[Detecting minimal residual disease status in allogeneic hematopoietic stem cell transplantation of patients with high-risk acute leukemia].
OBJECTIVE
To explore the relationship between minimal residual disease (MRD) and the outcome of patients with high-risk acute leukemia (AL) undergoing allogeneic hematopoietic stem cell transplantation (HSCT).


METHODS
By 4/5-color multi-parameter flow cytometry (MFC, CD45/SSC gating) for detecting MRD at pre-(day-30) and post-transplant (day +30, +60, +100, 6 months, 9 months and 12 months), the investigators retrospectively analyzed the MRD levels and the prognosis of 90 high-risk patients. According to the MRD cutoff value of 0.1%, the low-level and high-level groups were defined. In the high-level group, the patients were divided into two sub groups according to the subsequent treatment (intervention therapy group and non-intervention therapy group).


RESULTS
MRD pre-transplant had no predictive value for the clinical outcome. The patients with high levels of MRD post-transplant (+60 d and +100 d) showed higher relapse rates than those of the low-level group. In addition, regarding MRD +100 d post-transplant, differences were significant among 3 groups (high-level MRD and intervention therapy group, high-level MRD and non-intervention therapy group and low-level MRD group) including 1-year relapse-free survival (RFS) (100% vs 60.87% vs 91.30%, P < 0.05) and 3-year RFS (85.71% vs 44.72% vs 68.48%, P < 0.05). The median time from first high level MRD detected to clinical relapse was 2.5 (1 - 26) months. In the high level MRD group (+100 d post-transplant), 7 of 30 patients received intervention therapy without relapse. However another 23 patients had no intervention treatment and 11 of them relapsed latter (P < 0.05).


CONCLUSIONS
The MFC-based quantification of MRD post-transplant reveals important prognostic information in patients with high-risk AL. MRD check point at day +100 (cutoff: 0.1%) may discriminate different risk populations. Those patients with MRD levels ≥ 0.1% should receive early intervention at an early stage and a low tumor burden so as to reduce the relapse rate and boost survival.
Department of Hematology, First Affiliated Hospital, Soochow University, Jiangsu Institute of Hematology; Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Suzhou 215006, China.
Xiao-lan
XL
Shi
Xiao-wen
XW
Tang
Xiao-ai
XA
Wei
Bing-rui
BR
Zhao
Qian-lan
QL
Zhou
Fan
F
Ye
Yu-xia
YX
Lu
Xing-wei
XW
Sun
Ming-qing
MQ
Zhu
Wen-hong
WH
Shen
Hui-ying
HY
Qiu
Ai-ning
AN
Sun
De-pei
DP
Wu
D000293:Adolescent; D000328:Adult; D002648:Child; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation / Q000379:methods*; D006801:Humans; D007951:Leukemia, Myeloid / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D018365:Neoplasm, Residual / Q000175:diagnosis* / Q000473:pathology; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate; D014184:Transplantation, Homologous; D016896:Treatment Outcome; D055815:Young Adult