Automated vs Manual Flow-cytometry Gating for Measurable Residual Disease in Acute Myeloid Leukaemia (DUALFLOW)

Acute myeloid leukaemia remains associated with high relapse rates despite complete remission after induction chemotherapy. Sensitive identification of residual leukaemic blasts (MRD) guides risk-adapted therapy. Flow cytometry is applicable to nearly all patients but relies on operator-dependent manual gating, which may lack reproducibility when rare or immunophenotypically atypical blasts are present. A data-driven alternative based on FlowSOM clustering was developed at Bordeaux to overcome these limitations. DualFlow retrospectively analyses paired flow-cytometry standard (FCS) files from 60 AML patients (≈ 100 MRD determinations) drawn from the DATAML Bordeaux adult database and the paediatric haemato-oncology service. Files are distributed to three partner centers for blinded re-analysis. Each sample undergoes: (1) conventional manual gating in two expert centers; (2) unsupervised FlowSOM gating in one center; (3) molecular MRD assessment when available. Primary analysis calculates sensitivity, specificity, predictive values and Cohen/Fleiss kappa for MRD ≥ 0.1 %. Secondary analyses include concordance with molecular MRD, Bland-Altman and correlation for MRD 0.01-0.1 %, impact on relapse-free and overall survival using Kaplan-Meier and Cox models, and operator reproducibility for manual gating. Covariate effects (age, cytogenetics, molecular risk, treatment) are explored through stratified and multivariable methods. No additional interventions or specimens are collected; only de-identified FCS files and routine clinical data are used.

• Concordance of flow-cytometry MRD (both methods) with molecular MRD [Срок оценки: up to 8 weeks after initiation first cycle of intensive therapy and after initiation of second cycle of intensive therapy]
• Agreement of MRD 0.01-0.1 % between manual and unsupervised gating [Срок оценки: up to 8 weeks after initiation first cycle of intensive therapy and after initiation of second cycle of intensive therapy]
• Concordance of flow-cytometry MRD (both methods) with molecular MRD [Срок оценки: From diagnosis up to 60 months]
• Inter-operator reproducibility of manual gating [Срок оценки: up to 8 weeks after initiation first cycle of intensive therapy and after initiation of second cycle of intensive therapy]