Engraftment and Chimerism
Neutrophil engraftment with a sustained absolute neutrophil count of greater than 500 (109/L) occurred in 5 patients at a median of 15 (range 8-21) days post-transplantation. Platelet engraftment with a sustained platelet count greater than 20,000 (109/L) without transfusion occurred at a median of 12 (range 9-16) days post-transplantation. Patient 3 started engraftment with an absolute neutrophil count 400 x109/L on day +11 with 100% chimerism, however she died before engraftment due to sepsis and multiorgan failure. Patients 5 and 6 engrafted with 90% of donor cells but 3 months post-transplantation started to decrease chimerism; despite early discontinuation of immunosuppression and repeated donor lymphocyte infusions they developed secondary engraftment failure one-year post-transplantation.