
- Bone marrow & thymus (“BMT”)
- Lymphocyte production from these sites is continuous & Ag-independent.
These send partially differentiated lymphs to The Secondary Lymphoid Tissues .
Lymphoid Maturation
The Secondary Lymphoid Tissues
- The Secondary Lymphoid Tissues:
- Lymph nodes, spleen, tonsils, & MALT (Mucosal Associated
Lymphoid Tissues in respiratory & GI tracts, such as Peyer’s patches
(in ? __The small intestines _________________). - These act as main repositories for already differentiated lymphs
- Lymphoblast “blast”
- Small to medium sized cell
- Round-to-oval nucleus containing loose chromatin and one or more active
nucleoli - Cytoplasm is scanty and has basophilia in proportion to amount of RNA
- Prolymphoblast “Pro”
- Clumped chromatin
- Cytoplasm is more abundant than blast, but deeply basophilic
Lymphocyte Characteristics
Size
- Can vary in size from 9 μm to 15 μm
- Small (resting) lymphs - 7-10 μm; scanty cytoplasm, large N:C ratio.
- Large lymphs - 11-25 μm; have abundant cytoplasm
Lymphocyte Characteristics
- Both have round or oval nuclei
- Chromatin appears blocked or “smudgy”
- Cytoplasm stains blue; may include some azurophilic granules
- Both types are NORMAL
Small Lymphocyte
Wright-Giemsa Stain
size
color of cytoplasm
Plays a big role in the
- 8-12μm in diameter with high N:C ratio
- nucleus is round with coarse, dense
chromatin - cytoplasm is weakly basophilic,
homogenous and clear without inclusions - plays a big role in the body’s immune
response, particularly in viral infections
Large Lymphocyte
Wright-Giemsa Stain
Size
nucleus appears
Cytoplasm is
Plays a big role
- 12-16μm in diameter with an irregular
outline - nucleus can appear irregular and the
chromatin is not as coarse as in small
lymphocytes - cytoplasm is abundant and tends to be light
blue - plays a big role in the body’s immune
response, particularly in viral infection
Plamsa cells
secrete Igs. & responsible for
antibody production
B-cells
- Differentiation occurs in the adult bone marrow
- Seen primarily in p.b. as small, resting lymphs.
- Upon Ag exposure in the 2o lymphoid tissues, these
enlarge, differentiate into
two types of B cells
- Plasma cells - secrete Igs. & responsible for
antibody production - Memory cells
T cells act in 2 major roles:
Effector cells
5 major types of “not-self pathogens”?
Example of T cell
Effector cells - responsible for cell-
mediated immunity: defense vs. which
5 major types of “not-self pathogens”?
viruses, fungi, bacteria, parasites, & tumor cells
- Ex., Cytotoxic T cells (Tcyto ) – usually CD8+.
Destroy Ag-specific target cells on contact.
T cells act in 2 major roles (cont.)
Regulatory cell
induce or suppress proliferation /
differentiation of effector cells; for example
T cells act in 2 major roles (cont.)
Regulatory cell
Helper/ Induced T cells
TH ) - CD4+. Induce other
lymph to carry out certain functions (Ex., inducing B
cells to produce Abs.)
T cells act in 2 major roles (cont.)
Regulatory cell
Delayed hypersensitivity T cells (TD )
pro-duce
chemotactic lymphokines in response to Ags.
T cells act in 2 major roles (cont.)
Regulatory cell
- Suppressor T cells (TS) -
CD8 +; regulate humoral &
cell-mediated responses. (Not solely suppressive,
despite name.)
Natural Killer (NK) cells
Type of larger what
type of large granular
lymphocyte, or LGL (LGL is a descriptive term derived
from flow cytometry studies; it may NOT be
obviously granular on Wright’s stain!)
NK cells lyse
Lyses some tumor cells & virus-infected cells
Natural Killer (NK) cells majority are ______ positive
D56+ CD16+
Nk cells note
Not all LGLs seen in p.b. are NK cells, but some are. You
couldn’t tell unless you did flow analysis
LGL also _______
(also “atypical” due to number of granules
Cells That Confuse Lymphocyte ID
Blasts
- Large lymphs may be similar in size to blasts, & occa-
sionally may even contain nucleoli
Cells That Confuse Lymphocyte ID
Monocytes
- Have lacy chromatin (with brain-like convolutions); the
nucleus is not stained as darkly as it does in lymphs.
Monocyte cytoplasm tends towards blue-gray, & has an
opaque, “ground-glass appearance.”
Cells That Confuse Lymphocyte ID
Rubricytes/polychromatic normoblasts
Similar in size to lymphs, but rubricyte cytoplasm has a
grayish-blue appearance, whereas lymph cytoplasm is a
clearer blue. Also, rubricyte chromatin is much denser
than lymphocytes’ chromatin.
Lymphocytosis definition
normal range
absolute ↑ in # of circulating lymphs above
normal range:
* ↑ 4.0 x 10 3/uL in adults
* ↑ 9.0 x 10 3/uL in children (Note difference!)
Lymphopenia
absolute ↓ in # of circulating lymphs below
normal range
(due to ↓ production, alterations in lymph traffic, and/or ↑
lymph destruction.)
Morphology of Reactive/Atypical Lymphs
Type one
– some call this “Plasmacytoid lymph”
* Smallest of the atypicals (9-20 um).
* Variable basophilic cytoplasm; vacuolated, may contain
granules.
* “Foamy” or “frilly” nuclear appearance, but chromatin still
dense. Most likely a triggered (i.e., immunocompetent) B
cell.
* Classically, this is type most commonly confused with
monocytes, but it can also appear in an easier to ID form .
. .
Morphology of Reactive/Atypical Lymphs
Type 2
aka. “Downey cells”.
* These are the classical reactive or atypical lymphs
* Classically seen in Infectious Mononucleosis!
* Abundant cytoplasm, irregularly- shaped & edges
indented by surrounding structures.
* Overall “fried egg” or “flared skirt” type of
appearance.
* No nucleoli
Morphology of Reactive/Atypical Lymphs
Type III
Largest of the atypicals (12-35 um).
* Vacuolated, very basophilic cytoplasm.
* Immature chromatin with nucleoli!
* So how do you tell these highly reactive lymphs (reactive
lymphocytosis) from blasts (in a malignant
lymphocytosis)?
The extreme pleomorphism of the reactive lymphs -
a malignant lymphocytosis looks more clonal, with
a more homogeneous cell population.
Plasma cells –
Generally smaller then
abundant deep blue
Eccentrically located what
generally smaller
than Type III atypicals (10-28 um).
* Abundant, deep blue, & agranular cytoplasm.
* Eccentrically located nucleus.
* General “cometary” type appearance.
Thrombocyte maturation
Megakaryoblast
Promegakaryocyte
Basophilic/Granular Megakaryocyte
Megakaryocyte
Thrombocyte
Wright-Giemsa Stain
- A normal platelet measures 1,5–3 μm in
diameter. - round or oval in EDTA-anticoagulated blood.
In blood films made directly from capillary
blood they appear aggregated. - Thrombocytes are fragments of the of the
megakaryocyte cytoplasm. - Platelet size is of diagnostic significance
particularly when considered in relation to
the platelet count. - Thrombocytes play a big role in the body
coagulation process
