Sickle cell disease (SCD) is a group of inherited blood disorders. Affected hemoglobin inside your red blood cells (RBCs) causes them to lose their flexible donut shape and take on a “C” shape. These cells also become hard and sticky and don’t live as long as other RBCs.
The result is a constantly short supply of RBCs in people with SCD. The remaining cells can easily become stuck in blood vessels or cause painful disruptions to blood flow.
RBCs move things such as iron, protein, oxygen, and carbon dioxide around your body. A shortage of RBCs can cause fatigue and weakness or anemia. People with SCD often develop anemia and other disruptions to blood flow due to their sickle-shaped RBCs. Blood transfusions remain the most common treatment for these complications.
A blood transfusion is a procedure where you receive a donor’s blood that matches your blood type. A transfusion can help you if you’re anemic due to SCD by adding to your body’s RBC supply. This allows your body to transport vital gases and nutrients.
This article will discuss the benefits, risks, and procedure for blood transfusions in people with SCD.
A transfusion can replace your RBCs, enabling more oxygen to reach your organs and tissues. A transfusion can also add more blood with healthy RBCs to dilute the sticky, sickle-shaped cells. This keeps them from piling up in your blood vessels and blocking blood flow.
Without a transfusion, your body may lack the oxygen it needs to function, resulting in hypoxemia and other problems.
A blood transfusion can help you if you have a sudden or urgent complication of SCD, such as:
acute chest syndrome, when sickled RBCs block blood vessels in the lungs splenic sequestration, a sudden swelling of the spleen
As SCD is a chronic condition, blood transfusions can help maintain your RBC count to prevent complications such as severe anemia, hypoxemia, and stroke from disrupted blood flow. This is called prophylactic treatment.
Transfusions can also prevent problems associated with surgery in people with SCD. The American Society of Hematology recommends blood transfusion for people with SCD who will be under anesthesia for more than an hour.
Types of sickle cell disease
There are a few types of SCD. How you manage SCD — including how often you may need a blood transfusion — can depend on the type you have.
- HbSS: This form of SCD develops in people who inherit two “S” type sickle cell genes, one from each parent. Also called sickle cell anemia, this is the most severe type of SCD.
- HbSC: With this type of SCD, you inherit an “S” gene from one parent and an irregular “C” type hemoglobin gene from the other parent. This type of SCD is usually milder than HbSS.
- HbS beta thalassemia: People with this condition have an “S” gene from one parent and a gene for another type of anemia called beta thalassemia from the other parent.
- HbSD, HbSE, HbSO: These are rare forms of SCD where you inherit an “S” gene from one parent and a “D,” “E,” or “O” hemoglobin gene from the other parent. The severity of these types of SCD can vary.
- HbAS: Also known as the sickle cell trait, this means that you have the “S” gene from one parent but inherit regular genes from your other parent. People with this form of SCD don’t usually develop any symptoms but carry sickle genes and can possibly pass the trait on to their children.
There are risks related to blood transfusions for everyone, whether you have SCD or not. While you might be worried about the risks of contracting a bloodborne disease from your blood donor, this is very rare.
Donated blood undergoes careful screening. There’s about a 1 in 2 million chance of contracting HIV from a blood transfusion, and about half that chance of being infected with some form of hepatitis.
The bigger risk for most people isn’t an infectious disease but rather your body’s reaction to the donated blood. This can take several forms:
- Allergic reaction: These reactions can occur even when you receive a matching blood type. Sometimes your body will still mount an immune response to donated blood, causing an allergic reaction that will require your medical team to stop the transfusion and treat your reaction with antihistamines or other medications.
- Acute immune hemolytic reaction: This is a reaction where your body is shocked by the introduction of donated blood and rejects the transfusion. Transfusion reactions are rare but serious and usually develop when the blood you’re receiving isn’t an exact match to your blood type. Talk with a doctor about your risk, especially if it’s happened to you before.
- Fever: As one of the more common side effects of a transfusion, a fever may occur as your body reacts to donated white blood cells entering your body. Your immune system recognizes these cells as foreign and triggers an immune response, causing a fever. In some cases, a fever might disrupt your transfusion.
While these risks are the same for everyone, people with SCD are at higher risk due to the many transfusions they can require in a lifetime. Other complications due to frequent transfusions include:
- Hemosiderosis: Frequent transfusions may cause too much iron to collect in your body. Hemosiderosis is an iron overload disorder that may lead to organ damage.
- Alloimmunization: This occurs when your body develops antibodies in response to donor blood cells. It happens in about a third of people with SCD. Alloimmunization can cause a potentially fatal delayed hemolytic transfusion reaction.
There are several reasons a doctor may decide you need a blood transfusion as a treatment for SCD. Some of the indications for transfusion include:
- severe anemia
- acute ischemic stroke
- severe pain
- chest pain
- prolonged erection (priapism)
- high blood pressure
- multi-organ failure
Simple vs. exchange transfusion
A simple transfusion is a transfusion where you receive donor blood to supplement your own.
In an exchange transfusion, some of your own blood is removed from your body and replaced with donor blood. Exchange transfusions are also helpful when you need to increase your RBCs without thickening the blood (increasing hematocrit). The procedure is a dialysis-type process and takes longer.
If you need a blood transfusion to treat SCD or its complications, you’ll first need to know your blood type and discuss your transfusion history with a medical team. They need to know of any past reactions and how many transfusions you’ve received. This information can help a doctor take steps to reduce the chances of problems such as iron overload.
The first step is a blood test, called a type and screen, to determine your blood type and crossmatch it with donors’ blood types. If you’ve had more than 10 transfusions in your life, a doctor may order a ferritin blood test prior to your transfusion to track your iron levels.
When it’s time to start the transfusion, here’s what you can expect:
- The medical team will access your blood vessels with an intravenous (IV) catheter or another device. A large peripheral IV line inserted into your arm is usually enough for a simple blood transfusion. Repeated or frequent transfusions may warrant the placement of a deeper or more permanent access line.
- A nurse or doctor will review your history, lab work, allergies, and why you’re having the transfusion.
- Your blood type will be checked, crosschecked, and checked against the donor’s blood before the transfusion begins.
- Your medical team will collect vital signs, including your heart rate, blood pressure, temperature, and other measures.
- A doctor will set the transfusion amount and speed. A simple transfusion can take between 1 and 4 hours.
- While you receive the blood transfusion, a team will monitor you closely. They’ll check your vital signs again to watch for any transfusion reactions.
- When the blood transfusion is complete, the medical team will still monitor you for a time. They’ll likely remove your IV line if you received blood as an outpatient procedure. The IV site may be sore for a few days after your transfusion.
How often do people with sickle cell disease need blood transfusions?
How often you need a transfusion will depend on your condition and the type of SCD you have. For example, prophylactic transfusions are most common in specific groups, such as pregnant people.
Are there alternatives to blood transfusion?
Hydroxyurea is a treatment that may reduce your need for transfusions, but there’s no real way to supplement your RBC count without a blood transfusion. Instead, this oral medication helps make RBCs grow larger and stay softer and more flexible, and it may help prevent organ damage.
Bone marrow transplants and stem cell transplants may also be used to try to “cure” your SCD by reprogramming how your body creates new RBCs. But these options are very complicated and carry their own serious risks.
Can people with the sickle cell disease or trait donate blood?
People with SCD can’t donate blood, but people with the sickle cell trait can. Your blood may have issues during filtration though. You may be encouraged to donate platelets, as they don’t need to be filtered.
Questions for a doctor
If you’re discussing a blood transfusion for SCD with a doctor, you may want to ask the following questions, both for your knowledge in the future and to help prevent any reactions.
- What’s my blood type?
- Does my donor blood require any special preparation (such as leukoreduction to reduce the number of white blood cells in the donated blood)?
- What’s my iron level?
- What kind of IV access will you use?
- Are there any special instructions I need to know for after my transfusion?
If you’re receiving a transfusion as part of chronic disease management or for prophylactic reasons, you may also want to ask a doctor about follow-up testing or any additional treatments or transfusions you might need.
SCD is a blood disorder that causes your RBCs to become sticky, brittle, and oddly shaped. People with these cells can experience clots, low RBC counts, and other complications. Doctors use blood transfusions to manage SCD, but this treatment doesn’t come without possible risks.
Talk with a doctor about the risks and benefits of a blood transfusion to manage your SCD, and be sure to tell a doctor about any allergies you have or prior reactions to blood transfusions.