Treatment for transfusion-dependent beta thalassemia

One of the many functions of blood is supplying the body’s many cells, tissues, and organs with oxygen. Cells require oxygen to function, produce energy, and survive. Low levels of oxygen in the blood cause problems.

Essential to this process is a protein called hemoglobin. Hemoglobin is one of the main components of red blood cells. It’s the part of red blood cells that attaches to oxygen molecules, enabling blood to deliver oxygen molecules to cells throughout the body. Hemoglobin also attaches to carbon dioxide, which is transported away from cells, back to the lungs, and exhaled. Carbon dioxide is a byproduct produced when cells use oxygen.

Beta thalassemia is a genetic blood disorder that affects the production of hemoglobin. Beta thalassemia occurs when a person has mutations or variant versions of the HBB gene. This gene contains instructions for making beta-globin, one of the key components of hemoglobin.

The mutations that cause beta thalassemia interfere with the body’s ability to produce beta-globin. This interferes with the body’s ability to produce hemoglobin. Without enough hemoglobin, red blood cells do not develop normally.

Beta thalassemia and anemia

Abnormal red blood cells are less effective at transporting oxygen throughout the body. People with beta thalassemia will have anemia, a condition that occurs when there is a shortage of red blood cells.

In some cases, anemia will be mild. In other cases, it will be severe. Beta thalassemia can be categorized based on the severity:

• Beta thalassemia major. Also known as transfusion dependent beta thalassemia. People with this type will require frequent blood transfusions to raise the amount of healthy red blood cells in the body.
• Beta thalassemia intermedia. This is the less severe type. It is referred to as “non-transfusion dependent” because a person with this type will not require regular blood transfusions. This causes less severe anemia.
• Beta thalassemia minor. This type causes few or no symptoms.

Managing transfusion-dependent beta thalassemia

Beta thalassemia major is usually diagnosed in the first year or two of a person’s life. Mentioned above, people with beta thalassemia major will require regular blood transfusions. A person may also be prescribed a medication to help reduce the frequency of blood transfusions.

Because frequent blood transfusions can cause levels of iron in the blood to become too high, a person may also need iron chelation therapy—medications that remove excess iron from the blood.

Treatment will also need to address additional complications caused by beta thalassemia, such as enlarged spleen, liver disease, and cardiac problems.

Stem cell transplants

In some cases, beta thalassemia major may be treated with a bone marrow transplant, also called a stem cell transplant. This procedure can potentially cure beta thalassemia. It also comes with a risk of serious complications, and involves specialized care, significant side effects, and healthcare costs. It requires a compatible stem cell donor, and the person receiving the transplant must undergo chemotherapy and/or radiation therapy to eliminate the disease-causing cells in the bone marrow.

Gene therapy

There are also several gene therapies that are available, and others under development. These therapies add or alter a person’s genes, aiming to counteract the gene mutations that are causing the disease. These are delivered in the form of modified blood-forming stem cells—cells that are collected from a person’s bone marrow, modified in a lab, and then reintroduced into the body.  Similar to a bone marrow transplant, a person being treated with gene therapy must undergo chemotherapy to eliminate the disease-causing stem cells from the bone marrow. Gene therapy is a long, multi-step process that requires up to 6 weeks in a hospital to recover from.