急性淋巴细胞白血病患者造血干细胞移植后监测E2A-PBX1融合基因的意义初探

OBJECTIVE: To investigate the clinical characteristics of E2A-PBX1 (immunoglobulin enhancer binding factor-pre-B leukemia) fusion gene in patients with acute lymphoblastic leukemia (ALL) after allogeneic stem cell transplantation (allo-HSCT). METHODS: Clinical data of 10 patients received allo-HSCT in Peking University Institute of Hematology from December 2010 to January 2015 were retrospectively collected. The E2A-PBX1 gene was examined by real-time quantitative polymerase chain reaction (RQ-PCR). The correlation between its expression level and the disease status was analyzed. RESULTS: Among 10 cases of enrolled ALL, the E2A-PBX1 expression of six patients converted to positive after transplant at a median time of 90 days (range, 75–180 days). The expression level of the first positive sample was 25.200% (range, 0.022%–353.600%). The duration from E2A-PBX1 positive to hematological relapse was 30 days (range, 0–74 days). Finally, 4 patients underwent relapse at a median time of 164 days (range, 75–240 days) after allo-HSCT. The expression of E2A-PBX1 and minimal residual disease (MRD) level examined by flow cytometry were positive correlated (Spearman r=0.743, P=0.002). Once E2A-PBX1 expression converted to positive after transplant, MRD would increase rapidly. Patients with this type of ALL would have little response to the current intervention towards relapse. CONCLUSION: Monitoring E2A-PBX1 by RQ-PCR could be used to evaluate MRD status after allo-HSCT. Patients with positive E2A-PBX1 at early stage of transplant will have a poor prognosis.