In my visits to the many MS Internet forums, the topic of stem cells, and their potential use to help MS patients, seems to create more confusion than almost any other. CCSVI ( click here for info ) is the hot topic of the day, and there are indeed many misconceptions flying around about CCSVI as well. But CCSVI has generated so much discussion that many patients are reasonably well-versed on the basics of the idea. When it comes to stem cells, though, there seems to be an air of mystery and controversy about them that continues to obscure the issue.
I'm not going to discuss embryonic stem cell research here, simply because the use of such cells in any therapeutic manner is still many years off. Surely, the debate over embryonic stem cells stirs passions on both sides, but I'd like to focus here on stem cell therapies that are currently, or will soon be, available to MS patients, all of which entail the use of adult or umbilical cord stem cells, the application of which circumvents any arguments over the meaning of "life".
There are currently two very different approaches to using stem cells to treat MS, both of which are currently or will soon be undergoing human trials. One approach uses stem cells to reboot a patient's immune system, and the other uses the cells in an attempt to directly repair the damage done the central nervous system by the MS disease process. These two approaches are vastly different, and it's extremely important for patients to make the distinction between the two.
The approach that tries to reboot the immune system (often called autologous hematopoietic stem cell therapy, or HSCT) uses very powerful chemotherapy drugs to completely destroy the patient's immune system. Once the immune system is entirely ablated, mesenchymal stem cells, derived from the patient's bone marrow (which had been harvested previous to wiping out the immune system), are intravenously infused back into the patient, in the expectation that they will rebuild a new immune system that is free of the "defects" that previously lead it to attack the patient's CNS. This approach largely assumes that MS is primarily an autoimmune disease, and that by giving the patient a new immune system, their MS will be eradicated.
This therapy has been tested for over a decade, and has proven to be most effective in patients with aggressive early-stage disease. When HSCT was first attempted, there was a high rate of patient mortality (about 10%) due to the toxic combination of chemotherapy drugs being used. Since then, the process has been refined, and patient mortality, while still a concern, is not as big an issue. Periodically, news stories circulate about patients whose conditions have apparently been greatly improved by this process ( click here for article ).
There is also a process known as HyCy (also known as Revimmune) that is similar in approach but does not require the transplantation of stem cells. Instead, the patient's resident stem cells are protected during the immune ablation process, and then stimulated through the use of drugs to reconstitute the patient's immune system. Again, this approach has been shown to be effective in RRMS patients, but less so in patients suffering from the progressive forms of the disease ( click here for article ).
There has been an increasing body of research (most of which has involved the postmortem examination of the CNS lesions of deceased MS patients, the "freshest" of these lesions showing no signs of immune cell involvement) that appears to demonstrate that the immune response seen in MS is secondary to some other process (Infectious?, Genetic?, Vascular?, Toxic?) that attacks the CNS, to which the immune system then responds ( click here for article ). In other words, "autoimmunity" is looking more and more to be a symptom than a cause of MS, and this calls into question the long-term efficacy of approaches that "reboot" a patient's immune system, since the underlying cause of the disease remains unaddressed. Still, as stated above, this approach has seen its share of success.
Another, entirely different approach is to use stem cells to directly try to repair the damage that has been done to the CNS by whatever MS disease process is attacking it. In this approach, mesenchymal stem cells, which can be harvested from a patient's bone marrow or fat cells, are injected directly into the patient's spine (intrathecal injection) in the expectation that the cells will migrate to damaged areas of the CNS and effect repairs. There are also some clinics that use umbilical cord cells, often in combination with mesenchymal cells, in this same approach.
Often, mesenchymal cells are also given intravenously in an attempt to modulate the immune system of the patient undergoing therapy. These cells have been shown to have extreme anti-inflammatory properties, which can also be of benefit to MS patients.
There are several locations internationally that are attempting to use stem cells to repair the damaged central nervous systems of MS patients. I've been in contact with several patients who have traveled to Israel for this type of therapy, where the protocol involves extracting stem cells from the patient's bone marrow, multiplying the cells over the course of several months, and then injecting the cells back into the patients, primarily intrathecally, but also sometimes intravenously. The actual transplant of the cells is usually done in Greece, since the procedure is not yet approved in Israel. The patients I've corresponded with have generally told me that the results of this therapy can range from extremely subtle to fairly dramatic, but that the benefits seem to level off and often recede after six or eight months.
This regression make sense, because even though the stem cells seem to be effective at repairing damaged CNS tissues (axons, neurons, and oligodendrocytes), the MS disease process is left unaltered, and the disease eventually once again does damage to the repaired cells. As long as they MS disease process remains a puzzle, this approach would require multiple applications over the course of months and years to keep a patient stable.
The Cleveland Clinic is preparing to start a small, 24 person human trial using mesenchymal cells to repair damaged nerve tissue. The trial is supposed to start sometime later this year ( click here for info ).
In England, a physician named Dr. Neil Scolding has been conducting a 20 person trial, the results of which are encouraging, but not miraculous ( click here for info ). Prof. Scolding reports that his patients, who received intravenous infusions of their own mesenchymal stem cells, experienced an approximate 20% increase in nerve function. Although 20% might not seem like much, restoring nerve function to damaged cells in the CNS has long been a holy grail of medical research, so these results are tremendously significant.
In addition, clinics in Costa Rica, Panama, Mexico, China, and Germany also make variations of this procedure available to patients, at a price. Some of these operations are outright shams, while others seem to be serious endeavors, and some patients who have visited some of these clinics do report significant improvement in their condition. Unfortunately, all such accounts are strictly anecdotal, as none of these clinics has ever published their results in any scientifically valid matter.
There are also some clinics, based primarily in China or Russia, that claim to use embryonic stem cells as a treatment for MS. I would strongly urge all readers to not even remotely consider undergoing such treatment at this time. The use of embryonic cells can and has led to recipients developing fatal cancers, as the technology to control the action of embryonic cells has not yet been perfected.
A few months ago, I had a discussion with one of the higher-ups at the Myelin Repair Foundation (one of my favorite MS nonprofits- click here for website ), who told me that some of the research his organization is funding has shown that after migrating to areas of nervous system damage, stem cells apparently secrete a variety the of chemicals that trigger cell repair. In theory, this could lead to the isolation of these chemicals, which could then be synthesized and used to create compounds that would stimulate nervous system repair without the use of stem cells. Of course, the use of such breakthrough technology is still many years away.
My own feelings are that stem cells hold enormous promise in repairing damaged nervous system tissue (including myelin), but that researchers still have much to learn. In addition to experimental neuroregenerative drugs ( click here for info ), stem cells likely offer the greatest hope for patients seeking to regain function lost to Multiple Sclerosis.
Still, the most vital piece of the MS puzzle is to figure out just what it is that triggers nerve cell damage in the first place. This is one of the reasons why research into CCSVI is so important, because if vascular abnormalities significantly impeding the flow of blood through the CNS do indeed prove to be an underlying cause to the MS disease process, we might for the first time be able to stop that process, which would then allow stem cell repairs to be that much more effective. The dream of MS researchers is a one-two punch that would permanently stop the disease process in its tracks, and then repair the damage that that process has already done. Advancement towards these goals has thus far been slow, but research is gaining momentum, and some startling revelations could very well be coming within the next few years.