The clinical significance of minimal residual disease detecting in monitoring relapse of acute lymphoblastic leukemia

Objective To investigate the clinical significance of minimal residual disease(MRD) detection in acute lymphoblastic leukemia used for predicting relapse and guiding chemotherapy.Methods 160 Bone marrow aspirate was collected from 32 patients of newly diagnosed B-ALL from 2008.1-2012.7,Selecting 2-3 antibodies combination,MRD was detected by four-color multiparameter flow cytometry(FCM) with CD45/SSC gating from the 33th days of induction treatment,and was done once more every one or three months.Results The MRD level of the 32 cases in the 33th day of induction treatment were devided into three groups.high group(MRD 1×10-2)、moderate group(MRD between 1×10-2and 1×10-4) and low group(MRD1×10-4).There was statistical significance between high group and low group(P0.05).There wasn't statistical significance between moderate group and low group(P0.05).Patients with a level of MRD10-4had good prognosis.The childhood B-ALL were not found relapse when MRD were positive occasionally and MRD10-2.The patients were found MRD positive over 10-2 before relapse,all of them were relapsed after three or six month.Conclusion The result showed that MRD detection can predict relapse earlier than the traditional bone marrow cells morphology.So it has an important clinical significance to predict relapse and guide the individualized chemotherapy with continuous monitoring of MRD.