Metaphor warning!!! The end of this report involves simplistic analogies to explain something I barely understand.
Yesterday’s blog was my attempt at understanding and “simplifying” the information in the review article in the journal, Rheumatology concerning using a patient’s own bone marrow stem cells to treat Multiple Sclerosis, Scleroderma, Rheumatoid Arthritis, Lupus and other autoimmune disease (AD).
I’ve read the report again as well as other references from that Google search, and some of the points I didn’t understand are a little more clear.
For the most part, the cells that are killed by the radiation or chemotherapy in preparation for the stem cell transplant are the cells in the body that are actively dividing cells at that time. Those cells that are not dividing, either because they are dormant (asleep or inactive) or because they are mature may not all be destroyed. The grown up, matured white blood cells in the lymph nodes may survive and can be the cause of relapse, later on.
In other words, not all of the immune system is killed or “ablated.”
In fact, if all the old immune cells were killed, we wouldn’t have to worry about rejection of transplants, at all — there wouldn’t be anything around to reject it.
The review article explains that some of the cells and antibodies that cause the trouble in AD are still present and measurable after the stem cell transplant. In fact, it’s these factors that seem to cause a relapse in those patients who get sick again. There are lots of theories as to what is happening in the 1/3 of the patients who do not get sick again. There’s probably several different mechanisms and processes going on.
I believe that the ultimate result of the research will be the identifications of some chemicals, proteins or “factors,” or perhaps a certain type of (adult) stem cell that can then be manufactured or grown in the lab and given to the patient. In that case, there won’t be the need for the dangerous chemotherapy, radiation or bone marrow transplant, at all.
Think of it this way: the house has some bad paint that’s actually eating away the wood and letting the windows leak and we’re afraid the whole thing will colapse. We sand blasted away all the paint we could see, but there is some paint in a few cracks and between the boards that may or may not affect the new coat of paint. We know those spots can cause the new paint to bubble or peel, but we don’t know how to get rid of them without damaging the house beyond repair. We hope the researchers will come up with a magic paint that will let us skip the scraping, sandblasting and repainting all together. We want to be able to spray one wall of the house in order to get the old paint to look like new and protect the house from any more damage.
In the meantime, we’ll do the hard work required to protect the wood of the house as best we can and try not to poke any permanent holes in the walls.