14 - interpretation of leukograms Flashcards
what is the importance of absolute leukocyte counts
- percentage leukocyte counts can be misleading
- each leukocyte count has its own kinetics
- each leukocyte count has its own functions
T/F only absolute cell counts are used when evaluating CBC data
true - percentages can be misleading
what are the species difference for carnivores on leukograms
neutrophils predominate in blood carnivores
what are the species difference for ruminants and rodents on leukograms
lymphocytes predominate in blood of ruminants and rodents
what is a breed difference that can show up in leukograms
lower neutrophil counts in greyhound and belgian tervuren dogs
how can age affect leukograms
Neonates - blood lymphocytes increase after birth
geriatric dogs - lower blood lymphocytes
explain bone marrow cell mitosis to maturation and storage
mitosis: myeloblast - promyelocyte - myelocyte
– to –
maturation: metamyelocyte - band - neutrophil (segmented)
what does a left shift mean in a leukogram
Increased immature neutrophils
what can cause a left shift on a leukogram
- inflammation
- infectious
- non infectious - neoplasia (CML, AML)
- hereditary (pelger huet, IMHA)
what makes a left shift regenerative
Regenerative left shift
- neutrophilia with left shift
- mature neutrophils predominate
what makes a left shift degenerative
- normal neutrophil count or neutropenia
- immature neutrophils predominate
what is the most common causes of toxic left shifts
strong inflammatory conditions, with severe bacterial infections
- toxicity generally less prominent with immune- mediated, neoplastic, or hereditary disorders
list some causes of neutrophilia
- epinephrine
- glucocorticoids (endogenous or exogenous)
- inflammation ( infectious or noninfectious)
- chemical and drug poisoning
- hemorrhage and hemolysis
- malignancy including leukemia
- hereditary neutrophil defects, especially adhesion molecule deficiencies
what happens during epinephrine-induced neutrophilia
- no neutrophil toxicity or left shift
- short duration (about 30 mins)
- also lymphocytosis in young animals (especially cats)
what happens during a glucocorticoid- induced neutrophilia
- neutrophilia without left shift
- lymphopenia
- eosinopenia
- monocytosis (dogs)
There is a peak response the occurs in 4-8 hours. Neutrophil count may return to normal after several weeks of increased blood glucocorticoid concentration, but lymphopenia and eosinopenia remain
why does lymphopenia happen with glucocorticoids
glucocorticoid result in sequestration of lymphocytes in lymphoid organs
- long term glucocorticoid administration results in lysis of certain lymphocyte type or stages
why does eosinopenia happen with glucocorticoids
glucocorticoids inhibit release of eosinophils from bone marrow
what happens during “leukemoid” neutrophilia
- total neutrophil count above 50,000/uL
- marked left shift to include myelocytes
what are some causes of “leukemoid” neutrophilia
- infectious processes such as pyothorax, pyelonephritis, septic peritonitis, pyometra, abscess and pneumonia
- immune-mediated disorders such as immune-mediated hemolytic anemia, glomerulonephritis, polyarthritis, and vasculitis
** differentiate from chronic myelogenous leukemia (CML)
inflammation in cattle, sheep, manatees on a leukogram
- sometimes minimal leukogram changes
increased acute phase proteins including SAA, fibrinogen and haptoglobin
what is leukocyte adhesion deficiency I (LAD I)
a defect in CD18 (beta subunit of B2-integrin adhesion molecule) in irish setter dogs and holstein cattle
** marked neutrophilia
what is leukocyte adhesion deficiency III (LAD III)
- kindlin-3 protein deficiency in German shepherds
- lack of activation of leukocyte and platelet integrins (B2-intergrin activation is critical)
—– marked neutrophilia, platelet function defect also
How does neutropenia happen in the body (pathophys)
decreased marrow production (decreased marrow progenitor cells)
- decreased precursor cells
- myelophthisis with decreased presursors
- dysgranulopoiesis
increased exit from the blood
- migration into tissue
- destroyed within blood
shift from circulating to marginal pool
(healthy belgian tervuren dogs)