When Robert Ramirez was diagnosed with Parkinson's disease in 2006, his doctor gave him medication, but little hope: "He told me there wasn't much I could do except wait to 'pass to the other side.'"
Ramirez, a Peruvian-American mechanic in northern New Jersey, watched helplessly as his symptoms worsened. His left arm grew weak. His leg muscles went rigid. His trembling intensified.
Then his wife, Elvira, saw Jorge Tuma on a Peruvian news show. The Peruvian doctor, based in Lima, claimed to be treating Parkinson's and other diseases with injections of stem cells. They checked out his Web site: For $6,000, relief could be theirs. They booked a flight to Lima.
Ramirez is one of an increasing number of patients seeking stem cell therapies overseas—experts put the number in the thousands. And Tuma is one of dozens of non-U.S. doctors offering such treatments.
The trend is significant enough that the International Society for Stem Cell Research (ISSCR) released guidelines today for doctors using stem cells and would-be "stem cell tourists."
U.S. experts fear that some foreign doctors are rashly treating patients without waiting for clinical trials to validate the safety of their procedures.
"There are many doctors tapping into the public's sense of stem cells' potential to cure in countries with looser medical regulations," said Sean Morrison, director of the University of Michigan Center for Stem Cell Biology, and treasurer of ISSCR. "But the details of stem cell treatment are much more complicated."
Yet stem cell therapies are becoming a lucrative area of medical tourism, even though science has yet to divine their potential and controversy plagues the field.
The cells, found in embryos and certain adult body tissues, have the potential to grow into many different types of cells. But ethical issues surrounding the use of embryos as stem cell sources has slowed research in countries such as the U.S. and U.K.
Researchers in the U.S. are conducting clinical trials using both adult and embryonic stem cells to treat diseases, but the U.S. Food and Drug Administration has yet to license any such treatment.
The new ISSCR guidelines require that every treatment must be evaluated by experts with no vested interest in the procedure. The guidelines also advocate for an informed consent process, which would provide patients with full information about their procedure, and transparency in reporting of clinical trial results.
The ISSCR's handbook for patients advises against experimental stem cell treatments—those that are not part of official clinical trials. It also lists warning signs for dubious treatments, such as the claim that multiple diseases can be treated with the same type of cell.
That's just one of many optimistic assertions being made by foreign doctors, often on Web sites.
Timothy Caulfield at the University of Alberta's Health Law Institute surveyed 19 sites proffering stem cell treatments, and released his findings today. Ten sites portrayed the treatments as "very ready for public access," rather than experimental.
Most people learn about stem cell treatment offerings from "direct-to-consumer advertising" on the Internet, he said.
"There is a mismatch between what is being offered and what the existing scientific literature says," Caulfield said. "The people offering the treatments are able to trade on two things: the genuine excitement about stem cell research and the social controversy around it."
Clinics charge on average U.S. $21,500 for stem cell treatment, the survey noted, but recent news reports indicate that clinics in China may be charging as much as $70,000.
Researchers have found that unproven stem cell treatments can also cause complications for patients. In 2006, neurologist Bruce Dobkin, of the University of California, Los Angeles, found that some patients contracted meningitis after operations for chronic spinal cord injuries.
Nervous system complications and infections have also been reported after the use of stem cells to treat blood diseases.
Caulfield said that not all doctors offering stem cell therapy are quacks, but he also believes that anyone selling treatment should be publishing data to back up their claims.
"There are still real scientific barriers to this research—even the top stem cell researchers at Stanford University and in the United Kingdom are struggling with clinical trials," Caulfield said.
In the Trenches
Tuma, the cardiologist sought out by Ramirez, the Parkinson's patient, promises to restore ailing organs and tissues using adult stem cells harvested from the patients' own bodies.
Since 2005, Tuma has treated some 600 patients—about a quarter from outside Peru—for a range of conditions from Parkinson's to Type 2 diabetes to emphysema.
His method: injecting the affected organ with stem cells from the patient's own bone marrow.
"I always tell my patients this is not a cure, but I believe it is a tremendous new alternative to improve quality of life," Tuma said.
He operated on Ramirez in October 2007 in a simple procedure lasting 45 minutes. Tuma extracted and prepared bone marrow cells from Ramirez's spine and injected them into an artery in the brain. There, Tuma said, they began to generate new cells that would inhibit the advance of Parkinson's.
Within a week, Ramirez said he began to notice his legs loosen. Then some strength returned to his left arm. He feels better than before the operation and his symptoms are less discernible.
"I can dance with my wife and live almost a normal life," Ramirez said. "I'm very grateful to Dr. Tuma."
Like many doctors offering stem cell treatments, Tuma's approach has not been sanctioned by his country's government.
Though he's published small-scale results of his heart therapies in journals including the Journal of Cardiac Failure and Cardiovascular Revascularization Medicine, he's yet to release papers on the efficacy of his other treatments.
According to Insoo Hyun, a professor of bioethics at Case Western Reserve University and the chairman of the ISSCR Stem Cell Guidelines Task Force, charging patients for unproven treatments is considered unethical.
"Either you're doing research or you're offering a proven therapy, but some of these stem cell doctors seem to want it both ways," Hyun said.
No Time to Wait
Timothy Henry, a cardiologist at the Minneapolis Heart Institute/Abbott Northwestern Hospital, is authorized by the FDA to conduct randomized clinical trials using adult stem cells for heart conditions. He has treated 150 people and said the early data are promising.
But the United States has lagged behind the rest of the world in stem cell research because of the ethical concerns raised over embryonic stem cell research, he admits.
"Adult stem cell research has been very challenging with all the misinformation and confusion about embryonic stem cells," Henry said.
Desperate patients like Ramirez are reluctant to wait on hard evidence and FDA approval, however.
Roberto Brenes is another doctor performing adult stem cell implants. He attracts patients to a clinic in San Jose, Costa Rica, through the Web site cellmedicine.com.
He and his colleagues have treated between 50 and 70 multiple sclerosis patients with stem cells taken from fat tissue, charging between $15,000 and $25,000, with what he said are "pretty good success rates."
While Brenes acknowledges that there has never been a clinical trial demonstrating the efficacy of stem cell therapy for MS, he said many patients do not want to wait.
"This area is going to progress a lot in the next ten to 15 years, but a lot of patients need therapeutic help now and want to go through with the procedure," Brenes said.
Even if it means expensive follow-up visits: Tuma has told Ramirez to see him every six months so that he can check on his progress. And Tuma said that if the Parkinson's symptoms return, another procedure might be needed.
"I know the therapy is not a complete cure, but I don't think it's dangerous and would do it again," Ramirez said.
The ISSCR's Morrison, however, remains skeptical.
"A lot of patients will spend $6,000 to buy hope, but that still doesn't make it right to sell snake oil."
Posts
No comments:
Post a Comment