Мониторинг минимальной остаточной болезни и В-клеточных субпопуляций у больных острым B-лимфобластным лейкозом, леченных по протоколу «ОЛЛ-2016»

Introduction . The Russian multicentre trial on treatment of Acute Lymphoblastic Leukaemia (ALL) in adults (RALL-2016) regulates a centralised detection of minimal residual disease (MRD) on days 70 (end of induction II), 133 (end of consolidation III) and 190 (end of consolidation V). Aim  — the assessment of tumour cell clearance and normal B-cell precursor, mature B-cell and plasma cell dynamics. Materials and methods . The study period of December 2016 — August 2019 covered 59 B-ALL patients; the control cohort included four allogeneic blood stem cell donors. The MRD detection was performed with bone marrow samples in flow cytometry. Results . The patient majority have reached MRD-negativity at control timepoints, 60.4, 75.6 and 91.2% on days 70, 133 and 190, respectively. No correlation was observed between MRD values and tumour cell immunophenotype. B-cell precursors were undetected in 54.4, 38.8 and 59.4% patients on days 70, 133 and 190, respectively. Mature B-cells were fewer compared to donors’ on days 133 and 190. The relative plasma cell count did not differ significantly over therapy and between patients and donors. Conclusion . The RALL-2016 protocol facilitates MRD-negativity in the patient majority despite reduced cytostatic intensity.