Bone marrow transplants can reverse severe sickle cell disease in adults, a small study by government scientists found, echoing results from a similar technique used in children.
The researchers and others say the findings show that age need not be a barrier and that the technique could change practice for some adult patients when standard treatment fails.
The transplant worked in 26 of 30 adults, and 15 of them were able to stop taking drugs that prevent rejection one year later.
"We're very pleased," said Dr. John Tisdale, the study's senior author and a senior investigator at the National Institutes of Health. "This is what we hoped for."
Sickle cell disease is a genetic condition that damages oxygen-carrying hemoglobin in red blood cells that then form sickle shapes that can block blood flow through veins. It can cause anemia, pain and organ damage. The disease affects about 100,000 Americans and millions worldwide.
The treatment is a modified version of bone marrow transplants that have worked in kids. Donors are a brother or sister whose stem cell-rich bone marrow is a good match for the patient.
Tisdale said doctors have avoided trying standard transplants in adults with severe sickle cell disease because the treatment is so toxic. Children can often tolerate it because the disease typically hasn't taken as big a toll on their bodies, he said.
The disease is debilitating and often life-shortening. Patients die on average in their 40s, Tisdale said. That's one reason why the researchers decided to try the transplants in adults, hoping the technique could extend their lives.
The treatment involves using chemotherapy and radiation to destroy bone marrow before replacing it with healthy donor marrow cells. In children, bone marrow is completely wiped out. In the adult study, the researchers only partially destroyed the bone marrow, requiring less donor marrow. That marrow's healthy blood cells outlast sickle cells and eventually replace them.
Results from the adult study, involving patients aged 29 on average, were published Tuesday in the Journal of the American Medical Association.