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Sickle Cell Disease

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Sickle Cell Disease

Sickle Cell Disease


• An inherited disease of red blood cells
(erythocyctes)
• Affects a protein inside the red blood cells
called hemoglobin.
• Sickle-shaped red cells interrupt blood flow by
blocking small blood vessels
• Tissue that has no blood flow is damaged and
causes pain
Sickle Cell Disease
A person with sickle cell
disease has one different
substance in the way it
makes hemoglogin. This
substance is the amino
acid valine in one spot
where there should be
glutamic acid.
This one change causes
the chemical to form long
strings when it lets loose
of its' oxygen. This
causes the red cell to
become deformed into a
"sickle" shape.
Sickle Cell Hemoglobin

Beta S
Beta S
Hemoglobin SC

Beta S
Beta C
Diagnosis
The most widely used blood test for sickle cell disease and
trait is the hemoglobin electrophoresis. A blood sample is
placed in an electric field on filter paper and the different
hemoglobins travel at different speeds to the negative
pole. Click here to see the test for four blood samples:
HbAA -Normal, Hb AS - Trait, Hb SS - Disease, Hb SC
Hb AA HB AS HB SS Hb SC
Start

Hb A
Hb S
Hb C
Diagnosis Sickledex
The presence of sickle hemoglobin can be rapidly
determined by a five minute solubility test (Sickledex).
This test is only helpful by excluding sickle cell disease
when negative in a patient older than six months of age
without severe anemia or a very high fetal hemoglobin
level. It is impossible to separate sickle cell disease from
trait with this test.The test is positive if 10 percent Hb S is
present, making it impossible to separate sickle cell trait
from individuals with disease
Diagnosis - Blood Smear

Sickle red cells


Normal vs. Sickle
Hemoglobin
Normal Sickle
• disc-Shaped • sickle-Shaped
• soft(like a bag of jelly) • hard (like a piece of
• easily flow through wood)
small blood vessels • often get stuck in
• lives for 120 days small blood vessels
• lives for 20 days or
less
Normal Shape to Sickle
Long rods of
hemoglobin form
deforming the
red cell

Microscope view
of long rods in a
sickle red blood
cell
Normal Shape to Sickle
Normal vs. Sickle red cells

If no oxygen, then pain


and damage occurs
Sickle red cells are stickier

Sticky red cells block blood flow, then


pain and damage occurs
Worldwide Distribution

Hemoglobin S

Hemoglobin D

Hemoglobin C
Worldwide Distribution
Hemoglobin S
Sickle Cell Disease is found in
Africans, Turks, Greeks, Saudi
Arabians, Egyptians, Iranians,
Italians, Latin Americans and
Asiatic Indians.
Trait vs.. Disease
About half of the hemoglobin in the red cell is sickle and the
cell will exhibit sickling when under severe conditions of low
oxygenation. Hematuria or blood in the urine is the most
common problem. There are case reports of people with sickle
cell trait having more severe sickle related problems when
placed under severe conditions such as extreme pressure and
low oxygen conditions. Those with trait should be advised of
the risks of extreme physical activity, severe pressure
changes, deep sea diving, and the possibility of hematuria.
Trait vs.. Disease
Pedigree

A pedigree is a map of the types of hemoglobin in


the family tree. This helps to identify those with
the trait and those with disease. In this pedigree,
both parents have sickle trait, 1 in 4 children will
have Sickle cell disease, one half will have trait
and 1 in4 will have normal hemoglobin
Pedigree

AS AS

AA AS AS SS
There are two genes for hemoglobin, one of which is inherited
from each parent. If one normal gene and one
abnormal gene is passed on by each parent, only half of the
hemoglobin produced will be abnormal and the individual
will be a carrier of the abnormal gene. This is commonly
referred to as having the trait of the disease.
Pedigree

AS AS

AA AS AS SS

If an individual inherits an abnormal gene from each parent, 80-


100 percent of the abnormal hemoglobin will be manufactured
and the disease will result. There is a 1 in 4 chance of this
happening
Managing Sickle Cell
• Fluids
• Antibiotics
• Rest
• Pain Medication
• Prevention of infections
• Healthy lifestyle
Complications From Sickle Cell
Disease
• Sickle cells become trapped and destroyed in
the spleen causing Splenic Sequestion
• Shortage of red blood cells or anemia
• Pain episodes
• Stroke or Brain Damage
• Kidney failure
• Pneumonia or Chest Syndrome
• Increased Infections
Spleen Function
• Acts a filter against foreign organisms that infect
the bloodstream.
• Filters out old red bloods cells from the
bloodstream and recycles them.

Minor role:
Manufactures red blood cells only
toward the end of fetal life and
after birth the function is taken
over by the bone marrow.
Acts as a blood reservoir
Spleen Location
• Soft, purplish-red
organ that lies under
the diaphragm on the
left side of the
abdominal cavity.
• The spleen is like a
filter inside to recycle
old blood cells and
clear bacteria
Spleen Stick
• A tongue depressor
can be used to
measure and track
spleen size
• Place the tip on the
left nipple and
make a mark where
the spleen tip is felt
Spleen Stick
• On one side of the
stick write the
child’s name, sickle
cell type, and
average
hemoglobin level
• One the back put 1/1/98
dates above the line
where the spleen
tip was
What is Splenic Sequestion
• Sudden trapping of blood
within the spleen
• Usually occurs in infants
under 2 years of age
• May be associated with
fever, pain, and
respiratory symptoms.
• Circulatory collapse and
death can occur in less
than thirty minutes.
Treatments For Splenic Sequestion

• Intravenous fluids
• Blood transfusion as necessary
• Spleen removal or splenectomy
Hand Foot Syndrome - Dactylitis
Sickle dactylitis is one of
the first complications in
sickle cell syndromes with
the highest incidence
between ages six months
and two years.
The sickle red cells cause
painful swelling of the
hands and feet. This is
treated with fluids and
pain medication. It usually
will go away in a few days
without any problems.
Kidney

Kidney damage starts very early


and progresses throughout life
causing complications in many
individuals with sickle syndromes.
The kidneys may not filter normally,
passing protein and/or excessive
amounts of water.
Bone Pain
More prolonged and constant
pain can be seen with bone
infarction, sickle arthritis, and
aseptic necrosis of the femur or
humerus. With chronic pain,
non-steroidal anti-inflammatory
medications should be used.
TENS units, relaxation
techniques, occupational and
physical therapy approaches
may be useful in reducing pain
and maintaining a good
lifestyle.
Eye Problems

Sickle cells can cause


damage to the blood
vessels in the eye,
especially in SC
disease. New weaker
blood vessels may form
and break open and
bleed. Early treatment
with laser therapy can
prevent such bleeds.
Strokes
Strokes are a blockage of blood flow to a part of the brain
caused by the sickle cells. The symptoms include one sided
weakness, numb feelings, seizures, slurred speech or facial
weakness. Treatment is with chronic transfusion to
maintain the Hb S level at less than 30% to prevent recurrences
or even prevent the first stroke.
Present evidence suggests that the need for transfusion may
be life-long and complications such as alloimmunization, iron
overload, and exposure to infectious disease may be common
complications. Bone marrow transplantation may, in the future,
offer these children the best chances for a more normal life.

Click Here to
go to STOP
study
Anemia - Jaundice
Anemia or a low red blood cell count,
is lifelong, starting in the first year of
life. The average red cell life is
reduced from a normal of 120 days
down to an average of 10 to 20 days
in sickle cell anemia. This produces
anemia, a high reticulocyte count,
and a bone marrow factory that is
producing 3 to 4 times more red cells
than normal. Other problems related
to the anemia are yellow eyes or
jaundice (elevated indirect
bilirubin),which later in childhood
and early adult life can cause
gallstones
Acute Chest Syndrome
Pneumonias or infections
in the lung, and acute
chest syndrome, caused
by sickling red cells
blocking blood vessels in
the lung, are the most
common complications.
Infections are treated
with antibiotics and
acute chest is treated
with blood transfusions
It’s hard to tell the two
apart so both treatments
are used
Priapism
Priapism is the painful erection
of the penis caused by sickling
red cells.
This complication usually has
an onset at age 5 to 35. It often
occurs as a severe episode
requiring hospitalization
following multiple episodes of
short duration termed
stuttering. Onset in the early
morninga waking the patient is
common. Treatment includes
pain relief, hydration, exchange
transfusion, and surgical shunt
procedures .
Leg Ulcers
Leg ulcers are seen in 10 to
15% of older children and
adults with sickle cell
anemia. They may start as
a simple insect bite or cut
that will not heal. They are
likely caused by poor
circulation to the skin.
Treatment includes saline
wet-to-dry dressings, Unna
boots ,and special wound
dressings. Leg elevation
and use of elastic stockings
are very important to
speed healing.

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