pubmed > ABL1 > polymerase chain reaction

BCR-ABL1 transcript doubling time as a predictor for treatment-free remission failure after imatinib discontinuation in chronic myeloid leukaemia in chronic phase.
The doubling time (DT) of the BCR-ABL1 quantitative polymerase chain reaction (qPCR) transcript level reflects the re-growing fraction of leukaemic cells after discontinuation of tyrosine kinase inhibitor (TKI). The present study analyzed monthly DT within six months after imatinib discontinuation in 131 patients. Monthly DT was calculated as x = ln(2)/K, where x is the DT and K is the fold BCR-ABL1 change from the previous value divided by the number of days between each measurement. The optimal DT value was determined as 12·75 days at two months using a recursive partitioning method. The patients were stratified into three groups: the high-risk group (DT<12·75 days but >0, with rapidly proliferating chronic myeloid leukaemia (CML) cells; n = 26) showed the lowest molecular relapse-free survival (mRFS) of 7·7% at 12 months, compared to 53·6% in the intermediate-risk group (DT≥12·75 days, with slowly proliferating CML cells; n = 16) or 90·0% in the low-risk group (DT≤0, i.e., without proliferating CML cells; n = 71; P < 0·001). Monthly assessment of DT helps identify high-risk patients for treatment-free remission failure with an imminent risk of molecular recurrence, and to define low-risk patients who can be spared the frequent monitoring of monthly molecular tests.
Publication Date: 2021-09-09
Journal: British journal of haematology

BCR-ABL1 p210 screening for chronic myeloid leukemia in patients with peripheral blood cytoses.
Chronic myeloid leukemia (CML) usually presents with leukocytosis with neutrophilia, left shift, and basophilia. Documentation of the BCR-ABL1 fusion is required for diagnosis, and this is often achieved via p210 BCR-ABL1 real-time polymerase chain reaction (RT-PCR). Patients undergoing first-time testing for p210 BCR-ABL1 at our institution were retrospectively identified. The medical record was reviewed, and the patient age, sex, clinical indication for testing, and concurrent CBC with differential were identified for 518 patients. BCR-ABL1 p210 testing had been performed using a laboratory-developed quantitative RT-PCR assay. Statistical analysis of the results was performed using an unpaired t test, and P values of <.05 were considered statistically significant. Twenty-four patients received a new diagnosis of CML (4.6%). As compared to patients with a negative PCR, these patients were more likely to have a markedly elevated white blood cell count (WBC), neutrophilia, and a mild anemia. Ninety-two percent (22/24) of new CML patients had a WBC ≥20 × 10 The peripheral blood parameters of total WBC ≥20 × 10
Publication Date: 2021-06-30
Journal: International journal of laboratory hematology

Assessment of droplet digital polymerase chain reaction for measuring BCR-ABL1 in chronic myeloid leukaemia in an international interlaboratory study.
Measurement of BCR activator of RhoGEF and GTPase -ABL proto-oncogene 1, non-receptor tyrosine kinase (BCR-ABL1) mRNA levels by reverse transcription quantitative polymerase chain reaction (RTqPCR) has been critical to treatment protocols and clinical trials in chronic myeloid leukaemia; however, interlaboratory variation remains a significant issue. Reverse transcriptase droplet digital PCR (RTddPCR) has shown potential to improve testing but a large-scale interlaboratory study is required to definitively establish this. In the present study, 10 BCR-ABL1-positive samples with levels ranging from molecular response (MR)
Publication Date: 2021-06-12
Journal: British journal of haematology

Fluctuation of BCR-ABL1 qPCR
Fluctuation of BCR-ABL1 real-time quantitative polymerase chain reaction in International Scale (qPCR
Publication Date: 2021-05-26
Journal: The Medical journal of Malaysia

BCR/ABL1-positive B-lymphoblastic Lymphoma Successfully Treated with Dasatinib-combined Chemotherapy.
We herein report a rare case of BCR-ABL1-positive B-lymphoblastic lymphoma (B-LBL). An 18-year-old woman had a history of persistent left-sided chest pain. Positron emission tomography showed increased metabolic activity in the fifth rib, duodenum, and pancreas. The pathological findings of the pancreas, duodenum, and bone marrow confirmed the diagnosis of B-LBL. Polymerase chain reaction of duodenum and bone marrow also revealed a minor BCR-ABL1 fusion gene. She was diagnosed with BCR-ABL1-positive B-LBL and administered dasatinib and prednisolone. She achieved complete remission two weeks after the initiation of the treatment. She received stem cell transplantation after consolidation chemotherapy and sustained complete remission.
Publication Date: 2021-04-06
Journal: Internal medicine (Tokyo, Japan)

miR-486-5p: A Prognostic Biomarker for Chronic Myeloid Leukemia.
MicroRNA miR-486-5p has been reported as a potential biomarker for diagnosis, prognosis, and as a therapeutic target in various cancers. In this study, we analyzed alterations in the expression of miR-486-5p in chronic Myeloid Leukemia (CML) patients. Initially, the expression of miR-486-5p was studied in the BCR-ABL1+ve CML K562 cell line by quantitative real-time polymerase chain reaction (qRT-PCR). The results indicated that the miR-486-5p expression was significantly upregulated in K562 cells after imatinib exposure, as compared to untreated K562 cells (
Publication Date: 2021-03-30
Journal: ACS omega

One-Step Multiplexed Droplet Digital Polymerase Chain Reaction for Quantification of p190 BCR-ABL1 Fusion Transcript in B-Lymphoblastic Leukemia.
Quantification and detection of the t(9;22) (BCR-ABL1) translocation in chronic myelogenous leukemia and B-lymphoblastic leukemia are important for directing treatment protocols and monitoring disease relapse. However, quantification using traditional reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) is dependent on a calibration curve and is prone to laboratory-to-laboratory variation. Droplet digital polymerase chain reaction (ddPCR) is a novel method that allows for highly sensitive absolute quantification of transcript copy number. As such, ddPCR is a good candidate for disease monitoring, an assay requiring reproducible measurements with high specificity and sensitivity. To compare results of ddPCR and RT-qPCR BCR-ABL1 fusion transcript measurements of patient samples and determine if either method is superior. We optimized and standardized a 1-step multiplexed ddPCR assay to detect BCR-ABL1 p190 and ABL1 e10 transcripts. The ddPCR optimization included varying cycle number and primer concentration with standardization of droplet generation and droplet number and analyses to improve data sensitivity. Following optimization, ddPCR measurements were performed on clinical samples and compared with traditional RT-qPCR results. Droplet digital polymerase chain reaction was able to detect the BCR-ABL1 p190 transcript to 0.001% (1:10-5) with a calculated limit of detection and limit of quantitation of 4.1 and 5.3 transcripts, respectively. When tested on patient samples, ddPCR was able to identify 20% more positives than a laboratory-developed 2-step RT-qPCR assay. Droplet digital polymerase chain reaction demonstrated increased detection of BCR-ABL1 compared with RT-qPCR. Improved detection of BCR-ABL1 p190 and the potential for improved standardization across multiple laboratories makes ddPCR a suitable method for the disease monitoring in patients with acute B-lymphoblastic leukemia.
Publication Date: 2021-03-27
Journal: Archives of pathology & laboratory medicine

Assessment of Outcomes After Stopping Tyrosine Kinase Inhibitors Among Patients With Chronic Myeloid Leukemia: A Nonrandomized Clinical Trial.
Tyrosine kinase inhibitors (TKIs) have been associated with improved survival of patients with chronic myeloid leukemia (CML) but are also associated with adverse effects, especially fatigue and diarrhea. Discontinuation of TKIs is safe and is associated with the successful achievement of treatment-free remission (TFR) for some patients. To evaluate molecular recurrence (MRec) and patient-reported outcomes (PROs) after TKI discontinuation for US patients with CML. The Life After Stopping TKIs (LAST) study was a prospective single-group nonrandomized clinical trial that enrolled 172 patients from 14 US academic medical centers from December 18, 2014, to December 12, 2016, with a minimum follow-up of 3 years. Participants were adults with chronic-phase CML whose disease was well controlled with imatinib, dasatinib, nilotinib, or bosutinib. Statistical analysis was performed from August 13, 2019, to March 23, 2020. Discontinuation of TKIs. Molecular recurrence, defined as loss of major molecular response (BCR-ABL1 International Scale ratio >0.1%) by central laboratory testing, and PROs (Patient-Reported Outcomes Measurement Information System computerized adaptive tests) were monitored. Droplet digital polymerase chain reaction (ddPCR) was performed on samples with undetectable BCR-ABL1 by standard real-time quantitative polymerase chain reaction (RQ-PCR). Of 172 patients, 89 were women (51.7%), and the median age was 60 years (range, 21-86 years). Of 171 patients evaluable for molecular analysis, 112 (65.5%) stayed in major molecular response, and 104 (60.8%) achieved TFR. Undetectable BCR-ABL1 by either ddPCR or RQ-PCR at the time of TKI discontinuation (hazard ratio, 3.60; 95% CI, 1.99-6.50; P < .001) and at 3 months (hazard ratio, 5.86; 95% CI, 3.07-11.1; P < .001) was independently associated with MRec. Molecular recurrence for patients with detectable BCR-ABL1 by RQ-PCR was 50.0% (14 of 28), undetectable BCR-ABL1 by RQ-PCR but detectable by ddPCR was 64.3% (36 of 56), and undetectable BCR-ABL1 by both ddPCR and RQ-PCR was 10.3% (9 of 87) (P ≤ .001). Of the 112 patients in TFR at 12 months, 90 (80.4%) had a clinically meaningful improvement in fatigue, 39 (34.8%) had a clinically meaningful improvement in depression, 98 (87.5%) had a clinically meaningful improvement in diarrhea, 24 (21.4%) had a clinically meaningful improvement in sleep disturbance, and 5 (4.5%) had a clinically meaningful improvement in pain interference. Restarting a TKI resulted in worsening of PROs. In this study, TKI discontinuation was safe, and 60.8% of patients remained in TFR. Discontinuation of TKIs was associated with improvements in PROs. These findings should assist patients and physicians in their decision-making regarding discontinuation of TKIs. Detectable BCR-ABL1 by RQ-PCR or ddPCR at the time of TKI discontinuation was associated with higher risk of MRec; clinical application of this finding should be confirmed in other studies. ClinicalTrials.gov Identifier: NCT02269267.
Publication Date: 2020-11-13
Journal: JAMA oncology

Standardization of BCR-ABL1 p210 Monitoring: From Nested to Digital PCR.
The introduction of tyrosine kinase inhibitors in 2001 as a targeted anticancer therapy has significantly improved the quality of life and survival of patients with chronic myeloid leukemia. At the same time, with the introduction of tyrosine kinase inhibitors, the need for precise monitoring of the molecular response to therapy has emerged. Starting with a qualitative polymerase chain reaction, followed by the introduction of a quantitative polymerase chain reaction to determine the exact quantity of the transcript of interest-p210 BCR-ABL1, molecular monitoring in patients with chronic myeloid leukemia was internationally standardized. This enabled precise monitoring of the therapeutic response, unification of therapeutic protocols, and comparison of results between different laboratories. This review aims to summarize the steps in the diagnosis and molecular monitoring of p210 BCR-ABL1, as well as to consider the possible future application of a more sophisticated method such as digital polymerase chain reaction.
Publication Date: 2020-11-12
Journal: Cancers

Why is it critical to achieve a deep molecular response in chronic myeloid leukemia?
The primary goal of tyrosine kinase inhibitor (TKI) therapy for patients with chronic myeloid leukemia is survival, which is achieved by the vast majority of patients. The initial response to therapy provides a sensitive measure of future clinical outcome. Measurement of BCR-ABL1 transcript levels using real-time quantitative polymerase chain reaction standardized to the international reporting scale is now the principal recommended monitoring strategy. The method is used to assess early milestone responses and provides a guide for therapeutic intervention. When patients successfully traverse the critical first 12 months of TKI therapy, most will head towards another milestone response, deep molecular response (DMR, BCR-ABL1 ≤0.01%). DMR is essential for patients aiming to achieve treatment-free remission and a prerequisite for a trial of TKI discontinuation. The success of discontinuation trials has led to new treatment strategies in order for more patients to reach this milestone response. DMR has been incorporated into endpoints of clinical trials and is considered by some expert groups as the optimal treatment response. But is DMR a stable response and does it provide the ultimate protection against TKI resistance and death? Do we need to increase the sensitivity of detection of BCR-ABL1 to better identify the patients who would likely remain in treatment-free remission after TKI discontinuation? Is it necessary to switch current TKI therapy to a more potent inhibitor if the goal is to achieve DMR? These are issues that I will explore in this review.
Publication Date: 2020-10-16
Journal: Haematologica

Comparison of Droplet Digital PCR versus qPCR Measurements on the International Scale for the Molecular Monitoring of Chronic Myeloid Leukemia Patients.
BCR-ABL1/ABL1 p210 measurement by quantitative polymerase chain reaction (qPCR) is used worldwide to monitor the molecular response in chronic myeloid leukemia (CML) patients. Droplet digital polymerase chain reaction (ddPCR) seems to show a greater sensitivity than qPCR, probably due to the high number of replicates analyzed in ddPCR for the comparison. Additionally, in a recently published comparison, ddPCR measurements were not adequately transformed into International Scale (IS). We have analyzed 50 CML patients and ten non-CML donors in parallel by qPCR and ddPCR. To the best of our knowledge, this is the first study comparing both techniques under similar conditions, with BCR-ABL1/ABL1 measurements performed via both techniques transformed into IS. Qualitative and quantitative comparisons showed excellent results. The qualitative correlation showed a Kappa index of 0.94 (95% confidence interval [CI] 0.90-0.98) (P < 0.001). In the quantitative comparison, the absolute intra-class correlation coefficient was 0.868 (95% CI 0.734-0.937; P < 0.001), and Lin's concordance correlation coefficient was 0.863. The Passing-Bablock test indicated a slight proportional difference between qPCR and ddPCR. A quantitative and qualitative subanalysis including 40 patients with a molecular response of 3.0 or deeper showed similar results in every test. In addition, the proportional difference in the Passing-Bablock test disappeared. There were no differences in the sensitivity for BCR-ABL1 detection between qPCR and ddPCR (McNemar test, P = 0.5). In conclusion, our results show very good quantitative and qualitative correlations between BCR-ABL1/ABL1 p210 results obtained by qPCR and by ddPCR and confirm previous scarce data regarding the lack of an increase in sensitivity of ddPCR over qPCR in this setting.
Publication Date: 2020-09-03
Journal: Molecular diagnosis & therapy

Comparison of BCR-ABL1 quantification in peripheral blood and bone marrow using an International Scale-standardized assay for assessment of deep molecular response in chronic myeloid leukemia.
Background Monitoring of molecular response (MR) using quantitative polymerase chain reaction (PCR) for BCR-ABL1 is a pivotal tool for guiding tyrosine kinase inhibitor therapy and the long-term follow-up of patients with chronic myeloid leukemia (CML). Results of MR monitoring are standardized according to the International Scale (IS), and specific time-dependent molecular milestones for definition of optimal response and treatment failure have been included in treatment recommendations. The common practice to use peripheral blood (PB) instead of bone marrow (BM) aspirate to monitor the MR monitoring in CML has been questioned. Some studies described differences between BCR-ABL1 levels in paired PB and BM specimens. Methods We examined 631 paired PB and BM samples from 283 CML patients in a retrospective single-center study using an IS normalized quantitative reverse transcription (qRT)-PCR assay for quantification of BCR-ABL1IS. Results A good overall concordance of BCR-ABL1IS results was found, a systematic tendency towards higher BCR-ABL1IS levels in PB was observed in samples of CML patients in a major MR. This difference was most pronounced in patients treated with imatinib for at least 1 year. Importantly, the difference resulted in a significantly lower rate of deep MR when BCR-ABL1IS was assessed in the PB compared to BM aspirates. Conclusions In summary, our data suggest that the classification of deep MR in patients with CML is more stringent in PB than in BM. Our study supports the current practice to primarily use PB for long-term molecular follow-up monitoring in CML.
Publication Date: 2020-02-23
Journal: Clinical chemistry and laboratory medicine

Standardization of BCR-ABL1 quantification on the international scale in China using locally developed secondary reference panels.
For patients with chronic myeloid leukemia, reverse transcription quantitative polymerase chain reaction is widely used in laboratories to quantify BCR-ABL1 fusion gene transcripts for disease management. Many efforts have been made to standardize the BCR-ABL1 testing assay, including the primary and secondary reference reagents, but the secondary standards have not been developed and used in the standardization program in China. With the use of armored RNA technology, armored RNA of BCR-ABL1 and control genes was manufactured to prepare the secondary reference material anchored to the World Health Organization primary reference calibrators for standardization of BCR-ABL1 testing assays. The secondary reference was sent to 30 laboratories in China for validation. Data from an external quality assessment after the standardization process were collected and analyzed as well. The assigned %BCR-ABL1/ABL1
Publication Date: 2019-12-22
Journal: Experimental hematology

Treatment-free remission in chronic myeloid leukemia.
Tyrosine kinase inhibitors (TKIs) represent a major breakthrough in the treatment of chronic myeloid leukemia (CML). Thanks to these agents, CML has been transformed from a disease with limited treatment options and a dismal prognosis into a more indolent disease with survival comparable to that of the general population. The need for ongoing TKI therapy remains controversial for several reasons, including cost and toxicity. Studies in CML patients with a sustained deep molecular response have demonstrated that stopping TKI therapy is feasible and safe. Given the heterogeneity of results reported in clinical trials, practice guidelines for optimal patient selection and proper monitoring after discontinuation of TKIs are proposed outside of clinical trials. Current data available show that 40% to 60% of patients who stop therapy relapse; molecular relapses typically occur within 6 months, but nearly all relapsing patients regain response upon reinitiation of the TKI. Several factors that predict for relapse have been investigated. Duration of prior TKI therapy, achievement of deep molecular response, depth of molecular response, prior interferon treatment, and Sokal risk score have been shown to be potential predictors for relapse. Leukemia stem cells that are resistant to TKIs, and that persist despite undetectable BCR/ABL1 transcript levels, likely are responsible for disease relapse after discontinuation. Efforts geared toward better identification of low levels of BCR/ABL1 transcript using new techniques such as digital polymerase chain reaction, along with eradicating CML clones using combination therapies with agents such as pegylated interferon or venetoclax with TKIs, will hopefully lead to a functional cure of this disease.
Publication Date: 2019-12-19
Journal: Clinical advances in hematology & oncology : H&O

Assessing Measurable Residual Disease in Chronic Myeloid Leukemia. BCR-ABL1 IS in the
Chronic myelogenous leukemia (CML) is a malignancy of the myeloid cell lineage characterized by a recurrent chromosomal abnormality: the Philadelphia chromosome, which results from the reciprocal translocation of the chromosomes 9 and 22. The Philadelphia chromosome contains a fusion gene called BCR-ABL1. The BCR-ABL1 codes for an aberrantly functioning tyrosine kinase that drives the malignant proliferation of the founding clone. The advent of tyrosine kinase inhibitors (TKI) represents a landmark in the treatment of CML, that has led to tremendous improvement in the remission and survival rates. Since the introduction of imatinib, the first TKI, several other TKI have been approved that further broadened the arsenal against CML. Patients treated with TKIs require sensitive monitoring of BCR-ABL1 transcripts with quantitative real-time polymerase chain reaction (qRT-PCT), which has become an essential part of managing patients with CML. In this review, we discuss the importance of the BCR-ABL1 assay, and we highlight the growing importance of BCR-ABL1 dynamics. We also introduce a mathematical correction for the BCR-ABL1 assay that could help homogenizing the use of the ABL1 as a control gene. Finally, we discuss the growing body of evidence concerning treatment-free remission. Along with the continuous improvement in the therapeutic arsenal against CML, the molecular monitoring of CML represents the
Publication Date: 2019-10-15
Journal: Frontiers in oncology

Systematic Review of Normal Subjects Harbouring BCR-ABL1 Fusion Gene.
The treatment of chronic myeloid leukaemia (CML) requires quantitative polymerase chain reaction (qPCR) to monitor BCR-ABL1 in International Scale (IS). Some normal subjects were found to harbour BCR-ABL1. We performed a systematic review on normal subjects harbouring BCR-ABL1. A literature search was done on July 16, 2017 using EBSCOhost Research Databases interface and Western Pacific Region Index Medicus. Two authors selected the studies, extracted the data, and evaluated the quality of studies using the modified Appraisal Tool for Cross-Sectional Studies independently. The outcomes were prevalence, level of BCR-ABL1IS, proportion, and time of progression to CML. The initial search returned 4,770 studies. Eleven studies, all having used convenient sampling, were included, with total of 1,360 subjects. Ten studies used qualitative PCR and one used qPCR (not IS). The mean prevalence of M-BCR was 5.9, 15.5, and 15.9% in cord blood/newborns/infants (CB/NB/I) (n = 170), children (n = 90), and adults (n = 454), respectively, while m-BCR was 15, 26.9, and 23.1% in CB/NB/I (n = 786), children (n = 67), and adults (n = 208), respectively. No study reported the proportion and time of progression to CML. Nine studies were graded as moderate quality, one study as poor quality, and one study as unacceptable. The result of the studies could neither be inferred to the general normal population nor compared. Follow-up data were scarce.
Publication Date: 2019-08-12
Journal: Acta haematologica

Treatment and monitoring of Philadelphia chromosome-positive leukemia patients: recent advances and remaining challenges.
The Philadelphia (Ph) chromosome, resulting from the t(9;22)(q34;q11) translocation, can be found in chronic myeloid leukemia (CML) as well as in a subset of acute lymphoblastic leukemias (ALL). The deregulated BCR-ABL1 tyrosine kinase encoded by the fusion gene resulting from the translocation is considered the pathogenetic driver and can be therapeutically targeted. In both CML and Ph-positive (Ph+) ALL, tyrosine kinase inhibitors (TKIs) have significantly improved outcomes. In the TKI era, testing for BCR-ABL1 transcript levels by real-time quantitative polymerase chain reaction (RQ-PCR) has become the gold standard to monitor patient response, anticipate relapse, and guide therapeutic decisions. In CML, key molecular response milestones have been defined that draw the ideal trajectory towards optimal long-term outcomes. Treatment discontinuation (treatment-free remission, TFR) has proven feasible in a proportion of patients, and clinical efforts are now focused on how to increase this proportion and how to best select TFR candidates. In Ph+ ALL, results of trials with second- and third-generation TKIs are challenging the role of intensive chemotherapy and even that of allogeneic stem cell transplantation. Additional weapons are offered by the recently introduced monoclonal antibodies. In patients harboring mutations in the BCR-ABL1 kinase domain, prompt therapeutic reassessment and individualization based on mutation status are important to regain response and prevent disease progression. Next-generation sequencing is likely to become a precious tool for mutation testing because of the greater sensitivity and the possibility to discriminate between compound and polyclonal mutations. In this review, we discuss the latest advances in treatment and monitoring of CML and Ph+ ALL and the issues that still need to be addressed to make the best use of the therapeutic armamentarium and molecular testing technologies currently at our disposal.
Publication Date: 2019-04-25
Journal: Journal of hematology & oncology

A new highly sensitive real-time quantitative-PCR method for detection of BCR-ABL1 to monitor minimal residual disease in chronic myeloid leukemia after discontinuation of imatinib.
Tyrosine kinase inhibitors (TKIs) targeting the BCR-ABL1 fusion protein, encoded by the Philadelphia chromosome, have drastically improved the outcomes for patients with chronic myeloid leukemia (CML). Although several real-time quantitative polymerase chain reaction (RQ-PCR) kits for the detection of BCR-ABL1 transcripts are commercially available, their accuracy and efficiency in laboratory practice require reevaluation. We have developed a new in-house RQ-PCR method to detect minimal residual disease (MRD) in CML cases. MRD was analyzed in 102 patients with CML from the DOMEST study, a clinical trial to study the rationale for imatinib mesylate discontinuation in Japan. The BCR-ABL1/ABL1 ratio was evaluated using the international standard (IS) ratio, where IS < 0.1% was defined as a major molecular response. At enrollment, BCR-ABL1 transcripts were undetectable in all samples using a widely-applied RQ-PCR method performed in the commercial laboratory, BML (BML Inc., Tokyo, Japan); however, the in-house method detected the BCR-ABL1 transcripts in five samples (5%) (mean IS ratio: 0.0062 ± 0.0010%). After discontinuation of imatinib, BCR-ABL1 transcripts were detected using the in-house RQ-PCR in 21 patients (21%) that were not positive using the BML method. Nineteen samples were also tested using a commercially available RQ-PCR assay kit with a detection limit of IS ratio, 0.0032 (ODK-1201, Otsuka Pharmaceutical Co., Tokyo, Japan). This method detected low levels of BCR-ABL1 transcripts in 14 samples (74%), but scored negative for five samples (26%) that were positive using the in-house method. From the perspective of the in-house RQ-PCR method, number of patients confirmed loss of MMR was 4. These data suggest that our new in-house RQ-PCR method is effective for monitoring MRD in CML.
Publication Date: 2019-03-06
Journal: PloS one

Analysis of major BCR-ABL1 mRNA by digital polymerase chain reaction is useful for prediction of international scale.
Major BCR-ABL1 mRNA in patients with chronic myeloid leukemia (CML) has generally been analysed by real-time polymerase chain reaction (PCR). Application of the international scale (IS) for the quantification of major BCR-ABL1 mRNA has been recommended in several sets of guidelines, including those of the European LeukemiaNet. The aim of this study was to clarify the efficacy of digital PCR technology for the IS of BCR-ABL1 mRNA in the patients with CML by comparing with real-time PCR. The analysis of BCR-ABL1 mRNA was carried out by the Ipsogen The correlation between the data obtained by digital PCR and by real-time PCR was really high at R = 0.96. The detection limit of digital PCR was up to 0.003% and was equal to IS with 0.01% or less in comparison with real-time PCR. Digital PCR technology is promising for predicting the IS value with similar efficacy to real-time PCR and should be useful for simple monitoring of the effects of tyrosine kinase inhibitor (TKI) treatments.
Publication Date: 2019-02-25
Journal: International journal of clinical oncology

Detection of
The presence of BCR-ABL1 fusion gene resulting from a t(9; 22) reciprocal chromosome translocation is the molecular hallmark of chronic myeloid leukemia (CML). In the diagnosis and treatment of CML, peripheral blood or bone marrow samples are usually taken for analysis. However, both methods are invasive sample collection methods, thus a noninvasive saliva sample method for the detection of the fusion gene transcripts (BCR-ABL) was investigated in some Nigerians with CML. Real-time (RT)-polymerase chain reaction (PCR) analysis was used to detect BCR-ABL1 fusion gene in the saliva and blood of 42 Nigerian CML patients. RNA was extracted using RNeasy kit and reverse transcribed by random hexamer priming using murine Moloney reverse transcriptase. BCR-ABL1 transcript types were first detected by multiplex PCR and then quantified by a duplex RT-PCR-TaqMan chemistry with MGB probe and Black Hole Quencher. Of the 42 subjects, transcript types were detected in 36 (85.7%) samples, e13a2 fusion transcript sub-type was detected in 9 (21.4%), whereas e14a2 subtype was found in 27 (67.3%); six (14.3%) of the samples did not reveal any of the fusion transcript subtypes. The median BCR-ABL1 messenger RNA values were 9.38 × 10 Saliva may offer an alternative easy-to-collect, readily available, and noninvasive sample for the diagnosis and treatment of CML.
Publication Date: 2019-01-23
Journal: Nigerian journal of clinical practice

digital polymerase chain reaction(7)

transcription quantitative polymerase chain(6)

bcr-abl1 fusion transcripts(7)

q34 q11 2(5)

bcr-abl1-positive acute lymphoblastic(5)

breakpoint cluster region(5)

tyrosine kinase inhibitor(5)

quantitative reverse transcription(5)

peripheral blood(7)

bcr-abl1 mrna(7)

reaction rt-pcr(6)

inhibitors tkis(6)

reaction qpcr(5)

etv6-runx1 tcf3-pbx1(4)

philadelphia ph(4)

response mr(3)

imatinib mesylate(3)

q11 bcr-abl1(2)

bcr-abl1 etv6-runx1(2)

respectively(5)