People
with sickle cell conditions
make a different form
of hemoglobin A called
hemoglobin S (S stands
for sickle). Red blood
cells containing mostly
hemoglobin S do not
live as long as normal
red blood cells (normally
about 16 days). They
also become stiff, distorted
in shape and have difficulty
passing through the
bodys small blood
vessels. When
sickle-shaped cells
block small blood vessels,
less blood can reach
that part of the body.
Tissue that does not
receive a normal blood
flow eventually becomes
damaged. This is what
causes the complications
of sickle cell disease.
Types
of Sickle Cell Disease
There
are several types of
sickle cell disease.
The most common are:
Sickle Cell Anemia
(SS),
Sickle-Hemoglobin C
Disease (SC)
Sickle
Beta-Plus Thalassemia
and Sickle Beta-Zero
Thalassemia.
What
is Sickle Cell Trait?
Sickle
Cell trait (AS) is an
inherited condition
in which both hemoglobin
A and S are produced
in the red blood cells,
always more A than S.
Sickle
cell trait is not a
type of sickle cell
disease. People with
sickle cell trait are
generally healthy.
Inheritance
Sickle
cell conditions are
inherited from parents
in much the same way
as blood type, hair
color and texture, eye
color and other physical
traits.
The types of hemoglobin
a person makes in the
red blood cells depend
upon what hemoglobin
genes the person inherits
from his or her parents.
Like most genes, hemoglobin
genes are inherited
in two sets
one
from each parent.
Examples:
How
will I know if I have
the Trait?
A
SIMPLE PAINLESS BLOOD
TEST followed by a laboratory
technique called Hemoglobin
Electrophoresis will
determine the type of
hemoglobin you have.
When you pass an electric
charge through a solution
of hemoglobin, distinct
hemoglobins move different
distances, depending
on their composition.
This technique differentiates
between normal hemoglobin
(A), Sickle hemoglobin
(S), and other different
kinds of hemoglobin
(such as C, D, E, etc.).
Medical
Problems
Sickle
cells are destroyed
rapidly in the body
of people with the disease
causing anemia, jaundice
and the formation of
gallstones.
The
sickle cells also block
the flow of blood through
vessels resulting in
lung tissue damage (acute
chest syndrome), pain
episodes (arms, legs,
chest and abdomen),
stroke and priapism
(painful prolonged erection).
It also causes damage
to most organs including
the spleen, kidneys
and liver. Damage to
the spleen makes sickle
cell disease patients,
especially young children,
easily overwhelmed by
certain bacterial infections.
Treatment
Health
maintenance for patients
with sickle cell disease
starts with early diagnosis,
preferably in the newborn
period and includes
penicillin prophylaxis,
vaccination against
pneumococcus bacteria
and folic acid supplementation.
Treatment of complications
often includes antibiotics,
pain management, intravenous
fluids, blood transfusion
and surgery all backed
by psychosocial support.
Like all patients with
chronic disease patients
are best managed in
a comprehensive multi-disciplinary
program of care.
Blood transfusions
help benefit sickle
cell disease patients
by reducing recurrent
pain crises, risk of
stroke and other complications.
Because red blood cells
contain iron, and there
is no natural way for
the body to eliminate
it, patients who receive
repeated blood transfusions
can accumulate iron
in the body until it
reaches toxic levels.
It is important to
remove excess iron
from the body, because
it can gather in the
heart, liver, and other
organs and may lead
to organ damage. Treatments
are available to eliminate
iron overload.
Promising
Treatment Developments
In
search for a substance
that can prevent red
blood cells from sickling
without causing harm
to other parts of the
body, Hydroxyurea was
found to reduce the
frequency of severe
pain, acute chest syndrome
and the need for blood
transfusions in adult
patients with sickle
cell disease. Droxia,
the prescription form
of hydroxyurea, was
approved by the FDA
in 1998 and is now
available for adult
patients with sickle
cell anemia. Studies
will now be conducted
to determine the proper
dosage for children.
Other treatment options
in clinical development
include new, more convenient
options than current
therapies to eliminate
iron overload caused
by repeated blood transfusions.