Clark’s white blood count (WBC) continues to approach zero, as expected. The drop is a result of the conditioning (chemo) from Day -10 to 0. Once it bottoms out, and the new marrow starts to engraft, we will slowly see his counts rise again.
With his low, or absent WBC, Clark is prone to illness. This includes viral, bacterial and fungal infections. Right now, Clark is in the “danger zone”. His body is unable to fight off a mild cold, let alone anything more serious.
Clark has received an allogenic transplant. Meaning he is using marrow from someone other than himself. Patients undergoing allogeneic transplantation are at a greater risk of infection because of a longer time to achieve engraftment (prolonged neutropenia) and the added risk of GvHD.
Engraftment is the process in which the transplanted stem cells find their way to the bone marrow spaces in the centre of the large bones of the body. Only then can the transplanted stem cells begin to produce new blood cells. Engraftment happens in stages:
The first sign of engraftment is the gradual rise of Neutrophil (WBC). This can occur as early as 10 days after transplant but is more common around 14-20 days.
Shortly after Clark’s WBC starts to show signs of engraftment, his platelet counts will start to rise. A platelet count of 20,000 to 50,000 is a sign of platelet engraftment.
Lastly, we have red blood cells (RBC). The engraftment of RBC’s Usually occurs a couple of weeks after everything else. There is no “exact” time frame for engraftment to occur. Many things play a roll in how Clark’s body reacts, such as his specific disease, his age, and the quality of his old blood cells.
While there are many risks involved in Clark having a bone marrow transplant, the hope is the benefits outweigh the risks. In Clark’s case, without a BMT, he would most definitely die at a very young age. But thankfully, with a successful transplant, Clark can at least live a life without the need of regular blood transfusions.