WBCs Flashcards
sequence of neutrophil production
myeloblast–>progranulocyte–>myelocyte–>metamyelocyte–>band neutrophil–>segmented neutrophil
become smaller, chromatin condenses and nuclei become progressively more elongated and segmented
6-7 days in health
increased stimulation and demand-2-5 days
Neutrophil pools in bone marrow
proliferation pool-myeloblasts, progranulocytes and myelocyts, mitotically active
maturation and storage pools-metamyelocytes, bands and segs
neutrophil pools in blood
circulating pool-freely flowing in vasculature, meausred on CBC
marginated pool-“rolling” along and loosely adhered to endothelial surfaces via selectins
dynamic
marginated:circulating is 1:1 (except cats, 3:1)
neutrophil pool in tissue
migrated into tissues and do not return to circulation
what size is the maturation/storage pool?
largest in dog
intermediate in cats and horses
smallest in ruminants
dogs have more capacity to respond to an increased peripheral demand for neutrophils compared to ruminants
where do neutrophils go?
migrate to sites of infl
apoptosis
transmucosal migration
left shift
increased numbers of bands
result of depletion of seg PMN within BM
significant inflammatory stimulus
hallmark of acute inflammation (acute/ongoing demand)
regenerative left shift
segs>bands
degenerative left shift
seg<bands></bands>
<p>
worse px</p>
<p>
interpretation different in SAM vs LAM</p>
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neutrophilia mechanisms
shift from marginated pool to circulating pool (min/hr)
increased release from maturation/storage pools in BM (hr)
increased pdn by BM (d)
causes of neutrophilia
inflammation
steroid neutrophilia
epinephrine neutrophilia
neoplasia
paraneoplasitc
leukocyte adhesion deficiency
inflammation neutrophilia
numerous underlying causes
left shift often present
Mechanism: increased release from BM, increased production by precursors in BM
steroid neutrophilia
results from increased glucocorticoids-stress, Cushing’s, Glucocorticoid therapy
mature neutrophilia
mechanism: shift from marginated to circulating pool, increased release from marrow
epinephrine neutrophilia
due to effects of catecholamines (fear, strenuous exercise, excitement)
transient
cats and young horses!
mature
mechanism: shift from marginated to circulating pool
neoplasia neutrophilia
chronic granulocytic leukemia
paraneoplastic neutrophilia
tumor pdn of G-CSF
Leukocyte adhesion deficiency neutrophilia
defective integrin molecule (CD18)
mechanisms for neutropenia
shift from circulating to marginated pool
decreased pdn within BM
overwhelming tissue demand
inflammatory neutropenia
LA (esp cattle) with acute infl
left shift often present
mechanism: overwhelming tissue demand
difficult to differentiate from endotoxemia neutropenia
endotoxemia neutropenia
infection with gram-negative bacteria (LPS)
mechanism: shift from circulating to marginated pool
difficult to differentiate from inflammatory neutropenia
decreased pdn neutropenia
damage to precursors or BM microenvironment
Parvo, FeLV, Erlichia
mechanism: decreased pdn within BM
toxic change
cytoplasmia vacuolization, basophilia, Dohle bodies
giant PMN-rare
toxic granulation-rare
associated with inflammatory conditions
Which animal has small numbers of Dohle bodies in health?
Cats!
peripheral destruction neutropenia
rare
immune mediated neutropenia
autoimmune dz char by presence of anti-neutrophil abs
infectious agents in neutrophils
bacteria-morulae or Anaplasma & Ehrlichia
Histoplasma capsulatum-yeast
distemper inclusions
Protozoa-Hepatozoon sp, Toxoplasma sp
Pelget-Huet Anomaly
inherited
occurs in several breeds of dogs, DSH cats and Arabian horses
hyposegmented nuclei in PMN, Eos, Baso
nuclei-band to oval shaped with mature appearing chromatic pattern
normal function
Chediak Higashi syndrome
rare
cats (perian), cattle and other mammals (mink, whale)
large eosinophilic cytoplasmic inclusions
neutrophil fcn somewhat abn
animals usually healthy but slight tendency to bleed due to abn platelet fcn
Birman cat neutrophil granulation
rare
fine eosinophilic cytoplasmic granules within neutrophils
fcn normal, cats are healthy
lymphocyte pdn
not solely dependent on BM pdn
produced in lymphoid tissues-LN, spleen
lymphoid tissue pool
consists of lymphocytes wihtin LNs, spleen, etc
tissue lymphocyte pool
lymphocytes that have migrated into tissues
can return into circulation via lymphatics
reactive lymphocytes
due to infl/antigenic stimulation
increased cytoplasmic basophilia
perinuclear clear zone
increased size
increased amount of cytoplasm
nuclear atypia
lymphoblasts
not normally found in circulation
char by large size, presence of nucleoli & immature chromatic pattern
neoplasm vs reactive lymphocytes?
epinephrine lymphocytosis
due to effects of catecholamines (fear, strenuous exercise, excitement)
transient
cats, young horses
mechanism: shift from marginated pool to circulating pool
granular lymphocytes
CD8, NK cells
small numbers of fine, pink, cytoplasmic granules
low numbers in healthy animals
increased numbers with reactive conditions
Chronic inflammation leukocytosis
due to chronic antigenic stimulation
lymphoid hyperplasia
esp Ehrlichia/Anaplasma sp
may see reactive lymphocytes
vaccination
lymphoproliferative disorder lymphocytosis
lymphoid leukemia/lymphoma
persistent lymphocytosis of cattle (BLV inf), of cats (FeLV)
hypoadrenocorticism lymphocytosis
due to absence of glucocorticoid effects
Steroid lymphopenia
sequestration of lymphocytes within lymphoid tissues, decreased lymphopoiesis
most consistent feature of steroid leukogram
acute bacterial/viral infection lymphopenia
due to increased margination in the vasculature and migration of lymphocytes to lymphoid nodes and inflamed tissues
depletion/loss lymphopenia
GI loss (eg PLE, GI lymphoma, lympangectasia)
chylothorax
congenital lymphopenia
due to lymphoid hypoplasia
eg combined immunodeficiency syndrome of Arabian foals
lymphopenia associated with lymphoma
result of damage to lymph tissue and/or altered lymphocyte circulation
causes of monocytosis
inflammation
steroids
neoplasia-monocytic leukemia
inflammation monocytosis
infectious, immune-mediated disease, necrosis, hemorrhage, trauma
steroid monocytosis
increase endogenous/exogenous glucocorticoids in dogs & occasinoally cats
eosinophilia
parasitism
hypersensitivity reaction
Mast cell degranulation
paraneoplastic
idiopathic eosinophilic conditions
neoplasia
can have significant tissue eosinophilia while having normal eos conc in peripheral blood
eosinopenia
steroid leukogram
marrow hypoplasia
basophilia
parasitism
allergic/hypersensitivity reactions
neoplasia
mastocytemia
inflammation/allergic rxn
mast cell neoplasia
epinephrine leukogram
Mature neutrophilia-up to 2x URL for most spp (3x for cats)
normal neutrophils
lymphocytosis
cats and horses
transient change
steroid leukogram
mature neutrophilia-up to 2-3x URL
neutrophils normal or hypersegmented
lymphopenia
+/-monocytosis-dog
+/-eosinopenia-dog
classic inflammatory leukogram
neutrophilia +/- toxic change, left shift
+/- monocytosis
with chronicity, left shift and degree of toxic change may decrease or disappear as pdn of neutrophils in BM cataches up with peripheral demand
inflammatory leukogram (overwhelming tissue demand)
neutropenia +/- left shift, toxic change
poor px factor in SAM
pattern is anticipated in LAM (esp ruminants) because they have small marrow storage pools and slower marrow response times
endotoxemia leukogram
early-neutropenia due shift from circulating pool to marginated pool
rebound-neutrophilia or WRI
marrow suppression leukogram
neutropenia
lymphocytes WRI
+/- anemia and thrombocytopenia-delay in these cytopenia due to longer life span
Dog WBC special facts
neutrophil is predominated circulating leukocyte
monocytosis due to steroids most often seen in dog
lymphocytes are small
relatively large neutrophil storage pool and proliferative capacity
Cat WBC special facts
neutrophil is predominate circulating leukocyte
healthy cats can have a small amount of Dohle bodies within neutrophils
epinephrine leukogram-more often seen
lymphocytes are small
Cattle WBC special facts
Neutrophils>lymphocytes at birth
lymphocytes may be > neutrophils after 1 week
with significant infl, neutropenia or degenerative left shift-due to relatively small bone marrow reserve pool and proliferative capacity
lymphocyte morphology variable with small, medium and large lymphocytes
BLV (persistent lymphocytosis and leukemia)
increased fibrinogen concentration may be an early indicator of infl
horse WBC special facts
Neutrophils>lymphocytes at birth (N:L ~3)
Neutrophils>lymphocytes in adults (N:L ~1-2)
epinephrine leukogram seen more often (esp young horses)
increased fibrinogen concentration early indicatory of infl
may develop neutropenia/degenerative left shift with acute infl
