Objective: To explore the different values of minimal residual disease (MRD) detection by multiparameter flow cytometry (MFC) and real-time quantitative polymerase chain reaction (RQ-PCR) before hematopoietic stem cell transplantation (HSCT) for predicting relapse, leukemia-free survival (LFS) , and overall survival (OS) in Philadelphia chromosome-positive ALL (Ph(+) ALL) . Methods: A retrospective study (n=280) was performed. MRD was determined using multiparameter flow cytometry and RQ-PCR. Results: MRD analysis with MFC and RQ-PCR of the BCR-ABL fusion transcript showed a strong correlation before transplantation. The positive rates of MRD detected by MFC and RQ-PCR before transplantation were 25.7% (72/280) and 60.7% (170/280) , respectively. MFC MRD-positive (MRDpos) Ph(+) ALL patients had a higher 3 year cumulative incidences of relapse (CIR) than did MFC MRD-negative (MRDneg) Ph(+) ALL patients (23.6%vs 8.6%; P<0.001) . However, the RQ-PCR MRDpos group had similar rates of 3 year OS, LFS, and NRM compared with those in the RQ-PCR MRDneg group. Moreover, patients with RQ-PCR MRD ≥1% experienced higher 3 year CIR (23.1%vs 11.4%; P=0.032) , lower LFS (53.8%vs 74.4%; P=0.015) , and OS (57.7% vs 79.1%; P=0.009) compared with the RQ-PCR MRD<1% group. Multivariate analyses confirmed the association of MFC MRD status and RQ-PCR MRD ≥1% with outcomes (P<0.05) . The sensitivity, specificity, positive predictive value (PPV) , and negative predictive value (NPV) of MFC detection MRD to predict recurrence were 48.50%, 77.56%, 23.62%, and 87.16%, respectively. Moreover, the sensitivity, specificity, PPV, and NPV were 23.00%, 88.59%, 17.15%, and 91.84%, respectively, when RQ-PCR MRD ≥1% was used to predict recurrence. Additionally, the sensitivity, specificity, PPV, and NPV were 54.29%, 73.88%, 45.7% and 91.87%, respectively, when MRD-positive status before transplantation (MFC MRDpos or RQ-PCR MRD ≥1%) was used to predict recurrence after transplantation. Conclusions: Both MFC and RQ-PCR detection of pretransplant MRD levels can predict the prognosis of Ph(+) B-ALL patients receiving allogeneic HSCT. MFC MRD-positive status before transplantation is the risk factor of leukemia recurrence after transplantation. The combined use of the two methods (MFC MRDpos or RQ-PCR MRD ≥1%) can improve the sensitivity, PPV, and NPV of predicting recurrence and help to better screen high-risk patients for intervention, thereby improving clinical efficacy.
目的： 探讨多参数流式细胞术（MFC）与实时定量聚合酶链反应技术（RQ-PCR）两种方法检测费城染色体阳性（Ph(+)）急性B淋巴细胞白血病（B-ALL）患者异基因造血干细胞移植（allo-HSCT）前微小残留病（MRD）的预后意义。 方法： 回顾性分析2014年7月至2018年2月在北京大学血液病研究所接受allo-HSCT的280例Ph(+) B-ALL患者，同时用MFC和RQ-PCR法（检测BCR-ABL融合基因表达）检测移植前MRD。 结果： RQ-PCR与MFC检测MRD具有相关性（rs=0.435，P<0.001）。MFC、RQ-PCR法检测移植前MRD的阳性率分别为25.7%（72/280）、60.7%（170/280）。移植前MFC-MRD阳性组患者移植后白血病3年累积复发率（CIR）明显高于MFC-MRD阴性组（23.6%对8.6%，P<0.001）。RQ-PCR检测BCR/ABL融合基因阳性组（RQ-PCR MRD阳性组）的3年CIR、非复发死亡（NRM）、无白血病生存（LFS）、总生存（OS）与BCR/ABL融合基因阴性组（RQ-PCR MRD阴性组）相比差异均无统计学意义（P>0.05）。移植前RQ-PCR MRD≥1%组比<1%组具有更高的3年CIR（23.1%对11.4%，P=0.032）、更低的LFS率（53.8%对74.4%，P=0.015）与OS率（57.7%对79.1%，P=0.009）。多因素分析显示，移植前MFC-MRD阳性是影响移植后CIR的危险因素（HR=2.488，95%CI 1.216~5.088，P=0.013），移植前RQ-PCR MRD≥1%是影响LFS（HR=2.272，95%CI 1.225~4.215，P<0.001）、OS（HR=2.472，95%CI 1.289~4.739，P=0.006）的危险因素。MFC检测MRD预测复发的敏感性、特异性、阳性预测值（PPV）、阴性预测值（NPV）分别为48.50%、77.56%、23.62%、87.16%。以RQ-PCR MRD≥1%预测复发的敏感性、特异性、PPV、NPV分别为23.00%、88.59%、17.15%、91.84%。移植前MFC-MRD阳性或RQ-PCR MRD≥1%二者任一成立为指标预测移植后复发的敏感性、特异性、PPV、NPV分别为54.29%、73.88%、45.70%、91.87%。 结论： MFC和RQ-PCR法检测移植前MRD水平均可预测Ph(+) B-ALL患者移植预后。移植前MFC-MRD阳性是移植后复发的危险因素。联合使用两种方法（移植前MFC-MRD阳性状态或RQ-PCR MRD≥1%成立）可提高预测移植后复发的敏感性、阳性预测值与阴性预测值，有助于更好筛选出高危患者。.
Keywords: Flow cytometry; Leukemia, lymphocytic, acute; Minimal residual disease; RQ-PCR.