Diagnostic Significance of RBC Flashcards
What causes rouleau formation?
cells lose repelling forces
Name that morphology
rouleau
What is significant about seeing rouleaux formations in a blood smear?
seen with hyperglobulinemia a/o hyperfibrinogenemia
due to inflammation a/o dehydration
In which species is it “normal” to see rouleaux formations in healthy animals?
horses - form easily
dogs and cats too - moderate
Approximately what percentage of the blood smear should be affected before we consider a morphological change to be abnormal?
greater than or equal to 30%
Which area of the blood smear is the area of interest when looking at RBC morphology?
monolayer
How does agglutination form between RBCs? (usually)
usually caused by antibodies forming bridges between RBCs
1 differential when agglutination is observed on a blood smear
IMHA
Name that morphology
agglutination
How will agglutination affect the values in a CBC?
increased calculated Hct
decrease [RBC]
increase MCV
Explain the saline dilution (dispersion) test
used to determine the cause of agglutination
1 drop blood + 9 drops saline
agglutination resolves = inflammation a/o dehydration
agglutination persists = IMHA
Which species have a prominent central pallor in their RBCs? mild? none?
prominent = K9
mild = cattle
none = equine, fel
1 differential for polychromatophilic erythrocytes
RBC regeneration (accelerated erythripoiesis, regenerative anemia)
Name that morphology
polychromatophilic
1 differential for hypochromic erythrocytes when there is high MCV and low MCHC
regenerative anemia
What causes hypochromic RBCs to form?
incomplete Hgb synthesis
1 differential diagnosis for hypochromic RBC with low MCV and low MCHC
iron deficiency
Reticulocyte =
immature erythrocyte
What type of stain is used to identify reticulocytes?
NMB stain
(stain polychromatic with Wright’s stain - not specific to indentify reticulocytes)
Name that morphology
reticulocytes
Anisocytosis =
different sized RBC
What causes macrocytes to form?
incomplete maturation or skipped cell division
1 differential diagnosis for macrocytes in blood smear
RBC regeneration
Name that morphology
macrocyte
What causes microcytes to form?
increased cell divisions during development
Which CBC analyte will we expect to be lower when microcytes are present?
MCV
1 differential diagnosis for microcyte formation (and why)
iron deficiency because iron stops mitosis during erythropoiesis
Name that morphology
microcyte
Discocytes aka
normocytes
Name that morphology
discocytes
Poikilocyte =
abnormal erythrocyte shape
Echinocyte
spiny
regularly spaced membrane projections