Transcript Anemia: Part Three

MLAB 1415: Hematology
Keri Brophy-Martinez
Anemia
Part Three
RBC Shape Variations

Alterations in the shape of the RBC is
called poikilocytosis.
2
Target Cells (Codocytes)
Occur due to an increased
red blood cell surface area.
 Appear as "targets" on
peripheral blood
smear. Have a pale central
area with most of the
hemoglobin around the rim
of the cell.
 Are always hypochromic.

3
Target Cells (Codocytes)
Mechanism in formation is related to excess
membrane cholesterol and phospholipid, and to
decreased cellular hemoglobin.
 Osmotic fragility is decreased.

4
So what is Osmotic Fragility?
It is a test to measure RBC resistance to
hemolysis
 The quicker the hemolysis occurs, the
greater the osmotic fragility
 What affects osmotic fragility?

◦ Surface to volume ratio
◦ Cell membrane permeability
Target Cells (Codocytes)

Seen in patients with:
◦
◦
◦
◦
◦
◦
Liver disease
Hemoglobin C Disease or Trait
Post-splenectomy
Iron Deficiency Anemia
Any Hemoglobin Abnormality
Can be artifactual
6
Spherocytes
Have a low surface-tovolume ratio.
 Smaller than normal red cell;
hemoglobin relatively
concentrated; and, have no
area of central pallor.
 Shape change is irreversible.

7
Spherocytes
Several mechanisms
for formation, but all
involve loss
of membrane; aging,
antibody coating or
genetic defect
 Is the final stage for
red cells before they
are sequestered in
the spleen.

8
Spherocytes

Seen in patients with:
◦
◦
◦
◦
Activated complement
Immune Hemolytic Anemia
Hereditary Spherocytosis
Post-Transfusion
9
Wait! What is Complement?
Complement refers to a complex set of 14
distinct serum proteins that are involved in
three separate pathways of activation.
 Major Functions
◦ Promote the inflammatory response by
opsonization which enhances susceptibility of
coated cells to phagocytosis.
◦ Alter biological membranes to cause direct
cell lysis.

Ovalocytes and Elliptocytes
Ovalocytes may appear normochromic or
hypochromic; normocytic or microcytic.
 Hemoglobin concentrated at both ends
 Exact mechanism of formation unknown.

11
Ovalocytes and Elliptocytes

Ovalocytes associated
with:
◦ Myelodysplastic Syndromes
◦ Thalassemias
◦ Megaloblastic Processes

Elliptocytes associated
with:
◦ Iron Deficiency Anemia
◦ Hereditary Elliptocytosis
◦ Idiopathic Myelofibrosis
12
Stomatocytes





Red cell of normal
size
Slit-like central area
of pallor
Exact mechanism of
formation unknown
Usually artifactual
Increased osmotic
fragility
13
Stomatocytes

Associated with following disorders:
◦ Hereditary Stomatocytosis
◦ Hemolytic, Acute Alcoholism
◦ Rh Null Phenotype
14
Sickle Cells (Drepanocytes)
Have at least one
pointed end.
 Surface area of cell
much greater than
normal cell.

15
Sickle Cells (Drepanocytes)
Low oxygen tension
causes hemoglobin to
polymerize, forming
tubules that line up in
bundles to deform cell.
 Most sickle cells can
revert back to normal
shape when oxygenated.

16
Sickle Cells (Drepanocytes)
 Associated
with the following
disorders:
◦ Sickle Cell Anemia
◦ Hemoglobin C Disease
17
Acanthocytes
Normal or slightly
smaller size
 Possess 3-12 thorny
projections of
uneven length along
periphery of cell
membrane.
 Projections are blunt

18
Acanthocytes
Specific mechanism of
formation unknown.
 Contain increased
cholesterol-tophospholipid ratio.
 Surface area increased
 Susceptible to removal by
spleen

19
Acanthocytes

Possible pathologies include:
◦
◦
◦
◦
◦
Alcohol Intoxication
Pyruvate Kinase Deficiency
Congenital Abetalipoproteinemia
Vitamin E Deficiency
Post-Splenectomy
20
Fragmented Cells

Includes:
◦ Burr Cells
◦ Helmet Cells
◦ Schistocytes

Fragmentation is defined
as a loss of a piece of cell
membrane that may or
may not contain
hemoglobin.
21
Fragmented Cells
Two pathways that lead to fragmentation:

◦
◦
Alteration of normal fluid circulation (vasculitis,
malignant hypertension, heart valve
replacement).
Intrinsic defects of red cell that make it less
deformable (spherocytes and antibody-covered
red cells).
22
Prominent Morphology
Fragmented Cells
Possible Pathology
Schistocytes
Burr Cells
Renal disease
Liver Disease
Burns
Prosthetic
Heart Valve
DIC
Microangiopat
hic Hemolytic
Anemia
TTP
Helmet Cells
Clostridial
Infections
HUS
G6PD
Deficiency
Pulmonary
Emboli
Burr Cells (Echinocytes)
Red cells with 10-30
evenly spaced
spicules over the
surface of the cell.
 Normocytic and
normochromic.
 In large numbers, are
an artifact of sample
contamination.

24
Burr Cells (Echinocytes)
"True" burr cells occur in small numbers in
uremia, heart disease, stomach cancer,
bleeding peptic ulcers, and in patients with
untreated hypothyroidism.
 Seen in liver disease, renal disease, and burn
patients.
 May occur in any situation that causes
change in tonicity of intravascular fluid
(dehydration).

25
Helmet Cells (Bite Cells)



Usually have two
projections surrounding
an empty area of red cell
membrane.
Looks as if cell has had a
bite taken out of it.
Caused by spleenic
pitting and impalement
of the RBC on fibrin
strands
26
Helmet Cells (Bite Cells)
In conditions where red
cells have large inclusion
bodies (such as Heinz
bodies
 G6PD deficiency
 May be seen in patients
with pulmonary emboli,
and disseminated
intravascular coagulation
(DIC)

27
Schistocytes
Extreme cell
fragmentation
 Cell is missing whole
pieces of
membrane.
 Causes bizarre
shapes of red cells.

28
Schistocytes
Caused by loss of
membrane by mechanical
means
 See in patients with
microangiopathic
hemolytic anemia, DIC,
heart valve surgery, or
severe burns.

29
Teardrop Cells


Appear as pear-shaped
cells. Length of tail
varies. May be
microcytic, normocytic,
or macrocytic.
Exact formation
process
unknown. Commonly
seen in red cells that
contain large inclusion
bodies.
30
Teardrop Cells

Most commonly
seen in idiopathic
myelofibrosis,
thalassemia, and iron
deficiency anemia.
31
References





Harmening, D. M. (2009). Clinical Hematology and
Fundamentals of Hemostasis. Philadelphia: F.A
Davis.
McKenzie, S. B., & Williams, J. L. (2010). Clinical
Laboratory Hematology . Upper Saddle River:
Pearson Education, Inc.
http://www.ezhemeonc.com/index.php/hematolog
ical-disorders/
http://www.wiwe.net/irene/lab/chemheme/heme/
microscope/stomatocyte.htm
http://home.ccr.cancer.gov/oncology/oncogenomic
s/WEBHemOncFiles/Review%20of%20Terms.html