Hello all! Asking for more prayers for Caleb’s health and continued recovery today… and that we get some good news in the next several weeks. Caleb’s blood work has shown some good progress since discharge, but it appears we aren’t quite out of the woods yet with regard to fixing his still weak immune system. 

We learned this past Friday via a test results phone call that Colten’s whole blood count percentage in Caleb’s body has continued to decrease. They look at these values and percentages via an involved blood test called a chimerism. This particular chimerism test had to be sent off to Seattle for evaluation and processing, so it took a while to get the results. Essentially Colten’s whole blood count percentage in Caleb’s body has gradually dropped since we came home- from the high 90s to 84 percent (previous read) to now 67 percent. So it appears Caleb’s immune system is attempting to start taking a hold again. We don’t want this to happen because, as we know, Caleb’s cells can’t make normal B cells and Colten’s cells need to be “in charge.” The test doesn’t have to show that Caleb’s cell makeup is 100 percent Colten (a small percentage of Caleb’s cells can remain), but the percentage needs to be maintained as primarily Colten and not drop. We don’t yet understand all of this or the extent of the concerns, but we are in the information gathering stage right now- so not a lot of answers.

One piece of good news is that we do know the specific B cell count itself remains consistently high – 92 percent Colten as of last week. Caleb was actually not making any functioning B cells before transplant, so this is a big victory and shows that the BMT was, in part, effective and successful. However, Colten’s T cell count in Caleb’s body continues to be pretty low, meaning that Caleb still has no protection against viral illness; and the doctor believes this COULD be a part of the reason that whole blood count percentage is dropping. 

This “whole blood count” represents an overall (yet complicated) picture of the immune system, so Caleb’s BMT doctor needs some more time to determine a potential cause or course of action. The first step is to remove the tacrolimus (immune suppresant medicine) completely, which has been supressing Colten’s T cells to prevent them from attacking Caleb and giving him GVHD (again, very delicate balance.) She has asked me to wean his tacrolimus super quickly so as to weed this out as a factor. Originally, the wean would have ended November 1, but now his last dose is actually tonight. We have to watch very closely for signs of GVHD (diarrhea, rash, vomiting) due to the very quick wean, but she hopes this won’t be a problem due to being past day +100 (from day of transplant). 

What we do know is that if the whole blood count percentage drops again, we will be moving forward with somewhat of a “repeat” stem cell transplant. Technically, it is not called a bone marrow transplant (BMT), because it will not involve more chemo for Caleb, a direct access to Colten’s bone marrow via surgery, or (God willing) a hospital stay for either of the boys. But Colten will likely undergo what an adult stem cell donor would. They call it a “donor lymphocyte infusion.” Potentially no anesthesia…and it is ideally outpatient…but Colten will have to be hooked up to a machine via a peripheral IV for about 4 hours to extract stem cells and T cells from his blood. They will store each of these in a freezer, and each month they will infuse a very small amount into Caleb’s body to help boost Colten’s T cell count. It must be done very slowly or it would cause a graft failure or rejection (because they do not intend to suppress Caleb’s cells with chemotheraphy again.) It is important to note that Colten is not aware of this yet, as we don’t know for sure what will happen. We are sad and hesitant to put him through something like this again, though it’s the only option, and want to be 100% confident in the path forward before we explain it to him. Sigh…

Sometimes, the BMT doctors see slow improvement with reduced intensity transplants like Caleb’s because they didn’t kill all of the patients’ cells with the chemo like they would have in the event of cancer or malignancy. They are confident this was still the right way to go, due to reduced toxicity… but it can complicate full recovery.

This also doesn’t change (and could complicate) Colten’s back to school timeline since we won’t know if the stem cell extraction/infusions will be necessary until probably late October around his 5th birthday. They won’t repeat the chimerism test until the third week in October… at which point, when we get results within about a week or so, they will make the final decision on whether to move forward with this or not. Basically as of today, this route is looking much more likely. Repeating the chimerism test on October 4 at clinic this week is too soon and wouldn’t accurately show whether the tacrolimus wean made any difference in the whole blood cell or T cell counts.

This is the current impression we have, but it seems the transplant fixed part of the problem… but it didn’t fix everything. So now we have to “do it again” in a way to fix the other part of the problem. We will hopefully have more details about our options (especially for Colten) this week, and then a clearer path forward the week of October 18th.

Upcoming NWC Appointments

October 4
BMT Clinic – (information gathering only, no further test results)

October 10
Sleep Evaluation/Clinic (preliminary, potential repeat apts)

October 18
BMT Clinic (repeat chimerism test, test results and answers within a week or so)

November 7
Developmental/Behavioral Pediatrician Evaluation (preliminary, potential repeat apts)