Immunophenotypic measurable residual disease monitoring in adult acute lymphoblastic leukemia patients undergoing allogeneic hematopoietic stem cell transplantation

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) offers a survival benefit to adult patients affected by acute lymphoblastic leukemia (ALL). However, to avoid an overt disease relapse, patients with pre or post transplant persistence or occurrence of measurable residual disease (MRD) may require cellular or pharmacological interventions with eventual side effects. While the significance of multiparametric flow cytometry (MFC) in the guidance of ALL treatment in both adult and pediatric patients is undebated, fewer data are available regarding the impact of MRD monitoring, as assessed by MFC analysis, in the allo-HSCT settings. Aim of this article is to summarize and discuss currently available information on the role of MFC detection of MRD in adult ALL patients undergoing allo-HSCT. The significance of MFC-based MRD according to sensitivity level, timing, and in relation to molecular techniques of MRD and chimerism assessment will be also discussed.

Automated summary

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) benefits adult ALL patients, but those with MRD may require interventions with side effects. The significance of MFC in ALL treatment is widely recognized, but there is limited data on MRD monitoring in allo-HSCT settings. This article aims to summarize and discuss the role of MFC detection of MRD in adult ALL patients undergoing allo-HSCT, including sensitivity, timing, and relation to other MRD assessment techniques.