The problem- stem cell therapy works- we think. The problem- we still can’t do the proper research. The problem- physicians are using it on patients anyway.
One doc reads a paper that says you can take stem cells from bone marrow and repair recalcitrant ankles. So, he does it anyway- and it works. Was he lucky or does the data substantiate same?
We are now performing initial studies using adult stem cells (as reported here, among other places) to treat diabetes, multiple sclerosis, cardiac impairment, Parkinson’s disease, vision impairment, leukemia, lymphoma- you name it.
One of the more promising routes of research is to use the patient’s own stem cells. Just like many patients now bank their own blood before undergoing an operation to insure that there are no reactions, using one’s own stem cells obviates many problems.
A group of researchers from Columbia University performed thigh replacement therapy in rabbits using thighs developed from the rabbit’s own stem cells. This is exactly the same process that would be used to replace a hip grown from your own stem cells (this study is called a “proof of concept”). However, this hip replacement would be useful for younger patients (who have more time for the artificial hip to grow and mature, to be ready for replacement).
Some two decades ago, embryonic stem cells were the rage. But, then President Bush put the kibosh on that promising avenue. And, even though President Obama loosened the strictures, we seem to be restricting the use of embryonic stem cells to determine disease progression or to screen potential drugs to treat diseases.
We’ve been using bone marrow for decades to treat leukemia and lymphoma. (Routine screenings are advertised almost everywhere seeking bone marrow donors.) Adult stem cells are known to suppress the immune system and to stimulate tissue repair. The patient’s bone marrow stem cells are irradiated (to kill them); it also leaves the cavity available for the stem cell transplant . The use of radiation is what one hopes would not be associated with other stem cell therapies; this would ameliorate patient harm and shorten the recuperation processes.
But even as we proceed with these developments, the principle of caveat emptor (assuming you are the patient) must prevail. For example, a group of researchers recently injected stem cells into a patient’s kidney, hoping they would regenerate into viable kidney cells. Instead, tissue damage resulted and the patient died from infection. This happened in spite of research that demonstrated injected stem cells directly into organs (including the kidney) should be a safe process.
In other words, there is still a large gap between our comprehension of scientific principles clinical outcomes.