多参数流式细胞术与实时定量PCR技术检测Ph阳性急性B淋巴细胞白血病异基因造血干细胞移植前微小残留病的预后意义比较

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。

Comparison of prognostic significance between multiparameter flow cytometry and real-time quantitative polymerase chain reaction in the detection of minimal residual disease of Philadelphia chromosome-positive acute B lymphocytic leukemia before allogeneic hematopoietic stem cell transplantation

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 MRDpositive(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.