What Is Thalassemia Intermedia?

A Review of Non-Transfusion Dependent Thalassemia

Physician Discussing Condition with Patient
Physician Discussing Condition with Patient. Hero Images/Creative RF/Getty Images

Thalassemia is a group of disorders affecting hemoglobin, a protein, inside red blood cells (RBC). People who inherit thalassemia are unable to produce hemoglobin normally leading to anemia (low RBC count) and other complications.

Thalassemia can be broken into three large categories:

  • Trait: Person carries the gene for mutation but does not have disease. This is sometimes called thalassemia minor.
  • Intermedia: Person with thalassemia somewhere between trait and major.
  • Major: Person with thalassemia who require lifelong RBC transfusions.

How Is Thalassemia Intermedia Diagnosed?

Although, most of the time thalassemia major will be identified on the newborn screen, people with thalassemia intermedia may not be identified until years later. These people are generally identified on routine complete blood count (CBC). The CBC will reveal a mild to moderate anemia with very small red blood cells. This can be confused with iron deficiency anemia.

Diagnosis is confirmed by a hemoglobin profile (also called electrophoresis). In beta thalassemia intermedia and trait this testing reveals elevation in hemoglobin A2 (a 2nd form of adult hemoglobin) and sometimes F (fetal). Alpha thalassemia intermedia is generally called hemoglobin H disease as this is the predominant hemoglobin seen on the profile.

What Are the Complications of Thalassemia Intermedia?

Complications of thalassemia intermedia include:

  • Iron overload
  • Osteoporosis: Weakening of the bones
  • Extramedullary hematopoiesis: This refers to enlargement of spleen, liver and/or bone marrow to increase red blood cell production. The bones most notably affected are in the skull - forehead and cheek bones. 
  • Hypogonadism: Reduced production of sexual organs. This may prevent puberty from occurring naturally.
  • Gallstones: 
  • Blood clots

Why Do People With Thalassemia Intermedia Develop Iron Overload?

There are two reasons why people with thalassemia intermedia develop iron overload.

  1. Repeat red blood transfusions: Even though children with thalassemia intermedia generally don't require transfusions every 3 to 4 weeks like children with thalassemia major, they still may require several blood transfusions every year. Each red blood transfusion received is like an intravenous (IV) dose of iron. The body does not have a great way to remove this iron from the body. So over time these repeated transfusions may result in the development of iron overload, although generally later in life (adulthood) than people with thalassemia major (childhood).
  2. Increased absorption of iron from food: The body recognizes that the bone marrow is not doing a good job producing hemoglobin and red blood cells. Hepcidin is a protein that blocks the absorption of iron. In thalassemia, hepcidin levels are low allowing more iron to be absorbed than is needed. It is recommended that people with thalassemia intermedia follow a low iron diet and drink tea with meals as tea blocks the absorption of iron.

    What Are Treatment Options for Thalassemia Intermedia?

    • Routine medical care: Not every person with thalassemia intermedia will require treatment, but it is important to continue close medical care to monitor for complications.
    • Transfusions: People with thalassemia intermedia may require transfusions, but generally not as frequently as people with thalassemia major until adulthood. Transfusion may be needed in times of increased growth and development (puberty), illnesses particularly those with fever, pregnancy, or in preparation for surgery.
    • Folic acid: Some physicians may recommend folic acid daily to support RBC production.
    • Splenectomy: In thalassemia, the spleen may enlarge (splenomegaly) in an effort to improve RBC production. This is often ineffective and may worsen anemia and/or increase transfusion need. In these circumstances, splenectomy may be considered.
    • Hydroxyurea: Hydroxyurea is a daily medication taken by mouth in an effort to increase hemoglobin, thereby reducing the need for RBC transfusions. 
    • Low iron diet: Because people with thalassemia intermedia are at risk to develop iron overload from increased absorption of iron in the diet, a low iron diet may be recommended. Tea, particularly black tea, decreases the absorption of iron and may be recommended with meals.

    Learning you have thalassemia intermedia can be shocking as you may have not had any symptoms. Be sure to follow up with your physician as schedule so that you can be monitored for potential complications.

    Sources:

    Benz EJ. Molecular pathology of thalassemia syndromes, Clinical manifestations and diagnosis of thalassemia, and Treatment of beta thalassemia. In: UpToDate, Post TW (Ed), UpToDate, Waltham, MA.

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