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Si oxynitride films (with thicknesses of about 40-80 Angstrom) with different chemical compositions were deposited on Si wafers by three kinds of method: electron cyclotron resonance (ECR) chemical vapour deposition, magnetron sputtering, and direct nitration of Si wafers in an ECR plasma. The chemical composition of Si oxynitride films was examined by x-ray photoelectron spectroscopy. Electroluminescence (EL) from the semitransparent Au/Si oxynitride film/Si structures, and the effects of chemical composition of the films on EL have been studied. The dependence of EL on thermal annealing has also been reported. Experimental results show that the dominant EL peak position varies from 640 to 700 nm, but the shoulders at about 520 and 820 nm have no apparent shift when the Si content in the Si oxynitride films increases.

It is found in oxygen there are a weight loss and an endothermal anomaly in compound of Y 1-x Ca x Ba 2 Cu 3 O y starting at about 320 °C, while in nitrogen at about 370 °C and a mixed atmosphere, N 2(50%)+ O 2(50%), at about 350 °C. The results are different from those in undoped YBa 2 Cu 3 O y and some doped systems. It is suggested that Ca prefers a sixfold coordination, which causes the oxygen loss in Cu (2)- O plane and the weight and heat anomalies at different temperature in different atmospheres. The oxygen loss in Cu (2)- O plane is also responsible for Tc suppression in Y 1-x Ca x Ba 2 Cu 3 O y.

The effect of YBCO nanoparticles added into MgB 2 on Tc, Jc, and flux pinning was studied for MgB 2( YBCO )x with x =0, 5, 10, 15 wt%. Phase analysis shows that none of elements are doped into the MgB 2 lattice in the samples with YBCO addition. For the samples with YBCO addition, the Jc-H characteristics behave poorly in comparison with the pure sample. Our experimental results show that the nanoscale size of addition dosen't comprise the only condition for its effectiveness as pinning centers.

The higher doping level Y 1-x Ca x Ba 2-x La x Cu 3 O y samples were synthesized with x from 0.25 to 0.55. Structure and superconductivity have been investigated. Comparing with the results of lower doping level, the Tc of these samples keeps almost constant when dopant increasing. While some structural characters, such as Cu (1)- O (4), Cu (2)- O (4) bond lengths change randomly in a narrow range. The relationship between Ba / La position and Tc is rather interesting. The results give another evidence that the influence of structural change on superconductivity is independent of carrier concentration.

To explore the efficacy and adverse effects of clofarabine for relapsed/refractory acute lymphoblastic leukemia in children.Twenty-six pediatric patients with relapsed/refractory acute lymphoblastic leukemia were treated with clofarabine. There were 22 males and 4 females, with a mean age of 9.5 years (ranging from 4 to 17 years). They received clofarabine 52 mg/m2 intravenously over 2 hours daily for 5 days. Thirteen patients received two cycles and one patient received three cycles.In the first cycle of clofarabine, complete remission was obtained in 11 children (42%) and partial remission was obtained in 7 children (27%). Eight children (31%) were considered unresponsive. In the second cycle, 11 (85%) of the 13 children obtained complete remission, 1 (8%) partial remission and 1 (8%) was unresponsive. One child received three cycles and obtained complete remission in each cycle. The common adverse events were myelosuppression, infection, liver dysfunction and gastrointestinal adverse reactions. There were no chemotherapy-related deaths.Clofarabine is effective in the treatment of children with relapsed/refractory acute lymphoblastic leukemia and its adverse effects can be tolerated. Clofarabine could be a promising new treatment for relapsed/refractory acute lymphoblastic leukemia.

The electroluminescence (EL) at room temperature from Au-extra-thin silicon oxynitride (ETSON)-p-Si and Au-ETSON-n-Si structures is reported. The ETSON films (similar to 80 Angstrom) were deposited by the rf magnetron sputtering technique, and Si3N4-Si composite targets were used (the area ratio of Si to Si3N4 was similar to 6%). The EL spectra were measured under forward bias greater than or equal to 4 V after the ETSON films had been annealed at 300, 600, 800, and 1000 degrees C in N-2 ambient for 30 min. The Au-ETSON-p-Si structure has a dominant EL band with peak wavelength around 680 nm, and its integrated EL efficiency is an order of magnitude higher than that from a Au-extra-thin Si-rich SiO2 (ETSSO) film (similar to 80 Angstrom)-p-Si structure. Distinguishing it from the Au-ETSSO-Si structure, which emits visible EL only when it is fabricated on p-Si, EL can also be observed in the Au-ETSON-n-Si structure under forward bias, and the two dominant EL bands peak one at around 700 nm and one at around 800 nm. Electron beam irradiation induces a new EL band peaked at 500 nm in the EL spectrum from an Au-ETSON-p-Si structure. From the experimental results it is suggested that electrons and holes from opposite sides tunnel into the ETSON layer and recombine radiatively at luminescence centres there.

Bulk MgB2 with SiO2 nanoparticles added has been synthesized using a simple solid-state reaction route. The lattice constant in the c direction increases with additive content due to a small amount of Si being doped into the lattice of the MgB2; however, Tc is almost fixed at 37.2?K. The addition of SiO2 nanoparticles also improves the Jc?H and Hirr?T characteristics of MgB2 when the additive content is lower than 7%. At 20?K and 1?T, Jc for the sample with 7% additive content reaches 2.5 ? 105?A?cm?2. Microstructural analysis reveals that a high density of MgSi2 nanoparticles (10?50?nm) exists inside the MgB2 grains, leading to the formation of a nanocomposite superconductor.

Efficacy, safety and pharmacokinetics of clofarabine in Chinese pediatric patients with refractory or relapsed acute lymphoblastic leukemia: a phase II, multi-center study

To investigate the expression of the Wilms' tumor 1 (WT1) mRNA in childhood myelodysplastic syndrome (MDS), and to evaluate WT1 as a tool to differentiate MDS from aplastic anemia(AA).The quantitative expression of WT1 transcript by using real-time quantitative polymerase chain reaction (RQ-PCR) was performed in the bone marrow samples of 36 childhood MDS and 49 childhood AA, the samples were collected from September 2008 to December 2011.(1) The positive rate of WT1 in severe AA (SAA) was 0, 14.3% in chronic AA (CAA), 58.6% in refractory cytopenia (RC), 100% in refractory anemia with excessive blast (RAEB) and 97.5% in acute myeloid leukemia (AML). The mean level of WT1 in SAA, CAA, RC, RAEB and AML was 0.041%, 0.357%, 7.037%, 12.680% and 24.210%, respectively. The positive rate of WT1 in RC patients was higher than that of SAA (P = 0.000) and CAA (P = 0.001). (2) The positive rate of WT1 in patients with hypoplastic MDS was 66.7% and was higher than that of SAA (P = 0.000) and CAA (P = 0.001). The mean level of WT1 in patients with hypoplastic MDS was (3.022 ± 5.040)% and higher than that of SAA \[(0.041 ± 0.047)%, P = 0.000\] and CAA\[(0.351 ± 0.479)%, P = 0.002\].The level of WT1 in childhood MDS was higher than that of childhood AA. The degree of WT1 expression in MDS increased during disease progression. WT1 is a useful tool for differentiating the childhood hypoplastic MDS from AA.

Background: Relapsed/refractory leukaemia is associated with poor prognosis. T cells genetically modified to express CD19-specific chimeric antigen receptor (CD19CAR) in patients (pts) with chronic lymphoblastic leukemia (CLL) and acute lymphoblastic leukemia (ALL) have shown a remarkable ant-cancer activity. However, many questions remain related to the predictive indicators of long-term response and the management of cytokine release syndrome (CRS) after CAR-T cell infusion. In this phase II multi-center clinical trial, we evaluated the safety and efficacy of a fourth generation, safety-improved CD19-CAR (4SCAR19) in B-ALL pts. Patients and Methods: Fifty evaluable B-ALL patients (pts), with demonstrated persistent disease following salvage chemotherapy from 14 hospitals in China between July 2013 and June 2015 have been enrolled. The mean age is 14 (from 3 to 65) including 26 children and 24 adults. Leukemic genotypes include 16 Bcr-Abl (13 pT315I), 11 WT-1, 3 MLL-AF4, 3 E2A-PBX-1, 1 TEL/AML1, 1 IKZF1, 1 K-ras and the remaining 14 pts have undetectable genotype. Their disease characteristics include: 4 hypercritical acute leukemia, 10 extramedullary leukemia (7 CNSL, 3 multiple sites), with associated co-morbidity: 12 Aspergillus pneumonia, 4 cGVHD, 2 pleura/pericardial cavity effusion, 2 hepatitis B, 2 diabetes mellitus, 1 gastrointestinal hemorrhage, and 1 liver/spleen abscess. Twenty-one (42%) pts received allo-HSCT including 15 haplo-identical, 5 matched related donor (MRD) and 1 unrelated cord blood (URD-CB). These pts who relapsed after transplantation have received chemotherapy (chemo), combined with Tyrosine Kinase Inhibitors (TKIs, 10), donor leukocyte infusion (DLI, 19), or dendritic cells-cytokine induced killer cell (DC-CIK)/NK cell infusions (7). CAR-T cells were prepared from autologous (37), transplant donor (12) or non-transplant donor mother (1). T cells. Peripheral lymphocytes were collected from leukapheresis, and T cells were transduced with a 4th generation, safety-engineered, CD19scFv/CD28/CD137/CD27/CD3ζ-iCasp9 (4SCAR-19) lentivector. Pre-CAR-T lymphodepleting chemotherapy includes individualized chemo in 17 pts, and the others received Fludarabine (Flu) + Cyclophosphamide (Cy)(FC), or either Flu or Cy regimen: (1) FC: Cy 250mg/m2/d x3d and Flu 30mg/m2/d x3d ,or (2) either Flu x3 days, or (3) Cy x3 days, followed by CAR-T infusions at a dose of 2.13 (range from 0.42 - 5.9) x106 CAR-T cells per kg body weight per infusion. Results: For statistical analysis, 50 patients were divided into 2 cohorts: Cohort 1: B-ALL with morphological blast Toxicities: CRS occurred in most pts within the first 10 days of CAR-T cell infusion. 47/50 (94%) pts developed fever with elevated IL-2, IL-6, IL-10, and interferon gamma. Eight (16%) pts required either 12.5 mg Etanercept or 8 mg/kg tocilizumab, and three pts were treated with both drugs. Four pts developed hypotension and fully recovered after receiving dopamine. Four pts were treated once by methylprednisolone (1 mg/kg/day). The median follow-up was 4 months (range from 3~24 month), with 16 pts followed up for more than 6 months. Clinical outcomes: 1. LFS: The 120 days LFS for pts in cohort 1 and cohort 2 were 86% (CI,80%~93%) and 44.4% (CI, 31%~58%, P=0.0030), respectively. 2. OS (10 month) probabilities for patients in cohort 1 and cohort 2 were 82% (73%~91%) and 36% (19%~52%) (P= 0.0029), respectively. Conclusion: Our results indicate the potential of rapid leukemia eradication kinetics of 4SCAR19 therapy in treating chemo-resistant B-ALL. This therapy dramatically improves the prognosis of B-ALL pts by either providing a bridging approach to allo-HSCT or a better remission induction with longer period of CR than the routine treatment. Moreover, pts with morphological blasts Disclosures Dong: America Yuva Biotech: Consultancy, Other: clinical consultation.

OBJECTIVE To study the clinical and biological characteristics and prognosis of t(8;21)/AML1-ETO-positive childhood acute myeloid leukemia (AML).The clinical data of 55 children who were diagnosed as t (8; 21)/AML1-ETO-positive AML were retrospectively studied. Event-free survival (EFS), disease-free survival (DFS), and overall survival (OS) rates were estimated by the Kaplan-Meier method. Prognostic factors were evaluated by COX regression analysis software.Of the 55 patients, 4 patients gave up treatment after the diagnosis was confirmed and 4 patients were lost to follow-up after the first chemotherapy course. The remaining 47 patients received a double-induction therapy. The total complete remission (CR) rate was 71% and 94% after the first and second chemotherapy course, respectively. The disease was relapsed in 10 patients (21%). The 5-year EFS, DFS and OS rates were (56.1 ± 7.9)%, (59.8 ± 8.1)%, and (72.0 ± 8.1)%, respectively. Multivariate analysis showed that age was an independent risk factor for the long-term prognosis. The older children had a greater risk of experiencing an accident or death (P0.05). The 5-year OS rate in 27 patients with regular consolidation chemotherapy was significantly higher than 13 patients with irregular chemotherapy after CRz [(47.5 ± 17.1)% vs (38.9 ± 17.3)%; P0.01].Childhood t(8;21)/AML1-ETO-positive AML is a highly heterogeneous disease, with a high CR rate and a good long-term prognosis. Age is one of the important factors affecting the long-term therapeutic effect. Regular consolidation chemotherapy applied after CR usually is helpful.

To study the clinical features and etiological spectrum of pancytopenia in children.The clinical data of 174 children with pancytopenia between September 2003 and January 2010 were retrospectively reviewed.Pale face was the most common clinical manifestation (147 cases, 84.5%), followed by bleeding (87 cases, 50.0%) and fever (41 cases, 23.6%). Mild to moderate anemia, severe thrombocytopenia and mild leucopenia were common in complete blood count. Of the 174 children, pancytopenia was attributed to hematopoietic system diseases in 155 cases (89.1%) and non-hematopoietic system diseases (virus infections, systemic lupus erythematosus, hypersplenism and neuroblastoma) in 6 cases (3.4%). Aplastic anemia (91 cases, 52.3%) was the most common cause of pancytopenia, followed by myelodysplastic syndrome (37 cases, 21.3%), acute leukemia and other hematological tumours (11 cases, 6.3%) and hemophagocytic syndrome (6 cases, 3.4%). The cause of pancytopenia was not identified in 13 cases (7.5%).Anemia, bleeding and fever are the main clinical manifestations of pancytopenia in children. Pancytopenia is mostly caused by aplastic anemia in children. Myelodysplastic syndrome, hematological tumours and hemophagocytic syndrome are also the common causes.

To investigate whether there were differences in the clinical characteristics, cytogenetic characteristics, immunophenotype and prognosis in children with B cell type acute lymphoblastic leukemia (B-ALL) carrying different fusion genes.The research included 80 children with B-ALL from Peking University People's Hospital between March 2006 and December 2008. Eighteen children were positive for TEL/AML1, 14 for E2A/PBX1, 11 for BCR/ABL,and 2 cases for MLL/AF4, and 35 cases were negative for all of the 4 fusion genes. Data including clinical characteristics, morphology, immunophenotype and cytogenetic characteristics were collected, and the disease-free survival (DFS) was evaluated. The children were followed up until April 2009.In the 18 children with TEL/AML1+B-ALL, 66.7% were younger than 5 years old. They had low tumor load. FAB-L2 morphology was commonly observed, but t(12;21) was often absence in these children. Up to now,17 children who survived were disease-free. In the 14 children with E2A/PBX1+B-ALL, the majority were female. Thirteen children showed FAB-L1 morphology. Twelve children showed pre-B-ALL immunophenotype. The EFS was close to 80%. In the 11 children with BCR/ABL+B-ALL, 10 children showed common B type immunophenotype. FAB-L1 and FAB-L2 morphology was found in 4 children respectively. The DFS was less than 20%. Two children with MLL/AF4 positive B-ALL had high tumor load. Their morphologic diagnosis was FAB-L1. Both showed the Pro-B-ALL immunophenotype. One child discontinued treatment at the early stage of chemotherapy, and the other child survived disease-free until now.The B-ALL children with different fusion genes have different clinical characteristics, immunophenotypes and prognosis.

The aim of study was to investigate the application of a novel microarray approach for the eight most common leukemia translocations in children for routine molecular diagnostic hematopathology practice. Bone marrow samples from 84 children with leukemia were analyzed by multiplex nested RT-PCR combined with oligonucleotide microarray. The results showed that out of 84 leukemic samples, 31 (36. 90%) carried 8 types of fusion genes including tel/aml1, e2a/pbx1, bcr/ablp190, bcr/ablp210, mll/af4, aml1/eto, pml/raralpha, cbfbeta/myh11. The sensitivity and specificity of the assay is comparable with the RT-PCR technique. In conclusion, this multiplex nested RT-PCR could quickly screen 8 types of chromosome structural aberrations at the same time. It can provide reliable and helpful information for risk stratification, therapy evaluation and prognosis prediction in childhood leukemia. There are both advantages and disadvantages in applying this new method. The microarray-based assay will be an effective and reliable tool in the clinical screening of leukemia patients for the presence of specific gene rearrangements with important diagnostic and prognostic implications.

To evaluate the possibility of applying oligonucleotide microarrays for detection of the fusion genes in childhood acute lymphoblastic leukemia (ALL).To detect five types of fusion genes emerging frequently in childhood ALL including TEL/AML1, E2A/PBX1, BCR/ABLp190, BCR/ABLp210, MLL/AF4, probes were designed, synthesized and spotted on the chemical-material-coated-glass plates in array. The total RNAs were extracted from patients' bone marrow or peripheral blood cells at the beginning of diagnosis, analyzed by multiplex nested reverse-transcription-polymerase chain reaction (RT-PCR), and labeled by fluorescein. The products of RT-PCR were hybridized with microarray in order to detect specific types of fusion genes in leukemia cells.Distinctive hybridization signals were obtained for internal positive control and specific types of fusion genes. TEL/AML1 gene was found positive in 2 of the 36 cases, E2A/PBX1 gene in 3, BCR/ABLp190 gene in 2, BCR/ ABLp210 gene in one, and MLL/ AF4 gene in one. The results of the microarray and RT-PCR were consistent.The microarray-based assay could screen 5 types of chromosome structural aberrations and the splice variants at the same time. It can provide reliable and helpful information for patient stratification, evaluation of therapeutic effects and prediction of prognosis in childhood ALL, although there are both advantages and disadvantages in applying this new method.

To retrospectively analyze the treatment outcomes and side effects of childhood acute promyelocytic leukemia (APL) treated with all-trans retinoic acid (ATRA) or ATRA + arsenic trioxide (As2O3).From 1992 to 2006, 45 patients with newly diagnosed APL were enrolled. All of them were PML-RAR alpha positive. 24 patients were induced with ATRA (group A) and 21 with ATRA + As2O3 (group B). The remission rate and side effects were observed.1) 19 (79.2%) patients in group A achieved CR, while 21(100%) patients in group B achieved CR. The CR rate in group A was lower than that in group B (P=0.027). 2) The recovery time of coagulation parameters and PLT count in group B was shorter than that in group A. 3) The overall survival (OS) and event-free survival(EFS) in group A were 77.8% and 66.9% at 41 months of follow-up, and in group B were 100% and 100% respectively at 34 months of followup. Group A had a significant lower EFS (P=0.0357)than group B. 4) The time of PML-RAR alpha fusion gene converting to negative in group A was longer (P=0.026) than that in group B.ATRA + As2O3 for patients with newly diagnosed childhood APL is a feasible treatment with higher CR rate, less side effects and longer long-term survival.

To evaluate the significance of FCM in minimal residual disease (MRD) detection, the immunophenotyping and leukemia-associated immunophenotypes (LAIP) of leukemia cells from 273 adult and 142 childhood patients with B lineage acute lymphoblastic leukemia (B-ALL) were detected by four to six antibody combinations of 4-color CD45/SSC gating multiparametric flow cytometry (FCM). The results showed that the B-ALL patients could be classified into 4 subtypes based on different expression CD34 and CD10: subtype I (CD34(+)/CD10(-)), subtype II (CD34(+)/CD10(+)), subtype III (CD34(-)/CD10(+)), subtype IV (CD34(-)/CD10(-)). The LAIP was observed in 100% and 92% patients of subtype I and subtype II, respectively, whereas only 79.2% in subtype III. The incidence of LAIP in total B-ALL cases was 90% by using the antibodies detected in this investigation. There was no significantce different for incidence of LAIP between adult and pediatric patients. LAIP was observed in 77.6% of patients by labeling only CD34/CD10/CD19/CD45 4-color antibody combination. It is concluded that in 90% of childhood and adult B-ALL patients LAIP can be found, which suits MRD detection by multiparameter flow cytometry.

To compare the leukemia-associated immunophenotypes (LAIP) in patients with B lineage acute lymphoblastic leukemia (B-ALL) at diagnosis and relapse, and investigate its implications for minimal residual disease (MRD) detection.The immunophenotype of leukemia cells from 410 newly diagnosed and 6 relapsed patients with B-ALL were detected by four to six antibody combination, mainly CD34/CD10/CD45/CD19 of 4-color CD45/SSC gating flow cytometry (FCM).The proportion of CD45 under-expressed or negative in relapsed patients was much higher than that in newly diagnosed patients, being 69.2% and 37.8% respectively. Immunophenotypic changes occurred in 9 relapsed patients (including 8 hematological relapse and 1 central nerves system relapse) when analyzed by paired samples analysis at diagnosis vs at relapse: 4 cases showed CD45 down-modulation and 2 up-modulation; 4 CD34 down-modulation and 2 CD10 up-modulation, while the expression of CD19 remained no change. MRD was observed in all 7 cases of hematological relapse 2 - 4 months before relapse, and the immunophenotype of MRD cells was the same as that in relapse.A high frequency of immunophenotypic changes occurred at relapse and even in MRD before relapse, however the accuracy of MRD monitoring seemed not affected by the FCM strategy used in this investigation.

Introduction CBF-acute myeloid leukemia (AML) is a heterogeneous disease that requires prognostic factors for patient differentiation. c-KIT mutations are predominantly detected in CBF-AML among AML cases, and reported frequencies vary significantly. To date, the clinical significance of c-KIT mutations in CBF-AML has been intensively studied; however, the results are controversial and a final conclusion has not been reached. Large-scale studies with subgroup analysis should be performed to elucidate the clinical effects of c-KIT mutations in CBF-AML. Methods A total of 351 patients with CBF-AML [t(8;21) (n = 253) or inv(16) (n = 98)] were included in this study. Overall, 250 patients [42 pediatric t(8;21);146 adult t(8;21); 11 pediatric inv (16) and 51 adult inv (16)] received standard treatment and underwent follow up. Induction therapy consisted of one or two cycles of combined anthracycline and cytarabine for adult patients, whereas cytarabine, idarubicin, and etoposide were used for pediatric patients. 131, 17, and 93 of the patients further received intermediate-dose cytarabine-based chemotherapy, chemotherapy with auto-hematopoietic stem cell transplantation (HSCT), and chemotherapy with allogeneic (allo)-HSCT for consolidation, respectively. c-KIT mutations in exon 8 and 17 were screened by direct sequencing. Patients who received allo-HSCT were censored at the time of transplantation for relapse and survival analysis to exclude the effects of allo-HSCT on outcome. The median follow up time was 10 months (3 to 93 months) for the 211 living patients. Results Overall, 36.5% (128/351) of the patients were found to have a c-KIT mutation. The frequencies of c-KIT mutations were similar between pediatric and adult patients with t(8;21) AML (41.7% vs. 38.5%, P > 0.05), whereas pediatric patients tended to have higher frequency of c-KIT mutations than the adult patients with inv(16) AML (53.8% vs 25.9%, P = 0.053). In adults, the frequency of c-KIT mutations was significantly higher in patients with t (8;21) than those with inv(16) (P = 0.043). In adults, the frequency of mutations in exon 17 was significantly higher in t(8;21) than inv(16) AML (P < 0.0001). In pediatric group, the frequencies of mutations in exon 17 and exon 8 were similar for t(8;21) and inv(16) AML (P > 0.05). The low PLT count (¡Ü 30∙109/L) in pediatric t(8;21) AML tended to be associated with the presence of c-KIT mutations ( P = 0.063). High white blood cell (WBC) count (>10∙109/L), WBC index, and AML1-ETO transcript levels in adult t(8;21) AML patients were significantly correlated with the presence of c-KIT mutations (P = 0.015, 0.0051, and 0.030, respectively). Moreover, low CBF¦Â-MYH11 transcript levels in adult inv(16) AML tended to be significantly related to c-KIT mutations (P = 0.059). No difference was observed in CR rates between patients with and without c-KIT mutations (P > 0.05). c-KIT mutations were significantly associated with less reduction in fusion transcript levels after the first induction therapy in adult inv(16) patients (P = 0.021). c-KIT mutations in adult t(8;21) AML patients (n = 137) significantly correlated with higher CIR rates at 2 years and low 2-year DFS and OS rates (73.2% vs. 46.2%, P = 0.0070; 26.8% vs. 49.1%, P = 0.013; 48.9% vs. 65.7%, P = 0.0055, respectively. Figure 1). In contrast, c-KIT mutations had no impact on CIR, DFS, and OS rates in pediatric t(8; 21)(n = 42), as well as in adult inv (16) (n = 51; all P > 0.05. Figure 1). Multivariate analysis demonstrated that c-KIT mutation was the only independent prognostic factor for relapse (hazard ratio (HR) = 2.47, 95% CI = 1.25 to 4.86, P = 0.009) and DFS (HR = 2.23, 95% CI = 1.17 to 4.41, P = 0.016). Moreover, c-KIT mutation and PLT count were independent prognostic factors for OS (HR = 3.68, 95% CI = 1.57 to 8.63, P = 0.003; HR = 0.37, 95% CI = 0.16 to 0.87, P = 0.023). Conclusion CBF-AML is a heterogeneous disease with regard to c-KIT mutations. c-KIT mutations have a strong adverse impact on relapse and survival in adult t(8;21) AML. Grant support Nature Science Foundation of China (81170483 and 81370639) and Beijing Municipal Science & Technology Commission£¨Z141100000214011). Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

To evaluate the method and value of detecting bone marrow minimal residual disease (MRD) in B lineage acute lymphoblastic leukemia (B-ALL) by multiparameter flow cytometry (FCM).The FCM immunophenotyping of B-lymphocyte precursors in regenerating stage and MRD was analyzed by using two sets of 4-color antibody panels, including mainly CD34, CD10, CD45, CD19, in 26 regenerating bone marrow samples after chemotherapy and 297 consecutive bone marrow specimens from 50 patients with B-ALL, respectively. The immunophenotype of leukemia cells of B-ALL was also detected by four to six antibodies combination of 4-color CD45/SSC gating FCM. The CD19, CD10, CD34 fluorescence intensity of B-cell precursors in normal and leukemic bone marrow was compared by relatively quantitative method.Twelve patients were MRD positive (MRD(+)) among 50 patients during MRD monitoring, the percentages of residual leukemia cells were 0.06% to 7.73%. Eleven cases displayed CD45, CD34, CD19, CD10 antigens aberrant expression. Five patients were bone marrow relapsed and 4 of them were MRD (+) 7-17 weeks before relapse. The percentages of leukemia cells in all the 4 patients were over 0.1%. Only one patient relapsed with MRD negative. The regenerated B precursors could be divided into 3 stages according to the expression of CD45, CD34, CD19, CD10, CD22, and CD20 antigens. Abnormal expression of CD45, CD34, CD19, and CD10 were detected in 71.8% of 213 patients with B-ALL, the percentage of only aberrant expression of CD38 and myeloid antigen was 8.1%.Detection of MRD by multiparameter flow cytometry is a rapid, quantitative and sensitive approach, and has a higher predictability for relapse.

Flow cytometry may be used to detect minimal residual disease (MRD) in acute lymphoblastic leukemia because leukemic cells often display aberrant phenotypes when compared to normal cells. The present study was designed to establish a flow cytometric method for detecting MRD in children with B-ALL and evaluate its clinical prognostic value. The investigators also aimed to study the value of the detection of MRD by flow cytometry in childhood B-ALL without effective antibody combinations.Thirty-six cases of childhood B-ALL with effective antibody combinations were performed MRD analysis after induction therapy. The authors detected MRD in 6 cases without effective antibody combinations by the four-color antibody combinations consisting of CD(45)/CD(19)/CD(10)/CD(34) and CD(45)/CD(19)/CD(20)/CD(22) and detected the aberrance of the minor subsets of CD(19)(+) cells.(1) Forty-two cases of childhood B-ALL were screened for antibody combinations of interest and were identified in 86% (36/42) of the cases. The sensitivity of this method was 0.01%. (2) Patients with MRD levelsor = 0.01% at 9 and 12 months of therapy had significantly low disease-free survival compared with patients with MRD levels0.01%. (3) Six out of seven patients with recurrence in the BM had MRD levelsor = 0.1% prior to recurrence. Patients with MRD levelsor = 0.1% during chemotherapy had significantly low disease-free survival as compared with patients with MRD values0.1%. (4) Two out of seven patients with recurrence had positive results of the qualitative PCR prior to recurrence. (5) Five patients with recurrence had no shift of antigen expression at relapse except that a patient missed CD(13). (6) Detectable MRD was not found in six patients without effective antibody combinations.(1) Flow cytometry is a sensitive and specific method for detecting MRD of childhood ALL, and could predict the coming relapse. (2) Patients with MRD levels10(-3) had poor prognosis. (3) The levels of MRD at month 9 and 12 had prognostic value. (4) The value of antibody combinations consisting of CD(45)/CD(19)/CD(10)/CD(34) and CD(45)/CD(19)/CD(20)/CD(22) should be further investigated in patients without effective antibody combinations.

Hematologic relapse remains the greatest obstacle to the cure of acute lymphoblastic leukemia (ALL), especially T-lineage acute lymphoblastic leukemia (T-ALL) in children. Recent studies have shown that patients with increased risk of relapse can be identified by measuring residual leukemic cells, called minimal residual disease (MRD), during clinical remission. Current polymerase chain reaction (PCR) methods, however, for measuring MRD are cumbersome and time-consuming. To improve and simplify MRD assessment, the author developed a real-time quantitative PCR (RQ-PCR) assay for the detection of leukemic cells that harbor the tal-1 deletion. In addition, the author discussed the significance of MRD levels at different stages in treatment and prognosis of children with T-ALL.A total of 50 consecutively enrolled patients with T-ALL were analysed for detection of leukemic cells harboring the most common tal-1 deletion. Serial dilutions of leukemic DNA were studied to find the sensitivity of detection with RQ-PCR assay. The MRD of 28 samples in clinical remission from 10 patients were quantified by RQ-PCR assay and limiting dilution assay. The results detected by both methods were compared statistically with correlation analysis.(1) A total of 10 patients presented tal-1 deletion involving the sildb1 breakpoint rearranged to tal1db1 in 50 cases with T-ALL. The breakpoints of relapsed samples are the same as those of the corresponding diagnostic samples; (2) The RQ-PCR assay had a sensitivity of detection of one leukemic cell among 100,000 normal cells. In 24 samples, MRD levels10(-5) could be detected with both methods. The percentages of leukemic cells measured by the two methods correlated well (r = 0.898, P0.001); (3) The MRD levels of 3 patients out of the 8 cases undergoing disciplinary regimen were over 10(-4) at the end of induction chemotherapy. They all relapsed in bone marrow during chemotherapy. The higher the MRD levels, the earlier the relapse. The other 5 patients with MRD levels10(-4) had been relapse-free survival (RFS) for 4-59 months, one of whom with increased MRD levels10(-4) for twice at the continuation stage had been RFS for 27 months till now.The sildb1-taldb1 deletion presents in 20% of T-ALL, and is an ideal PCR marker for its specificity, uniform and stability; The tal-1 RQ-PCR can be used for the rapidly, sensitively and accurately quantitative assessment of MRD in T-ALL with the tal-1 deletion. MRD levels at different stages of chemotherapy have different significance in prognosis and treatment.

This study was aimed to investigate the clinical value of quantification of AML1/ETO fusion transcripts using real-time reverse transcription PCR. Fourteen AML1/ETO positive children out of 52 AML children were selected. A serial dilution of AML1/ETO plasmid was used as a template for the AML1/ETO real-time PCR. AML1/ETO was quantified according to the expression of the GAPDH housekeeping gene at new diagnosis and during/after chemotherapy and transplantation. SPSS statistics was used to analyze the data. The results showed that the ratio of AML1/ETO: GAPDH expression level at new diagnosis varied in the range 0.219-2.080 (median 0.648) among the patients, without relevance with percentage of blasts. The detection sensitivity was up to the dilution of 1:10(5). Six patients showed a slight decline of AML1/ETO (higher than 5 x 10(-2)) at 1 month, three of whom relapsed in the early stage and one later. Five patients had a higher level than 5 x 10(-3) at 3 months, three of whom relapsed. Four patients with always a higher level than 5 x 10(-3) all relapsed in early stage. After six months, four out of them with constant low-level expression (10(-4) - 10(-6)) were in continuous complete hematological remission (CCR). In another patient, a rapid rise of AML1/ETO transcripts could be detected at CR stage and he relapsed 5 months later. The AML1/ETO gene expression leveling off by 10(-5) - 10(-6) could be detected in 3 patients at their complete remission after 9 months. It is concluded that real-time RT-PCR is a suitable approach for quantifying AML1/ETO transcripts in monitoring of AML patients with t(8;21) during/after chemotherapy and provides data of diagnostic relevance.

The study was aimed to investigate the feasibility and clinical significance of quantitative detection of minimal residual disease (MRD) in childhood acute lymphoblastic leukemia (ALL) by real-time quantitative polymerase chain reaction (RQ-PCR).Clonal IgH gene rearrangements of samples at diagnosis were identified by standard PCR assay with consensus primers. Monoclonal IgH gene rearrangements were analyzed using DNAPLOT software. Upstream primers were designed with the Primer Express software and allele specific oligonucleotide developed complementary to the V-D or D-J junction. Samples at diagnosis were serially diluted to generate the patient specific standard curves. RQ-PCR method was used to quantify the MRD of the follow up samples collected at five time points during chemotherapy. To check the quantity and quality of DNA, the investigators used RQ-PCR analysis for the albumin gene.Totally 16 monoclonal IgH gene rearrangements were identified from 34 patients with B-ALL. The analysis of the 16 monoclonal rearrangements showed that the most frequently used V segment was from V3 family and J segment from J4 and J6. The RQ-PCR sensitivity of 10(-4) to 10(-5) was mostly reached. Non-specific amplification was seen in 6 patients. The number of inserted and deleted nucleotides did not appear to be related to the sensitivity (P0.05). The correlation coefficients of all 16 standard curves were excellent (or = 0.99). The mean slope of the standard curves was -3.4 +/- 0.37 and the mean intercept was 24.3 +/- 2.95. MRD analysis of follow up samples from the 16 patients showed an association between high degree of MRD and relapse. There was no apparent relationship between MRD degree at the end of induction chemotherapy and other high risk factors of ALL (P0.05).The study showed that the above approach with RQ-PCR was applicable to clinical detection of MRD in childhood ALL. Quantitative and dynamic study of MRD was of prognostic importance.