May 21, 2007 -- For the more than 13 million women in the U.S. who suffer from stress urinary incontinence, stem cells derived from their own muscle cells may improve the condition, a study shows.
"Five of eight women got a modest degree of improvement, and one woman was dry," says Michael Chancellor, MD, a urologist at the University of Pittsburgh.
Chancellor presented the results of a study at the 2007 annual meeting of the American Urological Association in Anaheim, Calif.
At the same meeting, other researchers reported their efforts in obtaining stem cells from the body's fat tissue, from urine, and from human cord blood to treat urinary problems.
Stress incontinence is more common in women than in men. An involuntary loss of urine occurs when a person coughs, sneezes, or laughs.
Muscle Stem Cell Study
Chancellor's research focuses on adult stem cells, a type of undifferentiated cell found throughout the human body that can be extracted and then coaxed in the laboratory into becoming different types of cells.
"For the past 10 years, we have been working on muscle-cell-derived stem cells," Chancellor says. The process begins, he says, by taking a small muscle biopsy, then isolating the stem cells. Next, they are grown in a culture and then implanted back into the patient who supplied them to strengthen the weakened sphincter.
"Our average follow-up was a year and a half," he says. "More than half started reporting improvement after three months. Improvement kept getting better for 10 months."
The average follow-up time, he says, was a year and a half. "This was just a safety study," Chancellor says, noting that the study is preliminary. The study was done in cooperation with the University of Toronto and was a clinical trial approved by Health Canada.
Another treatment option is sorely needed, Chancellor says, for stress urinary incontinence. Currently, doctors suggest women with the condition perform pelvic floor exercises (Kegels) to strengthen the pelvic floor muscles, biofeedback to retrain the muscles, or offer them surgery, if the condition is severe or interferes with daily activities.
In one surgery, for instance, a mesh-like tape is inserted as a kind of sling for the urethra, to support it and hold it in place so more normal function returns.
Fat Cells Might Work, Too
A woman's fat cells may provide another treatment option someday, says Tom Lue, MD, a University of California San Francisco urologist. Using fat to strengthen sphincter muscles is not new, he says. But using stem cells from fat is.
"As far back as 1994, a study was published talking about using fat [injections] for sphincter incontinence," he says. "But using the fat cells [themselves], they die. But using stem cells, they survive much better."
In his study of the concept in animals, his team harvested fat tissue, processed it to retrieve the stem cells, and then injected it back into the animals. A comparison group only got a buffered solution; the treatment group received both the fat stem cells and the buffered solution.
He found that the stem cells became muscle tissue as well as blood vessel and fat tissues. And by using a person's own stem cells, Lue says, "we bypass immunology problems and ethical concerns."
Stem Cells From Urine, Cord Blood
While tissue biopsy is the most common way to obtain adult stem cells, another researcher reported that he isolated them from human urine. Anthony Atala, MD, a researcher at Wake Forest University in Winston-Salem, N.C., took urine samples from nine men and isolated and expanded the cells. He implanted them in mice and found they maintained their cellular characteristics. That suggests urine may someday be a valuable additional source for stem cells to help urinary problems.
Yet another research team is looking at human cord blood as a source of stem cells that might help urinary incontinence. In a study done in South Korea, Chester Koh, MD, a researcher at the University of Southern California, Los Angeles, and his colleagues injected human cord blood stem cells into 39 women with stress urinary incontinence.
After one month, 80% of the women reported a 50% or greater improvement in quality of life.
Estimated Time Line
As promising as some of the research to help stress urinary incontinence sounds, the studies are in "extremely early" stages, Roger Dmochowski, MD, the moderator of the press briefing on tissue engineering, tells WebMD.
When might the new treatments be available? "At the earliest, three years, more likely five to seven years," says Dmochowski, a urologist at Vanderbilt University in Nashville, Tenn., and the president of the Society for Female Urology and Urodynamics.