Monitoring of minimal residual disease (MRD) after hematopoietic stem cell transplantation (HSCT) in patients with acute lymphoblastic leukemia (ALL) is vital for timely therapeutic intervention planning. However, interpreting low-positive results from the current standard method, quantitative PCR (qPCR) of immunoglobulin and T-cell receptor gene rearrangements (IG/TR), poses challenges due to the risk of false positivity caused by non-specific amplification. We aimed to improve MRD detection specificity using the next-generation amplicon sequencing (NGS) of IG/TR rearrangements for better relapse prediction. In pediatric and young adult ALL patients undergoing sequential post-HSCT MRD monitoring, we prospectively re-tested positive non-quantifiable qPCR results with NGS-MRD using the EuroClonality-NGS approach. We were able to confirm 13 out of 47 (27.7%) qPCR positive results using the more specific NGS-MRD method. Out of 10 patients with at least one MRD positivity confirmed by NGS, six relapsed (60%) 1-3.7 months after testing. Among 25 patients with all NGS-MRD results negative, two relapses occurred (8%) after 5.1 and 12.1 months. One-year RFS was 40% versus 96% and 3-year OS was 33.3% versus 94.4% for the NGS-positive and NGS-negative groups, respectively. The difference was not attributable to a varying rate of therapeutic interventions. Six patients out of 14 who had immunosuppressive treatment tapered or received donor lymphocyte infusion in response to MRD positivity developed significant graft versus host disease, leading to one fatality. This underscores the importance of enhancing the post-HSCT relapse risk prediction accuracy through NGS-MRD testing to avoid unnecessary interventions.

• Publikační typ
• časopisecké články MeSH

Minimal residual disease (MRD) is the most important independent prognostic factor in acute lymphoblastic leukemia (ALL). Since it has been implemented into in treatment stratification strategies, cure rates have improved significantly for all age groups. Real time quantitative (RQ)-PCR of clonal immunoglobulin and T-cell receptor gene rearrangements using allele-specific primers is currently regarded as the gold standard for MRD analysis in ALL, as it is not only highly sensitive and specific but also provides accurate MRD quantification. Following recent advances in next-generation sequencing (NGS), much attention has been devoted to the development of NGS-based MRD assays. This new technique can enhance sensitivity provided that sufficient numbers of cells are analyzed. Recent reports have shown that NGS-MRD also tends to be more specific for relapse prediction than RQ-PCR. In addition, NGS provides information on the physiological B- and T-cell repertoire during and after treatment, which has been shown to be prognostically relevant. However, before implementation of NGS-MRD detection in clinical practice, several issues must be addressed and the whole workflow needs to be standardized, including not only the analytical phase (spike-in calibrators, quality controls) but also the pre-analytical (e.g. sample preparation) and the post-analytical phases (e.g. bioinformatics pipeline, guidelines for correct data interpretation). These topics are currently addressed by a European network, the EuroClonality-NGS Consortium. In conclusion, NGS is a promising tool for MRD detection with the potential to overcome most of the limitations of RQ-PCR and to become the new gold standard for MRD detection in ALL.

• Klíčová slova
• Acute Lymphoblastic Leukemia, Marker Identification, Minimal Residual Disease, Minimal Residual Disease Detection, Multicolor Flow Cytometry,
• MeSH
• akutní lymfatická leukemie genetika   MeSH
• lidé MeSH
• prognóza MeSH
• receptory antigenů T-buněk genetika   MeSH
• reziduální nádor MeSH
• sekvenční analýza DNA metody   MeSH
• vysoce účinné nukleotidové sekvenování metody   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• receptory antigenů T-buněk MeSH

Minimal residual disease (MRD) monitoring via quantitative PCR (qPCR) detection of Ag receptor gene rearrangements has been the most sensitive method for predicting prognosis and making post-transplant treatment decisions for patients with ALL. Despite the broad clinical usefulness and standardization of this method, we and others have repeatedly reported the possibility of false-positive MRD results caused by massive B-lymphocyte regeneration after stem cell transplantation (SCT). Next-generation sequencing (NGS) enables precise and sensitive detection of multiple Ag receptor rearrangements, thus providing a more specific readout compared to qPCR. We investigated two cohorts of children with ALL who underwent SCT (30 patients and 228 samples). The first cohort consisted of 17 patients who remained in long-term CR after SCT despite having low MRD positivity (<0.01%) at least once during post-SCT monitoring using qPCR. Only one of 27 qPCR-positive samples was confirmed to be positive by NGS. Conversely, 10 of 15 samples with low qPCR-detected MRD positivity from 13 patients who subsequently relapsed were also confirmed to be positive by NGS (P=0.002). These data show that NGS has a better specificity in post-SCT ALL management and indicate that treatment interventions aimed at reverting impending relapse should not be based on qPCR only.

• MeSH
• akutní lymfatická leukemie * krev   diagnóza   genetika   terapie   MeSH
• dítě MeSH
• falešně pozitivní reakce MeSH
• lidé MeSH
• mladiství MeSH
• polymerázová řetězová reakce * MeSH
• předškolní dítě MeSH
• prognóza MeSH
• reziduální nádor MeSH
• transplantace hematopoetických kmenových buněk * MeSH
• vysoce účinné nukleotidové sekvenování * MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• klinické zkoušky MeSH
• multicentrická studie MeSH

The prognosis for children with high-risk relapsed acute lymphoblastic leukemia (ALL) is poor. Here, we assessed the prognostic importance of response during induction and consolidation treatment prior to hematopoietic stem cell transplantation (HSCT) aiming to evaluate the best time to assess minimal residual disease (MRD) for intervention strategies and in future trials in high-risk ALL relapse patients. Included patients (n=125) were treated uniformly according to the ALL-REZ BFM (Berlin-Frankfurt-Münster) 2002 relapse trial (median follow-up time=4.8 years). Patients with MRD ⩾10(-3) after induction treatment (76/119, 64%) or immediately preceding HSCT (19/71, 27%) had a significantly worse probability of disease-free survival 10 years after relapse treatment begin, with 26% (±6%) or 23% (±7%), respectively, compared with 58% (±8%) or 48% (±7%) for patients with MRD <10(-3). Conventional intensive consolidation treatment reduced MRD to <10(-3) before HSCT in 63% of patients, whereas MRD remained high or increased in the rest of this patient group. Our data support that MRD after induction treatment can be used to quantify the activity of different induction treatment strategies in phase II trials. MRD persistence at ⩾10(-3) before HSCT reflects a disease highly resistant to conventional intensive chemotherapy and requiring prospective controlled investigation of new treatment strategies and drugs.

• MeSH
• akutní lymfatická leukemie farmakoterapie   mortalita   patologie   MeSH
• dítě MeSH
• indukční chemoterapie MeSH
• lidé MeSH
• lokální recidiva nádoru farmakoterapie   mortalita   patologie   MeSH
• míra přežití MeSH
• mladiství MeSH
• monitorování fyziologických funkcí * MeSH
• následné studie MeSH
• prognóza MeSH
• prospektivní studie MeSH
• protokoly protinádorové kombinované chemoterapie terapeutické užití   MeSH
• reziduální nádor farmakoterapie   mortalita   patologie   MeSH
• rizikové faktory MeSH
• staging nádorů MeSH
• transplantace hematopoetických kmenových buněk MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• multicentrická studie MeSH
• práce podpořená grantem MeSH