Genomic breakpoint-specific monitoring of measurable residual disease in pediatric non-standard-risk acute myeloid leukemia

• Published in: Haematologica (Roma) 2024-03, Vol.109 (3), p.740-750
• Main Authors: Maurer-Granofszky, Margarita, Kohrer, Stefan, Fischer, Susanna, Schumich, Angela, Nebral, Karin, Larghero, Patrizia, Meyer, Claus, Mecklenbrauker, Astrid, Muhlegger, Nora, Marschalek, Rolf, Haas, Oskar A, Panzer-Grumayer, Renate, Dworzak, Michael N
• Format: Article
• Language: English
• Subjects: Acute Myeloid Leukemia; Child; Flow Cytometry; Gene Rearrangement; Genomics; Humans; Leukemia, Myeloid, Acute - diagnosis; Leukemia, Myeloid, Acute - genetics; Leukemia, Myeloid, Acute - therapy; Neoplasm, Residual - diagnosis; Neoplasm, Residual - genetics
• ISSN: 0390-6078; 1592-8721; 1592-8721
• DOI: 10.3324/haematol.2022.282424

Pediatric acute myeloid leukemia (AML) is a highly heterogeneous disease making standardized measurable residual disease (MRD) assessment challenging. Currently, patient-specific DNA-based assays are only rarely applied for MRD assessment in pediatric AML. We tested whether quantification of genomic breakpoint-specific sequences via quantitative polymerase chain reaction (gDNA-PCR) provides a reliable means of MRD quantification in children with non-standardrisk AML and compared its results to those obtained with state-of-the-art ten-color flow cytometry (FCM). Breakpointspecific gDNA-PCR assays were established according to Euro-MRD consortium guidelines. FCM-MRD assessment was performed according to the European Leukemia Network guidelines with adaptations for pediatric AML. Of 77 consecutively recruited non-standard-risk pediatric AML cases, 49 (64%) carried a chromosomal translocation potentially suitable for MRD quantification. Genomic breakpoint analysis returned a specific DNA sequence in 100% (41/41) of the cases submitted for investigation. MRD levels were evaluated using gDNA-PCR in 243 follow-up samples from 36 patients, achieving a quantitative range of at least 10-4 in 231/243 (95%) of samples. Comparing gDNA-PCR with FCM-MRD data for 183 bone marrow follow-up samples at various therapy timepoints showed a high concordance of 90.2%, considering a cut-off of ≥0.1%. Both methodologies outperformed morphological assessment. We conclude that MRD monitoring by gDNA-PCR is feasible in pediatric AML with traceable genetic rearrangements and correlates well with FCM-MRD in the currently applied clinically relevant range, while being more sensitive below that. The methodology should be evaluated in larger cohorts to pave the way for clinical application.