Transcript White blood cells - The Silver Sword

Dr Q Sedick
WHITE BLOOD CELLS
Haemopoeisis
 Haemopoeisis starts with a pluripotential
stem cell that gives rise to separate cell
lineages.
Leucocytes
May be divided into 2 groups:
1.Phagocytes:granulocytes & monocytes
2.Immunocytes:lymphocytes & plasma cells
Phagocytes & immunocytes serve to protect
the body against infection using
immunoglobin and complement systems.
Granulocytes
 Comprised of neutrophils, eosinophils &
basophils
Neutrophil development
Granulopoeisis
 Many growth factors are involved in the
maturation process
 Includes IL-1/IL-3/IL-5/IL-6/IL-11/GM-CSF/GCSF/M-CSF
 GF stimulate proliferation and differentiation
and also affect the function of mature cells on
which they act
Neutrophils
 Characterized by a dense nucleus consisting
of 2-5 lobes, pale cytoplasm with an irregular
outline containing many fine pink granules
Neutrophil granules
 Consists if primary & secondary granules
 Primary : myeloperoxidase/acid
phosphatase/acid hydrolases
 Secondary: collagenase/lactoferrin &
lysozyme
Monocytes
Large oval/indented nucleus, clumped chromatin
& abundant blue cytoplasm
Neutrophil/monocyte functions
1. Chemotaxis-phagocytes are attracted to
bacteria by chemotactic substances released
from the damaged tissues/by complement
or by leucocyte adhesion molecules
2. Phagocytosis-neutrophils & monocytes have
FC and C3B receptors which aid in
opsonization of bacteria
Neutrophil/monocyte function
3. Secretion of growth factors & chemokines-
aid in pro-inflammatory processes
4. Killing and digestion: via oxygen-dependant
and oxygen- independent pathways
Eosinophils
 Consists of 2-3 nuclear lobes/ red-staining
coarser cytoplasmic granules
 Enter inflammatory exudates
 Special role in allergic responses/defense
against parasites and removal of fibrin
formed during inflammation
Basophils
 Dark cytoplasmic granules which overly the
nucleus
 Contain heparin and histamine-released on
degranulation
 Have IGE attachment sites
 In tissues-mast cells
Defects of leucocytes
NEUTROPHIL LEUCOCYTOSIS:
>7,5 X 10^9/L
1. Bacterial infections, e.g. : periodontitis
2. Inflammation and tissue necrosis,
3. Metabolic disorders
4. Neoplasm's
5. Acute haemorrhage/ haemolysis
6. Drugs e.g. :lithium
Leucocytosis…
7. Haematological malignancies:
CML/myeloproliferative
disorders/polycythaemia
vera/myelofibrosis/AML
8. Treatment with myeloid growth factors
9. Asplenia
10. Rare inherited disorders, e.g.: Down
syndrome
The leukemoid reaction
 Reactive and excessive leucocytosis
characterised by the presence of immature
cells in the peripheral blood
 Seen in severe chronic infections/severe
haemolysis & metastatic cancer
Severe chronic infections
Malignancy
Eosinophilia
>0,4 x 10^9/l
Causes are as follows:
1. Allergy / atopy
2. Parasitic disease
3. Skin diseases- urticuria
4. Drug-induced
5. Asthma & pulmonary syndromesassociation with nasal polyps
Urticuria
Eosinophilia
6. Vasculitidis-polyarteritis nodosa
7. Malignancies-metastatic and
haematological
8. Chronic eosinophilic leukaemia
9. Hypereosinophilic syndrome
Allergy/atopy
Basophilia
 >0,1 x 10^9/l
 Causes include reactive and malignant
 Reactive: infections like small pox & chicken
pox
 Myeloproliferative disorders-Chronic myeloid
leukaemia
Monocytosis
>0,8 x 10^9/l
1. Chronic bacterial infections
2. Protozoan infections
3. Collagen vascular disease-SLE
4. Lymphoma
5. Myelodysplasia
Neutropaenia
<2,5 x 10^9/l
1. Infections of the mouth &
throat(bacterial/viral)
2. Immune-SLE,hypersensitivity,anaphylaxis
3. Drug-induced
4. Congenital - Kostmanns syndrome
5. Bone marrow failure
Lymphocytes
 Lymphocytes are the immunologically
competent cells that assist the phagocytes in
defense of the body against infection
 They are involved in processes such as
antigen specificity and immunological
memory
Lymphocyte development
 Consists of T and B cells
 B cells:
Derives from the stem cell,matures in the bone
marrow and circulates in the peripheral blood
until antigen recognition
On activation B cells secrete immunoglobulin
and is known as plasma cells
B cells/plasma cells
T cells
T CELLS:
 Derive from the thymus and differentiates into
mature T cells during its passage to the bone
marrow
 Involved in immunological processes such as cell
mediated cytotoxicity
Lymphocytosis
Acute infections-infectious
mononucleosis/rubella/pertussis/mumps/herpes/CMV/
HIV
2. Chronic infections-TB/brucellosis/syphillus
3. Chronic lymphocytic leukaemias
4. Acute lymphoblastic leukaemia/NHL
1.
Infectious mononucleosis