Research with adult stem cells surpassing embryonic type

NEW YORK — A few months ago, Dr. Thomas Einhorn was treating a patient with a broken ankle that wouldn't heal, even with multiple surgeries. So he sought help from the man's own body.

Einhorn drew bone marrow from the man's pelvic bone with a needle, condensed it to about four teaspoons of rich red liquid, and injected that into his ankle.

Four months later, the ankle had healed. Einhorn, chairman of orthopedic surgery at Boston University Medical Center, credits "adult" stem cells in the marrow injection. He tried it because of published research from France.

Einhorn's experience isn't a rigorous study. But it's an example of many innovative therapies doctors are studying with adult stem cells. Those are stem cells typically taken from bone marrow and blood — not embryos.

For all the emotional debate that began about a decade ago on allowing the use of embryonic stem cells, it's adult stem cells that are in human testing today. An extensive review of stem cell projects and interviews with two dozen experts reveal a wide range of potential treatments.

Adult stem cells are being studied in people who suffer from multiple sclerosis, heart attacks and diabetes. Early results suggest stem cells can help some patients avoid leg amputation. Recently, researchers reported that they restored vision to patients whose eyes had been damaged by chemicals.

Apart from these efforts, transplants of adult stem cells have become a standard lifesaving therapy for perhaps hundreds of thousands of people with leukemia, lymphoma and other blood diseases.

"That's really one of the great success stories of stem cell biology that gives us all hope," said Dr. David Scadden of Harvard, who notes stem cells also are used to grow skin grafts.

"If we can re-create that success in other tissues, what can we possibly imagine for other people?"

Embryonic cells await

That sort of promise has long been held out for embryonic stem cells, which were first isolated and grown in a lab dish in 1998. Controversy over their use surrounded the 2001 decision by former President George W. Bush to allow only restricted federal funding for studying them.

Proponents over the past decade have included former first lady Nancy Reagan and actors Michael J. Fox and the late Christopher Reeve. Opponents object that human embryos have to be destroyed to harvest the cells.

Embryonic cells may indeed be used someday to grow replacement tissue or therapeutic material for diseases such as Parkinson's or diabetes. On Friday, a biotech company said it was going ahead with an initial safety study in spinal-cord injury patients. Another is planning an initial study in eye disease patients this year.

In the near term, embryonic stem cells are more likely to pay off as lab tools, for learning about the roots of disease and screening potential drugs.

Observers say they're not surprised at the pace of progress.

As medical research goes, the 10 years or so since the embryonic cells were discovered "is actually a very short amount of time," said Amy Rick, immediate past president of the Coalition for the Advancement of Medical Research. The group has pushed for embryonic stem cell research for about that long.

Hank Greely, a Stanford University law professor who works in bioethics and has followed stem cells since the 1990s, said: "Give it another five years, and I'll be surprised if we don't have some substantial progress" beyond initial safety studies.

The Pro-Life Secretariat of the U.S. Conference of Catholic Bishops continues to oppose embryonic work. Deirdre McQuade, an official there, said that compared to adult stem cell research, work on embryonic cells is proving "fruitless."

More diseases studied

Adult cells have been transplanted routinely for decades, first in bone marrow transplants and then in procedures that transfer just the cells. Doctors recover the cells from the marrow or bloodstream of a patient or a donor, and infuse them as part of the treatment for leukemia, lymphoma and other blood diseases. Tens of thousands of people are saved each year by such procedures, experts say.

It is harnessing these cells for other diseases that has encouraged many scientists lately.

In June, for example, researchers reported they had restored vision to people whose eyes had been damaged by caustic chemicals. Stem cells from each patient's healthy eye were grown and multiplied in the lab and transplanted into the damaged eye, where they grew into healthy corneal tissue.

A couple of months earlier, the Vatican announced it was funding adult stem cell research on the intestine at the University of Maryland. And on Friday, Italian doctors said they had transplanted two windpipes injected with the recipients' own stem cells.

These developments only hint at what's being explored in experiments across the United States.

Much of the work is early, and even as experts speak of its promise, they ask for patience and warn against clinics that aggressively market stem cell cures without scientific backing.

Some of the new approaches, like the long-proven treatments, are based on the idea that stem cells can turn into other cells. Einhorn said the ankle-repair technique, for example, apparently works because of cells that turn into bone and blood vessels. But for other uses, scientists say, they're harnessing the apparent abilities of adult stem cells to stimulate tissue repair or to suppress the immune system.

"That gives adult stem cells really a very interesting and potent quality that embryonic stem cells don't have," said Rocky Tuan of the University of Pittsburgh.

Helping ailing hearts

One major focus of adult stem cell work for about a decade has been the ailing heart. While researchers remain committed, much of the early enthusiasm from patients, doctors and investors has slacked off because results so far have not matched expectations, said Dr. Warren Sherman of Columbia University.

"Everyone, including myself, is impatient and would like to see positive results appear quickly," said Sherman, who hosts an annual international meeting of researchers. But he called for patience.

In treating heart attack, for example, studies show stem cell injections help the heart pump blood a bit better, Sherman said. The research has not yet established whether injections cut the risk of death, more heart attacks or future hospitalizations, he said.

Sherman hopes a large study of those patient outcomes can be done in the next couple of years, and he's "very optimistic that patients will benefit."

Similarly, in heart failure, research indicates stem cells can ease symptoms, but larger studies are needed to show how much good the treatments provide, he said. The doctor noted that current studies are testing stem cells taken not only from bone marrow and leg muscle, but from fat.

Another heart-related condition under study is critical limb ischemia, where blood flow to the leg is so restricted by artery blockage that it causes pain and may require amputation. The goal is to encourage the growth of new blood vessels by injecting stem cells into the leg.

Sherman said limb ischemia research is moving fast and the results "are very, very encouraging."

The injected cells may serve as building blocks while stimulating local tissue to grow the vessels, said Dr. Douglas Losordo of Northwestern University. His own preliminary work suggests such a treatment can reduce amputation rates.

Dr. Gabriel Lasala of TCA Cellular Therapy also has reported positive preliminary results. One success is Rodney Schoenhardt of Metairie, La.

Schoenhardt had undergone surgery on both legs for the disease, and his surgeon was talking about amputating his left leg. Schoenhardt suffered so much pain in his left leg while standing that he used a wheelchair instead.

For Lasala's research, Schoenhardt got 40 shots in each leg about 18 months ago, with stem cells going into his left calf and a placebo dose into the other. Soon, he said, the pain in his left leg was gone.

Schoenhardt, 58, now mows his lawn, and he remodeled his living room to fix damage from Hurricane Katrina.

"My wheelchair is in my garage, collecting dust," he said. "I'm even thinking about taking up a little tennis again."

With all the heart-related stem cell studies, the president of the American Heart Association said, "We should be enthusiastic, but cautiously so." Beyond the promising indications of early studies, researchers need definitive evidence that the treatments not only make patients better but also don't cause unintended harm, said Dr. Clyde Yancy.

Among other diseases being studied for stem cell treatments are multiple sclerosis, Type 1 diabetes and cancers such as melanoma and kidney cancer.

Avoid 'snake oil'

Scientists are making progress in testing stem cells to treat a variety of diseases, but they're warning about clinics that push unproven treatments.

There are clinics 'selling snake oil' all over the world, warns Sean Morrison, a stem cell expert at the University of Michigan.

The International Society for Stem Cell Research says it's concerned about aggressive marketing of treatments by clinics that may not have safeguards to ensure safety or likely benefit.

In June, the society introduced a website • closerlookatstemcells.org • for people interested in such clinics. It has attracted more than 10,000 hits.

The website offers background information on stem cell research and suggests questions to ask at a particular clinic, such as:

• What is the scientific evidence that this new procedure could work for my disease or condition• Where is this published?

• Is there any independent oversight or accreditation of the clinic where the treatment will be done and the facility where the cells are processed?

• What are the risks of the procedure and the possible side effects, both immediate and long-term?

The website also invites readers to submit the names of clinics, which the society then will contact for specific information as it builds a public list of facilities. The list will reveal whether these clinics provided evidence of appropriate oversight and patient protections.

At a U.S. government website • clinicaltrials.gov • patients and families can search for formal treatment studies all over the world that are aimed at particular diseases.