engraftment
The process by which transplanted stem cells establish themselves and begin producing new blood cells.
Full Definition
Engraftment refers to the successful establishment and functioning of transplanted hematopoietic stem cells in the recipient's bone marrow following stem cell transplantation. The process involves stem cell homing to the bone marrow niche, survival, proliferation, and differentiation into mature blood cell lineages. Neutrophil engraftment is typically defined as achieving an absolute neutrophil count greater than 500/μL for three consecutive days, usually occurring 2-4 weeks post-transplant in pediatric patients. Platelet engraftment, defined as achieving a platelet count greater than 20,000-50,000/μL without transfusion support, often occurs later. Successful engraftment is essential for immune reconstitution and prevention of life-threatening infections and bleeding complications.
Usage
Usage note: Specify which cell lineage when documenting engraftment (neutrophil vs. platelet) and include specific count thresholds.
In Context
- "Neutrophil engraftment occurred on day +16 following allogeneic stem cell transplantation." — Transplant progress note
- "The patient achieved platelet engraftment without evidence of graft-versus-host disease." — Post-transplant assessment