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Why is blood needed from diverse donors?

We need blood from diverse donors because a diverse group of patients will receive it. People with sickle cell disease or thalassemia can be any race or ethnicity, but almost all have ancestry from the parts of the world shown on the map below.

Since we all inherit our blood type from our parents, transfused blood is most likely to be a close match when the donor and the patient have similar ancestry. Donations from people with relatives or ancestors from the parts of the world shown in the map are key to the health and safety of those with sickle cell disease or thalassemia who need transfusions.

Many people who have sickle cell disease or thalassemia get blood transfusions to stay healthy. They may need them regularly their whole life, or for certain short periods of time, or off and on during health emergencies.

If someone gets transfused with blood that doesn’t quite match their own, their body can create antibodies to fight it off. This is not usually dangerous on the first exposure. But if that patient gets blood later with the same mismatch — even years later — their body can create a flood of antibodies trying to destroy the donor blood. This is very serious, even deadly.

So people who might get many transfusions in their lifetime — like people who have sickle cell or thalassemia — need to get donor blood that is a close match to their own every time. If they already have an antibody, they definitely need to avoid getting donor blood with the same mismatch.

Origins of Sickle Cell Disease and Thalassemia

(Based on information from The Centers for Disease Control and Prevention and the National Institutes of Health)

Why do patients with sickle cell disease need transfusions?

In patients with sickle cell disease, red blood cells become hard, sticky, and form a C-shape that looks kind of like a banana. These sickled red blood cells can get stuck in the blood vessels and block the normal flow of blood and oxygen through the body. This leads to a variety of health problems, including severe pain, organ damage, serious infections, and stroke.

Blood transfusions can help treat or prevent these health problems by providing normal red blood cells that help deliver oxygen to the body and unblock blood vessels.

Normal red blood cell

Hemoglobin carries oxygen and nutrients.

Blood flow is unobstructed.

Sickle red blood cell

Hemoglobin improperly forms long chains, giving the cell its sickle shape.

Sickle cells block blood vessels.

Why do thalassemia patients need transfusions?

In patients with Thalassemia, the body doesn’t make enough hemoglobin, which is found in red blood cells. Because of this lack of hemoglobin, the red blood cells don’t deliver as much oxygen throughout the body as they should. This can cause symptoms like dizziness, shortness of breath, fast heartbeat, and organ damage.

Blood transfusions are used to treat thalassemia by increasing the amount of healthy red blood cells and hemoglobin in a person’s body (

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