lab pro - WBC week 10

what are you determining in a WBC count

1. number of WBC

2. abnormalities

relative WBC count and absolute value

• minimum of 100 WBC counted

• each type of WBC recorded as a percentage

• after percent of each WBC determined, |x| can be calculated:

(total WBC count)(% of WBC type) = leukocyte / uL

two different ways of doing WBC counts

1. auto-analyzer machine (IDEXX Lasercyte)

2. Manually (leuko-ticanda hemocytometer)

what could an abnormal WBC count indicate

• immune system is fighting bacterial or viral infection

• parasites

• stress

• allergies

• cancer

what is the dilution factor for the lysing agent

20

which squares do you count on the hemocytometer and what is the method of counting them

• 4 corners

• if cells are touching the border/lines of the squares, only count those touching the TOP or LEFT side borders of each square

*to keep from double counting cells or miscounting cells

how do you get the total WBC/uL into SI units

1. first convert into litres, so x 10³

2. multiply WBC/uL by 10^6 so that final answer is in 10^9 

what is th eorder of leukocytes from least common to most common

BEMLN

functions of WBC

• phagocytosis

• antibody production

• modulate immune system

neutrophils characteristics, main function, and what do increased number indicate

• most abundant WBC

• nucleus irregularly shaped

• 3-5 nuclear lobes are normal

• main function: phagocytosis

• infection or inflammation

band neutrophils

• immature neutrophils; seen in a left shift

• nucleus is horseshoe shaped with large round ends

whats a left shift

when the bone marrow is spitting out too many cells

lymphocytes characteristics, main function, and what do increased number indicate

• most abundant in ruminants

• small size in cats/dogs

• slightly indented nuclei, coarsely clumped chromatin, blue-ish cytoplasm

• nucleus takes up most of cell

• function: producing antibodies

• indicates viral infection

monocyte characteristics, main function, and what do increased number indicate

• largest WBC

• variably shaped nuclei

  • kidney-bean shaped or elongated and lobed

  • diffuse chromatin

• cytoplasm is blue-gray color

• may have vacuoles and small, fine, pink granules

• function: phagocytosis

• indicates chronic infection

eosinophil characteristics, main function, and what do increased number indicate

• similar nucleus to neutrophils

• chromatin not clumped, not darkly stained

• cytoplasm more granular than neutrophils, stain red/pinkish

• shape and size vary among species and within species

• function: phagocytosis, immune system

• indicate allergies and parasitic infection

basophil characteristics, main function, and what do increased number indicate

• similar nuclei to monocyte

• much more granular

• function: immune system

• indicates inflammation or infection

dogs → granules stain purple-blue/black

cats → round granules and stain bright lavender colour

what are the abnormalities of WBC’s

• nuclear hyposegmentation

  • Pelger-Huet Anamoly

• nuclear hypersegmentation

• toxic changes

• intracytoplasmic inclusions

• reactive lymphocytes

• smudge cells

nuclear hyposegmentation (Pelger-Huet Anomaly)

• a congenital defect

• hyposegmentation of ALL granulocyte nuclei

nuclear hypersegmentation

• nuclei with >5 lobes

• can be due to aging neutrophils either in vivo or in vitro

toxic changes

• cytoplasmic basophilia, Dohle bodies (inclusions), toxic granulation, gigantism

• disease-induced cytoplasm changes in neutrophils

associated with:

• inflammation

• infection

• drug toxicity

intracytoplasmic inclusion

usually from disease process

• tick bite

reactive lymphocytes

aka immunocytes

• increase basophilic cytoplasm

• more abundant cytoplasm

• may be large, convoluted nuclei

• usually caused by antigenic stimulation

smudge cells

aka basket cells

• degenerative leukocytes

karyolysis

degenerative change to nucleus by dissolution of nuclear membrane

pyknosis

condensing of the nucleus as cell dies

karyorrhexis

fragmentation of the nucleus after cell death