Granulocytes Flashcards
Cytokines for granulopoeisis:
Neutrophils -
Eos -
Basophils -
Neutrophils G-CSF
Eosinophils IL-5
Basophils SCF (stem cell factor)
Myeloblasts
- agranular, primitive cells that differentiate to promyelocytes
- earliest commited granulocyte precursor recognizeable by light microscopy
Primary Granule Contents
- myeloperoxidase
- lysozyme
- defensins
Secondary neutrophilic granule contents
- lysozyme
- lactoferrin
- gelatinase
Neutrophil maturation
- Myeloblast
- Progranulocyte
- Neutrophilic myelocyte
- Metamyelocyte
- Band Neut.
- Mature Neut
- blood
- tissue
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Neutrophil cytokines
IL-L
GM-CSF (granulocyte/monocyte-colony stimulating factor)
G-CSF (granulocyte colony stimulating factor)
Epinephrine response
aka “Excitement” or “physiologic” neutrophilia.
Decreased marginating pool, expanded circulating neutrophil pool can cause neutrophilia on the leukogram.
(also lymphopenia, eosinopenia)
Corticosteroid response
“Stress neutrophilia”
- Decrease in marginating neutrophil pool, increase in circulating pool
- Incrased release of neutrophils form marrow storage pool
- Decreased extravasation and tissue migration of neutrophils.
May see increased segs, possibly bands on leukogram.
Toxic change in neutrophils
- Retention of primary granules
- Vacuolation
- Darker staining (retention of ribosomes in cytoplasm)
- Dohle bodies (dark blue irregular granules cauced by retained deposits of rough ER)
DDX for Persistent neutopenia due to bone marrow disorder and inadequate granulopoiesis
(usually moderate to severe, with no left shift , and no toxic change)
- Acquired neutropenia
- Infectious (esp. viral)
- Drugs, chemicals, or antibodies
- that selectively target neutrophil precursors
- idiosyncratic reactions causing immune-mediated destruction of neutrophils or precursors
- Bone marrow necrosis
- Neoplasia
- Hemopoietic
- Metastatic
- Fibroplaisa
- Idiopathic
- Aquired maturation disorder
- myelodysplasia of the neutrophil lineage
- disorder of release from the marros
- early recovery from damage to the neutrophil lineage
- Primary disorders of granulopoiesis or hemopoiesis
- rare, genetic
- Cyclic hemopoiesis of Grey Collies (affects the granulocytic, erythroid, and megakaryocyte precursor)
Diseases of Neutrophil Dysfunction
- Hereditary
- Adhesion deficiency
- Dogs CLAD
- Cattle BLAD
- Chediak-Higashi
- abnormal lysosomal granule formation, impaired neutrophil function
- Persian cats, some Cattle
- Pelger-Huet anomaly
- Hyposegmentation of granulocytes
- Funcion is not affected
- Can be misinterpreted as a severe left shift
- Adhesion deficiency
- Aquired
Normal neutrophil migration
- Circulating pool
- Marginated pool
- Rolling (integrins)
- Adhesion
- Migration
- Extravasation
- Chemotaxis
- Phagocytosis
- Killing/degradation
Cytokines necessary for Eosinophil development and maturation
- GM-CSF
- IL-3
- IL-5 (from T-helper lymphs?)
Contents of eosinophil granules
- eosinophil peroxidase
- eosinophil cationic protein
- eosinophil-derived neurotoxin
- major basic protein
Functions of eosinophils
- anthelminthic activity
- suppression of immeidate hypersensitivity reactions
- promotino of allergic inflammation
- tumor cell killing
- immune reactions involving T lymphs
- phagocytosis of some microbes, protein, and cellular materials
Whose eosinophils are these???
a. dog
b. cat
c. horse
d. cow
DDX for eosinophilia
- parasitic
- hypersensitivity
- inflammatory
- eosinophilic leukemia
- lymphoid neoplasia
- mast cell disorders/neoplasia
- hypoadrenocorticism
What is the mechanism behind glucocorticoid-induced eosinopenia
Who knows. Probably related to suppression of eosinophil survival factors (GM-CSF, IL-3, IL-5) and activation of eosinophil apoptosis.
Cytokines for basophil differentiation
- GM-CSF
- IL-4
- IL-3
- SCF (stem cell factor)
Appearance of basophil granules by species
Canine: scant, dark blue-purple
Feline: numerous, pale orange-lavender
Bovine: numerous, blue-black
Equine: irregular in size and number, dark blue-black
Whose basophils are these???
a. canine
b. feline
c. equine
d. feline
Differentiating a basophil from a neutrophil (dogs and cats)
Basophil is slightly larger, has purplish staining of cytoplasm.
Nucleus of the basophil will appear stretched, paler, and less lobulated in comparison to neutrophil nucleus.
Contents of basophil granules
- histamine
- heparin
- major basic protein
- other (enzymes, proteins)
DDX persistent basophilia
- parasitic
- hypersensitivity
- glucocorticoid deficiency
- inflammatory
- basophilic leukemia
- paraneoplastic (esp. to hemopoietic neoplasias)
