BMT Day +68
Chimerisms. In Greek Mythology there was a monster that was comprised of three or more monsters. Usually it had the head of a lion, the body of a goat, the wings of a dragon, and a tail that was a snake with the head coming out of the end. THere’s many variations of this creature throughout different mythologies and it was immediately what I thought of when they mentioned the test that they were going to run. The Chimerism (pronounced kia mir ah) test is lookin for multiple DNA within the blood. Similarly to the mythological creature that was one of many, so too we hope is my blood. Ideally the blood will be more donor than mine since it’s the bone marrow that makes blood. We want to have the bone marrow that was replaced with my donor’s so that when the new blood is formed it lacks the leukemia that mine had.
This test was done at day +30 and retested at day +60. Initially I was a little disappointed and rather pessimistic about the results. At day +30, while the blood test was 100% donor, only 55% of my T-cells were 55% donor. T-cells’ technical names are T-lymphocyte or thymocyte. They are part of the immune system that help fight viruses and potentially cancer. These are critical cells for me since they can aid in killing off any remaining leukemia that the chemo didn’t get to. This part of the process is also why the doctors do want some graft vs host disease (GvHD). The idea is to get my new immune system to kill off the remaining bad parts of me without trying to kill the good parts of me. It’s a delicate balance because not enough GvHD and the leukemia could come back and spread. Too much of the GvHD and my new immune system goes haywire and attacks everything since it all looks foreign to my donor’s immune system. When it goes haywire, it can attack my skin causing rashes, my liver or digestion system causing vomiting or diarrhea, or anything else and wreaking havoc across the spectrum.
My initial chimerism test was 55% T-cell donor. That was on Day +30. My new results came back from my new Day +60 test and they were at 58% donor. It’s an improvement. I guess, though, I was hoping for more sooner. While my overarching blood test reveals 100% donor, still some things within the blood itself aren’t quite fully donor. This means that it’ll really take some time, years likely, before I’m cured. I’m not sure what this means yet for my overall health or how long I’ll have to remain quarantined(-ish). For sure it means that my immune system is still compromised and I have to be very careful. Not just from covid but from anything. With a brand new immune system it means that I have zero database to fight off anything. Any vaccines I got throughout my life, I’ll have to receive again. I literally have the immune system of a brand new baby. It’s still developing and what immunity I did have had is gone.
Time will tell how quickly the T-cell donor percentage will increase. My hope is that as it becomes a larger number it’ll grow quicker and can multiply faster. That’s my unscientific rationalization. I’m glad to see those numbers growing and I’ve seen statistics though where it’s an estimated 5% growth every month. As those numbers grow I’ll become more optimistic about the procedure but I still maintain some hesitancy simply from past experiences and previous letdowns. A little hope is a good thing but too much hope is devastating when something does go wrong. “Hope for the best but plan for the worst.” I still have alternative and contingency plans in the back of my mind so that I’m ready if something were to go wrong. Plan and prepare.