The monitoring of minimal residual disease (MRD) in Philadelphia-negative acute lymphoblastic leukemia (ALL) requires the identification at diagnosis of immunoglobulin/T-cell receptor (Ig/TCR) rearrangements as clonality markers. Aiming to simplify and possibly improve the patients’ initial screening, we designed a capture-based next-generation sequencing (NGS) panel combining the Ig/TCR rearrangement detection with the profiling of relevant leukemia-related genes. The validation of the assay on well-characterized samples allowed us to identify all the known Ig/TCR rearrangements as well as additional clonalities, including rare rearrangements characterized by uncommon combinations of variable, diversity, and joining (V-D-J) gene segments, oligoclonal rearrangements, and low represented clones. Upon validation, the capture NGS approach allowed us to identify Ig/TCR clonal markers in 87% of a retrospective cohort (MRD-unknown within the Northern Italy Leukemia Group (NILG)-ALL 09/00 clinical trial) and in 83% of newly-diagnosed ALL cases in which conventional method failed, thus proving its prospective applicability. Finally, we identified gene variants in 94.7% of patients analyzed for mutational status with the same implemented capture assay. The prospective application of this technology could simplify clonality assessment and improve standard assay development for leukemia monitoring, as well as provide information about the mutational status of selected leukemia-related genes, potentially representing new prognostic elements, MRD markers, and targets for specific therapies.

In many clinical studies published over the past 20 years, adolescents and young adults (AYA) with Philadelphia chromosome negative acute lymphoblastic leukemia (Ph− ALL) were considered as a rather homogeneous clinico-prognostic group of patients suitable to receive intensive pediatric-like regimens with an improved outcome compared with the use of traditional adult ALL protocols. The AYA group was defined in most studies by an age range of 18–40 years, with some exceptions (up to 45 years). The experience collected in pediatric ALL with the study of post-induction minimal residual disease (MRD) was rapidly duplicated in AYA ALL, making MRD a widely accepted key factor for risk stratification and risk-oriented therapy with or without allogeneic stem cell transplantation and experimental new drugs for patients with MRD detectable after highly intensive chemotherapy. This combined strategy has resulted in long-term survival rates of AYA patients of 60–80%. The present review examines the evidence for MRD-guided therapies in AYA’s Ph− ALL, provides a critical appraisal of current treatment pitfalls and illustrates the ways of achieving further therapeutic improvement according to the massive knowledge recently generated in the field of ALL biology and MRD/risk/subset-specific therapy

Here, we describe the immunoglobulin and T cell receptor (Ig/TCR) molecular rearrangements identified as a leukemic clone hallmark for minimal residual disease assessment in relation to TP53 mutational status in 171 Ph-negative Acute Lymphoblastic Leukemia (ALL) adult patients at diagnosis. The presence of a TP53 alterations, which represents a marker of poor prognosis, was strictly correlated with an immature DH/JH rearrangement of the immunoglobulin receptor (p < 0.0001). Furthermore, TP53-mutated patients were classified as pro-B ALL more frequently than their wild-type counterpart (46% vs. 25%, p = 0.05). Although the reasons for the co-presence of immature Ig rearrangements and TP53 mutation need to be clarified, this can suggest that the alteration in TP53 is acquired at an early stage of B-cell maturation or even at the level of pre-leukemic transformation.

Next-generation sequencing (NGS) clonality assessment has the potential to overcome the conventional limitations of PCR-based methods. This study aimed at comparing the performance and concordance of the EuroClonality-NGS approach and the LymphoTrack^® Dx assay for immunoglobulin (IG)/T-cell receptor (TR)-marker identification at diagnosis. Across four quality-control rounds, six Italian laboratories analyzed 23 acute lymphoblastic leukemia (ALL) and five chronic lymphocytic leukemia (CLL) cases. Overall, 171 rearrangements were identified; 80.7% were detected by both methods. Among shared targets, the concordance was 89.1%, with a higher agreement for IG (IGH 100%–IGK 92.1%) than for TR loci (TRG 78.9%–TRB 81.8%). Bland–Altman analysis indicated no statistically significant systematic bias between methods [mean bias 1.99% (95% CI: −5.29 to +1.31%)]. The Spearman correlation was ρ = 0.680 (p < 0.001). Discordances (10.9%) rarely yielded suitable sensitive PCR assays for disease monitoring (20%) and were never the sole marker in individual patients. In larger independent cohorts, similar rates of no-marker cases were observed (~4–5% in adults), with higher frequencies in T-ALL and no association with blast percentage (Spearman’s ρ = 0.447, p = 0.450 in adults and ρ = 0.700, p = 0.188 in childhood). These findings support the reliability of both methods for diagnostic screening, while highlighting locus-specific variability and the importance of multi-target identification.