Detection of BCR-ABL Fusion Gene in Chronic Myeloid Leukemia by Novel Digital PCR / 中国实验血液学杂志

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-ABLp190/210/230.@*METHODS@#A new dPCR system for detecting BCR-ABLp190/210/230 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-ABLp190/210/230. 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.

Genetic analysis of a case of B-acute lymphoblastic leukaemia with double Philadelphia chromosomes and double derivative chromosome 9s / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a rare case of acute B-lymphocytic leukemia (B-ALL) with double Philadelphia chromosomes (Ph) and double derivative chromosome 9s [der(9)].@*METHODS@#A patient with double Ph and double der(9) B-ALL who presented at Shanghai Zhaxin Intergrated Traditional Chinese and Western Medicine Hospital in June 2020 was selected as the subject. Bone marrow morphology, flow cytometry, G-banding karyotyping, fluorescence in situ hybridization (FISH), genetic testing and chromosomal microarray analysis (CMA) were used to analyze bone marrow samples from the patient at various stages.@*RESULTS@#At initial diagnosis, the patient's bone marrow morphology and flow immunotyping have both supported the diagnosis of B-ALL. G-banded karyotyping of the patient indicated double Ph, in addition with hyperdiploid chromosomes involving translocations between chromosomes 9 and 22. BCR-ABL1 fusion gene was positive. Genetic testing at the time of recurrence revealed presence of a heterozyous c.944C>T variant in the kinase region of the ABL1 gene. FISH showed a signal for ABL1-BCR fusion on both chromosome 9s. CMA showed that the mosaicism homozygosity ratio of chromosome 9 was about 40%, and the mosaicism duplication ratio of chromosome 22 was about 43%.@*CONCLUSION@#Since both der(9) homologs were seen in 40% of cells, the possible mechanism for the double der(9) in this patient may be similar to that of double Ph, which might have resulted from non-disjunction during mitosis in the Ph chromosome-positive cell clone.

Research Advance of BCR-ABL Mutation and the Efficacy of Second and Third Generation TKI in Chronic Myeloid Leukemia--Review / 中国实验血液学杂志

The treatment of chronic myeloid leukemia (CML) was revolutionized with the advent of the first-generation tyrosine kinase inhibitors (TKIs), but drug resistance developed during treatment, leading to the development of the second-generation (dasatinib, nilotinib, and bosutinib) and third-generation (ponatinib) TKI. Compared with previous treatment regimens, specific TKI can significantly improve the response rate, overall survival rate and prognosis of CML. Only a few patients with BCR-ABL mutation are insensitive to the second-generation TKIs, so it is suggested to select the second-generation TKIs for patients with specific mutations. For patients with other mutations and without mutations, the second-generation TKI should be selected according to the patient's medical history, while the third-generation TKIs should be selected for mutations that are insensitive to the second-generation TKIs, such as T315I mutation that is sensitive to ponatinib. Due to different BCR-ABL mutations in patients with different sensitivity to the second and third-generation TKIs, this paper will review the latest research progress of the efficacy of the second and third-generation TKIs in CML patients with BCR-ABL mutations.

Recent Advance of Newly Therapy for Chronic Myeloid Leukemia with BCR-ABLT315I Mutation--Review / 中国实验血液学杂志

BCR-ABLT315I mutation is the main mechanism of resistance to the first and second generation tyrosine kinase inhibitor (TKI) for patients with chronic myeloid leukemia (CML). Ponatinib as the third generation TKI has been found that can significantly improve the prognosis of CML patients with T315I mutation. However, the latest report has discovered that the T315I compound mutant is even resistant to ponatinib, which aroused the enthusiasm of research on the mechanism of CML resistance and targeted therapy once again. Previous studies have shown that TKI combined with other targeted drugs is effective to CML patients with drug resistance or relapse due to T315I mutation. The latest research has found that the allosteric inhibitor asciminib combined with TKI therapy is equally effective to CML patients with T315I compound mutant, but the specific mechanism is not yet clarified. This review will focus on the latest research progress of therapy for CML with BCR-ABLT315I mutation, hoping to provide reference for researching new drugs and improve therapy for treating CML with T315I mutation.

Leukemia Genotype Analysis of Children with Acute Lymphoblastic Leukemia in Yunnan Area / 中国实验血液学杂志

OBJECTIVE@#To analyze 43 leukemia genes in children with acute lymphoblastic leukemia (ALL) in Yunnan province, and provide the basis for the diagnosis and treatment of children with ALL in this area.@*METHODS@#The clinical data of 428 children with newly diagnosed ALL in Yunnan area from January 2015 to December 2020 were retrospectively analyzed. Multiple nested PCR technology was used to detect 43 common leukemia genes.@*RESULTS@#Among the 428 children with ALL, 159 were positive for leukemia genes, with a positive rate of 37.15% (159/428), and a total of 15 leukemia genes were detected. Among the 159 leukemia gene-positive children, ETV6-RUNX1+ accounted for 25.79% (41/159), followed by E2A-PBX1+ and BCR-ABL+, accounting for 24.53% (39/159) and 23.27% (37/159) respectively. MLL+ accounted for 6.29% (10/159), WT1+ accounted for 4.40% (7/159), IKZF1 gene deletion and CRLF2+ accounted for 3.77% (6/159) respectively. The positive rate of MLL (46.15%) was the highest in ＜1-year old group, the positive rate of ETV6-RUNX1 (10.56%) was the highest in 1-10-year old group, and BCR-ABL+ rate (23.65%) was the highest in >10-year old group. The distribution of leukemia genes in different age groups was statistically significant (P <0.05).@*CONCLUSION@#The most common fusion gene of children with ALL in Yunnan is ETV6-RUNX1, followed by E2A-PBX1 and BCR-ABL.

Distribution of ETV6-ABL Fusion Gene in Hematopoietic Cell Populations of Myeloproliferative Neoplasm / 中国实验血液学杂志

OBJECTIVE@#To explore the expression level of ETV6-ABL fusion gene in different cell populations in patients with myeloproliferative neoplasm (MPN) and therapeutic effect of tyrosine kinase inhibitor (TKI).@*METHODS@#A 42-year-old man who presented with fever, marked leukocytosis and chronic myelogenous leukemia (CML) like MPN was reported. ETV6-ABL fusion gene was detected by real-time PCR and confirmed by direct sequencing. ETV6-ABL mRNA expression in each cell population sorted from peripheral blood by flow cytometry was detected by real-time PCR.@*RESULTS@#ETV6-ABL fusion gene was found out in bone marrow cells and confirmed as type A by direct sequencing. ETV6-ABL fusion gene transcript level in polymorphonuclear cells was nearly 3.6-fold relative to that in total cells, which was significantly higher than that in T cell, B cell and monocyte subsets. The complete blood count (CBC) returned to normal level after treatment with imatinib (400 mg) daily for three months. After TKI treatment for 6 months, the ratio of ETV6-ABL/ABL decreased from 174.1% to 1.9%.@*CONCLUSION@#ETV6-ABL fusion gene positive MPN may have a CML clinical presentation and is sensitive to TKI. ETV6-ABL fusion gene is specifically expressed in polymorphonuclear cells.

Investigation of Laboratory and Clinical Feature in the Patients with Myeloproliferative Neoplasm Co-expression of BCR-ABL1 and JAK2 V617F / 中国实验血液学杂志

OBJECTIVE@#To analyze the comprehensive laboratory test data of BCR-ABL1 fusion gene and JAK2 V617F mutation co-expressed in myeloproliferative neoplasm (MPN) patients, and investigate its relative clinical significance.@*METHODS@#Data of 1 332 MPN patients were comprehensively analyzed, BCR-ABL1 (P190/P210/P230) fusion gene and JAK2 V617F mutation were detected by real time-polymerase chain reaction (RT-PCR) technique, the CALR, MPL, JAK2 12 and 13 exon mutations were detected by the First Generation Sequencing, the bone marrow cell morphology and pathological characteristics were evaluated by bone marrow smear and biopsy technique, the immune phenotypes of bone marrow cells were evaluated by flow cytometry, the chromosome karyotypes of bone marrow cells were analyzed by chromosome G banding technique.@*RESULTS@#Four of the 1 332 patients were found to have the co-existence of BCR-ABL1 fusion gene and the JAK2 V617F mutation, with a 0.3% incidence and a median age of 70 years old, including 2 cases of polycythemia vera, 1 case of primary myelofibrosis, and 1 case of chronic myeloid leukemia-accelerated phase. The clues of double positive genes of such patients at the time of initial diagnose could not be cued only by age, physical signs and cell morphology, they should be analyzed by comprehensive test data.@*CONCLUSION@#The co-existence of BCR-ABL1 fusion gene and JAK2 V617F mutation in the same case is a kind of disease with special clinical significance. The application of multiple detection methods can improve the detection of this disease, which is conducive to early detection, reasonable diagnosis and treatment by clinicians.

Clinical Effect of Tyrosine Kinase Inhibitors in the Treatment of P230 Chronic Myeloid Leukemia / 中国实验血液学杂志

OBJECTIVE@#To observe the curative efficacy of tyrosine kinase inhibitors (TKIs) in the treatment of e19a2 transcript (P230) CML chronic phase (CML-CP) patients.@*METHODS@#The clinical data of 11 P230 CML-CP patients were collected from July 2008 to December 2019. Blood routine examination, bone marrow cytology, chromosome, and BCR-ABL qualitative and quantitative tests were performed at initial diagnosis. After TKIs treatment, BCR-ABL (P230)/ABL in peripheral blood was regularly detected to evaluate molecular response by real-time quantitative PCR.@*RESULTS@#There were 11 patients (7 males and 4 females) in chronic phase from 6 domestic hospitals enrolled, their median age was 46 years old (range from 19 to 56 years old). Among 4 patients treated with imatinib (400 mg, qd) firstly, 3 cases switched to nilotinib (400 mg, bid) and 1 case switched to dasatinib (100 mg, qd) due to failure to achieve best molecular response at the landmark time or mutation of ABL kinase. Then major molecular response (MMR) was obtained within 1 year. In addition, 5 patients were treated with nilotinib (300 mg, bid) and 2 patients with dasatinib (100 mg, qd) as first-line treatment, all of them got MMR within 6 months.@*CONCLUSION@#For intolerance or resistance to imatinib, second-generation TKIs can enable P230 CML patients to achieve deeper molecular response, and MMR in a short time.

Analysis of Clinical Characteristics of JAK2 V617F and BCR-ABL Double-Mutant Myeloproliferative Neoplasms / 中国实验血液学杂志

OBJECTIVE@#To analyze the disease types, clinical manifestations, efficacy and outcome of JAK2 V617F and BCR-ABL double-mutant myeloproliferative neoplasms (MPN), and provide a reference for the diagnosis, treatment and prognosis of MPN.@*METHODS@#The clinical characteristics, diagnosis, therapeutic efficacy and outcome of JAK2 V617F and BCR-ABL double-mutant MPN were analyzed comprehensitively by combining a clinical case diagnosed and treated in our hospital with literature cases from CNKI and PubMed databases.@*RESULTS@#A total of 38 related literatures were retrieved from the two databases by searching "JAK2 V617F" and "BCR-ABL" as key words from 1990 to 2019, and 59 cases were involved. Among all the 60 cases, 41 were males (68.3%) with a median age of 61 (32-77) years old, while 19 were females (31.7%) with a median age of 58 (21-82) years old. The BCR-ABL fusion gene and JAK2 V617F mutation were found simultaneously in 21 cases (35%), 19 cases (31.7%) with JAK2 V617F mutation were found during the treatment of Philadelphia chromosome (Ph)-positive chronic myelogenous leukemia (CML). Ph@*CONCLUSION@#As cases of BCR-ABL and JAK2 V617F double-mutant MPN are reported, simultaneous detection of JAK2 V617F mutation and BCR-ABL fusion gene in MPN patients is necessary to avoid misdiagnosis and missed diagnosis.

Therapeutic Effect of Imatinib Made in Real World to Newly Diagnosed Chronic Myeloid Leukemia / 中国实验血液学杂志

OBJECTIVE@#To evaluate the clinical efficacy and safety of domestic imatinib (made in China) in patients with newly diagnosed chronic myeloid leukemia chronic phase(CML-CP).@*METHODS@#Fifty-seven newly diagnosed CML-CP patients who did not receive any other anti-CML treatment were treated by domestic imatinib 400 mg once a day. The hematological, cytogenetic and molecular reactions and safety were observed and evaluated after 3, 6 and 12 months of treatment.@*RESULTS@#Fifty-six patients were treated for ≥3 and 6 months, among which 50 patients were treated for ≥12 months. After 3 months of treatment, 49 patients underwent hematological examination, 47 patients (95.9%) achieved complete hematological response (CHR), 49 patients underwent cytogenetic examination, 39 patients (79.6%) achieved major cytogenetic response (MCyR), and 12 patients (24.5%) achieved complete cytogenetic response (CCyR). 49 patients underwent the level of BCR-ABL test, including 41 patients (83.7%) with BCR-ABL@*CONCLUSION@#In the real world, Domestics imatinib mesylate is effective and safe in the treatment of newly diagnosed CML-CP patients, but long-term follow-up data are still necessary to verify its long-term efficacy.

Effect of Etoposide on Elimination of Chronic Myeloid Leukemia Stem Cells by Imatinib in Vivo / 中国实验血液学杂志

OBJECTIVE@#To investigate the effect of etoposide (ETO) on elimination of chronic myeloid leukemia (CML) stem cells by imatinib mesylate(IM) in vivo.@*METHODS@#SCL-tTA/BCR-ABL mice were used as CML animal model. Flow cytometry was used to assess the effect of ETO alone or in combination with IM on the number of leukemia stem cell （LSC） in bone marrow and spleen, and peripheral blood neutrophils in CML mice and normal control FVB mice.@*RESULTS@#The results showed that in CML mice, the number and proportion of LSC in bone marrow and the proportion of neutrophils in peripheral blood decreased significantly after ETO and IM combined treatment, and the degree of decrease was more significant than that of both alone. While in wild type FVB mice, the combination of ETO and IM showed no significant effect on the number and proportion of LSK cells in bone marrow and the proportion of neutrophils in spleen.@*CONCLUSION@#ETO can selectively enhance elimination of CML LSC by IM in vivo.

Research Advance on the Effect of Autophagy on the Survival of Chronic Myeloid Leukemia Cells--Review / 中国实验血液学杂志

Tyrosine kinase inhibitor (TKI) has significantly improved the treatment of chronic myeloid leukemia (CML), however the resistance often resulted in treatment failure. Currently, it is known that the survival of CML cells can be affected by regulating autophagy, oxidative stress and mitochondrial metabolism, among which autophagy is an evolution-conserved catabolism process, and closely related to the pathogenesis of CML, thus playing a dual role in regulating the biological characteristics of cells. On the one hand, autophagy can promote the apoptosis of CML cells, and also can induce the drug resistance of CML cells on the other hand. In this review, the effect of autophagy on CML cells was summarzed briefly, so as to provide a useful idea to explore the combination of TKI with the autophagy inhibitor or inducer to overcome the resistance of CML to TKI.

Prognostic significance of a normal karyotype in adult patients with BCR-ABL1-positive acute lymphoblastic leukemia in the tyrosine kinase inhibitor era

OBJECTIVE: The occurrence of cryptic Philadelphia (Ph) chromosome translocation is rare in BCR-ABL1-positive acute lymphoblastic leukemia (BCR-ABL1+ ALL) and is of unknown significance in the tyrosine kinase inhibitor (TKI) era. METHODS: We retrospectively studied a series of adult patients receiving TKI-based therapy to evaluate the prognostic impact of the normal karyotype (NK) (n=22) in BCR-ABL1+ ALL by comparison with the isolated Ph+ karyotype (n=54). RESULTS: There were no statistically significant differences in clinical characteristics and complete remission rate between the two groups. Compared with the isolated Ph+ group, the NK/BCR-ABL1+ group had a higher relapse rate (55.0% versus 29.4%, p=0.044). Overall survival (OS) and disease-free survival (DFS) were significantly shorter in the NK/BCR-ABL1+ group than in the isolated Ph+ group [median OS: 24.5 versus 48.6 (months), p=0.013; median DFS: 11.0 (months) versus undefined, p=0.008]. The five-year OS and DFS for patients with NK/BCR-ABL1+ were 19.2% and 14.5%, respectively; those for patients with isolated Ph+ were 49.5% and 55.7%, respectively. Thirty-four (44.7%) patients underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) in this study. Among the patients who received allo-HSCT, the median OS and DFS in the NK/BCR-ABL+ group (n=9) were 35.5 and 27.5 months, respectively, while those in the isolated Ph+ group (n=25) were undefined. There was a trend of significant statistical difference in the OS between the two subgroups (p=0.066), but no significant difference in the DFS. Multivariate analysis revealed that NK was independently associated with worse OS and DFS in BCR-ABL1+ ALL patients [Hazard ratio (HR) 2.256 (95% confidence interval (CI), 1.005-5.066), p=0.049; HR 2.711 (95% CI, 1.319-5.573), p=0.007]. CONCLUSION: Our results suggest that the sub-classification of an NK could be applied in the prognostic assessments of BCR-ABL1+ ALL. In addition, allo-HSCT should be actively performed to improve prognosis in these patients.

Detection of BCR/ABL Fusion Gene and ASS1 Gene Deletion by Using Tricolor Dual-fusion Probe / 中国实验血液学杂志

OBJECTIVE@#To analyze the significance of various abnormal signal patterns appreared in CML and B-ALL patients by using BCR/ABL/ASS1 tricolor dual-fusion probe, and to explore its application value in detecting BCR/ABL fusion gene and ASS1 gene deletion.@*METHODS@#50 newly diagnosed CML patients and 50 newly diagnosed B-ALL patients were detected by fluorescence in situ hybridization (FISH) with BCR/ABL/ASS1 tricolor dual-fusion probe. Meanwhile, karyotype analysis was performed on all the patients using the 24 hours short-term culture and R-banding.@*RESULTS@#Among the 50 CML patients, Ph was found in 49 cases, 5 normal interphase karyotype was observed in 1 case. FISH detection showed that BCR/ABL fusion gene existed in all patients (100%), while the positive signal pathway showed that 1R1G2B2F was observed in 39 cases (78%), 2R1G2B1F in 2 cases (4%) and 1R1G2B1F in 6 cases (12%), simultaneous existence of 1R1G1B1F and 1R1G2B3F in 1 case (2%), 2R1G1B1F in 1 case (2%) 1R1G3B3F in 1 case (2%). FISH detection also showed that the karyotype of 6 case at ASS1 gene deletion (1R1G1B1F) all were simple t (9; 22) translocation, and other abnormalities not were observed. Among 50 cases of B-ALL, Ph was found in 13 cases, the numerical aberration and structural aberration of non t (9; 22) in 16 cases, normal karyotype in 20 cases, absence of mitotic phase in 1 case. FISH detection showed that 16 cases (32%) had BCR/ABL fusion gene including 13 cases (26%) of 1R1G2B2F, 1 case (2%) of stimultaneous exitance of 1R1G2B2F and 1R1G3B3F 1 case (2%) of 2R1G1B1F, 1 case (2%) of 1R1G3B2F. FISH detection also showed that 3 cases had BCR/ABL fusion gene, including 1 case with ASS1 gene deletion (2R1G1B1F), 1 case with classical t (9; 22) translocation (1R1G2B2F) and 1 case with BCR/ABL fusion gene and increase of ASS1 gene copy (1R1G3B3F).@*CONCLUSION@#Tricolor dual-fusion FISH probe for detecting BCR/ABL fusion gene and ASS1 gene deletion is simple, rapid, sensitive and stable. It can detect various forms of molecular fusion and avoid the false positive results due to coincidental overlap of signals generated by D-FISH probe and ES-FISH probe. In addition, this detection method not only can directly observe the presence or absence of ASS1 gene deletion, but also improve the reliability of the positive results of newly diagnosed BCR/ABL fusion gene and accuracy of monitoring results of minimal residual disease for the subsequent visit.

Curative Efficacy of First Generation TKI in the Treatment of CML-CP Combined with vPh and Analysis of Its Genetic Characteristics / 中国实验血液学杂志

OBJECTIVE@#To investigate the curative efficacy of first generation TKI in the treatment of CML-CP combined with vPh and genetic characteristics.@*METHODS@#60 patients with CML-CP combined with vPh from January 2010 to May 2017 in the First Affiliated Hospital of Kunming Medical University were chosen as CML-CP-vPh group, and 107 patients with CML-CP combined with typical Ph chromosome at the same time were chosen as control group. The patients in two groups were treated with imatinib; The curative efficacy, karyotype and FISH signal type were compared between 2 groups, and the factors influencing long-term survival of patients were analyzed by Cox risk model.@*RESULTS@#There was no significant difference in the demographic and hematological baseline data between 2 groups (P＞0.05), and there was no significant difference in the incidence of drug-resistance between 2 groups (P＞0.05). The incidence of primary drug-resistance and primary hematological drug-resistance in the CML-CP-vPh group were significantly higher than that in control group (P＜0.05). There was no significant difference in the accumulative CCyR rate, accumulative MMR rate, OS and EFS between 2 groups (P＞0.05). Multivariate Cox model analysis showed that vPh not correlated with OS and EFS of patients with CML-CP (P＞0.05). The factors influencing OS in CML-vPh patients included high risk of Sokal scores, peripheral blood basophils proportion ≥10%, BCR-ABL in 3 months after treatment＜10%, achieviag CCyR in 6 months after treatment and achieviag MMR in 12 months after treatment (P＜0.05). The factors influencing EFS included BCR-ABL＜10% in 3 months after treatment and achieving MMR in 12 months after treatment (P＜0.05). The regions with high frequency of heterotopic involvement included 12q1, 12q2 [9 cases (15.00%)] and 1p3 [8 cases (13.33%)]. The percentage of 2G2R1Y, 1G1R2F, 1G2R1Y, 2G1R1Y and 1G1R1Y in FISH signal types were 73.33%, 10.00%, 1.67%, 1.67% and 1.67% respectively.@*CONCLUSION@#Patients with CML-CP combined with vPh possess higher primary drug-resistance rate and primary hematological drug-resistance rate for the first generation TKI, while second-generation TKI can efficiently improve long-term survival, its efficacy is similar to efficacy for patients with typical Ph chromosomes. CML-CP combined with vPh does not display special demographic and hematological characteristics. The main involved regions of heterotopic variants include 12q1, 12q2 and 1p3, while 2G2R1Y type is the most common type of FISH signal.

Does BCR-ABL transcript type influence the prognosis of patients in chronic myelogenous leukemia chronic phase?

ABSTRACT Introduction and objective: In this study, we evaluated the influence of the transcript type on hematological and clinical parameters, as well as the event-free survival of 50 patients in the Chronic myeloid leukemia chronic phase. Methods: We reviewed the medical records of 55 patients with Chronic myeloid leukemia. The eligibility criteria were based on the availability of hematological and clinical baseline data in the medical records. Data on BCR-ABL transcripts were obtained from medical records. Results: Eighteen patients (36%) had the b2a2 transcript, 24 (48%) had b3a2 and 8 (16%) had b2a2/b3a2. The median platelet count for transcripts b2a2, b3a2 and b2a2/b3a2 was 320.65 × 103/L, 396 × 103/L, and 327.05 × 103/L, respectively (p = 0.896). We could not find any differences in relation to the other hematological parameters, when compared to the transcript type. Comparison between spleen and liver size and type of transcript did not differ inside the groups (p = 0.395 and p = 0.647, respectively) and the association between risk scores and transcript type did not show statistical significance (p > 0.05). The 21-month probability for event-free survival was 21%, 48% and 66% for the transcripts b2a2, b3a2 and b2a2/b3a2 respectively (p = 0.226) Conclusion: We conclude that the expression BCR-ABL transcripts have no influence on hematological, clinical and event-free survival parameters of patients in the Chronic myeloid leukemia chronic phase.

Comparison of clinical efficacy between first-generation and second-generation tyrosine kinase inhibitors based regimen in the treatment of patients with BCR-ABL positive acute lymphoblastic leukemia / 中华血液学杂志

Objective: To explore the clinical efficacy and prognostic factors of first-generation and second-generation tyrosine kinase inhibitors (TKI) based regimen in the treatment of patients with BCR-ABL positive acute lymphoblastic leukemia (ALL) . Methods: Retrospectively analyze the clinical characteristics and prognostic factors of 89 patients with BCR-ABL positive ALL from April 2012 to June 2018 in our hospital, the clinical efficacy of first-generation and second-generation TKI was compared. Results: 60 patients were classified into the first-generation TKI (imatinib) group, and 29 patients were in the second-generation TKI (dasatinib) group. There were no significant differences in gender, age, WBC, hemoglobin concentration, PLT, chromosomal karyotype, the types of fusion genes, allogeneic hematopoietic stem cell transplantation (allo-HSCT) and TKI initiation time between the two groups. The first-generation and second-generation TKI groups, for which the complete remission (CR) rate at the fourth week of induction therapy was 83.3% and 89.7% (P=0.637) , respectively, and the complete molecular remission (CMR) was 48.3%and 58.6% (P=0.363) , respectively, the difference was not statistically significant. The 2-year overall survival (OS) rate of first-generation and second-generation TKI group was 34.9% and 64.0% (χ(2)=4.743, P=0.029) , the 2-year relapse free survival (RFS) rate was 17.2% and 55.0% (χ(2)=8.801, P=0.003) , respectively. Multivariate analysis showed that complete molecular remission (HR=0.281, 95%CI 0.151-0.523, P<0.001) was independent favorable prognostic factor for overall survival (OS) , complete molecular remission (HR=0.209, 95%CI 0.112-0.390, P<0.001) and second-generation TKI (HR=0.318, 95%CI 0.158-0.641, P=0.001) were independent favorable prognostic factors for RFS. Conclusion: For TKI-based regimen of BCR-ABL positive ALL, second-generation TKI is superior to first-generation TKI in OS and RFS time.

BAX Gene Deletion Reduces the Sensitivity of BCR-ABL-Induced B-ALL Cells of Mice to Imatinib / 中国实验血液学杂志

OBJECTIVE@#To investigate the effect of BAX gene deletion on the sensitivity of BCR-ABL-induced B-ALL cells of mice to imatinib and the related mechanism.@*METHODS@#The target gene-knock out (BAX) mice were used as bone marrow cell donors; the wild type bone marrow cells(B6BM) and BAX bone marrow cells(B6BM-BAX) of mice were transfected by using reverse transcription virus, then the BCR-ABL transfected B6BM cells and B6BM-BAX cells were treated with imatinib at different concentration (0,0.5, 1.0 and 2.0 μmol/L) for 48 hours. The number of viable cells was detected by trypan blue, the flow cytometry was used to detect the cell apoptosis, the Western blot was used to detect the changes of BAX, Caspase expression.@*RESULTS@#In BCR-ABL transfected bone marrow cells treated with imatinib, the numbers of viable cells of BAX deletion group was significantly higher than that of wild type groups with statristcal difference(P<0.05), and effect- and dose-dependency(r=-0.9533 for BAX deletion group, and r=-0.9812 for wild type group). The flow cytometry showed that the cell apoptosis in BAX deletion group signifincantly decreased, compared with wild type group(P<0.05). The Western blot showed that the expression of apoptotic protein Caspase 3 in BAX deletion group was significantly higher than that in wild type group(P<0.05).@*CONCLUSION@#BAX deletion can reduce the sensitivity of BCR-ABL-induced B-ALL cells to imatinib.

Clinical Biological Characteristics and Prognostic Factors of Children with PhALL / 中国实验血液学杂志

OBJECTIVE@#To investigate the clinical biological characteristics of children with Ph ALL and the factors that affecting its prognostic.@*METHODS@#34 children with Ph ALL were selected retrospectively in the period from January 2006 to December 2017; the clinical biological characteristics, clinical efficacy for short-term and survival time for long-term were recorded and the related factors that affecting the clinical efficacy for short-term and survival time for long-term were evaluated.@*RESULTS@#The median overall survival time was 16.5 months and the cumulative OS rates for 2 years and 5 years with followed-up were separately (61.57±7.09)%, (50.75±8.22)%. The median progression-free survival time was 13.5 months and the cumulative progression-free survival rates for 2 years and 5 years with followed-up were separately (54.49±6.77)%, (48.77±7.42)%. The early treatment response of patients with myeloid antigen expression were significantly lower than the patients without myeloid antigen expression (P＜0.05). The CR rate in one treatment course of patients with good response for early treatment response group were significantly higher than the patients with poor response for early treatment response (P＜0.05). The CR rate in one treatment course of the patients with TKI addition in induction therapy period group were significantly higher than the patients with chemotherapy used alone（P＜0.05）. The OS rate and PFS rate of patients in chemotherapy + TKI + allo-HSCT and chemotherapy + TKI group were significantly higher than the patients with chemotherapy used alone group（P＜0.05）. Univariate analysis showed that the factors affecting OS rate of children with Ph ALL for 2 years with followed-up included baseline WBC count level, LDH level, distances between lower hepatic margin and costal margin, distances between lower splenic margin and costal margin, combined myeloid antigen (+), early treatment response, FCM-MRD status after one treatment course, BCR-ABL status after one treatment course and TKI application (P＜0.05) and the factors that the affecting PFS rate of children with Ph ALL for 2 years with followed-up included LDH level, distances between lower hepatic margin and costal margin, distances between lower splenic margin and costal margin, combined myeloid antigen (+), early treatment response, FCM-MRD status after one treatment course, BCR-ABL status after one treatment course and TKI application (P＜0.05). Multivariate analysis showed that the distances between lower splenic margin and costal margin 3 cm were independent risk factors on OS rate and PFS rate of children with Ph ALL (P＜0.05).@*CONCLUSION@#Children with Ph ALL possess unique clinical and biological features. The prognosis of patients with chemotherapy used alone is more poor, and the combination of chemotherapy and TKI can effectively increase the survival benefit; patients with Ph ALL combined with myeloid antigen (+) shows a poor early treatment response. while the distances between lower splenic margin and costal margin 3 cm are independent risk factors on clinical prognosis of children with Ph (+) ALL.

Clinical characteristics of chronic myeloid leukemia with T315I mutation and the efficacy of ponatinib / 南方医科大学学报

OBJECTIVE@#To analyze the clinical features of chronic myeloid leukemia (CML) with T315 I mutation (CML-T315I) and compare the effectiveness of different treatments.@*METHODS@#We retrospectively analyzed the clinical data and outcomes of 19 patients with CML-T315I receiving different treatments. The T315 I mutations in these patients were detected by examination of BCR-ABL kinase domain (KD) mutation by RTQ-PCR and Sanger sequencing. The relapse following the treatments, defined as hematological, cytogenetic and molecular biological recurrences, were analyzed in these patients.@*RESULTS@#Of the 19 patients with CML-T315I, 14 (73.7%) were in CML-CP stage at the initial diagnosis, and 13 (81.2%) were high-risk patients based on the Sokal scores. All the 19 patients were treated with TKI after the initial diagnosis, and during the treatment, 15 (78.9%) patients were found to have additional chromosomal aberrations, and 10 (52.6%) had multiple mutations; 13 (68.4%) of the patients experienced disease progression (accelerated phase/blast crisis) before the detection of T315I mutation, with a median time of 40 months (5-120 months) from the initial diagnosis to the mutation detection. After detection of the mutation, 12 patients were treated with ponatinib and 7 were managed with the conventional chemotherapy regimen, and their overall survival rates at 3 years were 83.3% and 14.2%, respectively ( < 0.001).@*CONCLUSIONS@#CML patients resistant to TKI are more likely to have T315I mutations, whose detection rate is significantly higher in the progressive phase than in the chronic phase. These patients often have additional chromosomal aberrations and multiple gene mutations with poor prognoses and a high recurrence rate even after hematopoietic stem cell transplantation. Long-term maintenance therapy with ponatinib may improve the prognosis and prolong the survival time of the patients.