These results indicate that RT-PCR amplification of the AML1/ETO fusion transcript is a powerful tool for diagnosing and monitoring minimal residual disease in AML-M2 patients.
Persistence of the AML1/ETO transcript has been demonstrated by PCR in patients with t(8;21) in long-term remission, but the rearranged AML1 gene could not be detected by Southern analysis, showing that the t(8;21) clone existed as minimal residual disease (MRD).
We have evaluated the frequency of this newly described translocation in acute lymphoblastic leukemia (ALL), and the feasibility of minimal residual disease (MRD) monitoring by polymerase chain reaction (PCR) amplification of TEL-AML1 transcripts.
We analysed the TEL-AML1 transcript using reverse transcription-polymerase chain reaction (RT-PCR) in order to detect minimal residual disease (MRD) in seven children with t(12;21)-associated B-lineage ALL.
Here we studied minimal residual disease (MRD) of patients with acute myeloid leukemia (AML) who have PML/RAR alpha or AML1/ETO as well as the phenotypic analysis of lymphocyte subsets involved in antitumor immunity.
Detection of minimal residual disease in patients with AML1/ETO-associated acute myeloid leukemia using a novel quantitative reverse transcription polymerase chain reaction assay.
Interim analysis of the minimal residual disease (MRD) detection shows heterogeneity within the group of newly diagnosed TEL/AML1-positive leukaemias--10 out of 24 patients tested at the end of induction therapy had detectable levels of MRD.
Interestingly, in samples obtained from seven patients at diagnosis, during induction chemotherapy, or relapse, the level of TEL-AML1 in peripheral blood (PB) and bone marrow (BM) was found to differ only by threefold, suggesting that MRD may be evaluated in PB samples in most patients.
Furthermore, we could detect the TEL-AML1 transcript in the peripheral blood of t(12;21)-positive patients and we used this to assess minimal residual disease (MRD) in patients during chemotherapy.
The results suggest that we may easily monitor MRD in patients with t(8;21) AML through quantitative analysis of AML1-ETO transcripts in blood samples.
The aim of this study was threefold: (i) to assess the frequency and clinical association of the fusion gene in patients with and without a cytogenetically detectable chromosome 12 and/or 21 abnormality or failed cytogenetic results, (ii) to characterize alternative forms of ETV6/AML1 transcripts, and (iii) to use ETV6/AML1 as a molecular marker for the investigation of minimal residual disease (MRD).
In 11 TEL/AML1-positive patients, the minimal residual disease (MRD) level at the end of induction therapy was quantified in a limiting dilution assay using IGH or TCRD junctional regions as polymerase chain reaction (PCR) targets.
In 34/36 bone marrow samples the Ig/TCR RQ-PCR and TEL-AML1 RQ-PCR revealed equal levels of MRD and these results had a strong correlation (P < 0.0001, R2 = 0.84).
Furthermore, real-time quantitative-polymerase chain reaction (RQ-PCR)-based detection of TEL/AML1 represents an accurate technique for the reproducible assessment of minimal residual disease (MRD).
The IgH, TCR and TEL-AML1 markers can be used as targets by real-time PCR under the same cycling profile, allowing quantitation of MRD in more 95% of patients with pre-B ALL.
After adjusting for known prognostic features such as presence of the TEL-AML1 rearrangement, National Cancer Institute (NCI) risk status, ploidy, and race, the G allele of a common polymorphism in chemokine receptor 5 (CCR5) was associated with more favorable MRD status than the A allele (P = .009, logistic regression), when comparing "best" and "worst" risk groups.
Presence of good prognostic markers TEL-AML1 or trisomies of chromosomes 4 and 10 still provided additional prognostic information, but not in National Cancer Institute high-risk (NCI HR) patients who were MRD(+).
To examine the prognostic significance of minimal residual disease (MRD) in t(8;21) acute myeloid leukemia (AML), 96 bone marrow samples from 26 Japanese patients in complete remission (CR) were analyzed regarding the RUNX1/MTG8 transcript using real-time reverse transcriptase polymerase chain reaction assay.
So, persistence of TEL-AML1 fusion as a MRD had no additive prognostic value over its measurement at diagnosis in terms of predicting the probability of OS.
ETV6-RUNX1 was associated with age 1-9 years, pre-treatment classification as low risk and lower levels of minimal residual disease (MRD) on day 19 of therapy (P<0.001).