Identification and surveillance of rare relapse-initiating stem cells during complete remission after transplantation.

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Dimitriou M, Mortera-Blanco T, Tobiasson M, Mazzi S, Lehander M, Högstrand K, Karimi M, Walldin G, Jansson M, Vonlanthen S, Ljungman P, Langemeijer S, Yoshizato T, Hellström-Lindberg E, Woll PS, Jacobsen SEW

Blood 143 (11) 953-966 [2024-03-14; online 2023-12-14]

Relapse after complete remission (CR) remains the main cause of mortality after allogeneic stem cell transplantation for hematological malignancies and, therefore, improved biomarkers for early prediction of relapse remains a critical goal toward development and assessment of preemptive relapse treatment. Because the significance of cancer stem cells as a source of relapses remains unclear, we investigated whether mutational screening for persistence of rare cancer stem cells would enhance measurable residual disease (MRD) and early relapse prediction after transplantation. In a retrospective study of patients who relapsed and patients who achieved continuous-CR with myelodysplastic syndromes and related myeloid malignancies, combined flow cytometric cell sorting and mutational screening for persistence of rare relapse-initiating stem cells was performed in the bone marrow at multiple CR time points after transplantation. In 25 CR samples from 15 patients that later relapsed, only 9 samples were MRD-positive in mononuclear cells (MNCs) whereas flowcytometric-sorted hematopoietic stem and progenitor cells (HSPCs) were MRD-positive in all samples, and always with a higher variant allele frequency than in MNCs (mean, 97-fold). MRD-positivity in HSPCs preceded MNCs in multiple sequential samples, in some cases preceding relapse by >2 years. In contrast, in 13 patients in long-term continuous-CR, HSPCs remained MRD-negative. Enhanced MRD sensitivity was also observed in total CD34+ cells, but HSPCs were always more clonally involved (mean, 8-fold). In conclusion, identification of relapse-initiating cancer stem cells and mutational MRD screening for their persistence consistently enhances MRD sensitivity and earlier prediction of relapse after allogeneic stem cell transplantation.

NGI Short read [Service]

NGI Uppsala (SNP&SEQ Technology Platform) [Service]

National Genomics Infrastructure [Service]

PubMed 38096358

DOI 10.1182/blood.2023022851

Crossref 10.1182/blood.2023022851

pmc: PMC10950475
pii: S0006-4971(23)14644-1