Thalassemia

Thalassemia is an inherited, lifelong disorder that affects the development and health of red blood cells, which transport oxygen. Lack of healthy red blood cells can cause a range of problems. Without treatment, more severe forms of thalassemia can restrict daily activities and even threaten your life.

Thalassemia results in problems with hemoglobin, the protein that carries oxygen for red blood cells. During the formation of new red blood cells in the bone marrow, hemoglobin develops from a careful linking of two distinct building blocks. At a certain point, the completed hemoglobin joins the maturing red blood cells.

With thalassemia, an inherited genetic change disrupts this crucial process. The change reduces production of one of the hemoglobin building blocks. Which building block is affected depends on the genes involved.

Without enough fully formed hemoglobin, the developing red blood cells die. Also, without proper partners, the other set of hemoglobin building blocks attaches to mature red blood cells and damages them, shortening their lives.

The subsequent impacts on red blood cell production and health include:

• Anemia, or a shortage of healthy red blood cells
• Arrhythmias (irregular heartbeats), heart failure, and pulmonary hypertension over time, with the heart and lungs working harder
• Bone marrow expansion as it attempts to make up for red blood cell loss, resulting in bone deformities, bone weakening, and fractures
• Damage to organs from lack of oxygen
• Gallstones, as dying red blood cells release a substance called bilirubin that collects in the gallbladder
• Hypercoagulability, or an increased tendency to form blood clots
• Leg ulcers
• Poor growth in children and failure to thrive in adults
• Production of red blood cells outside the bone marrow, including in the spleen, which can then enlarge

Thankfully, improvements in care have led to better control of thalassemia and its potential complications. Many people with the condition now enjoy longer, fuller lives. To take advantage of these advances, people with more severe forms of thalassemia may wish to receive focused care.

At Penn Medicine, adults seeking specialized thalassemia services can turn to our Comprehensive Adult Thalassemia Program.

Some types of thalassemia can lead to severe complications, while other forms only cause mild or moderate symptoms. People with thalassemia may also have different (or worse) symptoms and complications as they get older.

Thalassemia symptoms vary depending on the type of complication involved. With anemia, one of the more frequent complications, symptoms can include:

• Fatigue
• Pale skin
• Shortness of breath
• Weakness

The type of anemia caused by thalassemia can also lead the body to absorb more iron from food. This iron buildup can cause problems with certain organs and glands and possibly worsen the side effects of treatment.

Doctors diagnose thalassemia with blood tests that look at the number of red blood cells, their shape, and their size. The tests also evaluate hemoglobin subtypes. Genetic testing may be able to determine the changes responsible, though results may not alter the treatment approach.

Since at-risk couples can be identified, thalassemia may be diagnosed early in pregnancy. Otherwise, children with moderate or severe symptoms typically get diagnosed early in life.

With mild thalassemia, people may not learn they have it until adulthood. They may get a blood test for another reason or need care for anemia.

Thalassemia treatment depends on the type you have and how it affects you. Some people only need occasional treatment, if any. Others require ongoing therapy.

Standard thalassemia treatment involves transfusions of donated red blood cells, which are screened for safety. These transfusions help relieve anemia and other symptoms. They also slow the bone marrow’s unsuccessful attempts at continued red blood cell production.

Additional thalassemia treatments may help the body produce and maintain healthy red blood cells. These treatments may include hydroxyurea and luspatercept.

Researchers have also been developing ways to add the genetic information needed to make proper hemoglobin to the body. The Food and Drug Administration approved the first gene therapy for thalassemia in 2022. Doctors hope this one-time treatment will make people less dependent on blood transfusions or not need them at all.

Treatment side effects and chelation therapy

While blood transfusions provide critical treatment for thalassemia, they also further contribute to the harmful buildup of iron. This process occurs when the donated red blood cells reach their normal lifespan and break apart, releasing iron.

The excess iron tied to thalassemia-related anemia and blood transfusions can cause problems as it collects in certain parts of the body:

• Bones: Extra iron can combine with other thalassemia-related changes to cause osteoporosis.
• Endocrine system: The extra iron can lead to disorders such as diabetes and hyperthyroidism.
• Heart: The deposits can cause arrhythmias and heart failure.
• Liver: The iron can cause scarring that can eventually turn into cirrhosis. It can also raise the risk for liver cancer.

To prevent iron from building up, doctors use special medications called chelators to remove some of the minerals from the body. They also give these medications when iron has already been collected. Fortunately, advances in chelation therapy have made iron removal easier and much more effective.

Additionally, doctors watch for the side effects of iron buildup during regular checkups. They sample blood, test organs and glands, and use imaging to identify possible complications.