“Transplant is the only cure”
Once the decision has been made to go with the bone marrow transplant or stem cell transplant, an entirely different set of dangers arises from those faced because of the leukemia. In principle, the existing bone marrow is destroyed, and so the leukemia is destroyed. There is a significant possibility that it will return, but that danger is down the road.
The goal of this transplant is to completely eradicate her old, damaged bone marrow, and to replace it with new healthy and growing marrow that is capable of producing untainted blood cells. There is a great deal of danger in this process. Sometimes it seems to me that this is a case of “the cure is worse than the disease,” except the disease, CMML leukemia, is very bad indeed.
To eliminate the old bone marrow, Mom is going to be put through a regimen of “intense chemotherapy” (and note that the regular old kind of chemotherapy is bad enough for most people), with chemotherapy drugs with names like Fludarabine, Busulfan, and Thymoglobulin. These are still so far down the road that I haven’t yet looked them up. Then there are two day’s exposure to “total body irradiation”.
All of this will occur over a period of 6-8 days prior to the actual “transplant” (which in Mom’s case is then an infusion or a “graft” of stem cells from a non-related donor). In this process, not only is her bone marrow destroyed, but her immune system is destroyed.
For the first 30 days or so after the transplant, there is a danger that the graft will not “engraft”, that is, it will completely reject her system, but that risk is controlled with drugs, and it’s minimal. The larger possibility is that, with her depleted immune system, she will suffer from an infection. It can be bacterial, or viral, or fungal; she will likely develop “mouth sores”, she won’t be able to eat, and she’ll experience nausea, vomiting, and diarrhea. There are dangers of liver and kidney damage, and also pneumonia, which can be a killer.
There are drugs and antibiotics to deal with these. But still, the first 30 days is only the beginning.
When the “graft” becomes “engrafted,” there is a whole new set of dangers. Mom will have no immune system, and in essence, the “graft” will be in charge. The “graft” will have its own immunities, and they will have their way with her. There is a danger that they will reject her, in large and small ways. This is called graft vs host disease (GVH).
True, some of this GVH effect will do a clean-up job on any leftover bone marrow or leukemia from the old regime. In fact, “graft vs host” is what provides some of the magic of this transplant process. It’s often the final nail in the coffin of the leukemia.
Unfortunately, it’s also a killer in its own right. There are two phases: “acute”, while the actual “graft” is still moving around in there, and also “chronic”, beginning at approximately 100 days after the transplant, when the “son of graft” cells are taking over.
In all, the GVH period can last up to a full year or more. Symptoms may be as mild as a skin rash, but GVH can also affect major organs, and I have a friend whose wife died from GVH complications some two years down the road.
The good news is that, if Mom makes it down the road that far, there is an excellent, excellent chance that she will have beaten the leukemia and can look forward to a normal life span. There may be some lingering GVH symptoms – we’ve encountered a couple of people who can’t make tears.
But that’s a relatively minor thing to live with, compared to leukemia.