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Highlights l Performed DNA-based ddPCR to accurately monitor the MRD of AE (+) AML. l Identified quantification of the fusion gene correlates strongly with clinical prognosis., Relapse of childhood AML1-ETO (AE) acute myeloid leukemia is the most common cause of treatment failure. Optimized minimal residual disease monitoring methods is required to prevent relapse. In this study, we used next-generation sequencing to identify the breakpoints in the fusion gene and the DNA-based droplet digital PCR (ddPCR) method was used for dynamic monitoring of AE-DNA. The ddPCR technique provides more sensitive and precise quantitation of the AE gene during disease progression and relapse. Quantification of the AE fusion gene by ddPCR further contributes to improved prognosis. Our study provides valuable methods for dynamic surveillance of AE fusion DNA and assistance in determining the prognosis.

Blast crisis develops in a minority of patients with chronic myeloid leukemia even in the era of tyrosine kinase inhibitor (TKI) therapy. Reports suggest that we know little about the mechanism of BCR-ABL and AML1-ETO co-expression in blast crisis of chronic myeloid leukemia, and that other chromosomal abnormalities also coexist. Here, we document an unusual and interesting case of a 51-year-old female diagnosed in the chronic phase of chronic myeloid leukemia. After undergoing TKI treatment for 3 months, her bone marrow aspirates in the chronic phase had transformed to blast crisis. Molecular genetic testing indicated she was positive for p210 form of BCR-ABL (copy number decreased from 108.91% to 56.96%) and AML1-ETO fusion (copy number, 5.65%) genes and had additional chromosomal abnormalities of t(8; 21)(q22; q22)/t(9; 22)(q34; q11), t(2; 5)(p24; q13) and an additional +8 chromosome.

Coexistence of AML1-ETO and PML-RARa has rarely been reported, and there is limited information on a special subtype of AML characterized by co-expression of AML1-ETO and PML-RARa. Herein, we prese...

Rationale: Acute myeloid leukemia (AML) is a malignantly clonal and highly heterogeneous disease. Although the treatment of AML has brought promising outcomes for younger patients, prognosis of the elderly remains dismal. Innovative regimens are increasingly necessary to be investigated. Patient concerns: We present an 86-year-old AML patient with fever, cough, and sputum production. Diagnoses: A diagnosis of AML with maturation (AML-M2) and AML1/ETO was made. Interventions: The patient was treated with a regimen of Homoharringtonine coupled with arsenic trioxide. Outcomes: The AML-M2 patient with AML1/ETO achieved incomplete remission, but showed few toxic side effects and improved survival. Besides, we analyzed the dynamic counts of complete blood cells during the treatment. The count of white blood cell had a positive correlation with the percentage of blast cells (r = 0.65), both of which had a negative correlation with the percentage of segmented neutrophils (r = –0.63, –0.89). Lessons: Homoharringtonine and arsenic trioxide may induce both the apoptosis and differentiation of leukemic cells in AML-M2 with AML1/ETO.

Conventional/molecular cytogenetics is important in identification of genomic abnormalities, for prognostication and in risk stratification of de novo patients with acute myeloid leukemias (AML). Here we present an AML M2 case showing the sole karyotypic abnormality, the rare interstitial deletion in the long arm of chromosome 9 with the loss of segment q12–q13.

We analyze the prevalence and clinical features of a group of patients with t(8;21) (q22;q22) acute myeloblastic leukemia, identified in a single institution in México over a 10-year period. Fifteen patients presented at the Centro de Hematología y Medicina Interna de Puebla from February 1995 to August 2005; only nine were treated and followed in the institution. Median age was 24 years, (range 7-49); there was only one male. According to the French-American-British (FAB) morphological classification of leukemia, the morphology was M2 in four cases, M4 in three cases, M3 in one case and M0 in one. In addition to the myeloid markers, lymphoid markers were identified in 6 patients. Patients were induced to remission with combined chemotherapy and three subsequently underwent bone marrow transplantation (BMT). The median overall and disease-free survival has not been reached, being above 3390 days, the probability of survival at this time was 73%. In this single-center experience in México, we found that the t(8;21) (q22;q22) variant of leukemia was more frequent than in Caucasian populations, that the co-expression of lymphoid markers in the blast cells is very frequent and that this malignancy is associated with a relatively good prognosis.

JAK2 seems to be a typical cooperating mutation in therapy-related t(8;21)/ AML 1- ETO -positive AML

To the Editor : We have evaluated the occurrence of the AML1/ETO fusion transcripts by reverse transcription-polymerase chain reaction (RT-PCR) analysis[1][1] in 7 patients with t(8; 21)(q22; q22) acute myeloid leukemia (AML) who underwent allogeneic bone marrow transplantation (BMT; n = 6) or

The chromosomal translocation t(8;21)(q22;q22) is the cytogenetic hallmark of a distinct class of acute myeloid leukemias (AML) which are predominantly of the FAB-M2 subtype [1]. Approximately 25% of adult and 50% of childhood M2-leukemias possess this reciprocal translocation. Patients with a t(8;21) respond well to chemotherapy and have a favourable clinical outcome with high long-term survival rates2. Therefore, it seems important to identify these patients at diagnosis and to monitor their response to treatment.

Previous studies on either animal model or clinical settings have demonstrated that the expression of AML1/ETO9a (AE9a), a truncated version of AML1-ETO (AE) generated by alternative splicing during transcription, in patients with acute myeloid leukemia M2 subtype may have clinical significance. Moreover, the simultaneously expression of both AE and AE9a may even be more meaningful to the prognosis of the patients. To validate this hypothesis, we have measured the mRNA level of both AE and AE9a in each individual M2 patient by quantitative real-time RT-PCR, and correlated the ratio of AE/AE9a mRNA levels with the clinical outcome and prognosis in these patients. In 35 newly-diagnosed AML-M2 patients with t(8;21), expression of AE9a was detected in 30 cases (85.71%). The median value of the percentages of AE9a and AE within overall transcripts of the fusion gene in these patients were 18.16% and 81.84%, respectively (p

According to the World Health Organization (WHO) classification system, cases with t(8;21)(q22;q22) should be diagnosed as acute myeloid leukemia (AML) even with a blast count of less than 20 percent in blood or bone marrow. It is an uncommon manifestation, moreover hypocellularity is rarely observed in this subtype of leukemia. Here, we report a case of t(8;21) in a patient with marked hypocellularity of less than 5 percent and a blast count of less than 20 percent. This patient responded relatively well to chemotherapy. An allogeneic bone marrow transplantation was performed with good engraftment. This case suggests that hypocellular AML with a t(8;21) has as good a prognosis as hypercellular AML with t(8;21).