Your Body and Sickle Cell

Blood transfusions can be life-saving for people with sickle cell disease in emergency situations like severe acute chest syndrome. Chronic blood transfusions (scheduled blood transfusions every three to four weeks) are also important for some people with sickle cell disease like individuals who have had a stroke. While blood transfusion therapy is very helpful, transfusions also have risks such as alloimmunization and iron overload.

Alloimmunization

The immune system is like a national army protecting your body from foreign invaders. It functions to search and destroy all things in your body that are not you, like bacteria and viruses. One weapon the immune system makes to attack pathogens is antibodies. Antibodies are like little missiles that attach to foreign particles and mark them as an enemy to be destroyed.

What does the immune system have to do with blood transfusions?

The immune system can sometimes identify life-saving donor cells as "foreign" since your body did not make them. When this process happens your body makes antibodies against the donor cells. For example, when an individual has made antibodies against a particular red blood cell, if he or she receives a blood transfusion of that type of red blood cell, it would be destroyed and could cause major problems. These antibodies make it more difficult to obtain a blood donor match.

Just like it is crucial for you to know your allergies to medications, it is very important to know if you have developed any antibodies to donor red blood cells. This information can help find the best blood for you in the blood bank next time you need a transfusion. Information about alloantibodies to red blood cells should be on a medical alert bracelet that can "speak for you" when you are in an emergency situation.

Iron overload

Iron is an important mineral used by the body; however, too much iron causes problems. Blood contains iron so when an individual receives a blood transfusion, he or she also receives a significant amount of iron. The body does not remove iron well, so over time if an individual has had many blood transfusions, the amount of iron in his or her body can rise to dangerous levels. In particular, iron can cause problems in the heart, liver and endocrine glands.

How do you get rid of iron?

If your iron level reaches a certain level, you should start taking a medication to remove iron called "ExJade." It is very important to take this medication every day to bring the iron in your body to a safe level.

Avascular Necrosis (AVN)

Definition: Bones, like other organs in the body, need blood to stay alive and healthy. Unfortunately, sickle red blood cells can sometimes block the blood supply to the round part of either the hip or shoulder bone. This lack of blood flow causes the bone to die, resulting in long-term (chronic) hip or shoulder pain.

How is AVN diagnosed?

The best way to diagnose AVN is through magnetic resonance imaging (MRI). MRI gives a very good picture of the joint without any radiation.

How is AVN treated?

The bone damage in AVN unfortunately cannot be easily fixed. Pain medications and physical therapy can help. If AVN is causing significant problems, an orthopedic surgeon may recommend core decompression surgery or joint replacement surgery.

Bone marrow is the "factory" that produces the different types of blood cells—white blood cells, red blood cells and platelets.

Aplastic Crisis

Definition: Aplastic crisis occurs when the bone marrow "factory" shuts down and stops making blood cells. Some viral infections can cause this aplastic crisis and temporarily stop the production of blood cells. People with sickle cell disease need to constantly make red blood cells since their red blood cells do not typically live as long. When the production of red blood cells stops, the number of red blood cells in the body can drop to a dangerously low level.

Stroke

Definition: A stroke occurs when blood flow to the brain is blocked.

Signs of a stroke include suddenly having any of the following:

• Numbness or weakness - especially on one side of the body
• Confusion, trouble speaking or understanding
• Trouble seeing
• Trouble walking, dizziness and loss of balance
• Severe headache with no known cause

What should I do if I think I might be having a stroke?

Act fast. If you have signs of a stroke, immediately call 911.

Remember FAST:

• Face. Smile. Does it look uneven or droop?
• Arms. Raise both arms. Does one side drift down?
• Speech. Repeat a simple sentence. Does it sound abnormal or slurred?
• Time. If you answer yes to any of the above questions then brain cells could be dying and you need urgent medical treatment.

What is a TCD?

As a child, you should have had a test called a Transcranial Doppler (TCD) that measures the flow of blood to the brain. This test helps predict a person’s risk of having a stroke. Children who have blood flow measured by TCD faster than a certain speed are more likely to have a stroke. Many of these children are then placed on chronic blood transfusions to lower their risk of stroke. Also, individuals who have had a stroke are often started on chronic blood transfusion therapy to lower their risk of having another stroke.

Jaundice

Definition: Jaundice is a word used to describe the yellow color most easily seen in the normally white part of the eyes (sclera).

People with sickle cell have jaundice because of the breakdown of red blood cells that releases bilirubin, a yellow substance. Many people with sickle cell always have some mild jaundice because their red bloods cells are broken down much more often than people who do not have sickle cell. This jaundice is not concerning.

What if my eyes are more yellow than usual?

If you have increased yellowing of your eyes (increased jaundice):

• Your body might be destroying an increased number of red blood cells. Contact your doctor right away if you have increased jaundice, plus urine that is dark brown like the color of cola.
• You might be dehydrated. Drink more fluids, especially water.
• You could have a problem with your liver or gallbladder. Jaundice that is due to liver or gallbladder problems is less common. However, if you have increased jaundice that does not improve with rest and fluids, talk to your doctor about liver function tests.

Retinopathy

Definition: Retinopathy is a type of damage to the back of the eye that controls vision.

People can develop different types of retinopathy for various reasons and those with sickle cell disease can develop a specific type of retinopathy (sickle cell retinopathy). People with early retinopathy have no symptoms and may have perfect vision; however, retinopathy often worsens, causing vision problems and even blindness. Fortunately, retinopathy can usually be treated by laser surgery before it causes vision problems.

People with sickle cell should see an ophthalmologist (an eye doctor) to look for retinopathy every year starting at around age 10. It is very important to see the ophthalmologist even if you have 20/20 vision because you want to treat retinopathy before it causes problems.

The gallbladder is an organ is the right upper abdomen that stores bile, a fluid that helps with digestion.

Gallstones

People with sickle cell disease typically can develop types of gallstones called bilirubin gallstones. Bilirubin is a yellow substance made when hemoglobin in red blood cells is broken down. People with sickle cell disease have elevated bilirubin levels because of the constant break down of damaged red blood cells. This bilirubin can then collect to form gallstones. A few gallstones may not cause any problems. However, over time, gallstones can block the flow of bile out of the gallbladder causing two problems:

1. Biliary colic. This is the word used to describe the abdominal pain caused by gallstones. People with biliary colic can have severe abdominal pain located in the right upper abdomen. Often this pain is worse after eating fatty meals but then goes away.
2. Cholecystitis. Cholecystitis is an infection of the gallbladder that results from blocking the flow of bile. People with cholecystitis usually have fever in addition to severe right upper abdomen pain and tenderness. People with cholecystitis need treatment with antibiotics in the hospital.

If a person is having significant problems from gallstones, the treatment is surgery to remove the gallbladder (cholecystectomy).

Pulmonary Hypertension

Definition: Pulmonary hypertension is increased pressure in the blood vessels that go to the lung for oxygen transport. This increased pressure is caused by narrowing of these blood vessels.

To help understand pulmonary hypertension, think of two hoses with the same amount of water running through them.

Hose #1 is big. Water easily travels through the hose and does not push against it (low pressure).

Hose #2 is small. Water has a more difficult time traveling faster through the hose and pushes hard against it (high pressure).

Pulmonary hypertension is a problem because it can cause a strain on the heart that has to pump blood.

Symptoms of pulmonary hypertension include:

• Shortness of breath (dyspnea)
• Feeling tired all the time (chronic fatigue)
• Dizziness
• Fainting (syncope)
• Swollen ankles and legs (edema)
• Chest pain, especially during physical activity (angina)

An ECHO (a heart ultrasound) can help diagnose pulmonary hypertension.

The kidneys filter blood, removing waste to create urine.

Sickle Cell Nephropathy

Definition: Sickle red blood cells can damage the kidney so that it is unable to filter properly. This kidney damage is called sickle cell nephropathy. The first sign of this damage is protein in the urine (proteinuria). People with early sickle cell nephropathy have no symptoms; however, they can later develop renal failure. Renal failure means that the kidneys no longer work. Renal failure can cause dangerous levels of different electrolytes in the blood since the blood is not properly filtered. People with renal failure must go on dialysis or have a kidney transplant.

What to do if you have proteinuria?

If you have proteinuria, then you likely have early kidney damage. You should see a kidney specialist (nephrologist) to get started on medication to slow down this damage to the kidney.

Acute Chest Syndrome

Definition: Acute chest syndrome (ACS) is a term used to describe a type of sickle cell crisis involving the lungs. ACS is diagnosed by seeing a new infiltrate (evidence of a substance not normally present) on a chest X-ray. Some doctors may use the word "pneumonia" (inflammation of the lung) to describe this abnormality. In general, pneumonia in a person with sickle cell disease is the same thing as acute chest syndrome.

A person with acute chest syndrome has one or more of the following symptoms:

• Fever
• Cough
• Difficulty breathing
• Chest pain

It is very important to see a doctor if you have any of the above symptoms because people with ACS can become very sick.

How is acute chest syndrome treated?

Treating ACS involves helping to ensure that the person’s body is still receiving enough oxygen. Supplemental (extra) oxygen is often given. Breathing treatment medications like Albuterol or Pulmicort may also be given to help improve lung function especially if a person also has asthma. Sometimes a blood transfusion is necessary to further help with oxygen transport. Since ACS may be triggered by an infection, treatment can also involve antibiotics.

How can I prevent acute chest syndrome?

One important thing that you can do to prevent acute chest syndrome is incentive spirometry. An incentive spirometer is a device that helps encourage you to breathe in deeply. By taking deep breaths, your lungs will better deliver oxygen and prevent vasoconstriction of the blood vessels going to the lung that can cause acute chest syndrome. If you are in the hospital for a pain crisis, you should try to use your incentive spirometer 10 breaths every hour while awake, or once every time you see a TV commercial for example.

Another important thing you can do to prevent acute chest syndrome (and other problems) is to get your influenza (flu) vaccine every year. All people with sickle cell disease should get a flu vaccine before the start of the flu season in the early fall (usually first available in September). You need to get the influenza vaccine every year (unlike other immunizations which usually do not need to be repeated) because the influenza virus changes every year. The vaccine is specially made to protect against the influenza virus of the current season.

The spleen is an organ in the left upper abdomen that removes old or damaged red blood cells. The spleen is also part of the immune system and helps fight certain infections.

Sequestration

Definition: Splenic sequestration is the sudden enlargement of the spleen due to trapping of red blood cells. This pooling of blood in the spleen causes problems because fewer red blood cells are able to circulate throughout the rest of the body to transport oxygen. People with splenic sequestration need to be hospitalized and may need a blood transfusion.

After recovery from a splenic sequestration event, an individual may start chronic blood transfusion therapy or have the spleen removed (splenectomy) to prevent future episodes. Splenic sequestration usually only occurs in children with sickle cell disease (before they develop functional asplenia).

Functional Asplenia

Definition: The spleen in individuals with sickle cell disease usually becomes damaged over time by the many abnormal red blood cells traveling through it. Usually by adolescence, the spleen in individuals with sickle cell disease is non-functional because of this damage. Functional asplenia simply means not having a working spleen.

No spleen — Who cares?

People can live without a spleen. However, people who do not have a functioning spleen have an increased risk of certain infections, especially infections from bacteria called "pneumococcus." Because of this increased risk, all people with sickle cell should see a doctor immediately if they have fever. Fever could be the first sign of a serious bacterial infection that needs immediate antibiotic treatment.

• Fever = Oral temperature above 101.3° F or 38.5° C. Go to the Emergency Room (ER) or Sickle Cell Center.

As a child, you should have taken penicillin, an antibiotic to prevent blood infection by the bacteria called pneumococcus. It is recommended that all children with sickle cell disease less than six years old take penicillin every day. It is also recommended for older individuals to continue taking penicillin if they have had a past pneumococcus blood infection or had surgery to remove the spleen (splenectomy).