Durham, N.C. — For the past 20 years, cord blood stem cell transplants have been used to treat leukemia and other blood diseases.

Cord blood is most often used in children because the blood comes from the umbilical cord, which holds a limited quantity, according to the National Marrow Donor Program. Cord blood also doesn't have to be as close a blood or tissue match as bone marrow does.

Duke University Medical Center is a pioneer in cord blood stem cell transplants. Doctors have worked mainly with children, but not entirely.

Gayle Searls is proof the treatment can be used in adults as well. Twelve years ago, Searls was Duke’s first adult cord blood transplant patient.

In 1996, Searls began feeling unusual fatigue. She would bruise easily, and her lymph nodes were swelling.

“I was literally at work that day and in the hospital that night with leukemia,” Searls said.

Searls was diagnosed with acute lymphacytic leukemia that required a matching bone marrow donor, but none could be found.

At the time, doctors at Duke were just learning how to use the blood transplant and figuring out who it would best work for, said Dr. Joanne Kurtzberg, director of the Stem Cell Program at Duke.

Only 14 percent of donor units have enough cells to treat an adult, Kurtzberg said. Chemotherapy and radiation kill bone marrow, which allows the new stem cells to work.

“The transplant actually rescues the bone marrow after the therapy kills it,” Kurtzberg said.

After seven weeks in the hospital, Searls went home. A month later, she was off all medication and has stayed that way.

“I would have died if I had not had the stem cells – the cord blood stem cells,” Searls said.

Searls now works at Carolina's Cord Blood Bank – the source of her cure.

“She really is an example that cord blood can help adults,” Kurtzberg said.

Besides treating blood diseases, doctors have learned that stem cells from umbilical cord blood also help repair tissue damage in several organs like the heart. Researchers are trying to better understand how that happens.