Association of Minimal Residual Disease by a Single-Tube 8-Color Flow Cytometric Analysis With Clinical Outcome in Adult B-Cell Acute Lymphoblastic Leukemia

Minimal/measurable residual disease (MRD) measured by molecular and multiparametric flow cytometry (MFC) has been proven to be predictive of relapse and survival in patients with B-cell acute lymphoblastic leukemia (B-ALL). A universally applicable antibody panel at a low cost but without compromising sensitivity and power of prognosis prediction in adult B-ALL remains unestablished. To report our experience of using a single-tube 8-color MFC panel to measure the MRD status as a prognostic indicator in adult B-ALL patients. We retrospectively analyzed the characteristics, MRD status, and prognosis of adult B-ALL based on a large real-world cohort of 486 patients during a 10-year period. MRD assessed by MFC and polymerase chain reaction (PCR) assays for BCR-ABL+ patients showed concordant results in 74.2% of cases. MRD- status by our MFC panel could clearly predict a favorable relapse-free survival (RFS) and overall survival (OS) both at the end of induction and at the end of 1 consolidation course. Patients with continuous MRD- and with at least 1 MRD- result showed a favorable RFS and OS compared with those with at least 1 MRD+ result and continuous MRD+, respectively. The single-tube 8-color MFC panel demonstrated a low cost, decent sensitivity, and comparability with polymerase chain reaction-MRD but an excellent performance in predicting RFS and OS, and thus could potentially be taken as a routine indicator in the evaluation of the treatment response for adult patients with B-ALL.