Table. 2.

Table. 2.

Characteristics of emerging minimal residual disease assays used in pediatric acute lymphoblastic leukemia

Assay techniques and targets Applicability and sensitivity Advantages Disadvantages
Next-generation flow cytometry for identifying immunophenot-ypic deviations from normal counterparts >90% High sensitivity and wide applicability Requires fresh samples (<24 h)
10−5-106 Short turnaround time
Does not require prior information on patient-specific aberrant immunophenotype at diagnosis Requires 4 million cells for a sensitivity of 106
Lower risk of false negatives caused by immunophenotypic shift during therapy compared to MFC
Excludes apoptotic cells lacking leukemogenic potential Requires high-level expertise for interpretation
Analysis at cell population or single cell level
Standardized for B-ALL
Next-generation sequencing for IG/TCR gene rearrangements >90% High sensitivity and wide applicability Long turnaround time
10−5-106 Forgoes the need to design patient-specific/allele specific oligonucleotide primer sets Risk of disproportional target amplification during multiplex PCR
Does not require knowledge of IG/TCR gene rearrangement status at the diagnosis High cost
Can identify oligoclonality and clonal evolution
Provides information on B/T-cell background repertoire
Includes internal quality controls to monitor primer performance, technical variability, and quantitation
Freely available web-based bioinformatics pipeline
Standardized for B-ALL
Potentially useful for other gene mutations
Digital droplet PCR for fusion transcripts or IG/TCR gene rearrangements Applicability varies depending on targets: >90% for IG/TCR gene rearrangements and 25-30% for fusion transcripts High sensitivity and accuracy Limited experience for pediatric ALL
Does not require a standard curve Not yet standardized
10−5-106 Potentially useful for other gene mutations

B-ALL, B-cell acute lymphoblastic leukemia; IG/TCR, immunoglobulin/T-cell receptor; MFC, multiparameterflow cytometry; PCR, polymerase chain reaction

Clin Pediatr Hematol Oncol 2020;27:87-100
© 2020 Clin Pediatr Hematol Oncol