OBJECTIVETo revalidate the conversion factor（CF）for the conversion of BCR-ABL （P210）transcript levels to the international scale（BCR- ABLIS）in chronic myeloid leukemia（CML） which validated before.

METHODSPeking University People's Hospital（PKUPH）prepared the exchange samples for revalidation of CFs of 15 laboratories which validated nine or eighteen months ago. The fresh BCR-ABL（P210）（+）bone morrow or peripheral blood nucleated cells were diluted with BCR-ABL （P210）（-）cells to achieve different BCR- ABL levels, totally 16 sets and 24 samples per set were prepared. TRIzol reagent was added in each tube. Each laboratory tested BCR-ABL transcript levels of one set of samples. Agreement between BCR-ABLIS of each laboratory and PKUPH was assessed by the Bland- Altman method. For laboratories which did not meet the criteria of revalidation, linear regression equation was derived after the samples with maximum BCR-ABL deviation were removed until R²>0.98, then new CF was calculated.

RESULTS10 laboratories met the revalidation criteria with both bias within ±1.4 fold and 95% limits of agreement within ±6 folds, and their CFs still could be used for accurately conversion of BCR-ABLIS. New CFs were recalculated as of 1.8-6.3 folds of their previous CFs in 5 laboratories not met the criteria.

CONCLUSIONRevalidation of CF by sample exchange among laboratories was necessary for accurate and continuous application of BCR-ABLIS, which not only tested the validity of CF acquired before but also calculated new available CFs for those with invalid CFs.

Bone Marrow Cells ; Fusion Proteins, bcr-abl ; genetics ; Humans ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; diagnosis ; genetics

All kinds of tumors have their specific DNA methylation patterns. The study of DNA methylation changes in chronic myelogenous leukemia includes (1) the hypomethylation of carcinogenic gene, (2) the hypermethylation of tumor-suppressing gene, and (3) the hypermethylation of fusion gene. In this paper, DNA methylation change in chronic myeloid leukemia (CML) and its role in clinical stages and evaluation of prognosis were reviewed so as to illuminate the relationship between DNA methylation and CML.
DNA Methylation ; Humans ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; diagnosis ; genetics ; pathology ; Prognosis

OBJECTIVETo explore the effect of false positive signals during detection of BCR/ABL fusion gene by fluorescence in situ hybridization (FISH), and develop a method for calibration.

METHODSNormal specimens were mixed with BCR/ABL positive specimens in which presented signal pattern of 1-red-2-green-1-fusion (1R2G1F) using dual color dual fusion (DCDF) probes and 1-red-1-green-1-fusion (1R1G1F) using extra signal (ES) probes in different proportions. Mixed samples were detected using DCDF and ES probes. Results of DCDF probes, ES probe before calibration, ES probes after calibration and theoretical results were compared by binomial distribution in different proportions.

RESULTSThe rate of false positive signals has risen with increase of negative rate. A significant difference was found between theoretical proportion and results without calibration in negative level, 5%, 10% and 25% positive level (P<0.05). There was no significant difference between theoretical proportion and results without calibration in 50% and 90% positive level (P>0.05). Also there was no significant difference between theoretical proportion and calibrated results (P>0.05).

CONCLUSIONCalibration of FISH result can delimitate the effect of false positives, and can provide more reliable results in cases with low level positive rates.

Adult ; Calibration ; False Positive Reactions ; Female ; Fusion Proteins, bcr-abl ; genetics ; Humans ; In Situ Hybridization, Fluorescence ; methods ; standards ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; diagnosis ; genetics ; Young Adult

No abstract available.
Base Sequence ; Bone Marrow/pathology ; Fusion Proteins, bcr-abl/*genetics ; Humans ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive/diagnosis/*genetics ; Male ; Middle Aged ; Real-Time Polymerase Chain Reaction

OBJECTIVETo explore the clinical and laboratory features of chronic myeloid leukemia (CML) with atypical e14a3 and e19a2 BCR-ABL fusion gene subtypes.

METHODSWe retrospectively analyzed a cohort of CML patients with Ph chromosome positive confirmed by cytogenetic and FISH but classical e13a3(b2a2), e14a2(b3a2)and e1a2 fusion transcripts negative identified by conventional real-time quantification RT-PCR (RQ-PCR). Further RQ-PCR was done with the forward primer and reverse primer designed to detect rare atypical BCR-ABL fusion genes including e14a3 and e19a2 transcripts. Direct sequencing analysis was performed on the PCR products and mutations in the BCR-ABL kinase domain were detected. The clinical data of patients were retrospectively analyzed.

RESULTSSix CML patients were found to carry t(9;22) abnormality and BCR-ABL rearrangement confirmed by FISH but classical BCR-ABL fusion genes negative detected by RQ-PCR. Further RQ-PCR and sequencing analysis confirmed the fusion of BCR exon 14 and ABL exon 3 in five CML patients (case 1-5) and the fusion of BCR exon 19 and ABL exon 2 in one CML patient (case 6). E255K and I293T IM-resistant mutations were detected in case 1 and 2, respectively. Among five cases with e14a3 transcripts, four were CML-CP, one CML-AP. Four patients were male and one was female. The median age was 48 years. The patient (case 6) with e19a2 transcripts was 40-year-old female with a diagnosis of CML-CP and PLT count was more than 1 000×10⁹/L. Imatinib (IM) therapy was administer in case 1, 2, 3, 4 and hematopoietic stem cell transplantation (HSCT) was undergone in case 5 after hydroxyurea (Hu) or interferon failure. Case 1 who had E255K IM resistant mutation, responded poorly to IM but obtained a complete cytogenetic remission (CCyR) after a substitution of dasatinib for IM. Case 2 and 3 achieved CCyR 6 months later after IM treatment and had been maintained well with IM despite I293T mutation in case 2. Case 4 attained CCyR 3 months later after IM treatment but relapsed and died soon. Case 5 was still in CCyR after HSCT. Case 6 with e19a2 transcripts got complete hematologic response after Hu treatment and CCyR was achieved soon after IM therapy.

CONCLUSIONIncidence of CML with atypical transcripts is extremely low. They could benefit from tyrosine kinase inhibitors or HSCT. Rare and atypical BCR- ABL fusion gene subtypes could be missed by conventional RQ-PCR.

Adult ; Female ; Fusion Proteins, bcr-abl ; genetics ; Humans ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; classification ; diagnosis ; genetics ; Male ; Middle Aged ; Retrospective Studies

OBJECTIVETo investigate the comparability of bcr-abl (P210) transcript levels detected in different hospitals.

METHODSTen hospitals in China took part in the four times of sample exchange and comparisons from April, 2010 to August, 2011. The exchange samples were prepared by Peking University People's Hospital. Firstly, the BCR-ABL (P210)(+) cells from a newly diagnosed chronic myeloid leukemia patient were 10-fold serially diluted by BCR-ABL (P210)(-) cells and they covered 4 magnitudes. Then, TRIzol reagents were thoroughly mixed with cells in each tube. Every 12 samples (three samples per magnitude) were sent to the other 9 hospitals. The cell number of each sample was 8×10(6). The detection of bcr-abl transcript levels by real-time quantitative PCR were performed in every hospital according to their own protocols. Conversion factors (CF) were calculated using regression equation.

RESULTSDifferences in bcr-abl transcript levels did exist among results of 10 hospitals in each comparison. In general, the results of the most of hospitals were in line with the dilutions of cells. CF of every hospital fluctuated. Three hospitals had relatively stable CF, and their ranges were 2.8 - 5.2, 1.2 - 2.8 and 2.2 - 6.8, respectively; two hospitals had unstable CF with ranges 0.76 - 7.0 and 2.1 - 18.7; three hospitals couldn't be calculated CF one or two times because of the significant deviation of the results from the actually bcr-abl transcript levels, and their ranges of CF which could be calculated were 1.9 - 19.2, 3.6 - 7.6 and 0.18 - 14.7; One hospital only had two CF (3.3 and 5.0) because of the replacement of an important reagent during the period of comparisons.

CONCLUSIONSComparability of bcr-abl (P210) transcript levels between different hospitals could be achieved through CF which acquired by sample exchange and comparison. The stable and reliable detection system is the premise to acquire correct CF.

Bone Marrow Cells ; China ; Fusion Proteins, bcr-abl ; genetics ; isolation & purification ; Hospitals ; Humans ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; diagnosis ; genetics ; Reverse Transcriptase Polymerase Chain Reaction

OBJECTIVE: To establish a new digital polymerase chain reaction (dPCR) system for the detection of BCR-ABL fusion gene in patients with chronic myeloid leukemia (CML), and explore its analytical performance and clinical applicability in the detection of BCR-ABL^p190/210/230. METHODS: A new dPCR system for detecting BCR-ABL^p190/210/230 was successfully developed, and its sensitivity difference with qPCR and improvement of drug side effects in patients with CML during drug reduction or withdrawal were compared. RESULTS: Among 176 samples, qPCR and dPCR showed high consistency in the sensitivity of detecting BCR-ABL (82.39%), and the positive rate of dPCR was about 5 times higher that of qPCR (20.45% vs 3.98%). During follow-up, blood routine (25% vs 10%), kidney/liver/stomach (25% vs 20%) and cardiac function (10% vs 0) were significantly improved after drug reduction or withdrawal in patients with initial dPCR negative compared with before drug reduction or withdrawal. CONCLUSIONS This new dPCR detection system can be applied to the detection of BCR-ABL^p190/210/230. It has better consistency and higher positive detection rate than qPCR. Drug withdrawal or dose reduction guided by dPCR has a certain effect on improving drug side effects.
Humans ; Fusion Proteins, bcr-abl/genetics* ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive/diagnosis* ; Polymerase Chain Reaction ; Drug-Related Side Effects and Adverse Reactions ; Reverse Transcriptase Polymerase Chain Reaction

OBJECTIVETo compare the signal patterns of dual color extra-signal BCR/ABL probe (ES-FISH) and dual color dual fusion BCR/ABL probe (D-FISH) in the fluorescence in situ hybridization (FISH) detection of Ph-positive leukemia, and to explore their diagnostic value.

METHODSES-FISH probe and D-FISH probe were used, respectively, to detect the BCR/ABL fusion gene in 74 cases with typical t(9;22)(q34;q11) and 37 cases with variant t(9;22)(q34;q11) translocation or complex karyotypic abnormalities containing Ph translocation.

RESULTSThe BCR/ABL fusion gene in all cases with typical t(9;22)(q34;q11) could be detected by both FISH probes. D-FISH had a signal pattern of 1O1G2F, while ES-FISH showed a signal pattern of 2O1G1F. ES-FISH enables the minor breakpoint cluster region to be identified in 9 cases (12.2% ) of Ph-positive leukemia, whereas D-FISH could not differentiate the minor breakpoint cluster region from major breakpoint cluster region. D-FISH could distinguish simple ABL gene deletion from simultaneous deletion of the ABL and BCR genes in 8 cases (10.8%) of Ph-positive leukemia patients, but ES-FISH could not. For variant Ph translocation or complex karyotypic abnormalities containing Ph translocation, each FISH probe showed four or six types of signal pattern, most of which were atypical. The exact interpretation was dependent on conventional karyotypic analysis and FISH on metaphases.

CONCLUSIONES-FISH and D-FISH probes displayed different signal patterns in Ph-positive leukemia due to their differences in size and covered regions. ES-FISH and D-FISH probes may be selected as better probe for Ph-positive acute lymphocytic leukemia and Ph-positive chronic myeloid leukemia, respectively. When imatinib was used for treatment, there was no preference between ES-FISH and D-FISH probe, because major breakpoint cluster region, minor breakpoint cluster region and partial sequence deletion of derivative chromosome 9, would not affect the prognosis of Ph-positive leukemia. However, considering that ES-FISH probe has a better cost-performance than D-FISH probe does, it is recommended as first choice.

Case-Control Studies ; Chromosomes, Human, Pair 9 ; genetics ; Humans ; In Situ Hybridization, Fluorescence ; methods ; Karyotyping ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; diagnosis ; genetics ; Proto-Oncogene Proteins c-bcr ; genetics

This study was aimed to investigate the chimerism and fusion gene expression in patients with CML after allo-HSCT, to analyse engraftment and minimal residual disease by using STR-PCR combined with RT-PCR qualitative and quantitative assays, and to evaluate their clinical value for predicting disease relapse. 4 relapsed patients with CML after allo-HSCT were dynamically investigated. Qualitative analysis of donor chimerism was performed by multiplex PCR amplification of STR markers and capillary electrophoresis with fluorescence detection, qualitative detection of bcr/abl transcripts was performed by RT-PCR. The results showed that the 100% donor chimerism appeared in 4 patients on day 28 after transplantation and bcr/abl expression was negative, but the 4 patients were in status of unstable mixed chimerism (DC: 0% - 80.4%) at the different time points during the following up with bcr/abl gene positive. 2 patients of them were continuously mixed chimerism after relapse of CML, the other 2 changed from MC to CC by intervention of clinical treatment. Decreasing values of donor chimerism were detected prior to the occurrence of graft rejection and CML relapse, and bcr/abl gene expression was positive. It is concluded that the results of STR-PCR in the range of its sensitivity fully correspond with bcr/abl tests in patients. The combination of STR-PCR with RT-PCR will provide a highly sensitive and valuable tool for evaluating engraftment, graft rejection, and relapse and predicting GVHD. Furthermore, it can provide a basis for early intervention of clinical treatment, and can identify these high risk patients with molecular or cytogenetic relapse after allo-HSCT.
Fusion Proteins, bcr-abl ; genetics ; metabolism ; Hematopoietic Stem Cell Transplantation ; adverse effects ; Humans ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; genetics ; therapy ; Neoplasm Recurrence, Local ; genetics ; Neoplasm, Residual ; diagnosis ; genetics ; RNA, Messenger ; genetics ; metabolism ; Transplantation Chimera ; Transplantation, Homologous

This study was aimed to investigate the clinical, pathological and biological features of a special case of chronic myeloid leukemia (CML) with marked thrombocythemic onset. The morphological changes of cells were analyzed by using bone marrow smear and biopsy; Ph chromosome, a specific marker of CML, was assayed by conventional chromosomal analysis and fluorescence in situ hybridization, bcr/abl fusion gene was detected by reverse transcription-polymerase chain reaction. The results indicated that CML mimicked essential thrombocythemia (ET) at presentation was relatively rare and might be misdiagnosed as ET, bone marrow smear and biopsy revealed, marked thrombocytosis and moderate leukocytosis; RT-PCR, FISH and conventional chromosomal analysis demonstrated the existence of Ph chromosome and bcr/abl fusion gene. This special CML could progress into accelerated phase or blast crisis. The megakaryocytes in Ph+ ET were smaller than normal ones and had typically hypolobulated round nuclei. Patients diagnosed as Ph+ ET might progress into CML and showed a high tendency to myelofibrosis and blastic transformation. It is concluded that the value of routine cytogenetical and molecular biological analysis in diagnosis for potential CML cases, which mimicked ET as in this presentation, is very distinctive, and the importance is magnified by the recent availability of imatinib, a specific inhibitor of the bcr/abl tyrosine kinase produced by the Philadelphia chromosome. Every case of "ET" should be tested for the Philadelphia chromosome and bcr/abl transcript.
Adult ; Diagnosis, Differential ; Female ; Fusion Proteins, bcr-abl ; genetics ; Gene Rearrangement ; Humans ; In Situ Hybridization, Fluorescence ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; complications ; diagnosis ; genetics ; Megakaryocytes ; pathology ; ultrastructure ; Philadelphia Chromosome ; Reverse Transcriptase Polymerase Chain Reaction ; Thrombocythemia, Essential ; diagnosis