Will Stem Cell Retinal Transplants Cause Blindness (in critics)?
A clinical study involving stem cell retinal transplants as a potential cure for blindness has made the news lately with cautious optimism regarding whether or not it will actually lead to a cure for some forms of blindness. However, what may be just as significant as a cure is the effect it may have on critics opposed to stem cell research. Read on to discover why a success in a stem cell retinal transplant study may cause blindness of another type in people who do not want to see the future of medicine.
Since the very first days following the birth of Dolly the cloned sheep, stem cell research has raised more scientific and political debate than Roe v. Wade and the teaching of evolution in schools combined. And for good reason. All three are interrelated in the question of how we define ourselves physiologically, evolutionarily and spiritually.
The promise of stem cell research is that it may hold cures for the presently incurable. For genetic conditions that give us a silent prayer of, “There but for the grace of God and statistics, there go I.”
Opponents of stem cell research, however, carry a suspicion of such promises. They believe that aside from a moral and ethical slippery slope stem cell research may hold for us, their primary opposition is that stem cell research may involve the destruction of a potential life to save an existing life.
From lists possessing arguments against stem cell research, the argument that stem cell research violates the sanctity of human life (and that to take a life to save a life is no moral argument) is typically the number one argument on the list.
Fair enough…for now. But what of the other arguments against stem cell research? In particular, the second most common argument?
The second most common argument is that presently, no human being has ever been cured of a disease using embryonic stem cells; and, that adult stem cells hold as much if not more promise than embryonic stem cells. The argument of whether adult stem cells are better or more informative, and thereby dismisses the need for embryonic stem cell research, is an area where even scientists do not totally agree on.
However, the part of the argument that no one has ever been cured of a disease using embryonic stem cells reveals a chink in an important argument. What if someone becomes cured? What then? According to a press release issued by Advanced Cell Technology, Inc. a biotech company that specializes in regenerative medicine, they may have found a first cure.
In a paper to be published in the medical journal The Lancet, ACT researchers report their success in a clinical trial that demonstrates the safety of their human embryonic stem cell (hESC)-derived retinal pigment epithelium (RPE) cells for the treatment of blindness due to Stargardt’s macular dystrophy and dry age-related macular degeneration. Stargardt's disease is one of the main causes of blindness in young people, whereas dry age-related macular degeneration is the leading cause of blindness in the elderly.
The treatment involved taking healthy immature cells from a human embryo, which were then induced to develop into healthy retinal cells that were then injected into the test subjects’ diseased eyes.
After four months following treatment, no adverse effects such as abnormal growth or tissue rejection were observed in either of the study’s patients. The greatest concern was that the stem cells due to their ability to differentiate into other cell types would do so and become a tumor or some other unwanted structure. Results reported indicate that stem cell differentiation was well controlled in these patients and that no adverse safety signals were detected.
Reason for cautious optimism lies not only in the lack of any adverse effects, but also that structural evidence confirmed that the human embryonic stem cells survived and continued to thrive. Both patients have stated that their vision has already improved some, and vision tests show that measurable improvements in their vision have persisted for more than four months.
“It has been over a decade since the discovery of human embryonic stem cells,” says Robert Lanza, M.D., chief scientific officer of ACT, and co-senior author of the paper. “This is the first report of hESC-derived cells transplanted into patients, and the safety and engraftment data to date look very encouraging. Although several new drugs are available for the treatment of the wet type of AMD, no proven treatments currently exist for either dry AMD or Stargardt’s disease. Despite the progressive nature of these conditions, the vision of both patients appears to have improved after transplantation of the cells, even at the lowest dosage. This is particularly important, since the ultimate goal of this therapy will be to treat patients earlier in the course of the disease where more significant results might potentially be expected,” says Dr. Lanza.
With this success, future clinical trials are in the planning stages for determining the smallest therapeutic dose of embryonic stem cells to inject into patients, as well as additional studies toward treating Stargardt's disease using human embryonic stem cell (hESC)-derived retinal pigment epithelium (RPE) cells in curing blindness.
While it will be at least a few years before their embryonic stem cell treatment will be considered a qualified success in curing some forms of blindness, it will be interesting to note whether critics may turn a blind eye to the success and continue to argue against the validity of stem cell research based on the argument that no one has been cured of a disease owing to research using embryonic stem cells. If so, it may not matter. What does matter is that now that we know it can be done, others may pay attention and have a change of opinion about stem cell research.
Source of image: Courtesy of Wikipedia
Reference: The Lancet, Jan. 2012 “Embryonic stem cell trials for macular degeneration: a preliminary report”; Steven D Schwartz, Jean-Pierre Hubschman, Gad Heilwell, Valentina Franco-Cardenas, Carolyn K Pan, Rosaleen M Ostrick, Edmund Mickunas, Roger Gay, Irina Klimanskaya, Robert Lanza