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)
neutropenia is due to a decrease in what
marrow progenitor cells
what are some causes of neutropenia
- idiosyncratic drug reactions (phenylbutazone, trimethoprim/sulfadiazine, griseofulvin, and cephalosporins)
- estrogen toxicity in dogs and ferrets (extrinsic or intrinsic)
- cytotoxic chemotherapy drugs, colchicine toxicity
- parvovirus infections
- severe chronic Ehrlichia canis infection in dogs
- cyclic hematopoiesis in grey collie dogs
list some causes of myelophthisis
- lymphoid leukemia (primarily ALL)
- multiple myeloma
- myelofibrosis (often only anemia)
- osteosclerosis
- metastasis of lymphomas, carcinomas, and mast cell tumors
list some causes of neutropenia dysgranulopoiesis
- myelodysplastic syndrome (MDS)
- acute myelogenous leukemia (AML)
- inherited cobalamin deficiency
what are some causes of neutropenia because of increased utilization of destruction
- acute infection before granulocytic hyperplasia has has time to occur
- overwhelming sepsis or endotoxemia
- immune-mediated destruction
what are 2 types of inherited neutropenia
cyclic hematopoiesis in gray collies
- cyclic neutropenia
- neutropenia last 2-4 day
“trapped neutrophil syndrome” in border collies
- persistent neutropenia
-granulocytic hyperplasia in bone marrow
- mutation of the VPS13B gene
what are some factors that play into purulent (neutrophilic) inflammation numbers on a blood neutrophil count
- rate of margination
- rate of migration into the tissue
- rate of marrow disease
when are neutrophil counts generally higher
neutrophil counts are generally higher with localized infections than with generalized infections of septicemias
what are some causes of lymphocytosis (increase in lymphocytes)
- epinephrine effect (especially young cats and horses)
- antigenic stimulation (uncommon)
- persistent lymphocytosis in bovine leukemia virus (BLV) infected cattle (common)
- lymphocytic leukemias
- lymphomas with leukemic blood expression
what are some causes of lymphopenia
- corticosteroid induced
- acute systemic infections
- experimental injection of IL-1 and TNF
- interferons induce lymphopenia and lymphadenopathy (decreased egress from lymphoid tissues)
- immunosuppressive drugs and radiation
- loss of lymphocyte-rich lymph
- disruption of lymph node architecture
- hereditary T lymphocyte deficiency
when does monocytosis occur
- often occurs in association with neutrophilia
- acute and chronic inflammation
- glucocorticoids in dogs
- acute myeloid leukemia (M4 and M5)
T/F monocytopenia is not clinically sig as a single abnormality. monocytes may not be seen during manual differential counts
true
what can cause eosinophilia
- parasitic dz (especially nematodes and flukes)
- allergic hypersensitivities
- eosinophilic granulomas
- occasionally mast cell tumors and other solid tumors
- hyper eosinophilic syndrome/eosinophilic leukemia
- chronic myelogenous leukemia
what are some reasons for basophilia
- IgE- mediated disorders
- usually accompanies eosinophilia
- may be associated with mast cell neoplasia (especially noncutaneous type mastocytosis)
- basophilic leukemia (rare)
T/F - basopenia is not clinically sig as a single leukocyte measurement abnormality. Basophils generally not seen during manual differential counts in normal dogs and cats.
true
what can cause a mastocytemia
mast cell neoplasia
Dogs: inflammatory diseases, regenerative anemia, tissue injury, neoplasia other than mast cell tumors, and necrosis
cats: especially with splenic mast cell tumors
