Day 126 (D -12)
A fried of ours suggested that we explain the actual process of a stem cell/bone marrow transplant. So today's entry is for everyone who may still not quite understand whats about to happen in two days.
Ann has leukemia which is first and foremost a disease of the blood. Specifically it is a mutation that has occurred n one of her original stem cells as it developed towards becoming a lymphocyte or White Blood Cell. .Each successive generation of leukemia cells is a clone of this original mutation. This mutation continued to divide until it displaced all of her healthy stem cells which were busy developing into things she needed to live like Red Blood Cells, Platelets and White Blood Cells.
So to rectify this you have to remove all of the mutated clone cells. If you leave one then then the problem will start all over again eventually. Of course the problem is how do you separate all of the cancer from Ann. It's almost like having two organisms sharing the same body. The traditional approach to solving this problem has been to use chemotherapy drugs to kill off the mutations and then allow the healthy tissue to recover. In children this almost always works, but in adults it only works in about half of the cases or less.
The situation is complicated even more because leukemia's reaction to chemotherapy is largely defined by it's cytogenetics, which is the genetic defect that caused it to begin with. In Ann's case this is the infamous translocation of the 4th and 11th chromosome on one of the genes in the original mutated stem cell. The t(4;11) defect causes Ann's stem cells to in effect avoid natural aging cell death, called apotheosis. However, those cells retain some limited abilities that are exhibited by the immune system. Namely the ability to adapt to disease and react to foreign objects in the body. It is possible that the leukemia cells will adapt to the chemotherapy drugs and become refractory, or drug resistant. Then the mutation will again begin to spread uncontrollably, one again forcing healthy cells out.
The healthy cells permit this because the clone mutations display the correct marker proteins on their surface that identify them as part of Ann's body. If the markers were different then the healthy cells would attack and kill off the mutations. While it is not possible to change the surface proteins on the cancer cells it is possible to introduce, or transplant a new group of stem cells that will view them as foreign invaders and eliminate them because they have a slightly different group of marker proteins that they view as normal.
In order to transplant the new stem cells into Ann the first thing that needs to be done is kill off as much of her original tissue as possible. This includes both her existing healthy stem cells and the mutated clones. This is called Mobilization or Pre-Conditioning and typically takes place over a period of a week or so. It is accomplished by use of, TBI - Total Body Irradiation or High Dose Chemotherapy. In Ann's case MDA has chosen to use High Dose Chemo.
After the Mobilization then it is time to actually perform the transplant. Which is accomplished by placing the stem cells collected from an adult bone marrow donor or umbilical cords in an IV bag and pumping them into the patient's veins directly. No surgery is necessary apart from the insertion of a IV catheter into the patient. Ann had this done last week.
Then it is a matter of waiting until the new stem cells find the hollow portions of the bones and engraft there. This engraftment is signaled by the production of White Blood Cells that will protect the patient against infection. This period of waiting for engraftment can take upwards of 20 days. All during this time the patient will probably be supported by transfusions of Red Blood Cells and Platelets.
Once the patient has engrafted they will be released from the protective isolation of the hospital and be allowed to live within a 10 minute radius of MDA. From that point on for the next 2 or 3 months the patient has to return to MDA each day for evaluation. Specifically MDA is looking for the onset of fungal, respiratory, or other opportunistic infections. They are also looking for GvHD - Graft vs. host Disease. It is expected that during this period that the patient will be hospitalized for some additional period of time for some type of infection.
After the 100 Days is over then MDA may (or may not) clear us to leave the 10 minute radius and return to Baton Rouge. However, weather we are physiologically prepared to do that is another question entirely.
Update
Now that that is over with there is some news to report from today. Ann had her last ever (hopefully) blood draw from the leukemia lab. It turns out that Ann's WBC's have recovered into the normal range from all the Neogene that was used in the apheresis collection. However, her Magnesium level is low once again and our PA, Lorrie prescribed another baby bottle of the stuff for Ann to take tonight. Lorrie was really sad to see us go, wished us luck and gave Ann a big hug before siding us on our way.
Next we got the results of the Lumbar Puncture that the stem cell clinic performed yesterday. No white cells were detected and her spinal fluid looked very clear with just a few red cells that snuck in through the hole created by the needle. This is good news because it reinforces once more that the leukemia as not managed to get into her central nervous system.
Ann also had a bone density test today, as the final part of the study she was on for the prevention of bone loss. Now that Ann is going on to transplant the protocol for the study says that she has to be removed from the study. Considering that bone loss is a major problem for chemo patients she is really hopeful that someone benefits from it. Unfortunately we won't know the results of the bone density test until a week or so from now.
