Stem Cells To The Rescue?

Doctors said Wednesday they are attempting an experimental procedure to heal a teenage patient's heart by infusing it with the boy's own blood stem cells. It could take months to know whether it works, but doctors say they are already seeing encouraging results.

Doctors at William Beaumont Hospital in Michigan said the procedure on 16-year-old Dmitri Bonnville is believed to be the first of its kind.

Animal studies have shown that stem cells - the body's building blocks for all types of tissue - can be injected to grow new muscle and blood vessels, and researchers have expressed hope that the research could eventually help repair human hearts and other tissue.

As CBS News Correspondent Elizabeth Kaledin reports, at the time his case came in, Dr. Cindy Grines was in the midst of researching the use of adult blood stem cells to repair the damage from heart attacks.

"We didn't think he had much hope," says Grines.

"The hope is that these stem cells are going to go to the heart muscle and actually not only turn into heart muscle cells, which will allow the heart to contract and pump more efficiently, but also they have the potential to develop new blood vessels," said Grines.

Bonnville was working on a house remodeling project Feb. 1 when a co-worker playing with a nail gun fired a 3-inch nail into his chest. That co-worker is facing criminal charges. According to the Detroit Free Press, the co-worker asked Bonnville "Do you want to see what it's like to be shot?" and pulled the trigger.

Doctors removed the nail and patched the hole, but Bonnville soon suffered a heart attack that caused serious tissue death, severely reducing his heart's pumping efficiency.

On Feb. 17, doctors began giving Bonnville a drug to stimulate his bone marrow to make more blood stem cells - a type that does not carry the ethical questions raised regarding embryonic stem cells. A few days later, they harvested the cells and injected them into an artery that supplies blood to the heart.

The boy's heart's efficiency had increased within a few days, said Grines.

Stem cell researchers not involved in the experiment said they knew of no similar research in humans. There already is some evidence, however, that stimulating stem cell production alone can cause tissue regeneration, without having to inject cells into a particular area.

"I think it's extremely hopeful," said Dr. Neil D. Theise, a stem cell researcher at Beth Israel Medical Center in New York.

"We didn't think there was a considerable downside considering that we were taking the stem cells from his own blood stream and re-administering them back into his own heart," Dr. Steven Timmis told Kaledin.

Unlike tissue and bone, the heart is unable to repair itself, so research into using stem cells to do the job is proceeding at a furious pace.

"This could revolutionize the way we treat heart attack patients in the future," says Timmis.

But even if Bonnville continues to improve, it may be hard to know whether the therapy worked, and if so, how it worked, said Dr. Sam Dudley, a cardiologist at Emory University in Atlanta also involved in stem cell research.

"I think this is a wonderful thing that they did," Dudley said. But he added that carefully conducted studies will be needed before stem cell therapy becomes standard.

"We have to go judiciously because we need to know a little bit more what we're doing," he said.

Experts say Dimitri's case is an exciting milestone, but remains highly experimental.

"Before this becomes a treatment for many more patients we really need to study this in clinical trials," says Dr. Bonow, President of the American Heart Association

Beaumont doctors hope to proceed to clinical trials of their technique, which they say is the boy's only alternative to a heart transplant.

"We plan to follow him every couple of months with tests to look at the function of the heart muscle," said Grines.

The heart should be able to continue repairing itself for about three months, said Dr. William O'Neill, Beaumont's chief of cardiology. By then, it should be clear how much good the treatment did.