Mesenchymal stem cells are of recipient origin in pediatric transplantations using umbilical cord blood, peripheral blood, or bone marrow.

Chimerism status of bone marrow (BM)-derived mesenchymal stem cells (MSC) from children who received an allogeneic hematopoietic transplant is an interesting question, referring not only to hematopoietic transplant but also to cellular therapy. MSC are present in the BM but it is still controversial whether these cells maintain their capacity for homing to the BM. In this report, we studied chimerism of BM-derived MSC from children who underwent a hematopoietic stem cell transplant using BM, peripheral blood, and umbilical cord blood as source of hematopoietic stem cells.