Impact of Day 14 Peripheral Blood Chimerism after Allogeneic Hematopoietic Stem Cell Bone Transplantation on the Treatment Outcome of Non-Malignant Disease
Data from 56 patientswho received allo-HSCT between April 2007 and March 2016 were retrospectively analyzed. Chimerism was evaluated using short-tandem repeatpolymerase chain reaction, with mixed chimerism (MC) defined as greater than 1% recipient cells which was further categorized into low-level MC (> 1% and < 15% of recipient-derived cells) and high-level MC (≥ 15% of the recipient-derived cells).
RESULTS:
Thirty-six patients showed complete donorchimerism (CC), 14 low-level MC, and 6 high-level MC at day 14 post-transplant. The estimated 5-year event-free survival (EFS) was higher in the CC or low-level MC groups than in the high-level MC group (86.1% vs. 71.4% vs. 33.3%; P = 0.001). In BM or peripheral blood stem cell (BM/PBSC) transplants, the 5-year EFS was higher in the CC or low-level MC group than in the high-level MC group (93.1% vs. 66.7% vs. 0%; P < 0.001). However, in cord bloodtransplants, the 5-year OS and EFS according to the day 14 peripheral bloodchimerism did not reach statistical significance.
CONCLUSION:
Although CC is not always necessary after allo-HSCT for non-malignant diseases, our data suggest that day 14 peripheral bloodchimerism may predict outcomes in patients with non-malignant diseaseswho underwent BM/PBSC transplants.