Transcript WHITE BLOOD CELLS and the differential count

WHITE BLOOD CELLS
AND
THE DIFFERENTIAL COUNT
RAMLA A. SANDAG – JAILANI , M.D.
DEPARTMENT OF PHYSIOLOGY
KKUH / KSU
White Blood Cells (WBC) or Leucocytes
– are the mobile units of the body’s
immune defense system.
– formed partially in the bone marrow and
partially in the lymph tissue.
Leukocytes divide in two categories:
A. Polymorphonuclear Granulocytes
- neutrophils
- eosinophils
- basophils
B. Mononuclear Agranulocytes or
Lymphoid cells
- lymphocytes
- monocytes
* Specific Functions:
Granulocytes } … protect the body against
invading organisms mainly by
Monocytes
} ingesting them ( Phagocytosis )
Lymphocytes } … function mainly in connection
with the immune system
Normal WBC count: (both male and female)
= 4 – 11 x 10³/mm³
*Leukocytosis - > 10,000/mm³
*Leukopenia - < 4,000/mm³
NEUTROPHILS ( Polys, Segs, PMNs)
– are very active in phagocyting bacteria
– most numerous of the WBCs (50 – 70 % of the
total leukocytes)
– primary defense against infection.
– are present in large amount in the pus of wounds.
Bands / Stabs
– immature forms of neutrophils seen as an
early response to infection.
Neutrophils (cont.)…
Neutrophilia
- increase in the number of neutrophils
- causes:
> acute infection
- appendicitis, smallpox or rheumatic fever.
> acute inflammation
- after a heart attack, burns
Neutropenia
- decrease in the number of neutrophils
- cause:
> viral infection - influenza, hepatitis, rubella.
Neutrophils (cont.)…
A neutrophil has very tiny
light staining granules
(the granules are very
difficult to see).
The nucleus is frequently
multi-lobed with lobes
connected by thin strands
of nuclear material.
These cells are capable
of phagocytizing foreign
cells, toxins, and viruses.
EOSINOPHIL S
– attack parasites and phagocyte antigen-antibody
complexes.
– account for less than 5% of the WBC’s.
– modulate allergic inflammatory responses.
Eosinophilia – increase amount of eosinophils
– may be due to parasitic diseases, bronchial
asthma or hay fever.
Eosinopenia – decrease amount of eosinophils
– may occur when the body is severely stressed.
Eosinophils (cont.)…
This granulocyte has large
granules (A) which are acidophilic
and appear pink (or red) in a
stained preparation.
The nucleus often has two lobes
connected by a band of nuclear
material.
The granules contain digestive
enzymes that are particularly
effective against parasitic worms
in their larval form.
BASOPHIL S
– secrete anti-coagulant and vasodilatory substances
as histamines and serotonin.
– represent less than 0–1% of all leukocytes
– main function:
> secreting substances which mediate the
hypersensitivity reaction.
Basophils (cont.)…
Basophilia - an abnormally high number of basophils.
> may be associated with:
- hemolytic anemia or chicken pox
- radiation exposure
Basopenia (Basocytopenia) – decrease number
of basophils.
> causes:
- urticaria
- stress
- prolonged steroid therapy
Basophils (cont.)…
The basophilic granules in
this cell are large, stain deep
blue to purple, and are often
so numerous they mask the
nucleus.
These granules contain
histamines (cause vasodilation)
and heparin (anticoagulant).
> The nucleus is either bi-lobed or
tri-lobed.
LYMPHOCYTES
– are the second most numerous leukocyte.
– account for 20 – 40% of the white blood cells.
– not only fight infections but also provide immunity to
certain disease.
– play an important role in our immune response.
*T-lymphocytes act against virus infected cells
and tumor cells.
*B-lymphocytes produce antibodies.
Lymphocytes (cont.)…
Lymphocytosis
– increase in the number of lymphocytes.
– Causes:
> Infectious mononucleosis or a chronic infection.
> Ulcerative colitis
> Measles, Mumps, CMV
Lymphocytopenia
– decrease number of lymphocytes.
– causes:
> Chemotherapy, radiation, aplastic anemia
> CHF, SLE, renal failure
Lymphocytes (cont.)…
The lymphocyte is an agranular
cell with very clear cytoplasm
which stains pale blue.
Its nucleus is very large for the
size of the cell and stains dark
purple.
This cell is much smaller than
the three granulocytes (which are
all about the same size).
MONOCYTES
– the largest of the leukocytes.
– account for 2 – 6% of all leukocytes.
–These cells leave the blood stream (diapedesis) to
become macrophages.
– As a monocyte or macrophage, these cells are
phagocytic and defend the body against viruses
and bacteria.
Monocytes (cont.)…
Monocytosis – increase monocyte count
– causes:
> Bacterial infections
> Lymphoma
> Subacute Baxcterial Endocarditis (SBE)
> TB, Malaria, Typhoid fever
Monocytopenia – decrease monocyte count
– causes:
> HIV
> Steroid treatment
 The nucleus is most often
"U" or kidney bean shaped;
the cytoplasm is abundant
and light blue (more blue
than this micrograph
illustrates).
*What is the WBC/ Leukocyte Differential Count?
> Determines the number of each type of white blood
cell present in the blood.
> Can tell you what type of infection is present.
N⁰ values:
Neutrophils = 50 – 70%
Eosinophils = 1 – 4%
Basophils
= 0 – 1%
Lymphocytes = 20 – 40%
Monocytes = 2 – 6%
ERYTHROCYTE SEDIMENTATION RATE
(ESR)
* What is Erythrocyte Sedimentation Rate?
> It is the rate at which erythrocytes settle in a citrated
sample of blood in a specific time period, usually
one (1) hour.
> Is a nonspecific test used to help detect conditions
associated with acute and chronic inflammation.
Sedimentation occurs when the erythrocytes
clump or aggregate together in a column-like
manner , like “pile of coins”.
→ROULEAUX FORMATION
* 2 Commonly used methods of ESR determination:
1. Wintrobe method
2. Westergren method – mostly used
* Reagents and Apparatus:
1. Westergren’s sedimentation apparatus
2. Anticoagulant (EDTA)
3. Disposable sterile syringes and needles
Procedure:
> To perform the test, anticoagulated
blood is placed in an upright tube,
known as a Westergren tube, and the
rate at which the red blood cells fall is
measured and reported in mm/h.
Normal results:
After 1 hour:
males = 3 – 5 mm
females = slightly higher
After 2 hours:
males = 7 – 15 mm
females = slightly higher
*Increase ESR is seen in:
> Rheumatoid Arthritis (RA), gouty arthritis
> Polymyalgia rheumatica
> Temporal arteritis
> Pregnancy(3rd month to 3 weeks’ postpartum)
> Drugs
- Dextran
- Methyldopa
- Oral contraceptives
- Theophylline
- Vitamin A
*Decrease ESR is associated with:
> Polycythemia
> Sickle cell anemia
> Hereditary spherocytosis
> Drugs
- Aspirin
- Cortisone
- Quinine
* Clinical uses:
1. It is helpful in diagnosing two specific
inflammatory diseases, temporal arteritis and
polymyalgia rheumatica.
2. It is used to monitor disease activity and
response to therapy in both of these diseases.
3. It is a prognostic test.
* A rising ESR can mean an increase in
inflammation or a poor response to a therapy;
a decreasing ESR can mean a good response.
THANK YOU !