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Leukocytes (Leukocytosis/Leukopenia) Lipase 1359

Leukocytes (Leukocytosis/Leukopenia)
VetBooks.ir Definition

by inflammation can also be accompanied by
Leukocyte refers to a blood cell that can be release) is common in cats. Leukocytosis caused automated leukocyte counting methods,
so nRBCs falsely add to the total leukocyte
categorized as either granulocytic (neutrophils, band neutrophils (left shift), toxic neutrophilic concentration. A correction formula is used for
eosinophils, and basophils) or mononuclear changes, or both. Leukocytosis should be inter- calculating the concentration of total leukocytes
(lymphocytes and monocytes). Leukocytosis preted with physical exam findings, magnitude when nRBCs are present: correct WBC/mcL =
indicates an increase above the reference of increase, and other laboratory test results. counted WBC/mcL × 100/(100 + number of
interval; leukopenia indicates a decrease below nRBCs per 100 WBCs). Not all laboratories
the reference interval. Next Diagnostic Steps to Consider necessarily make this correction on the final
if Levels Are High CBC report, and “leukocytosis” in the presence
Synonym Evaluate the absolute concentrations of each of nRBC should prompt investigation of this
White blood cells (WBCs) leukocyte type to determine the specific cause possible artifact.
of leukocytosis.
Physiology Specimen Collection and Handling
Encompasses several different types of cells Causes of Abnormally Low Levels EDTA whole blood (lavender top tube) and
with different functions and kinetics. More Leukopenia is most often attributed to neu- freshly prepared blood smear for laboratory
specific analysis of neutrophils, lymphocytes, tropenia or lymphopenia. to stain
monocytes, eosinophils, and basophils is
indicated (see respective topics). Changes in Next Diagnostic Steps to Consider Relative Cost: $$ (reported as part of CBC)
the number and morphology of each different if Levels Are Low
leukocyte should be investigated. • Evaluate the absolute concentration of each Pearls
leukocyte type to determine the specific cause • Rather than total leukocyte count, the abso-
Reference Interval of leukopenia. lute concentrations of individual leukocytes
3
Dogs: 6-17 × 10 leukocytes/mcL; cats: 6-19 • In dogs with persistent neutropenia without should be evaluated: neutrophil, lymphocyte,
3
× 10 leukocytes/mcL an identifiable cause, consider bone marrow monocyte, eosinophil, and basophil.
aspiration for cytologic evaluation; in cats, • Severe leukocytosis (>50,000/mcL), regard-
Causes of Abnormally High Levels retroviral testing (feline leukemia virus, less of cause, is generally associated with a
Leukocytosis is usually due to increased neutro- feline immunodeficiency virus) should be guarded prognosis.
phils (neutrophilia) or lymphocytes (lympho- performed first.
cytosis). Leukocytosis does not automatically AUTHOR: Stephen D. Gaunt, DVM, PhD, DACVP
EDITOR: Lois Roth-Johnson, DVM, PhD, DACVP
equal inflammation; a stress leukogram (due Lab Artifacts
to cortisol release) is common in dogs, while Nucleated erythrocytes (nRBCs) cannot be
physiologic leukocytosis (due to epinephrine accurately differentiated from leukocytes by
Laboratory Tests

Lipase

Definition • Dogs: 100-750 IU/L Next Diagnostic Steps to Consider
Enzyme that hydrolyzes triglycerides to fatty • Cats: 10-195 IU/L if Levels Are Low
acids and glycerol Serum trypsin-like immunoreactivity, cobala-
Causes of Abnormally High Levels min, folate
Synonyms Pancreatitis, kidney disease, azotemia, hepatic
For pancreas-specific lipase immunoreactivity disease, gastrointestinal disease (gastroenteritis, Important Interspecies Differences
(spec cPLI and spec fPLI), see p. 1370. duodenal obstruction, peritonitis, inflammatory Total serum lipase levels are not a reliable
bowel disease [IBD]), neoplasia indicator of pancreatitis in cats; spec PLI is
Physiology much more sensitive and specific in both dogs
Lipase is present in pancreas, adipose tissue, Next Diagnostic Steps to Consider and cats.
gastric mucosa, and duodenal mucosa. if Levels Are High
Pancreatic lipase catabolizes triglycerides into If clinical signs suggest pancreatitis (dogs and Drug Effects
fatty acids and glycerol, monoglycerides, and cats), with or without increase in serum amylase Dexamethasone and prednisone therapy increase
diglycerides in the proximal small intestine. (dogs only), assess pancreatic lipase immuno- lipase activity, without concurrent increase in
Bile salts and colipase enhance the efficiency of reactivity (spec cPLI, fPLI) and/or abdominal amylase.
lipase activity. The pancreas is considered the ultrasound. Evaluate for concurrent disease (IBD,
primary source of serum lipase concentration, gastroenteritis, proximal intestinal foreign body, Lab Artifacts
although other tissues may contribute. hepatic disease, neoplasia, and especially in cats, Decrease: lipemia, hemolysis, icterus
cholangiohepatitis and hepatic lipidosis).
Reference Interval Specimen Collection and Handling
Serum lipase activity based on enzymatic Causes of Abnormally Low Levels Serum (red top tube) or serum separator
activity: Exocrine pancreatic insufficiency tube (red top SST). Fasted sample preferred.

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