Unit 3.5 DIFFERENTIAL COUNT Flashcards
This involves both quantitative and qualitative study of the types of leukocytes.
DIFFERENTIAL COUNT
It also includes quantitative and qualitative study of thrombocytes as well as morphologic abnormalities of erythrocytes
DIFFERENTIAL COUNT
represents the percentage distribution of the different WBCs
DIFFERENTIAL COUNT
METHODS OF BLOOD SMEAR PREPARATION
Preferred for bone marrow preparations
Coverslip Method
It has the advantage of superior leukocyte distribution
Coverslip Method
NOT for routine peripheral blood smear preparation.
Coverslip Method
Coverslip Method Procedure:
Place (?) at the center of coverslip held between thumb & forefinger
Invert another coverslip rotated (?)
As soon as the blood spreads, pull apart the 2 coverslips in a (?).
1 drop of blood
45O
firm and steady motion
Glass Slide-Coverslip Method
Place 1 drop of blood near (?) of a glass slide. Place coverslip.
As soon as the blood spreads, (?) the coverslip along the surface of the slide
one end
push forward
Most convenient and most commonly used.
Two-Glass Slide Method (Wedge slide/Push smear)
Two-Glass Slide Method (Wedge slide/Push smear) Disadvantages:
1. Tendency of larger cells to settle at the slide edges & (?)
2. (?) of nucleated cells
3. (?) to cells
feathered ends
Poor distribution
Greater trauma
Utilizes the wedge procedure
Miniprep/Hemaprep
A precision blood spreader prepares dual smears simultaneously at a constant angle and speed.
Miniprep/Hemaprep
Glass slides are placed on a platform inside the instrument
Hemaspinner
Instrument spins causing the slide to be covered with a monolayer of cells beam of sensor light to detect blood distribution
Hemaspinner
For finding reactive/immature or abnormal cells that are present in small numbers
Buffy Coat Smear
For easier location of bacteria & parasites
Buffy Coat Smear
Buffy coat smear is considered a concentrate smear for WBCs, thus it recommended when the WBC count is _________.
Buffy Coat Smear
For blood parasites examination.
Thick Blood Smear
CHARACTERISTICS OF A PROPERLY PREPARED WEDGE SMEAR
1. Length: must occupy at least (?) of the slide
2. Should be free of (?)
3. Should have (?) appearance
4. Should be (?) than the stationary slide
5. Must have (?) from thick to thin
6. (?) to allow proper fixation
7. Should terminate in a (?)
8. Should contain at least (?) in which 50% of the RBCs do no overlap each other; the remainder ma overlap in doublets or triplets and the central pallor should be clear
1/2 to 2/3
waves, holes, and ridges
smooth and even
narrower
gradual transition
Thin enough
feathery tail
10 LPF
Too large drop of blood
TOO THICK SMEAR
Too fast spread
TOO THICK SMEAR
Too high angle
TOO THICK SMEAR
High hematocrit
TOO THICK SMEAR
Too small drop of blood
EXTREMELY THIN SMEAR
Too slow spread
EXTREMELY THIN SMEAR
Too low angle
EXTREMELY THIN SMEAR
Low Hematocrit
EXTREMELY THIN SMEAR
Accumulation of nucleated cells
GRITTY APPEARANCE
large number of leukocytes
GRITTY APPEARANCE
Use of heparin as anticoagulant
GRITTY APPEARANCE
Too slow spreading/delay in spreading
GRITTY APPEARANCE
Using only a part of the drop of blood
GRITTY APPEARANCE
Rough edge or dirty spreader slide
GRITTY APPEARANCE
METHODS OF MANUAL DIFFERENTIAL COUNT
WBCs are counted in consecutive fields as the blood film is moved from side to side
Cross-sectional/Crenellation Method
WBCs are counted in consecutive fields from the tail toward the head of the smear
Longitudinal Method
Ideal if smear is thin enough since cells can be identified all the way.
Longitudinal Method
WBCs are counted in a pattern of consecutive fields near the tail on a horizontal edge. Count 3 consecutive horiontal edge fields, 2 fields towards the center, 2 horiontal and 2 vertical to the edge
Battlement Method
Using the Oil Immersion Objective:
Estimate (?); Examine (?)
Perform WBC Differential count - A total of (?) are counted and classified according to type
Platelets and WBCs
RBC morphology
100 WBCs
The total number of cells to be counted could be decreased or increased when any of the following criteria are observed:
(?) if the total WBC count is < 1 x 10 9/L (< 1,000/µL)
Count (?) if in the first 100 count, any of the following are observed::
50 Cells
additional 100 cells
> (?) Eosinophils
(?) Basophils
(?) Monocytes
(?) are greater than Neutrophils
10%
2%
11%
Lymphocytes
METHODS OF CLASSIFYING NEUTROPHILS
WBCs are classified based on the number of lobes indication their age
ARNETHS CLASSIFICATION
- WBCs are classified according to granulation
SCHILLINGSS CLASSIFICATION
Younger forms are placed on the left; mature and old forms on the right
SCHILLINGSS CLASSIFICATION
1 round or indented nucleus
I
5% (blast cells)
I
2 nuclear divisions
II
35 %
II
3 nuclear divisions
III
41 %
III
4 nuclear divisions
IV
17 %
IV
5 or more
V
2% (oldest)
V
Schillings Hemogram
1 2 3 4 5 Eos Baso Lym Mono
Schillings Hemogram Shift to the LEFT:
increase in immature forms
Schillings Hemogram Shift to the RIGHT:
- increase in mature forms
young forms with accompanying WBC count.
Regenerative Shift to the Left
Infections, appendicitis & acute sepsis
Regenerative Shift to the Left
young forms with N or WBC count
Degenerative shift to the Left
Typhoid fever and TB
Degenerative shift to the Left
Pernicious anemia or megaloblastic anemia
Shift to the RIGHT
: cells that possess segments or lobes connected with a distinct thin chromatin filament
Filamentous
: nucleus with thinned-out portion
Non-filamentous
REPORTING
1. Relative count - Cells are reported in
2. Absolute count - Cells are reported as
% or decimal
number per volume of blood (e.g.: cells /µL or /L )
Absolute count =
Relative count (%) x total WBC count
47 77%
PM Neutrophil
1.8 7.8 x 109/L
PM Neutrophil
0 7%
Band cells
0 0.7 x 109/L
Band cells
20 40%
Lymphocytes
1.0 4.8 x 109/L
Lymphocytes
2 10%
Monocytes
0.01 0.8 x 109/L
Monocytes
0 6%
Eosinophils
0 0.6 x 109/L
Eosinophils
0 1%
Basophils
0 0.2 x 109/L
Basophils
are volatile
Circulating cells
cause lymphocytes & eosinophils to disappear from circulation within 4 8 hrs
Corticosteroid hormones
causes granulocytosis within minutes
Epinephrine
CLINICAL SIGNIFICANCE of variation in counts:
Acute Infections -
Neutrophilia Pathologic causes
bacterial, some viral, fungal, parasitic
Neutrophilia Pathologic causes