Peripheral blood marker of residual acute leukemia after hematopoietic cell transplantation using multi-plex digital droplet PCR

• Type of Material: Article
• Authors: M Stanojevic, MedStar Georgetown Univ Hosp; M Grant, Emory University; SK Vesely, University of Oklahoma Health Sciences Center; S Knoblach, Children’s National Health System; CG Kanakry, National Cancer Institute, National Institutes of Health, Bethesd; J Nazarian, Children’s National Health System; E Panditharatna, Dana Farber Boston Childrens Canc & Blood Disorder; K Panchapakesan, Children’s National Health System, Washington; RE Gress, National Cancer Institute, National Institutes of Health, Bethesd; J Holter-Chakrabarty, University of Oklahoma; Kirsten Williams, Emory University
• Language: English
• Date: 2022-09-29
• Publisher: FRONTIERS MEDIA SA
• Publication Version: Final Published Version
• Copyright Statement: © 2022 Stanojevic, Grant, Vesely, Knoblach, Kanakry, Nazarian, Panditharatna, Panchapakesan, Gress, Holter-Chakrabarty and Williams
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.3389/fimmu.2022.999298
• Title of Journal or Parent Work: FRONTIERS IN IMMUNOLOGY
• Volume: 13
• Start Page: 999298
• End Page: 999298
• Grant/Funding Information: This research was supported by a Leukemia Lymphoma Society Translational Research Program grant 6562-19, a grant from the Rising Tide Foundation, Ben's Run Gift/Ben's Run Inc. Research reported in this publication was supported in part by the National Cancer Institute Cancer Center Support Grant P30CA225520 awarded to the University of Oklahoma Stephenson Cancer Center and used the Biostatistics and Research Design Shared Resource. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. Research reported in this publication was supported in part by the Oklahoma Tobacco Settlement Endowment Trust awarded to the University of Oklahoma//Stephenson Cancer Center. The content is solely the responsibility of the authors and does not necessarily represent the official views of the Oklahoma Tobacco Settlement Endowment Trust.
• Keywords: Life Sciences & Biomedicine; minimal residual disease; acute leukemia; ANTI-APOPTOSIS GENE; Immunology; ACUTE LYMPHOBLASTIC-LEUKEMIA; SURVIVIN; hematopoietic cell transplantation; DISEASE; CANCER; POLYMERASE-CHAIN-REACTION; WT1; PRAME GENE-EXPRESSION; relapse; PROGNOSTIC-SIGNIFICANCE; ACUTE MYELOID-LEUKEMIA; Science & Technology; digital droplet PCR
• Research Categories: Health Sciences, Oncology

Abstract

Background: Relapse remains the primary cause of death after hematopoietic cell transplantation (HCT) for acute leukemia. The ability to identify minimal/measurable residual disease (MRD) via the blood could identify patients earlier when immunologic interventions may be more successful. We evaluated a new test that could quantify blood tumor mRNA as leukemia MRD surveillance using droplet digital PCR (ddPCR). Methods: The multiplex ddPCR assay was developed using tumor cell lines positive for the tumor associated antigens (TAA: WT1, PRAME, BIRC5), with homeostatic ABL1. On IRB-approved protocols, RNA was isolated from mononuclear cells from acute leukemia patients after HCT (n = 31 subjects; n = 91 specimens) and healthy donors (n = 20). ddPCR simultaneously quantitated mRNA expression of WT1, PRAME, BIRC5, and ABL1 and the TAA/ABL1 blood ratio was measured in patients with and without active leukemia after HCT. Results: Tumor cell lines confirmed quantitation of TAAs. In patients with active acute leukemia after HCT (MRD+ or relapse; n=19), the blood levels of WT1/ABL1, PRAME/ABL1, and BIRC5/ABL1 exceeded healthy donors (p<0.0001, p=0.0286, and p=0.0064 respectively). Active disease status was associated with TAA positivity (1+ TAA vs 0 TAA) with an odds ratio=10.67, (p=0.0070, 95% confidence interval 1.91 – 59.62). The area under the curve is 0.7544. Changes in ddPCR correlated with disease response captured on standard of care tests, accurately denoting positive or negative disease burden in 15/16 (95%). Of patients with MRD+ or relapsed leukemia after HCT, 84% were positive for at least one TAA/ABL1 in the peripheral blood. In summary, we have developed a new method for blood MRD monitoring of leukemia after HCT and present preliminary data that the TAA/ABL1 ratio may may serve as a novel surrogate biomarker for relapse of acute leukemia after HCT.