Introduction and Case Study of DLC. Preliminary stuffs.

1. DIFFERENTIAL
LEUKOCYTE COUNTS
Md. Mobashir Rahman
Roll: FH-028

2. Definition of DLC
A Leukocyte Count measures the number of white
blood cells in your blood, and a differential
leukocyte count (DLC) determines the percentage
of each type of white blood cell present in your
blood.

3. White Blood Cells
White blood cells, or leukocytes, are the immune
system's warriors. So when an infection or disease
attacks the body, the system typically responds by
sending more white blood cells into the fray. This
means that checking the differential value of these
cells is a relatively easy way to detect and monitor
such conditions.

4. DLC technique
Best way to differentiate
between white blood cells
is the Giemsa-Wright
staining technique.
The morphology and
staining characteristics of
each type of WBC is
peculiar and is responsible
for the in specific typing
and identification.

5. Types of white blood cells
Granulocytes: with secretory granules in its cytoplasm.
• Neutrophils
• Eosinophils
• Basophils
Agranulocytes: Lacks granules in their cytoplasm.
• Monocytes
• Lymphocytes
BLAST cells: Immature WBCs.

6. Characteristics of the types
Illustration source: Scientific Cindy

7. Functions of the types
Type of white blood cell Function
neutrophil
helps stop microorganisms in infections by eating
them and destroying them with enzymes
lymphocyte
–uses antibodies to stop bacteria or viruses from
entering the body (B-cell lymphocyte)
–kills off the body’s cells if they’ve been
compromised by a virus or cancer cells (T-cell
lymphocyte)
monocyte
becomes a macrophage in the body’s tissues, eating
microorganisms and getting rid of dead cells while
increasing immune system strength
eosinophil
helps control inflammation, especially active during
parasite infections and allergic reactions, stops
substances or other foreign materials from harming
the body
basophil
produces enzymes during asthma attacks and
allergic reactions
Source: Scientific Cindy

8. DLC Procedure
Draw blood from your arm or hand by a small needle.
No special preparation before the test is necessary.
A drop of blood from your sample on a clear glass slide
and smears it to spread the blood around.
The blood smear is stained with a dye that helps to
differentiate the types of white blood cells in the sample.
Fix the slides

9. DLC Procedure
Then each type of WBC is counted.
There are 2 ways to count the types.
• Manual blood count, visually identifying the
number and size of cells on the slide.
• a machine analyzes your blood cells based on
automated measurement techniques.
Automated count technology uses electrical,
laser, or photodetection methods to provide a
highly accurate portrait of the size, shape, and
number of blood cells in a sample.

10. Demonstration of the visual of the cells
Fig: how the cells look after staining

11. Manual DLC counting
Fig: Partitioning in squared sections

12. Manual DLC counting
Then each type of cells from each
squared partition is are count and
expressed in percentages.
Percentage of a specific type =
𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑠𝑝𝑒𝑐𝑖𝑓𝑖𝑐 𝑐𝑒𝑙𝑙𝑠
𝑇𝑜𝑡𝑎𝑙 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑐𝑒𝑙𝑙𝑠
x 100

13. Reference value of the DLC
According to the American Academy
of Pediatric Dentistry,
the percentages of white blood cells in
healthy people are as follows:
• 54 to 62 percent neutrophils
• 25 to 30 percent lymphocytes
• 0 to 9 percent monocytes
• 1 to 3 percent eosinophils
• 1 percent basophils

14. Clinical significance of the DLC
Increase of any
WBCs above
average may mean:
Leukocytosis:
increase in the
number of white
cells in the blood
Acute bacterial,
viral or parasitical
infection.
Leukemia: high
numbers of
abnormal mature or
immature WBCs.
Decrease of WBCs
below average may
indicate:
Leukopenia:
Lack of WBCs.
increases risk of
infection.
A severe or
widespread
bacterial or viral
infection
Recent
chemotherapy or
radiation therapy
treatment

15. A case study
CBC and DLC of a 61 Year old caucasian male
Diagnosis:
• High differential values
of lymphocytes and
monocytes indicate
absolute
monocytosis. Further
examination indicates
acute pneumonia.
• High blast cells
indicate Leukemia.
Source: Case 726, Department
of Hepatology, University of
Pittsburgh

16. Thanks for everything 