Download An Identification Guide for Avian Blood Components

An Identification
Guide for Avian Blood
Components
Jordan Briscoe, RIT 2015
Contents
3. Introduction
4. Erythrocytes
5. Typical: Reticulocytes
6. Atypical: Poikilocytes
7. Atypical: Stain/Prep Artifacting
8. Atypical: Anemia/Disease
9. Heterophils
10. Typical
12. Atypical
13. Atypical: Round Granules
14. Atypical: Stain Artifacting
15. Atypical: Toxic
16. Eosinophils
17. Typical & Atypical
18. Basophils
19. Lymphocytes
20. Typical
21. Atypical
22. Atypical: Reactive
23. Monocytes
24. Typical
25. Thrombocytes
26. Typical: Clumped
27. Typical: Single
28. Parasites
29. Haemoproteus fringillae
30. Microfilaria
31. Resources
32. The Project
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Introduction
The Cell Types
There are a few main types of cell components in avian blood, the erythrocytes (like
human erythrocytes- red blood cells), the leukocytes (like human leukocytes-white
blood cells), thrombocytes (like human platelets), and occasional parasite.
When studying avian blood, a common method of judging overall health is to count
leukocytes by comparing the number of lymphocytes to the number of heterophils in
a given area of the sample. Some methods include counting the number of eosinophils
as well, and some may make a more inclusive count of all the common leukocytes,
which would then include basophils and monocytes. Erythrocytes are very common
cells, but are not counted because they are not leukocytes. Thrombocytes function as
human platelets do, and while they may give useful information, are also not generally
counted. Parasites are abnormal findings in blood samples, and should be studied on
an individual basis.
A Heterophil
A Lymphocyte
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Erythrocytes
Avian erythrocytes are oval shaped cells with nuclei. They are
generally larger than mammilian erythrocytes, and can have
many variations that are typical in normal blood samples.
Table of Contents
Erythrocytes
Typical: Reticulocytes
Reticulocytes are round, immature
erythrocytes, These cells have a more
basophilic cytoplasm than their mature
counterparts and more dispersed
chromatin structures in the nuclei.
Figure 3 shows a prorubicyte, an early
stage of erythrocyte development.
Figure 1.
Figure 2.
Figure 3.
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Erythrocytes
Atypical: Poikilocytes
Poikilocytes are irregularly shaped
erythrocytes that can be present in
normal blood samples. Some irregularity
may be artifactual from preparation
techniques, and some irregularity is
simply due to misshapen cells.
Figure 4.
The poikilocyte present in Figure 5 may
be irregular as a result of anemia.
Figure 5.
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Erythrocytes
Atypical: Stain/Prep Artifacting
The erythrocytes found in Figures 6-8
are atypical due to stain and preparation
artifacting. In Figure 6, leftover stain
may appear as stained ribosomes,
leading to an incorrect identification of a
reticulocyte. Figure 7 has a preparation
artifact from the glass slide used to make
the smear damaging the cells. Figure
8 shows leftover stain, which may be
mistaken for a lysed erythrocyte.
Figure 6.
Figure 7.
Figure 8.
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Erythrocytes
Atypical: Anemia/Disease
In Figure 9, these erythrocytes are
polychromatophilic
and
clumped
closely together, which is indicative of an
anemic subject. These cells were found
in a sample that contained parasites, and
the slides were also stained with a stain
that had expired. All of these factors
contribute to the atypical appearance.
Figure 9.
The erythrocyte in the top of Figure 10 is
a microcyte, which is typical of a subject
with iron deficiency anemia. This subject
was also stained with a stain that had
expired.
Figure 10.
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Heterophils
Heterophils are cell components in avian blood that function
similarly to mammilian neutrophils. These cells participate in
immune responses, and are phagocytic as well as bacteriocidal.
Table of Contents
Heterophils
Typical
In Figure 11, the heterophil present is
typical, with rod granules. Heterophils
are typically round with clear cytoplasm
and eosinophilic rod shaped granules.
Figure 11.
In Figure 12, the heterophil present is
typical, with rod granules. Heterophils
typically have lobed nuclei. With a
Wright-Giemsa stain, these nuclei
appear purple in color.
Figure 12.
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Heterophils
Typical
The heterophil in Figure 13 is typical,
however it has unusual granules. The
granules are densely packed, and are
rod-to-round in shape, which is typical
for some species. The cytoplasm is clear,
despite some areas looking blueish in
tone. This is an artifact from staining,
which can also be seen in the erythrocytes
beside it.
Figure 13.
In Figure 14, the heterophil to the left is a
typical heterophil adjacent to an atypical
heterophil. The heterophil to the right is
atypical due to a staining artifact.
Figure 14.
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Heterophils
Atypical
The heterophil present in Figure 15
is atypical due to the densely packed
granules and slight blue tint to the
cytoplasm, which is a staining artifact.
Figure 15.
These heterophils are atypical because
they have round granules and an
irregular shape. The distortion of the
cells may be due to improper preparation
techniques, and the round granules are
typical for some species.
Figure 16.
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Heterophils
Atypical: Round Granules
The heterophil in Figure 17 is atypical
due to its round granules. This cell is
also slightly distorted, most likely due to
improper preparation.
Figure 17.
The heterophil in Figure 18 may easily
be mistaken for an eosinophil due to its
blueish appearance in the cytoplasm.
This cell is not an eosinophil, however.
The blue tint is a result of improper
staining, and is not indicative of an
eosinophil, due to the number of similar
cells in this particular sample.
Figure 18.
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Heterophils
Atypical: Stain Artifacting
The heterophil in Figure 19 appears to be
more basophilic than typical heterophils.
It also has less visible eosinophilic
granules. This cell is a heterophil, the
appearance is due to stain artifacting.
Figure 19.
In Figure 20, this heterophil appears
faded and basophilic. This occurs when
a stain has expired, and granules do
not stain properly. This cells may be
confused easily with a toxic heterophil,
which appears very differently with
proper staining techniques.
Figure 20.
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Heterophils
Atypical: Toxic
Toxic heterophils are an indication
of an inflammatory response. The
number and severity of the toxicity
of the heterophils can be used to infer
the severity of an immune response.
These toxic heterophils were present
in a bird that was infected with blood
parasites. Toxic heterophils appear
more basophilic overall, with hypersegmented nuclei, and varying degrees
of basophilic granules depending on the
level of toxicity.
Figure 21.
Figure 22.
Figure 23.
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Eosinophils
Eosinophils can vary greatly in appearance from species to species.
Eosinophils are leukocytes, but their function in avian species is
still unclear. It is known that avian eosinophils may not function in
the same way as mammilian eosinophils, but it is clear that these
cells are active in immune responses.
Table of Contents
Eosinophils
Typical & Atypical
The eosinophil found in Figure 24 is a
typical eosinophil, with eosinophilic
round granules, a dark violet lobed
nucleus, and clear-blue cytoplasm.
These cells are rarely found in blood
samples, as they present themselves
in approximately 0-4% of all blood
samples.
Figure 24.
The eosinophil present in Figure 25
is atypical due to a stain defect. The
granules of the eosinophil are slightly
visible, but the cytoplasm stained darker
than usual. This could be due to an
expired stain being used, or simply an
error in the staining process.
Figure 25.
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Basophils
http://ctdslab.co.uk/wp-content/uploads/2012/04/Avian-basophil1.jpg
Basophils are very uncommon in avian blood smears, only found in
about 0-5% of all blood samples. Basophils are primarily involved
in immune responses relating to allergic reactions, producing
histamines.
Image courtesy of Carmichael Torrance Veterinary Diagnostic Laboratory.
Table of Contents
Lymphocytes
Lymphocytes in avian species perform the same functions as those
in mammilian species, to respond to antigens. These cells produce
antibodies as either T-lymphocytes (cell-mediated immunity), or
B-lymphocytes (adaptive immunity). These cells are common in
avian blood smears.
Table of Contents
Lymphocytes
Typical
The cell found in Figure 26 is a typical
lymphocyte. The cell is round, with a
large, non-lobed basophilic nucleus, and
a scant rim of blue stained cytoplasm.
Figure 26.
The lymphocyte in Figure 27 is also a
typical lymphocyte.
Figure 27.
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Lymphocytes
Atypical
The lymphocyte in Figure 28 is atypical
because of its larger size and abnormal
shape. The projections of cytoplasm
are referred to as “blebs,” and are more
commonly found in old blood samples,
as the lymphocytes begin to deteriorate.
Figure 28.
In Figure 29, an immunocyte is present.
Immunocytes
are
antigenically
stimulated lymphocytes, and appear
darker in color and slightly more irregular
in shape than typical lymphocytes.
Immunocytes are found in diseased
subjects or samples from birds that have
been recently immunized.
Figure 29.
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Lymphocytes
Atypical: Reactive
Reactive lymphocytes are present due
to antigenic stimulation generally from
infections. A low number of reactive
lymphocytes may be found in a normal
blood smear, but a high count is indicative
of an immune response. Figures 31 and
32 show reactive lymphocytes as a
response to parasitic infection.
Figure 30.
Figure 31.
Figure 32.
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Monocytes
Monocytes are generally the largest leukocytes found in an avian
blood smear. These cells are phagocytic, and are also motile using
ameboid movements.
Table of Contents
Monocytes
Typical
Monocytes are cells capable of
phagocytosis, and utilize lysosomes to
break down and engulf foreign invaders.
Monocytes do not have a lobed nucleus,
but rather a kidney-shaped nucleus, and
a pale blue cytoplasm. Figure 35 shows
a monocyte with artifacting due to
improper preparation.
Figure 33.
Figure 34.
Figure 35.
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Thrombocytes
Thrombocytes are present in avian blood to serve the same purpose
as human platelets, to aid in the clotting process (hemostasis).
Avian thrombocytes, however, are nucleated, and are not as “sticky”
as human platelets, and therefore have less of a tendency to form
clots while in arteries where an injury is not present.
Table of Contents
Thrombocytes
Typical: Clumped
In Figure 36, seven thrombocytes
are clumped together, and one single
thrombocyte can be found to the left.
Thrombocytes tend to clump in blood
smears, which can make cell counting
difficult.
Figure 36.
Figure 37 shows sixteen thrombocytes
clumped together in between many
erythrocytes. Immature to mature
thrombocytes may look very similar to
erythrocytes. They are both nucleated,
however
thrombocyte
cytoplasm
tends to stain clear, while erythrocyte
cytoplasm tends to stain an orange color.
These thrombocytes are past maturity
and are beginning to deteriorate.
Figure 37.
26
Thrombocytes
Typical: Single
The thrombocyte present in Figure 38 is
degenerating. Most thrombocytes found
in old blood stains will have a similar
appearance to this thrombocyte.
Figure 38.
Figure 39 shows a typical thrombocyte
that is past maturity, with cytoplasmic
projections. These thrombocytes may
appear shrunken in comparison to
immature thrombocytes, which are less
common in peripheral blood smears.
Figure 39.
27
Parasites
Blood parasites in avian species are very common. While there are
many types, two main types of avian parasites will be shown in
this guide, Haemoproteus fringillae and microfilaria.
Table of Contents
Parasites
Haemoproteus fringillae
Haemoproteus fringillae belongs to
the largest phylum of blood parasites,
Apicomplexa. This parasite infects
erythrocytes and reduces the cells’
ability to carry oxygen.
Figure 40.
Blood parasites such as Haemoproteus
fringillae are sensitive to environmental
conditions, and may affect avian hosts
in one area, but not hosts of the same
species in another area.
Figure 41.
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Parasites
Microfilaria
Microfilaria are a genus of blood parasite
that cannot be identified by morphology.
These parasites are nematodes, and
remain as extracellular parasites,
reducing the health of the host overall by
targeting cells in the blood.
Figure 42.
Microfilaria are also sensitive to
environmental change. It has been found
that increased temperatures associated
with global warming positively correlate
to the development and spread of this
parasite.
Figure 43.
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Resources
http://ex-epsilon.slu.se:8080/archive/00000869/03/Avian_hematology.pdf
http://people.eku.edu/ritchisong/birdcirculatory.html
https://exoticanimalmed.wordpress.com/2013/09/24/the-various-cells-found-onavian-blood-smears/
http://avianmedicine.net/content/uploads/2013/03/9.pdf
http://www.owen.fw.msu.edu/White%20Blood%20Cell%20Counts.html
http://www.bioone.org/doi/abs/10.1676/13-124.1
http://ctdslab.co.uk/photos/avian-haematology-photographs/avian-basophil-2/
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The Project
This project was completed in May of 2015 as a senior capstone project by Jordan
Briscoe, Biomedical Photographic Communications, 2015. The project may not be
sold or distributed without permission from the creator. This project is intended for
educational purposes only, and was created using the most recent knowledge at the
time of creation.
Special thanks is extended to Dr. Susan Smith Pagano ([email protected]) and Ms, Meghan
Oberkircher for their assistance and oversight throughout the project.
To view more work or get in contact with Jordan Briscoe, visit www.jbriscoe.com or
email [email protected].
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