Lecture 23 - RBC Morphology

Question 1

What is the anatomy of a normal RBC

Answer 1

biconcave disc
reddish color
central pallor

Question 2

How is Rouleaux different from agglutination

Answer 2

Rouleaux is the stacking of RBCs while Agglutination looks like grape clusters

Question 3

What species is Rouleaux normal in

Answer 3

Horses

Question 4

What does Rouleaux indicate is increased

Answer 4

globulin
fibrinogen

Question 5

What does agglutination indicate

Answer 5

immune-mediated hemolytic anemia

Question 6

Polychromasia

Answer 6

blueish to purple cells

Question 7

What correlates with polychromasia

Answer 7

very young reticulocytes

Question 8

T/F: polychromasia indicate regenerative conditions

Answer 8

TRUE

Question 9

in what species do we use aggregate reticulocytes? why?

Answer 9

cats; reference intervals are established and they can indicate a more immediate regenerative response

Question 10

Hypochromasia

Answer 10

increased central pallor with a think rim of hemoglobin

Question 11

What condition does hypochromasia indicate

Answer 11

iron deficiency

Question 12

Anisocytosis

Answer 12

variability in cell size

Question 13

Poikilocytosis

Answer 13

variability in cell shape

Question 14

Why do RBCs become spherocytes

Answer 14

decreased surface area to volume
loss of membrane

Question 15

What is the significance of spherocytes (what is the indication)

Answer 15

immune-mediated hemolytic anemia

Question 16

What do low numbers of spherocytes indicate

Answer 16

zinc deficiency
fragmentation or oxidative hemolytic anemia

Question 17

Ghost cells

Answer 17

pale, empty RBC membrane (lysed)

Question 18

What do ghost cells indicate

Answer 18

acute intravascular hemolysis

Question 19

Intravascular hemolysis

Answer 19

lysis of RBCs within the blood vessel - can lead to pink/red plasma (free hemoglobin)

Question 20

extravascular hemolysis

Answer 20

destruction of RBCs by macrophages

Question 21

where do macrophages interact with RBCs

Answer 21

spleen, liver, bone marrow

Question 22

Eccentrocyte

Answer 22

cell membranes fuse and hemoglobin is pushed to one side giving a ruffled appearance

Question 23

If an eccentrocyte has lost its membrane it is called a _____

Answer 23

pyknocyte

Question 24

what do eccentrocytes indicate

Answer 24

oxidative damage

Question 25

Schistocytes

Answer 25

fragmentations of RBCs due to stress trauma

Question 26

What can schistocytes help diagnose

Answer 26

- disseminated intravascular coagulation - hemangiosarcoma - liver disease

Question 27

what would help diagnose hepatic lipidosis in cats

Answer 27

schistocytes and acanthocytes

Question 28

Acanthocytes

Answer 28

cells with irregularly spaced blunted/spade-like projections with central pallor

Question 29

T/F: acanthocytes are best observed in canine RBCs

Answer 29

TRUE

Question 30

T/F: Acanthocytes do not indicate fragmentation injury like DIC or hemangiosarcoma

Answer 30

FALSE

Question 31

What is the difference between acanthocytes and echinocytes

Answer 31

echinocytes have evenly spaced projections and acanthocytes do not

Question 32

What are two factors that would cause similar artifact as an echinocyte on a blood smear

Answer 32

1. slow drying 2. old blood

Question 33

what do echinocytes indicate

Answer 33

dehydration electrolyte loss snake envenomation

Question 34

we would expect to see echinocytes in ______ due to the c3b deficiency that predisposes them to _____

Answer 34

Brittany spaniels; glomerulonephritis

Question 35

Keratocytes

Answer 35

blister cells round, clear hole at edge that can rupture

Question 36

what 3 fragmentation injuries do keratocytes indicate

Answer 36

1. mechanical damage 2. DIC 3. vasculitis

Question 37

Target cell

Answer 37

bell-shaped cell with extra membrane fold in center

Question 38

What is the most common indication of target cells

Answer 38

regenerative anemia

Question 39

Heinz bodies

Answer 39

denatured precipitated hemoglobin

Question 40

what are the two appearances of Heinz bodies when stained

Answer 40

1. small, pale region of cytoplasm 2. highlighted methylene blue stain

Question 41

what kind of damage do heinz bodies indicate

Answer 41

oxidative

Question 42

Howell-Jolly Bodies

Answer 42

remnant of nuclear material as a single, dark blue peripheral dot

Question 43

increased number of Howell-Jolly bodies indicates

Answer 43

regenerative anemia dysfunctional/absent spleen

Question 44

nucleated RBCs

Answer 44

dark homogenous nucleus with a ruffled periphery

Question 45

increased nRBCs indicated

Answer 45

premature release (bone marrow) or failure to remove (spleen)

Question 46

T/F: rare nRBCs are OK

Answer 46

TRUE

Question 47

Rubricytosis

Answer 47

nRBCs in circulation

Question 48

"appropriate" rubricytosis is considered

Answer 48

a strongly regenerative anemia

Question 49

Basophilic stippling

Answer 49

residual aggregates of RNA that appear as basophilic dots throughout cytoplasm

Question 50

T/F: basophilic stippling is not considered appropriate in any species

Answer 50

FALSE - appropriate in ruminants (regeneration) and carnivores (marked regeneration)

Question 51

Inappropriate basophilic stippling can be caused by

Answer 51

lead toxicity dyserythropoiesis