Relation between MRD and clearance of circulating lymphoblasts at day 10.

Cumulative incidence of relapse in children without (A) and with (B) circulating lymphoblasts after 10 days of initiation of treatment according to MRD studies at the end of remission induction. All patients were in complete morphologic remission at the time of the MRD studies. MRD positivity is defined as ≥0.01% of mononuclear cells expressing leukemia-specific immunophenotypes.