Anemia, Sideroblastic

Definition

Sideroblastic anemia is a term used to describe a group of rare blood disorders characterized by the bone marrow's inability to manufacture normal red blood cells.

Description

Named for the Greek words for iron and germ, sideroblastic anemia is one of the principal types of iron-utilization anemia. Abnormal, iron-saturated red cells are present in the blood of people who have this disease. Although the iron circulates normally from the plasma to the bone marrow, where new red blood cells are created, it is not properly incorporated into new red blood cells.

Sideroblastic anemia can be inherited, but the disease is usually acquired as a result of illness or exposure to toxic substances.

Sideroblastic anemia is a disease of adults.

Causes & symptoms

The cause of sideroblastic anemia cannot always be identified. Drug toxicity, alcohol abuse, and lead poisoning are common causes of this condition.

Sideroblastic anemia is also associated with:

• Leukemia.
• Lymphoma (cancer of the lymph glands).
• Myeloma (cancer of the bone marrow).
• Rheumatoid arthritis, and other inflammatory diseases.

Symptoms of sideroblastic anemia are the same as symptoms of the disease that causes the condition, as well as anemia.

Complications

Possible complications of sideroblastic anemia include:

• Congestive heart failure.
• Diabetes mellitus.
• Enlargement of the liver and spleen.
• Formation of liver nodules and scar tissue.
• Irregular heartbeat.
• Recurring inflammation of the sac that surrounds the heart.
• Secondary hypopituitarism (dwarfism).
• Skin darkening.
• Underactivity of the thyroid gland.

Diagnosis

Blood tests are used to examine the appearance and other characteristics of red cells and to measure the amount of iron in the blood. Bone marrow biopsy is also used.

Treatment

Acquired sideroblastic anemia may be cured when the condition that causes it is treated or removed.

If the cause of a patient's anemia cannot be determined, blood transfusions may be necessary. Medications are prescribed to stimulate excretion or excess iron that accumulates as a result of these transfusions.

In rare instances, treatment with oral pyridoxine (a B-complex vitamin) benefits patients whose sideroblastic anemia was present at birth. This treatment improves the condition of some patients but does not cure the anemia.

Prognosis

Sideroblastic anemia of unknown origin may lead to leukemia. It may take as long as 10 years for this disease progression to take place.

Further Reading

For Your Information

Books

• Tierney, Lawrence, M., Jr., et al, eds. Current Medical Diagnosis & Treatment. Stamford, CT: Appleton & Lange, 1998.

  Organizations

• Leukemia Society of America, Inc. 600 Third Avenue, New York, NY 10016. (212) 573-8484. http://www.leukemia.org.
• National Heart, Lung and Blood Institute Information Center. P.O. Box 30105, Bethesda, MD 20824-0105. (301) 251-1222.
• National Organization for Rare Disorders. P.O. Box 8923, New Fairfield, CT 06812-8923. (800) 999-6673. http://www.nord-rdb.com/~orphan.

  Other

• Iron-utilization anemias. http://www.merck.com/!!uxOIE29ZzuxOIE29Zz/pubs/mmanual/html/mknldkeg.htm. (3 June 1998).
• Sideroblastic anemia. http://www.icondata.com/health/pedbase/files/ANEMIAS_S.HTM. (25 May 1998).
• Sideroblastic anemia. http://www.anemiacenter.com/anemia/16.htm. (31 May 1998).

Gale Encyclopedia of Medicine. Gale Research, 1999.