Remarkable Progress Shown in Umbilical Cord Stem Cell Research

By Liz Townsend

Researchers around the world are reporting remarkable success in using umbilical cord stem cells to treat conditions as varied as spinal cord injury and leukemia.

With umbilical cord stem cell treatment, scientists in South Korea repaired the damaged spine of a 37-year-old woman who had been paralyzed for 20 years, Agence France-Presse (AFP) reported. Hwang Mi-Soon took a few steps at a November press conference to show her progress.

"This is already a miracle for me," Hwang told reporters, according to AFP. "I never dreamed of getting to my feet again."

Umbilical cord stem cells are derived without harming a person, unlike embryonic stem cells, which are extracted by killing a tiny human being. This case, the first known success using umbilical cord cells for spinal injury, needs to be further studied and replicated to confirm the results, researchers say.

"It is just one case and we need more experiments, more data," said researcher Oh Il-Hoon at the press conference, according to AFP. "I believe experts in other countries have been conducting similar experiments and accumulating data before making the results public."

Two studies published in the November 25 issue of the New England Journal of Medicine confirm that umbilical cord stem cells are very effective in treating leukemia. Leukemia patients are treated with chemotherapy or radiation that kills their diseased bone marrow cells, which then need to be replaced.

The most effective way to replace these cells is by a bone marrow transplant from a sibling. However, 80% of patients are not able to find such a match, according to the Cleveland Plain Dealer. These patients usually go on a list to find a compatible unrelated donor, which can take a very long time.

However, more doctors are now turning to umbilical cord cells.

The studies compared survival rates for patients who received different types of cell replacements. A European group studied 682 adults over a two-year period. They found a 42% overall survival rate with matched bone marrow, compared with 36% with cord blood, the Milwaukee Journal Sentinel reported.

In a U.S. study of 600 patients, the three-year overall survival rate was 20% with mismatched marrow, 26% with mismatched cord blood, and 35% with matched marrow, according to the Journal Sentinel.

"You might say that's a lousy number," Dr. Mary Laughlin, a blood cancer specialist at University Hospitals of Cleveland and one of the study's authors, told the Plain Dealer. "But it isn't a lousy number because the patients undergoing this procedure face 100 percent mortality without it."

The density of cells found in cord blood is much less than that in bone marrow, so doctors usually reserve the treatment for children. These studies were especially important because they showed that cord blood is effective even for adults. The study results may encourage doctors to use cord blood in adults as well as children.

Officials at facilities that do not use umbilical cord cells on adults now, such as the University of Wisconsin Hospital and Clinics in Madison, are rethinking their policies. "I think these [studies] are going to change our approach," Walter Longo, director of the adult bone marrow transplant program, told the Journal Sentinel. "It's very promising."

Further work still needs to be done to perfect the process of using umbilical cord cells for treatment. "Technical difficulties exist in isolating stem cells from frozen umbilical cord blood, finding cells with genes matching those of the recipient and selecting the right place of the body to deliver the cells," Han Hoon, president of a government-backed umbilical cord blood bank in Seoul, told AFP.

But despite the challenges ahead, stem cells derived from umbilical cords and other non-lethal sources have shown concrete results and more potential than the still-theoretical treatments promised by embryonic stem-cell proponents.

"These stem cells isolated from umbilical cord blood have emerged as an ethical and safe alternative to embryonic stem cells," AFP reported.