The impact of CD34+ cell dose on platelet engraftment in pediatric patients following unmanipulated haploidentical blood and marrow transplantation.
OBJECTIVE
Unmanipulated haploidentical blood and marrow transplantation has been developed as an alternative transplant strategy for pediatric patients with hematological diseases. The aim of this study was to investigate the effects of donor and recipient characteristics on hematopoietic recovery in pediatric patients following unmanipulated haploidentical transplantation.


METHODS
Factors correlating with hematopoietic recovery in 133 pediatric patients after unmanipulated haploidentical transplantation were analyzed retrospectively.


RESULTS
All patients reached an absolute neutrophil count of 500/microl in a median of 12 days (range, 9-49 days). One hundred thirty-three patients reached an untransfused platelet count of more than 20,000/microl in a median of 15 days (range, 7-180 days). Univariate analysis showed five factors associated with platelet engraftment. These were time to transplantation after diagnosis (P = 0.072), infused nuclear cells/kg of recipient weight (P = 0.028), CD3+ cells/kg of recipient weight (P = 0.082), CD4+ cells/kg of recipient weight (P = 0.083), and CD34+ cells/kg of recipient weight (P = 0.012). Multivariate analysis showed that infused CD34+ cells/kg of recipient weight (CD34+ cells more than 2.42 x 10(6)/kg vs. less than or equal to 2.42 x 10(6)/kg, HR = 1.733; 95% CI 1.222-2.549; P = 0.002) were significantly associated with an increased risk of platelet engraftment. Patients receiving a CD34+ cell dose more than 2.42 x 10(6)/kg had a short time [12 days (range, 7-176 days)] to achieve an untransfused platelet engraftment, compared to 18 days (range, 7-180 days) in patients receiving a lower dose (P < 0.001).


CONCLUSIONS
Our results suggest that low number of CD34+ cells in allografts is a critical factor associated with delayed platelet engraftment after unmanipulated haploidentical transplantation in pediatric patients.
Chang
Ying-Jun
YJ
Peking University People's Hospital, Peking University Institute of Hematology, Beijing, China.
Xu
Lan-Ping
LP
Liu
Dai-Hong
DH
Liu
Kai-Yan
KY
Han
Wei
W
Chen
Yu-Hong
YH
Wang
Yu
Y
Chen
Huan
H
Wang
Jing-Zhi
JZ
Zhang
Xiao-Hui
XH
Zhao
Xiang-Yu
XY
Huang
Xiao-Jun
XJ
D000293:Adolescent; D018952:Antigens, CD34; D001792:Blood Platelets / Q000502:physiology*; D016026:Bone Marrow Transplantation / Q000379:methods*; D002452:Cell Count; D002648:Child; D002675:Child, Preschool; D005260:Female; D006239:Haplotypes; D006410:Hematopoiesis; D018380:Hematopoietic Stem Cell Transplantation / Q000379:methods*; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D006801:Humans; D007938:Leukemia / Q000628:therapy; D008297:Male; D012189:Retrospective Studies; D019172:Transplantation Conditioning / Q000379:methods; D014184:Transplantation, Homologous; D016896:Treatment Outcome
D018952:Antigens, CD34