Afternoon.

Kp had a nice nap this morning. She also did a mile before lunch. We paced out the hallway here on the 4^th floor. It's about 175 yards per lap, that's ten laps to a mile. She's looking much perkier. The news about the bone marrow didn't really come as a surprise today. It has been an option since the beginning. The doc was optimistic about not needing it. Even if she had a solid remission with this round of "induction and consolidation", any relapse would be tackled by a transplant. In a way, it's good to know now, so it can be scheduled; this is far more convenient than another surprise. We had a lot of worried friends today, sorry if the last post was abrupt.

Here's what I know about bone marrow transplants. First, the bone marrow is not actually transplanted into her bones. It is taken from the donor's bones, filtered, and then injected into the blood stream. No big deal for the recipient, much bigger deal for the donor. The aim is to have the "hematapoietic stem cells" (top of this figure) from the donor's marrow take hold in her bones. So it is actually a stem cell transplant. The injection of marrow is preceded by intense chemo (much higher dose than what she's getting now), with the aim of killing off all of her existing marrow and lymphocytes. The donor stem cells will take over completely. This is like other organ transplants, but reversed. In other organ transplants, there is a risk of the host's immune system rejecting the organ. In this case the organ is the immune system, so there's a risk of the organ rejecting the host. This is a beneficial effect when the donor's immune system rejects the leukemic cells. It's a problem when this new immune system attacks her. Eventually, her new immune system will "learn" who she is. She will only be on anti-rejection immuno-suprresants for about a year. The doctors will strike a delicate balance between organ-leukemic rejection and organ-host rejection. The process of the transplant will actually take longer than is expected for this visit, about six weeks. For a part of this time, several weeks, she will be in isolation, with limited visits from anyone. Here is some more info with lots of illustrations.