Articles

Evaluation of Minimal Residual Disease in Acute Myeloid Leukemia with NPM1 Marker

Abstract

Background: Minimal residual disease (MRD) tests provide early identification of hematologic relapse and timely management of acute myeloid leukemia (AML) patients. Approximately, 50% of AML patients do not have clonal chromosomal aberrations and categorize as a cytogenetically normal acute myeloid leukemia (CN-AML). About 60% of adult CN-AML has a mutation in exon 12 of NPM1 gene. This mutation is specific for malignant clone and potentially is a good marker of MRD. In this retrospective study, we set up a quantitative test for quantifying NPM1 type A mutation and AML patients carrying this mutation at the time of diagnosis, were followed-up.
Materials and Methods: We prepared plasmids containing a cDNA fragment of NPM1 and ABL genes by PCR cloning. The plasmids were used to construct standard curves. Eleven patients were analyzed using established method. Serial PB and/or BM samples (n=71) were taken in 1-3 months intervals (mean 1.5-month intervals) and median follow-up duration after chemotherapy was 11 months (5-28.5 months).
Results: In this study, we developed RNA-based RQ-PCR to quantitation of NPM1 mutation A with sensitivities of 10(-5). The percent of NPMmut/ABL level showed a range between 132 and 757 with median of 383.5 in samples at diagnosis. The median NPMmut transcript level log reduction was 3 logs. Relapse occurred in 54.5% of patients (n=6), all cases at diagnosis demonstrated the same mutation at relapse. In patients who experienced relapse, log reduction levels of NPM1 mRNA transcript after therapy were 4 (n=2), 3 (n=2) and 1 log (n=2). Totally, NPMmut level showed less than 5 log reduction in all of them, whereas this reduction was 5-6 logs in other patients.
Conclusion: Despite the limitations of this study in terms of sample size and duration of follow-up, it showed the accuracy of set up for detection of mutation and this marker has worth for following-up at different stages of disease. Because of high frequency, stability, specificity to abnormal clone and high sensitivity, NPM1 is a suitable marker for monitoring of NPMc+ AML patients.

 

Falini B, Nicoletti I, Martelli MF, et al. Acute myeloid leukemia carrying cytoplasmic/mutated nucleophosmin (NPMc+ AML): biologic and clinical features. Blood. 2007; 109(3):874-85.

Yin CC. Detection and Molecular Monitoring of Minimal Residual Diseases in Acute Myeloid Leukemia’s. J Mol Biomark Diagn. 2012; 3(2): 1000e105-6.

Martelli MP, Sportoletti P, Tiacci E, et al. Mutational landscape of AML with normal cytogenetics: biological and clinical implications. Blood Rev. 2013; 27(1):13-22.

Chang JH, Olson MO. Structure of the gene for rat nucleolar protein B23. J Biol Chem. 1990; 265(30):18227-33.

Wang W, Budhu A, Forgues M, et al. Temporal and spatial control of nucleophosmin by the Ran-Crm1 complex in centrosome duplication. Nat Cell Biol. 2005; 7(8):823-30.

Falini B, Mecucci C, Tiacci E, et al. Cytoplasmic nucleophosmin in acute myelogenous leukemia with a normal karyotype. N Engl J Med. 2005; 352(3):254-66.

Falini B, Martelli MP, Bolli N, et al. Acute myeloid leukemia with mutated nucleophosmin (NPM1): is it a distinct entity? Blood. 2011; 117(4):1109-20.

Paietta E. Minimal residual disease in acute myeloid leukemia: coming of age. Hematology Am Soc Hematol Educ Program. 2012; 2012:35-42.

Kristensen T, Moller MB, Friis L, et al. NPM1 mutation is a stable marker for minimal residual disease monitoring in acute myeloid leukaemia patients with increased sensitivity compared to WT1 expression. Eur J Haematol. 2011; 87(5):400-8.

Schnittger S, Kern W, Tschulik C, et al. Minimal residual disease levels assessed by NPM1 mutation-specific RQ-PCR provide important prognostic information in AML. Blood. 2009; 114(11):2220-31.

Chou WC, Tang JL, Wu SJ, et al. Clinical implications of minimal residual disease monitoring by quantitative polymerase chain reaction in acute myeloid leukemia patients bearing nucleophosmin (NPM1) mutations. Leukemia. 2007; 21(5):998-1004.

Birnboim HC, Doly J. A rapid alkaline extraction procedure for screening recombinant plasmid DNA. Nucleic Acids Res. 1979; 7(6):1513-23.

Gorello P, Cazzaniga G, Alberti F, et al. Quantitative assessment of minimal residual disease in acute myeloid leukemia carrying nucleophosmin (NPM1) gene mutations. Leukemia. 2006; 20(6):1103-8.

Kronke J, Schlenk RF, Jensen KO, et al. Monitoring of minimal residual disease in NPM1-mutated acute myeloid leukemia: a study from the German-Austrian acute myeloid leukemia study group. J Clin Oncol. 2011; 29(19):2709-16.

Kronke J, Bullinger L, Teleanu V, et al. Clonal evolution in relapsed NPM1-mutated acute myeloid leukemia. Blood. 2013; 122(1):100-8.

Schnittger S, Weisser M, Schoch C, et al. New score predicting for prognosis in PML-RARA+, AML1-ETO+, or CBFBMYH11+ acute myeloid leukemia based on quantification of fusion transcripts. Blood. 2003; 102(8):2746-55.

Barragan E, Pajuelo JC, Ballester S, et al. Minimal residual disease detection in acute myeloid leukemia by mutant nucleophosmin (NPM1): comparison with WT1 gene expression. Clin Chim Acta. 2008; 395(1-2):120-3.

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IssueVol 10, No 3 (2016) QRcode
SectionArticles
Keywords
Acute myeloid leukemia MRD NPM1 mutation Q-RT-PCR

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How to Cite
1.
Alizad Ghandforoush N, Chahardouli B, Rostami S, Ghadimi H, Ghasemi A, Alimoghaddam K, Ghavamzadeh A, Nadali F. Evaluation of Minimal Residual Disease in Acute Myeloid Leukemia with NPM1 Marker. Int J Hematol Oncol Stem Cell Res. 2016;10(3):147-152.