Leukocytes and Leukograms Flashcards
What does a left shift on a leukogram indicate?
Increase in immature neutrophils
What kind of leukogram shift features more mature neutrophils than immature neutrophils?
Regenerative Shift
What kind of leukogram shift features more immature neutrophils than mature neutrophils?
Degenerative Shift
- Poor prognosis in small animals (gut hemorrhage)
- NL finding in large animals d/t no neutrophil storage.
T/F: The leukogram can indicate type of disease and prognosis.
TRUE
What is a drawback to doing a leukogram?
Single sample so things can change. Need serial sampling to get good idea of what’s really going on.
3 cell types that would be abnormal to see on a leukogram (should NL be found in tissues).
Plasma cells
Mast cells
Macrophages
T/F: When looking at a leukogram on a large animal, finding more immature neutrophils than mature neutrophils indicates degenerative shift and carries a poor prognosis.
FALSE
Large animals don’t have neutrophil stores, so finding more immature neutrophils is not significant as it is in small animals.
Which leukocyte predominates in most species?
Neutrophils
Approximate size of a neutrophil:
12um diameter
Specific granules for eosinophils, neutrophils, and basophils are formed at what stage of development?
Myelocyte
If a leukogram shows orderly maturation, how are the concentrations of each type of cell arranged?
Concentration increases with degree of maturity.
metamyelocytes < bands < segs
Regenerative left shift
If a leukogram shows disorderly maturation, how are the concentrations of cell types arranged?
Concentration doesn’t correlate with maturity. More immature than mature.
Degenerative left shift
What can a degenerative left shift indicate?
Severe peripheral consumption (gut hemorrhage)
Neoplasia (leukemia)
A blood film shows neutrophils with basophilic cytoplasm, vacuolation, and Dohle bodies. What process is causing these changes?
Accelerated bone marrow production associated with inflammation
Hypersegmentation of neutrophil nuclei is a relatively insignificant finding and can be caused by:
Corticosteroids causing longer neutrophil circulation time
Cells aging in blood tube prior to making film
What are the 3 basic mechanisms that cause neutrophilia?
Inflammation
Stress/Glucocorticoids
Catecholamines (fear/excitement)
A leukogram shows neutrophilia, and the blood film shows increased bands and metamyelocytes. Some of the cells have a more blue cytoplasm with a couple additional dark spots. What is the likely mechanism for neutrophilia?
INFLAMMATION
Increased precursors
Toxic change
A dog comes into the clinic for bloodwork, and you see increased neutrophils at about double the normal value. Eosinophils are slightly lower than normal, and you note that lymphocyte counts are also decreased. What is the likely mechanism for this type of leukogram?
STRESS/Glucocorticoid induced
Lymphopenia!
Neutrophilia - doubled! Decreased margination: most neutrophils are now in circulation.
A kitten is in the clinic for pre-spay labs, and the owner noted a runny nose about a week ago that has since resolved. The leukogram shows slightly elevated lymphocytes, and increased neutrophils at over double the normal value. What is likely causing the abnormalities on this leukogram?
CATECHOLAMINE release (fear/excitement)
Neutrophilia - doubled! Decreased margination.
Mild Lymphocytosis
Seen in kittens, cats, foals
A dog’s leukogram shows neutrophilia and mild lymphocytosis. Your colleague thinks this is just an excitement leukogram but you don’t think so. What process do you think is causing these changes in the dog?
Inflammation.
Excitement leukograms are seen in cats, kittens, and foals. In other species, it’s probably inflammation.
A case with mild neutrophilia shows precursor cells and toxic change. Is this an acute or chronic process?
Acute. Bone marrow usually adapts with chronic inflammation.
T/F: Neutrophilia at 100,000/uL is a hallmark of neoplasia.
FALSE
Approaching 100K, keep inflammation as the main differential, but add neoplasia to the list. Rule out anything treatable before diagnosing neoplasia!
What are the 3 main mechanisms causing neutropenia?
Increased consumption: overwhelming inflammation
Increased margination: endotoxemia
Decreased production: granulocytic hypoplasia d/t bone marrow disease
- # 4 - Increased destruction: immune mediated (rare)
What is the second most numerous WBC in most species?
Lymphocytes
*most numerous in rodents and ruminants
Lymphocytes are often classified by size (small, intermediate, large), in relation to which WBC?
neutrophils
While most animals have small lymphocytes (smaller than a neutrophil), bovines have variable sizes of lymphocytes, with most being:
Intermediate (same size as a neutrophil)
A blood film from a cow shows large lymphocytes with small magenta granules in the cytoplasm. What are these lymphocytes called and in what other circumstance are you likely to see them?
Large granular lymphocytes
Common in bovines and in dogs with Ehrlichia
A blood film from an 8 month old dog shows larger lymphocytes with deeply basophilic cytoplasm, an indented nucleus, and a paranuclear clear zone. Why do the lymphocytes look like this and what does this mean for the young dog?
They are reactive lymphocytes.
This is a normal variant in juveniles (in low numbers)
What are the 5 main reasons for lymphocytosis?
CHRONIC INFLAMMATION
CATECHOLAMINES
ABSENCE OF GLUCOCORTICOIDS (Hypoadrenocorticism)
Neoplasia: (leukemias)
Age, ie: juveniles
What are the 5 main reasons for lymphopenia?
STRESS/GLUCOCORTICOIDS: altered circulation and apoptosis
ACUTE INFLAMMATION
Viral mediated destruction (BVDV)
Lymphangectasia
Congenital or acquired immunodeficiency
What is the largest cell on a blood film, with a round/kidney/band/pseudosegmented nucleus, loosely clumped, magenta chromatin, and blue, vacuolated cytoplasm?
Monocytes
What are 4 things that cause monocytosis?
INFLAMMATION (usually chronic but can be acute, as with IMHA)
STRESS/GLUCOCORTICOIDS
CATECHOLAMINES
Monocytic leukemia
When would you expect to see monocytopenia?
In stressed cattle
*otherwise rare and not recognized as a clinical problem
Usually present in low numbers in the blood (300x more in tissues), these WBCs are attracted by histamine and are frequently present in hypersensitivity reactions and parasitic infections involving helminths.
Eosinophils
What is significant about eosinophils in sighthounds?
Washed-out granules. “Grey eosinophils”
What 3 conditions can cause eosinophilia?
Parasitic infections: heartworm, lungworm
Hypersensitivity/Allergic: FAD, inhalant allergies, Feline hypereosinophilic syndromes, gastroenteritis
Paraneoplastic: Mast cell tumors, T-cell lymphoma
Eosinopenia is uncommon, but is often associated with what disease?
Hyperadrenocorticism (increased glucocorticoids)
WBCs that are rare to find in healthy animals, contain histamine and heparin, have a ribbon-like nucleus, contain dark purple granules, and offer protective immunity against helminths.
Basophils
What is significant about feline basophils?
Lavender granules
Which species has a high marrow reserve of neutrophils, a rapid regenerative capacity, and a neutrophil range of 20K - 120K?
Canine
Which species has an intermediate marrow reserve of neutrophils, intermediate regeneration capacity, and a neutrophil range of 20K - 60K?
Feline
Which species has an intermediate marrow reserve of neutrophils, intermediate regeneration capacity, and a neutrophil range of 15K - 30K?
Equine
Which species has a low neutrophil reserve, slow regenerative capacity, and a neutrophil range of 10K - 25K?
Bovine
In which of the following species is a neutropenia not indicative of a severe lesion?
Dog
Cat
Horse
Cow
Cow. Very low neutrophil reserves, so it is not uncommon to see low neutrophil counts.
In inflammatory leukograms, changes in mainly neutrophils indicate _______ inflammation, while increases in multiple WBCs indicate ______ inflammation.
Acute
Chronic
What are 2 hallmark signs of a stress leukogram?
Lymphopenia
Neutrophilia (2x NL amount, but with NO left shift or toxic change)
What are the hallmark signs of an excitement leukogram?
Lymphocytosis and neutrophilia (2x NL and NO left shift)
