Adapting measurable residual disease evaluation to clinical practice for patients with acute lymphoblastic leukemia who underwent allogeneic stem cell transplantation.

Measurable residual disease (MRD) has become a critical biomarker in the management of acute lymphoblastic leukemia (ALL), particularly for patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). The incorporation of MRD-directed strategies into clinical practice can enable personalized therapy and improve outcomes in ALL patients. Growing evidence has demonstrated that MRD status not only reflects the treatment response and relapse risk but also informs clinical decisions across the transplant continuum, including transplant indications, donor selection, conditioning regimens, and post-transplant interventions. With the advent of highly sensitive technologies such as real-time polymerase chain reaction and next-generation sequencing, MRD assessment has reached unprecedented accuracy, enabling precision medicine for ALL. This review systematically addresses six key clinical questions related to the application of MRD in ALL patients undergoing transplantation. We discuss optimal MRD detection methods, timing and sampling strategies, the prognostic implications of MRD positivity or clearance, and MRD-directed approaches before and after allo-HSCT. We further highlight emerging immunotherapeutic options and research gaps that must be addressed to refine MRD-guided strategies. In summary, incorporating MRD evaluation into routine clinical practice has the potential to optimize transplant outcomes and reduce relapse in ALL patients.