Wednesday, October 1, 2014

The promise of stem cell therapies is closer to reality

Edgar Irastorza was just 31 when his heart stopped beating in October 2008.

A Miami property manager, break-dancer and former high school wrestler, Irastorza had recently gained weight as his wife’s third pregnancy progressed.

“I kind of got pregnant, too,” he said.

During a workout one day, he felt short of breath and insisted that friends rush him to the hospital. Minutes later, his pulse flatlined.

He survived the heart attack, but the scar tissue that resulted cut his heart’s pumping ability by a third. He couldn’t pick up his children. He couldn’t dance. He fell asleep every night wondering if he would wake up in the morning.

Desperation motivated Irastorza to volunteer for a highly unusual medical research trial: getting stem cells injected directly into his heart.

“I just trusted my doctors and the science behind it, and said, ‘This is my only chance,’ ” he said recently.

Over the last five years, by studying stem cells in lab dishes, test animals and intrepid patients like Irastorza, researchers have brought the vague, grandiose promises of stem cell therapies closer to reality.

Stem cells broke into the public consciousness in the early 1990s, alluring for their potential to help the body beat back diseases of degeneration like Alzheimer’s, and to grow new parts to treat conditions like spinal cord injuries.

Progress has been slow. But researchers have been learning how to best use stem cells, what types to use and how to deliver them to the body — findings that are not singularly transformational, but progressive and pragmatic.

As many as 4,500 clinical trials involving stem cells are underway in the United States to treat patients with heart disease, blindness, Parkinson’s, HIV, diabetes, blood cancers and spinal cord injuries, among other conditions.

Initial studies suggest that stem cell therapy can be delivered safely, said Dr. Ellen Feigal, senior vice president of research and development at the California Institute of Regenerative Medicine, the state stem cell agency, which has awarded more than $2 billion toward stem cell research since 2006 and is enrolling patients in 10 clinical trials this year.

But enthusiasm for stem cells sometimes outstrips the science. When Gov. Rick Perry of Texas had adult stem cells injected into his spine in 2011 for a back injury, his surgeon had never tried the procedure and had no data to support the experiment.

A June review in The New England Journal of Medicine found that “platelet-rich plasma” stem cell therapies praised by a number of athletes worked no better than placebos.

Such public chatter may imply that stem cell research is further advanced than it is, said Dr. Charles Murry, a co-director of the Institute for Stem Cell and Regenerative Medicine at the University of Washington.

Slick websites advertising stem cell therapies leave the impression that such treatments are ready to use and that “the only problem is the evil physicians and government, who want to separate people from lifesaving therapies,” said Murry, a cardiovascular pathologist. “Almost every one of these places are charlatans.”

In fact, very few therapies beyond bone marrow transplants have been shown to be effective, he said.

And still to be determined is the most cost-effective way to deliver stem cells.

Scientists presumed, for instance, that a patient’s heart would repair itself better when injected with its own stem cells. But the study that Irastorza volunteered for at the University of Miami showed that patients fared just as well with someone else’s stem cells, and their bodies did not mount an immune attack against the cells.

If supported by further studies, this means that future patients won’t need immune suppressants, and that stem cells can be made in large batches — and therefore more cheaply.

Treatment for Irastorza, who received his own cells, began with the withdrawing of some of his bone marrow. Researchers took adult cells believed to be stem cells from the marrow and then inserted them through a catheter directly into Irastorza’s heart.

About a third of his left ventricle had been destroyed by his heart attack, which was attributed to a hereditary cholesterol problem. It’s impossible to know for sure whether the bone marrow cells’ descendants became heart muscle cells or if repairs were spurred some other way, but today, his doctors tell him his heart is one third of the way back to normal.

It’s enough, Irastorza said, to allow him to dance again and to be the kind of father he wants to be: “My quality of life is like night and day to before the treatment.”

No comments: