Detection of minimal residual disease in adult acute myeloid leukemia via CD25
We detected the expression of CD25 in patients with acute myeloid leukemia (AML) to value whether CD25 could be a promising marker for minimal residual disease (MRD). Methods Two hundred and twenty bone marrow (BM) specimens from 98 adult patients with AML after chemotherapy were detected using flow cytometry. The expression of CD25 was compared between MRD positive and negative subgroups. Results About 38% of patients with MRD were positive for CD25. The mean percentage of CD25-positive cell
... bpopulation was 58.68% relative to the whole MRD cluster (0.05%-100%). The mean fluorescence index ratio (MFIR) of CD25 in these cell subpopulations was approximately13-fold greater than that in normal myeloblasts. The detection sensitivity of CD25 was as high as 10 -4 . CD25 was also expressed on non-leukemic stem cells that were positive for CD34 and CD38. Conclusion CD25, as assessed by flow cytometry, is a promising marker for MRD in patients with AML. Background In acute myeloid leukemia (AML), the presence of minimal residual disease (MRD), in which the number of leukemic cells is lower than the detection threshold of morphology, is an independent prognostic parameter of relapse and survival       . Flow cytometry (FC), molecular techniques, and cytogenetic analysis are three prominent technologies for detecting MRD [1, 4,     . Generally, there are two approaches for MRD detection by FC: detection of cells with leukemia-associated immunophenotypes (LAIPs), which differ from normal hematopoietic cells    ;detection of different from normal (DfN) patterns  .These approaches can also be combined as a "LAIP-based DfN approach"  . With the mounting number of LAIP [1,3] and the application of multiparameter FC, the detection sensitivities of FC can be as high as 1:1000 to 1:106 in BM samples [10, 14, 15] .All these methods are based on antigens with abnormal expression. To reduce the false detection of MRD-negative ratios and expand the application scope, novel MRD markers need to be developed. CD25 (interleukin-2 receptor) is expressed in 10%-20% of patients with AML [15, 16] . This marker is correlated with FLT3-ITD, DNMT3A, and NPM1 mutations [16, 17] . It has also been proven to be an independent, unfavorable prognostic parameter in AML    .More recently, CD25 has been 3 detected in leukemic stem cells (LSCs) in patients with myelodysplastic syndrome  . Here, we used CD25 as a novel marker to detect MRD in patients with AML. Methods Patients The BM samples were obtained with informed consent. The study was approved by the Ethics Committee of the Peking University International Hospital and was in compliance with the guidelines of the Helsinki Declaration of 2008. A total of 220 longitudinal BM specimens from 98 adult AML patients (55 males and 43 females) were collected after chemotherapy from Peking University International Hospital between June 2017 and June 2019. Among the samples, 165 BM samples from 43 patients were collected at different time points after chemotherapy.