A systematic review of outcomes after stem cell transplantation in acute lymphoblastic leukemia with or without measurable residual disease

Association of minimal residual disease levels with clinical outcomes in patients with mantle cell lymphoma: A meta-analysis

Some studies have elucidated that Minimal residual disease (MRD) in patient with Mantle Cell Lymphoma (MCL) was a significant prognostic factor, with potential value in assessing overall survival (OS) and progression-free survival (PFS). However, most studies were widely varied in included population, sample sources and MRD detection time points. Some studies even have conflicting results. In view of this, a meta-analysis was performed to evaluate association of MRD levels with clinical outcomes in patients with MCL. We identified 7 included articles, which were published in recent 20 years. Then, we extracted or calculated hazard ratios (HRs) and their 95 % confidence intervals (CIs). Our results reveal that patients with MRD negativity have improved OS (HR = 0.63; 95 % CI: 0.50-0.79) and PFS (HR = 0.40, 95 % CI: 0.21-0.76), comparing with patients with MRD positivity. There are also consistent results in subgroups based on sample sources and MRD detection time points. Our study also demonstrates that MRD level is a strong prognostic factor of clinical outcomes. Thus, MRD is expected to be an effective clinical indicator for assessing prognosis and guide treatment decisions in MCL patients.

How I Diagnose Minimal/Measurable Residual Disease in B Lymphoblastic Leukemia/Lymphoma by Flow Cytometry

OBJECTIVES

Assessment for minimal/measurable residual disease (MRD) is a powerful prognostic factor in B lymphoblastic leukemia/lymphoma (B-LL/L) that is quickly becoming standard of care in assessing patients with B-LL/L posttherapy. MRD can be assessed using methodologies including flow cytometry and molecular genetics, with the former being rapid, relatively inexpensive, and widely applicable in many hematopathology/flow cytometry laboratories.

METHODS

This article presents an approach to MRD detection in B-LL/L by flow cytometry through case presentations with illustration of several potential pitfalls. We review normal maturation patterns, antigens used for assessment, flow panels that can be utilized, considerations to be made during therapy, and clinical impact. The benefits and drawbacks when using the "different from normal" and "leukemia associated phenotype" approaches are considered.

RESULTS

Evaluation for MRD in B-LL/L by flow cytometry relies on a knowledge of normal immunophenotypic patterns associated with B-cell maturation in states of rest and marrow regeneration so that one can identify patterns of antigen expression that differentiate abnormal, leukemic populations from regenerating hematogones or B-cell precursors. The nature of therapy can affect normal patterns, a phenomenon especially important to take into consideration given the increased use of targeted therapies in the treatment of B-LL/L.

CONCLUSIONS

Flow cytometry is widely available in many laboratories and is a cost-effective way to evaluate for B-LL/L MRD. However, panel validation and interpreter education are crucial for accurate assessment.