WBC Flashcards
What are the main types of leukocytosis
Neutrophilia
Lymphocytosis
Monocytosis
Eosinophilia
Basophilia
What are the main types of leukopenia
Neutropenia
Lymphopenia
Monocytopenia
Eosinopenia
What are the 3 steps that need to occur for cells to leave blood vessels?
Marginalisation
Adhesion
Migration
Explain circulating vs marginal pool
Some WBCs (esp. neutrophils) exist in 2 pools within blood vessels: circulating (freely flowing in bloodstream) & marginal pool (briefly adhered to vessel walls)
Certain factors can cause shift from marginal to circulating pool, leading to increase in measurable WBCs in blood sample
What factors can produce a shift from marginal to circulating pool?
Epinephrine
Glucocorticoids
Infection
Stress
What determines the neutrophil count in the bloodstream?
neutrophil count depends on balance between:
- Neutrophils leaving blood to fight infection in tissues
- Bone marrow production & release of new neutrophils
How does inflammation affect neutrophil concentration?
Inflammatory conditions usually increase neutrophil count because bone marrow releases more
Severe inflammation can decrease neutrophil count if neutrophils are used up faster than bone marrow can replace them
A normal or low neutrophil count (neutropenia) in severe infections may indicate overwhelming inflammation
What are common causes of neutrophilia?
Inflammation
- Infections
- Immune mediated anaemia
- Necrosis
Steroid
- Stress
- Steroid therapy
- Hyperadrenocorticism
Physiological
- Epinephrine
- Fight or flight (excitement, fear, pain, exercise)
Chronic neutrophil leukaemia
Paraneoplastic
Give examples of mechanisms and causes of neutrophilia
What is the difference between a left shift and a right shift in neutrophilia?
Left shift: Increase in immature neutrophils, occurs in response to infection/inflammation
Right shift: Increased hypersegmented neutrophils due to prolonged circulation (e.g., glucocorticoid effect)
What is a regenerative left shift?
Segmented (mature)>immature
Neutrophils ↑
What is a degenerative left shift?
Immature>segmented
Neutrophils ↔ ↓ or (↑)
(bad news)
How do glucocorticoids cause a right shift?
Glucocoticoids down-regulate adhesion molecules, less neutrophils leave circulation to die, aged cells remain in circulation
(decreased extravasation into tissues)
What is neutrophil toxic change?
Rapid neutropoiesis (production)
Usually severe bacterial infection (high demand)
(Blood analysers cant tell about neutrophil toxic change, only seen via blood smear analysis)
What are signs of toxic neutrophil changes?
Less condensed chromatin (nucleus appears less mature)
Bluer cytoplasm due to retained ribosomal RNA
Cytoplasmic basophilia (focal, streaked, or diffuse)
Döhle bodies (pale blue inclusions of ribosome aggregates)
Frothy or vacuolated cytoplasm (lysosomal degranulation)
Larger cell size compared to normal neutrophils
Label the neutrophils
What are some common neutrophil inclusions?
Bacterial
- Ehrlichia, Anaplasma
Viral
- Canine distemper
Protozoa
- Toxoplasma
- Hepatozoon
Fungi
- Histoplasma
Hereditary/metabolic
-Chediak-Higashi, Birman cat anomaly, mucopolysidosis
What are heterophils and what species have them?
Functionally equivalent to neutrophils but granules stain red
Describe the neutrophil bone marrow reserve and regenerative capacity in dogs, cats, horses & cows
Describe the interpretation of neutropenia in acute inflammation in dogs, cats, horses and cows
Describe the order of progression of cytopenia when there is marrow disruption
What is the primary function of monocytes?
Differentiate into macrophages in tissues for phagocytosis and cytokine release
Describe appearance of basophils
What can cause presence of nucleated red cells?
regenerative anaemias
lead toxicity
Extramedullary haematopoiesis
Splenic contraction
Damaged marrow
erythroleukemia
