Transplant Reverses Sickle Cell Disease

A specialized A spongy tissue that contains blood-producing stem cells, which give rise to many types of blood cells. bone marrow transplant successfully reversed severe sickle cell disease in adults, in some cases without the need for extensive immune-suppressing drugs. Follow-up testing will be needed to further assess this experimental therapy.

Sickle cell disease affects more than 90,000 Americans, mostly of African descent. It causes red blood cells to become stiff, sticky, and sickle-shaped. The deformed cells can block blood flow, leading to pain, organ damage, and stroke.

Some affected children have been successfully treated with bone marrow transplants—an approach thought to be too toxic for adults. With this method, high doses of chemotherapy destroy all of a child’s bone marrow, which is then replaced with healthy marrow from a donor. Transplant recipients often require harsh immunosuppressants for years.

In the new study, a research team at the NIH Clinical Center tested a modified transplant procedure in 30 adults with severe sickle cell disease. A less toxic regimen destroyed only some of their marrow cells. They then received blood-forming stem cells donated by a healthy sibling.

The transplanted cells reversed the disease in 26 of 30 adults. They had fewer hospitalizations and needed less narcotics for pain. A year after the procedure, 15 patients no longer needed immune-suppressing drugs.

“Side effects caused by immunosuppressants can endanger patients already weakened by years of organ damage from sickle cell disease,” says NIH’s Dr. John Tisdale, the study’s senior author.

People with sickle cell disease interested in joining NIH blood stem cell transplant studies may call 1-800-411-1222 or visit www.clinicaltrials.gov for more information.