Lect 3 - Leukocytes Flashcards
Starting from the stem cell, name the stages of a maturation of a neutrophil [7]
Stem cell > myeloblast > progranulocyte > myelocyte > metamyelocyte > band neutrophil > segment neutrophil
In the bone marrow neutrophils are in 2 compartments: List the compartments and what they contain
Proliferation and maturation pool - stem cell and precursor up to myelocyte stage
Maturation and storage pool (post mitotic pool) - metamyelocytes, bands and mature granulocytes
The maturation and storage pool of neutrophils vary in size, which species has a large pool [2] and which has a small pool
Largest - Dogs and Cats
Small - Cow
Within the post mitotic pool is a sub pool, what is it called and what does it contain
SNP (storage neutrophils pool) and contains segmented neutrophils
What growth factors stimulate granulocyte differentiation [5]
IL-1, IL-3, IL-6, G-CSF and GM-CSF
How many days does it take for a stem cell to mature into a neutrophil
4-9day
WBC morphology - toxic changes indicates
Moderate to severe inflammation (most common cause) or drug toxicity during maturation in bone marrow
The four indicators of toxic change are
Cytoplasmic basophilia
Dohle bodies
Vacuolated cytoplasm
Toxic granulation
Dohle bodies are commonly seen in what species
Cats
Toxic granulation most commonly seen in what species
Horse
Abnormal granulation or vacuolation of neutrophils can be produced by
MPS
Hyposegmentation of neutrophils can be due to
Part of left shift if cells are immature
Pelger-Huet anomaly if nuclei mature but not segmented
Hypersegmentation of neutrophils can be due to
Aged neutrophils with prolonged blood transit time (via corticosteroids)
Typically, bone marrow samples are collected from sites that are expected to have active
haematopoietic tissue. What are the sites for these various animals:
In Dogs and Cats [2]
Horse
Cattle
In Dogs and Cats - iliac crest or proximal femur or humerus
Horse - sternebrae
Cattle - proximal ribs
The blood neutrophils can be divided into two pools
Circulating neutrophil pool (CNP)
Marginating neutrophil pool (MNP)
The MNP is equal to the CNP in what species? [3] but 3x larger in what other species?
Dog, horse and calf
Cat
What are the avain equivalent to mammalian neutrophils
Heterophils
The migration of neutrophils due to chemical substances generated by injured tissue
Chemotaxis
A left shift means
The number of immature neutrophils (usually bands) exceeds the reference range but is still less than the number of nuetrophils
Regenerative left shift is
neutrophilia with a left shift is present and the mature neutrophils (segmenters) predominate
Degenerative left shifts means
The number of immature granulocytes equals to or is greater than the number of segmenters
Degenerative left shifts usually implies severe disease with a guarded prognosis for all species except
The cow
Common causes of neutrophilia [4]
Physiological
Corticosteroid - associated
Inflammation and/or infection induced
Neutrophilia due to myeloproliferative disease
Physiological neutrophilia is associated with? when does it occur?
Epinephrine release
Fear, excitement, strenuous exercise or iatrogenic epinephrine
CBC of a physiological neutrophilia is characterized by
Leukocytosis, a mild neutrophilia without a left shift. Eosinophil or monocyte counts may or may not be increased
Corticosteroid-associated neutrophilia occurs as a result of
Endogenous cortisol release from the adrenal gland, or the administration of corticosteroids or ACTH
Potential causes of increased endogenous release of corticosteroids are
Pain, prolonged emotional stress, abnormal body temperature and hyperadrenocorticism
The stress leukon includes
Leukocytosis with neutrophilia (with or without a slight shift), monocytosis (especially dogs), lymphopenia (most consistent change) and eosinopenia
Neutrophilia is expected if there is substantial acute inflammation of subcutaneous tissues or internal tissues but Inflammation in the brain, spinal cord, superficial cutaneous tissues, lower urinary tract may not cause a neutrophilia, why?
b/c mediators are lost thru the urine and skin, or do not leave the protective environment of the brain or spinal cord
What species can respond with dramatic neutrophilia [2]
Dog and Cat
Which bacteria produces the greatest neutrophilia
Pyogenic
What is a leukaemoid reaction? When may you see this reaction
Occurs in dogs
Marked leukocytosis due to marked neutrophilia and a severe left shift
Pyometra
Neutropenia occurs as a result of [4]
Defective marrow neutrophil production
Shift from CNP to MNP
Emigration from blood
Immune mediated destruction
Neutropenia is synonymous with leukopenia in what species [2]
Dog and Cat
The major clinical consequence of neutropenia is
Infection
Reduced stem cell production of neutrophils
is a result of [3]
Stem cell death
Reduction in haemopoietic space
Cyclic stem cell proliferation
How does parvovirus cause neutropenia
Stem cell injury and emigration of neutrophils from circulation
Due to the small SNP in the bone marrow this species experiences a neutropenia that does not carry a grave prognosis
Cows
Give the names of some abnormalities of neutrophils [3]
Cyclic haemopoieses
Pelger-Huet anomaly
Chediak-Higashi sydrome
Cyclic haemopoiesis occurs in what breed of dog
Grey Collie
This neutrophil anomaly occurs in Aleutian mink, Killer Whales, Humans and Cats. Cats often have diluted blue smoke hair colour and yellow green eyes. Neutropenia is a common finding
Chediak-Higashi syndrome
Lymphocytes are found [3]
Lymphoid tisses (lymph node, spleen, tonsil, thymus, GIT and bronhus)
Bone marrow
Blood
Lymphocytes are small mononuclear cells but these species have both large and small [2]
Horse and Cow
These reactive lymphocytes are seen following antigenic stimulation
Immunocytes
What are types if lymphoid cells [4]
T and B
Plasma
Lymphoblast
NK
Where do T and B lymphocytes mature and what are their function. How long is their life span.
T - thymus, cell mediated immunity, mths to yrs
B - Bone marrow, humoral, dys to wks
Lyphocytosis can be caused by several things including [5]
Physiological lymphocytosis Prolonged or Abnormal antigen stimulation Hypoadrenocortism Persistent lyphocytosis in cattle Lymphoid neoplasia
Physiological lymphocytosis can be seen in what species [3]
Commonly in cats
Horses
Occasionally in dogs
Physiological lymptocytosis is cause by what
Catecholamine release
During fear, restraint, excitement, exercise
A normal lymphocyte count or lymphocytosis in severely ill and stressed dog should arouse suspicion of
Hypoadrenocortism (Addison’s disease)
Persistent lymphocytosis in cattle:-
This is a sub-clinical, non-neoplastic condition caused by. This is diagnosed after the absolute lymphocyte count is above normal for
BLV
3mths
Very young cattle may exhibit a lymphocytosis in response to infection or inflammation. This does not mean BLV infection.
Some causes of lymphopenia are [4]
Corticosteroid-associted lymphocytosis
Lymphopenia in acute infections
Loss, sequestration, blockage of lymph flow
Lymphocyte deficiencies
Corticosteroid-associted lymphopenia may occur due to
Exogenous admin of ACTH or corticosteroid or endogenous release
Internal loss of lymphocytes can be seen with
Chylothorax in cats
B lymphocyte deficiency can be seen in what species
Arabian foals
The monocyte is the immature cell in the blood that becomes
Tissue macrophage
What are the steps on the maturation of the monoctye [4]
Monoblast > promonocyte > monocyte > macrophage
Causes of monocytosis are [3]
Acute or chronic infection/inflammation/necrosis
Steroids
Monocytic or Myelomonocytic leukaemias
Monocytosis from infections/inflammation/necrosis very often accompanies a
Neutrophilia
The monocytosis due to steroids is usually observed in which species [2]
Dogs and Cats
The monocytosis due to steroids is accompanied by
Neutrophilia, Lymphopenia and sometimes an eosinopenia
Eosinophils are recognized by the bright red-orange granules in what type of stain
Romanowsky
“Moth-eaten,” vacuolated, or degranulated eosinophils in health
Grey Hounds
Eosinophil production and maturation is mediated by [2]
IL-5 produced by T-lymphocytes
Eosinophils migrate from the blood primarily to the
Skin, GIT, RespT
Causes of eosinophilia are [4]
Parasitism
Inflammation and or hypersensitivity reactions
Hyperesoinophilic syndromes
Tumor-associated eosinphilia
Eosinophilia is seen commonly in parasitic infestations, but is very uncommon with
Intracellular parasites protozoan infections
Idiopathic hypereosinophilic syndromes are most commonly seen in what species [2]
Cat and Rottweiler
Eosinopenia may be cause by [2]
Acute Infection/inflammation
Corticosteriod-associated eosinopenia
Eosinopenia occurs with endogenous corticosteroid release associated
Acute stress or hyperadrenocortism
Basophil differentiation is controlled by
IL3
Basophils stained with Romanowsky, stains the granules stain dark purple in most domestic animals except the
Cat in which they stain grey-blue when mature and are numerous
Basophilia usually occurs concurrently with
Eosinophilia
Basophilia is caused by [4]
Parasitism
Hypersensitivity and or inflammatory lesions
In occult heartworm infestation
Neoplasia
Leukocytosis can be cause by [3]
Physiological leukocytosis
Corticosteroid-associated leukocytosis
Leukocytosis in inflammatory disease
Physiological Leukocytosis:-
The elevated WBC count is characterized by
A neutrophilia without a left shift, normal or
elevated lymphocyte count and normal counts of eosinophils, basophils and monocytes
Corticosteroid-associated leukocytosis:-
The elevated WBC count is characterized by
a neutrophilia without a left shift or with a slight left shift, a lymphopenia and eosinopenia, and in some species a monocytosis
Leukocytosis in Inflammatory Disease:-
The elevated WBC count is characterized by a
Neutrophilia with/without a left shift and a possible monocytosis
In ruminant and horses, ____ may be the only laboratory sign of inflammation
Hyperfibrogenaemia
Leukopenias are usually due to
Neutropenia in dogs, cats and horses
Lymphopenia in ruminants
