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Fanconi anemia (FA) is a rare autosomal recessive, X-linked or autosomal dominant disease. Few large-scale FA investigations of rare disease cohorts have been conducted in China.We enrolled 148 patients diagnosed with FA according to evidence from the clinical phenotype, family history, and a set of laboratory tests. Next, the clinical manifestations and correlation between the genotype and phenotype of FA pediatric cases were investigated.The most common FA subtype in our cohort was FA-A (51.4 %), followed by FA-D2 and FA-P. Finger (26 %) and skin (25 %) deformities were the most common malformations. Based on family history, blood system diseases (51 %) had the highest incidence rate, followed by digestive system tumours. A set of new or prognosis-related mutation sites was identified. For example, c.2941 T G was a new most common missense mutation site for FANCA. FANCP gene mutation sites were mainly concentrated in exons 12/14/15. The mutations of FANCI/FANCD2 were mainly located at the α helix and β corners of the protein complex. FA-A/D1 patients with splicing or deletion mutations showed more severe disease than those with missense mutations. Chromosome 1/3/7/8 abnormalities were closely linked to the progression of FA to leukemia.Our study investigated the clinical features and genotype/phenotype correlation of 148 Chinese pediatric FA patients, providing new insight into FA.

Juvenile myelomonocytic leukemia (JMML) is an aggressive pediatric myeloproliferative disease, and newly diagnosed patients frequently cannot tolerate hematopoietic stem cell transplantation (HSCT) at diagnosis due to their poor condition. This retrospective analysis aimed to explore the short-term effect of decitabine-dominant therapy on improving the condition of JMML patients before HSCT. The subjects were 10 JMML patients. All patients were treated with decitabine after low-dose chemotherapy with an interval of 4 weeks before bridging to HSCT. The median treatment course was 3 cycles, and the overall response rate (ORR) was 70.0% after one cycle and 71.4% after three cycles. White blood cell (WBC) and monocyte counts were significantly lower after treatment, and spleen volume was also lower, though not significantly lower. The 12 month progression-free survival rate (PFS) was 80.0 ± 12.6%. Decitabine-dominant therapy was beneficial for reducing tumor burden and improving clinical condition.

This study retrospectively analyzed the clinical outcome of 172 children with newly diagnosed severe aplastic anemia (SAA) between January 2008 and April 2018, who received rabbit antithymocyte globulin (ATG) and cyclosporine (CsA) as first-line treatment. The median age at diagnosis was 5 years (range, 1–14). The overall response rates were 22.7%, 45.3%, and 61% at 40 days, 3 months, and 6 months, respectively, after rabbit ATG. In multivariate analysis, mild disease severity was the only predictor of favorable response at 6 months (P = 0.006). In the present study, median follow-up period was 63 months (range, 1–135). The 5-year overall survival (OS) and failure-free survival (FFS) rates were 90.5% and 70.4%. Multivariate analysis showed that erythroid burst-forming units (BFU-E) > 2/105 bone marrow mononuclear cell (BMMNC) (P = 0.037) and time interval before IST ≤ 30 days (P = 0.017) were independent positive predictors for OS, meanwhile BFU-E > 2/105BMMNC (P = 0.029) was the only favorable prognostic factor for FFS.

BackgroundThe aim of the study was to validate the diagnostic role of circulating tumor DNA (ctDNA) in genetics aberration on the basis of next-generation sequencing (NGS) in pediatric acute myeloid leukemia (AML).MethodsBone marrow (BM) and peripheral blood (PB) were collected from 20 AML children at the time of initial diagnosis, and a ctDNA sample was isolated from PB. Detection of mutation was performed on ctDNA, BM, and peripheral blood mononuclear cell (PBMC) by NGS based on a 185-gene panel.ResultsAmong 185 genes sequenced by the NGS platform, a total of 82 abnormal genes were identified in 20 patients. Among them, 61 genes (74.39%) were detected in ctDNA, PBMC, and BM samples, while 11 (13.41%) genes were found only in ctDNA and 4 (4.88%) were detected only in the BM sample, and 2 (2.44%) were detected only in PBMC. A total of 239 mutations were detected in three samples, while 209 in ctDNA, 180 in bone marrow, and 184 in PBMC. One hundred sixty-four mutations in ctDNA were shared by matched BM samples, and the median variant allelic frequency (VAF) of these mutations was 41.34% (range, 0.55% to 99.96%) and 44.36% (range, 0.56% to 99.98%) in bone marrow and ctDNA. It was found that 65.79% (75/114) of mutations with clinical significance were detected in three samples, with 9 mutations detected both in ctDNA and BM, and 2 mutations detected both in PBMC and BM. The consistency of mutations with clinical significance between ctDNA and BM was 77.06% (84/109). Among the 84 mutations with clinical significance detected in both sources, the concordance of VAF assessment by both methods was high (R2 = 0.895).ConclusionThis study demonstrates that ctDNA was a reliable sample in pediatric AML and can be used for mutation detection. Consistency analysis showed that ctDNA can mirror the genomic information from BM. In addition, a subset of mutations was exclusively detected in ctDNA. These data support the fact that monitoring ctDNA with next-generation sequencing-based assays can provide more information about gene mutations to guide precision treatment in pediatric AML.

Fanconi anemia (FA), an X-linked genetic or autosomal recessive disease, exhibits complicated pathogenesis. Previously, we detected the mutated Dynein Axonemal Heavy Chain 2 (DNAH2) gene in 2 FA cases. Herein, we further investigated the potential association between DNAH2 and the homologous recombination repair pathway of FA. The assays of homologous recombination repair, mitomycin C (MMC) sensitivity, immunofluorescence, and ubiquitination modification were performed in U2OS and DR-U2OS cell lines. In MMC-treated U2OS cells, the downregulation of the DNAH2 gene increased the sensitivity of cells to DNA inter-strand crosslinks. We also observed the reduced enrichment of FANCD2 protein to DNA damage sites. Furthermore, the ubiquitination modification level of FANCD2 was influenced by the deficiency of DNAH2. Thus, our results suggest that DNAH2 may modulate the cell homologous recombination repair partially by increasing the ubiquitination and the enrichment to DNA damage sites of FANCD2. DNAH2 may act as a novel co-pathogenic gene of FA patients.

Background Defects of bone marrow mesenchymal stem cells (BM-MSCs) in proliferation and differentiation are involved in the pathophysiology of aplastic anemia (AA). Infusion of umbilical cord mesenchymal stem cells (UC-MSCs) may improve the efficacy of immunosuppressive therapy (IST) in childhood severe aplastic anemia (SAA). Methods We conducted an investigator-initiated, open-label, and prospective phase IV trial to evaluate the safety and efficacy of combination of allogenic UC-MSCs and standard IST for pediatric patients with newly diagnosed SAA. In mesenchymal stem cells (MSC) group, UC-MSCs were injected intravenously at a dose of 1 × 106/kg per week starting on the 14th day after administration of rabbit antithymocyte globulin (ATG), for a total of 3 weeks. The clinical outcomes and adverse events of patients with UC-MSCs infusion were assessed when compared with a concurrent control group in which patients received standard IST alone. Results Nine patients with a median age of 4 years were enrolled as the group with MSC, while the data of another 9 childhood SAA were analysed as the controls. Four (44%) patients in MSC group developed anaphylactic reactions which were associated with rabbit ATG. When compared with the controls, neither the improvement of blood cell counts, nor the change of T-lymphocytes after IST reached statistical significance in MSC group (both p > 0.05) and there were one (11%) patient in MSC group and two (22%) patients in the controls achieved partial response (PR) at 90 days after IST. After a median follow-up of 48 months, there was no clone evolution occurring in both groups. The 4-year estimated overall survival (OS) rate in two groups were both 88.9% ± 10.5%, while the 4-year estimated failure-free survival (FFS) rate in MSC group was lower than that in the controls (38.1% ± 17.2% vs. 66.7% ± 15.7%, p = 0.153). Conclusions Concomitant use of IST and UC-MSCs in SAA children is safe but may not necessarily improve the early response rate and long-term outcomes. This clinical trial was registered at ClinicalTrials.gov, identifier: NCT02218437 (registered October 2013).

Variation in normal blood cells during chemotherapy has not been recognised as a risk factor guiding chemotherapy in childhood acute lymphoblastic leukaemia (ALL). This study aims to explore whether variations in normal haematopoiesis determine prognosis as well as to improve risk-stratified treatment in childhood ALL. A retrospective study of 279 cases of ALL treated with the CCCG-ALL-2015 regimen in the Division of Pediatric Blood Diseases Center, Institute of HematologyBlood Diseases Hospital, Chinese Academy of Medical SciencesPeking Union Medical College, from May 2015 to January 2017 was performed to analyse the prognostic impact of blood cell levels on day 19 of induction therapy by Kaplan-Meier method. Patients with childhood ALL with absolute neutrophil count (ANC) ≤ 90 cells/μl, absolute monocyte count (AMC) ≤ 10 cells/μl or absolute lymphocyte count (ALC) ≤ 1000 cells/μl on day 19 of induction therapy had a lower event-free survival (EFS) rate than those with higher values (all P0.05). Multivariate analysis confirmed that ANC ≤ 90 cells/μl and ALC ≤ 1000 cells/μl were independent adverse prognostic factors (HR = 1.981 and 2.162, respectively, both P0.05). Among patients with minimal residual disease (MRD)1% on day 19 of induction therapy, those with ANC ≤ 90 cells/μl had lower EFS than those with ANC90 cells/μl (70.8 ± 6.1% vs 86.4 ± 3.1%, P = 0.001). In the subgroup with the BCR/ABL1 fusion gene, patients with ANC ≤ 90 cells/μl on day 19 of induction therapy also had lower EFS than those with ANC90 cells/μl (34.4 ± 25.2% vs 25.0 ± 21.7%, P = 0.041). ANC and ALC during induction therapy are independent prognostic factors for childhood ALL. ANC contributes to guiding the prognosis of patients with low-level MRD or the BCR/ABL1 fusion gene.

Previous studies have shown that gut microbiota can affect human immune system in many ways. Our aim was to investigate quantitative differences in fecal bacterial compositions of childhood acute lymphoblastic leukemia (ALL) patients compared to those of healthy children, so as to identify individual bacterial species that are related to the etiology of ALL. We recruited 81 subjects, including 58 patients with ALL and 23 healthy controls. Fecal samples were collected and examined by 16S rRNA quantitative arrays and bioinformatics analysis. Both Principal Coordinates Analysis (PCoA) and Non-metric Multidimensional scaling (NMDS) demonstrated that the microbial composition of ALL patients deviated from the tight cluster of healthy controls. Multiple bacterial species exhibited significant changes (e.g., Roseburia faecis, Edwardsiella tarda, and Fusobacterium naviforme) in the ALL samples. Some of the differentially abundant taxa were correlated with the level of interleukin-10. The ALL cases could be efficiently distinguished from healthy controls by the random forest model based on differential species (area under ROC curve = 0.843). Taken together, the composition of gut microbiota differed from healthy controls to pediatric ALL patients. Our study identified a series of ALL-related species in the gut microbiota, providing a new direction for future studies aiming to understand the host-gut microbiota interplay in ALL pathogenesis.

Objective To explore the incidence rate and characteristics of symptomatic venous thromboembolism (VTE) after peripherally inserted central catheters (PICC) placement in children with acute leukemia (AL). Methods The authors performed a retrospective study aiming at children admitted to Pediatric Blood Diseases Center with a new diagnosis of AL and received a PICC insertion, collected the clinical materials of all venous thrombosis cases, and analyzed the incidence rate and characteristics in various types of AL. Results From September 2007 to December 2018, a total of 2423 patients got PICCs at least once, of whom 29 patients experienced thrombosis events and the overall incidence rate of symptomatic VTE after PICC insertion was 1.2%. Deep venous thrombosis accounted for the majority with 75.9%. Seven cases of cerebral venous sinus thrombosis were documented and they all developed in patients with acute lymphoblastic leukemia (ALL). No pulmonary embolism was detected. Patients with acute myeloid leukemia (AML) had an identical risk of thrombosis to patients with acute lymphoblastic leukemia (ALL) (1.7% vs. 1.09%, P>0.05). All thrombi in patients with AML were located on the upper extremity, whereas in the ALL group about half of the thromboembolism developed in other locations. There were no statistical differences between patients in different clinical trials of the ALL group (0.7% vs. 1.6%, P>0.05). Conclusions The incidence rates of symptomatic VTE after PICC placement in children with AL in our center were relatively low and acceptable. For patients with AML, PICC placement plays the most important role in venous thrombosis. However, in patients with ALL, the potential risk factors were more complex.

Background: Severe Aplastic Anemia (SAA) in children is a rare severe disease, and the prognosis after immunosuppressive therapy (IST) is heterogeneous. Few models could accurately predict the long-term outcomes of immunosuppressive therapy for children SAA patients. Previous researches mainly focused on a few pretreatment factors,because SAA patients need to test the bone marrow at 3, 6, 9, and 12 months after IST treatment, and response-based surrogates of outcome have been shown to be highly predictive in other diseases. Based on these, we collected clinical electronic medical records (EMR) from 203 children with SAA, including comprehensive clinical tests from blood routine to bone marrow examination throughout the entire treatment process, to establish a model with more effective prognostic factors to predict the prognosis of patients. Our study will provides a novel and more effective prognosis time node for reducing the times of bone marrow puncture and to guide the next treatment. Methods: Based on the machine learning methods, we established a model with the AUC 0.962 to predict the long-term outcomes in the early stage of SAA patients with IST. Findings: By analyzing the indicators related to long-term efficacy, we found that some of the indicators such as white blood cell count, lymphocyte count and absolute reticulocyte count (ARC) which are consistent with previous studies; but the age is not a suitable predictor for children with SAA, the lymphocyte ratio of bone marrow smear is more effective than lymphocyte count in blood, the C-reactive protein, level of vitamin B12, IL-6 and IL-8 in the early stage of the disease is highly correlated with long-term efficacy (P

The relationship between pathological changes in liver tissue and the level of hepatitis B surface antigen (HBsAg) remains unclear. This study aimed to analyze the pathological changes in liver tissue and its related factors in patients with low-level HBsAg in order to provide a basis for judging the condition of these patients. A retrospective study was performed on 96 chronic hepatitis B patients with HBsAg levels 1400 IU/ml and 0.05 IU/ml. The histopathological examination of these patients was conducted. Univariate and multivariate analyses were used to determine risk factors for pathological changes. Among the 96 patients, 57.3% (55) had inflammatory events ≥ G2 and 33.4% (33) had fibrosis ≥ S2. HBV infection duration (p = 0.001) and splenic vein diameter (p = 0.001) were independent risk factors of liver inflammation (≥ G2) in patients with low-level HBsAg, while AST (p = 0.006) and PLT (p = 0.005) were independent risk factors of liver fibrosis (≥ S2). Moreover, HBV infection duration (p 0.001) and spleen vein (p = 0.001) were independent factors of potential antiviral treatment. Liver inflammation and fibrosis are still common in patients with low-level HBsAg; thus, the monitoring and appropriate antiviral treatment cannot be ignored.

Objective: As a rare, aggressive pediatric myeloproliferative disease, juvenile myelomonocytic leukemia (JMML) encompassed both biological features of myelodysplastic syndrome and myeloproliferative neoplasm. Studies have shown that the methylation level in JMML patients is closely related to prognosis, and patients with high methylation level have poor prognosis. This study aimed to find clinical indicators that were associated with different methylation levels and prognosis. Methods: The clinical information of 24 JMML patients with DNA samples admitted to our center from December 2013 to May 2020 was retrospectively analyzed, and the DNA methylation level of their whole genome was detected. Results: The median age of onset was 14.5 months (0.1-153 months) among the 24 cases, including 17 males and 7 females. At diagnosis, the median WBC count was 27.1×10 9/L (6.2-98.1×10 9/L), and the median platelet count was 38×10 9/L (10-277×10 9/L). Chromosome karyotype abnormalities were found in 12.5% (3/24) of patients. Next-generation sequencing results showed that 79.2% (19/24) patients had at least one Ras pathway-related classical gene mutation, and 41.7% (10/24) patients had two or more somatic mutations. Genomic DNA methylation levels were divided into three groups: 10 cases in the hypomethylation group, 4 cases in the moderate methylation group, and 10 cases in the hypermethylation group. There were significant differences in age, platelets, PTPN11 gene mutation and the number of somatic mutations ≥2 in different methylation groups (P Conclusions: JMML patients with high methylation level in the DNA genome at diagnosis were older and with lower platelet levels, and hypermethylation were significantly correlated with high-risk prognostic factors such as PTPN11 gene mutation and ≥2 somatic mutations. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare. OffLabel Disclosure: Decitabine for treatment of children with JMML

// Congcong Sun 1 , Lixian Chang 1 and Xiaofan Zhu 1 1 Center for Pediatric Blood Disease, State Key Laboratory of Experimental Hematology, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences, and Peking Union Medical College, Tianjin, P.R. China Correspondence to: Xiaofan Zhu, email: // Keywords : ETV6/RUNX1, childhood acute lymphoblastic leukemia, mechanisms, initiation, relapse Received : November 21, 2016 Accepted : February 23, 2017 Published : March 18, 2017 Abstract ETV6/RUNX1 ( E/R ) is the most common fusion gene in childhood acute lymphoblastic leukemia (ALL). Multiple lines of evidence imply a “two-hit” model for the molecular pathogenesis of E/R -positive ALL, whereby E/R rearrangement is followed by a series of secondary mutations that trigger overt leukemia. The cellular framework in which E/R arises and the maintenance of a pre-leukemic condition by E/R are fundamental to the mechanism that underlies leukemogenesis. Accordingly, a variety of studies have focused on the relationship between the clones giving rise to the primary and recurrent E/R -positive ALL. We review here the most recent insights into the pathogenic mechanisms underlying E/R -positive ALL, as well as the molecular abnormalities prevailing at relapse.

In severe aplastic anemia (SAA), predictive markers of response to immunosuppressive therapy (IST) of porcine antilymphocyte globulin (pALG) have not been well defined. We investigated whether clinical and laboratory findings before treatment could predict response in a pediatric cohort. In this study, we included 70 newly diagnosed SAA children and treated them with pALG. The response rate was documented during follow-up. The log-rank test compared response rates between the potential predictive factors. The response rate was 57.1% at 24 months follow-up. In log-rank test, mild disease severity was the most significant predictive marker of better response (P

Background This study was aimed to explore the METTL3 and METTL14 expressions in children with ETV6/RUNX1(E/R)‐positive acute lymphoblastic leukemia (ALL) and investigate the relation between the METTL3 and METTL14 expressions with clinical features. Methods Thirty‐seven newly diagnosed E/R‐positive ALL children and six controls were included in this study. Real‐time quantitative polymerase chain reaction (RT‐PCR) was used to detect the mRNA expression level of METTL3 and METTL14. Results Among the 37 cases, 51.35% (n = 19) were boys and 48.65% (n = 18) were girls and the median age was 4.72 (1.72–11.99) years. Among the six controls, 50% (n = 3) were boys and 50% (n = 3) were girls and the median age was 5.24 (1.53–13.17) years. The expression level of METTL3 and METTL14 in E/R‐positive ALL patients were lower than in controls (p

Objective: Juvenile myelomonocytic leukemia (JMML) has both the disease characteristics of myelodysplastic syndrome and myeloproliferative neoplasm. Currently, hematopoietic stem cell transplantation (HSCT) is the only possible cure. Most of the newly diagnosed pediatric patients with JMML have high tumor burden, rapid disease progression, and may not tolerate HSCT. This study explored the short-term efficacy of decitabine combined with low-dose chemotherapy in the treatment of JMML before transplantation. Methods: A retrospective analysis of the patient files of 9 cases of JMML was performed from January 2019 to May 2020. All patients were given decitabine 20mg/m2× 5 days, supplemented with a small dose of cytarabine (50-100mg/m2×3~5 days), and/or etoposide (50mg/m2×3~5 days) chemotherapy. Each treatment interval is 3~4 weeks, bridging with HSCT after 3~4 treatment courses. Results: The median age of onset of 9 cases of JMML was 2 years old (0.5~4 y), male to female ratio was 8:1, the median size of spleen was 6.4cm (2.9~9.8cm) under the costal arch, and WBC was 28.03×109/L (7.3~127.69×109/L), monocytes were 9.25×109/L (1.66~15.79×109/L) at diagnosis. There were 8 cases in the high-risk group and 1 case in the low-risk group. Second-generation sequencing results show that 7 cases carried PTPN11 somatic mutations. Five in 9 cases had two kinds of classic JMML mutations, and 1 case had only NRAS mutation. Seven patients had normal chromosomal karyotypes, and 3 patients had abnormal 8, 11, and 18 chromosomes, respectively. Median treatment courses with decitabine are 3 courses (1~5 courses), the response rate of one course is 77.8% (7/9), the response rate of three courses is 80% (4/5), one case from high-risk group achieved complete remission after treated with 4 courses of decitabine and low-dose chemotherapy. The five-month progression-free survival rate was 77.8% (7/9). Conclusion: Treating JMML with decitabine combined with low-dose chemotherapy, can reduce patients' tumor burden, improve the general condition, and obtain approximately 80% clinical response rate. Decitabine combined with low-dose chemotherapy can be used as a treatment option for JMML before HSCT. Disclosures No relevant conflicts of interest to declare. OffLabel Disclosure: Safety and effecacy of decitabine applicated in JMML patients have not been confirmed.

e22501 Background: The aims of the study were to investigate the pharmacokinetics and pharmacodynamics of pegylated recombinant human granulocyte colony stimulating factor(PEG-rhG-CSF) in pediatric patients with acute lymphoblastic leukemia(ALL), and compare the efficacy and safety of PEG-rhG-CSF (brand name:jinyouli) and rhG-CSF. Methods: Pediatric patients with newly diagnosed ALL who planned to use CAM (cyclophosphamide, cytarabine, 6-mercaptopurine) for chemotherapy were assigned to PEG-rhG-CSF group or rhG-CSF group. In the PEG-rhG-CSF group, PEG-rhG-CSF (100ug/kg) was injected subcutaneously once 48 hours after chemotherapy. In the rhG-CSF group, rhG-CSF (150ug/d) was injected subcutaneously daily from 48 hours after chemotherapy until the absolute neutrophil count (ANC) was≥1.0×109/L. The serum concentration of PEG-rhG-CSF was detected by enzyme-linked immunosorbent assay (ELISA). Safety and efficacy of the two groups were evaluated. Results: Between November 2015 to April 2016, 17 pediatric patients were assigned to PEG-rhG-CSF(n = 9) or rhG-CSF(n = 8) groups. The main pharmacokinetic parameters (mean±SD) of PEG-rhG-CSF group were as follows: Cmax was 353.50±136.3 ng/ml, Tmax was 44.00±20.8 h, t1/2 was 14.58± 2.2h. The PEG-rhG-CSF serum concentration and ANC curve were consistent with the mechanism of neutrophil mediated clearance. The average value of ANC nadir in PEG-rhG-CSF group was 0.18 (±0.32)×109/L, and the rhG-CSF group was 0.08 (±0.09)×109/L, there was no significant difference between the two groups ( P = 0.469). Compared with rhG-CSF, the average time of ANC recovery in PEG-rhG-CSF group was earlier (18.33±2.18 vs. 21.50±2.33, P = 0.021). There were no significant differences in the incidence of FN and infection, the duration of grade Ⅳ neutropenia and hospitalization, and the safety of the two groups. Conclusions: PEG-rhG-CSF had favorable efficacy in pediatric patients with ALL receiving chemotherapy, and there was no serious adverse event. Compared with rhG-CSF, PEG-rhG-CSF needed only once in each chemotherapy cycle, which is more suitable for pediatric patients. Clinical trial information: NCT02953730.

Background The combination of all-trans-retinoic acid (ATRA) and arsenic trioxide (ATO) has been suggested to be safe and effective for adult acute promyelocytic leukaemia (APL). As of 2010, the role of cytarabine (Ara-C) in APL was controversial. The aim of this study was to test the efficacy and safety of ATRA and ATO in paediatric APL patients. Also, we assessed whether Ara-C could be omitted in ATO and ATRA- based trials in children. Methods We performed a randomized controlled trial in paediatric APL patients (≤14 years of age) in our hospital from May 2010 to December 2016. All of the patients were assigned to receive ATRA plus ATO for induction followed by one course of idarubicin (IDA) and ATO (28 days). The patients were then randomly assigned to receive two courses of daunorubicin (DNR, no- Ara-C group) or DNR + Ara-C (Ara-C group). All of the patients were followed with maintenance therapy with oral ATRA, 6-mercaptopurine, and methotrexate for 1.5 years. Results Among the 66 patients, 43 were male and 23 were female. All of the patients achieved complete remission (CR) with the exception of one who gave up the treatment. During induction therapy, all toxicity events were reversed after appropriate management. Thirty patients in the Ara-C group underwent 57 courses of treatment, and 35 patients in the no-Ara-C group underwent 73 courses of treatment. No significant differences in age, genders, white blood cell counts, haemoglobin levels, and platelet counts were found between the Ara-C and no-Ara-c groups. Greater myelosuppression and sepsis were observed in the Ara-C group during the consolidation courses. No patient died at consolidation, and only one patient relapsed. No differences were found in event-free survival, disease-free survival and overall survival between the two groups. Additionally, our analysis of the arsenic levels in the plasma, urine, hair and nails of the patients indicated that no significant accumulation of arsenic occurred after ATO was discontinued for 12 months. Conclusions Overall, ATO and ATRA are safe and effective for paediatric APL patients and Ara-C could be omitted when ATO is used for two courses. Trial registration ClinicalTrials.gov (NCT01191541, retrospectively registered on 18 August 2010).

To study the biological function of DNAH2 (Homo sapiens dynein, axonemal, heavy chain 2) gene, we constructed human stable U2OS cell line of DNAH2 gene knockout through CRISPR/Cas9n double nick system. The A, B sgRNAs (Single guide RNA) and complementary strands were designed and synthesized. The double-stranded structures were formed during annealing, and connected with BbsⅠ cohesive ends-containing pX462 linear vector to construct the recombinant eukaryotic expression plasmids, including pX462-DNAH2-A and pX462-DNAH2-B. After the co-transfection of the two plasmids into U2OS cells, the addition of puromycin and limiting dilution method were used to obtain positive monoclonal cell line. Western blotting assay was then performed to detect the expression of DNAH2 protein, and PCR-sequencing technology was finally utilized to analyze the mutation feature. The results showed that A, B sgRNAs duplex was successfully inserted into pX462 vector, and DNAH2 protein was not expressed and DNAH2 gene suffered from the frame-shift mutation in U2OS-DNAH2-KO monoclonal cell line. These demonstrated that DNAH2 knockout U2OS stable cell line was successfully constructed through CRISPR/Cas9n double nick system, which providing a useful tool for the study of DNAH2 gene.基于CRISPR/Cas9n double nick 技术构建人DNAH2 (Homo sapiens dynein, axonemal, heavy chain 2) 基因敲除的U2OS 稳定细胞株，旨在研究DNAH2 基因的生物学功能。首先设计并合成A、B 两个sgRNA (Single guide RNA) 以及各自的互补链，退火连接形成DNAH2 sgRNA-A、B 双链，再分别与带有BbsⅠ粘性末端的pX462 线性载体相连，形成pX462-DNAH2-A、pX462-DNAH2-B 重组真核表达质粒。质粒共转染至U2OS 细胞后，加入嘌呤霉素，以有限稀释法获得阳性单克隆细胞株，再以蛋白印迹实验检测DNAH2 蛋白的表达，最后通过PCR-基因测序技术分析突变特点。结果显示A、B sgRNA 双链成功插入pX462 载体，U2OS-DNAH2-KO单克隆细胞株中DNAH2 蛋白不表达，DNAH2 基因发生移码突变，从而证实利用CRISPR/Cas9n double nick系统成功构建人DNAH2 基因敲除的U2OS 稳定细胞株，为研究DNAH2 基因提供有利工具。.

Background Primary myelofibrosis (PMF) is quite rare in children. Mutations of JAK2V617F or MPLW515K/L were absent in pediatric patients with PMF according to previous studies. Recently, mutations in calreticulin (CALR) were described in adult patients with JAK2/MPL-unmutated PMF. Our study aimed to analyze the clinical and genetic features of Chinese pediatric patients with PMF. Procedures We retrospectively investigated 14 pediatric patients diagnosed as PMF according to WHO 2008 criteria. Direct sequencing was performed for the existence of genetic alterations in JAK2, MPL, TET2, CBL, ASXL1, IDH1, IDH2, SRSF2, EZH2, DNMT3A and CALR. Results In our cohort, all patients had anemia, three patients (21%) had splenomegaly, six patients (43%) had micromegakaryocytes at time of diagnosis. No patient had spontaneous remission and six patients (43%) transformed to acute myelocytic leukemia. In nine patients with evaluable cytogenetic information, three subjects (33%) had abnormal karyotypes. The median survival from time of diagnosis was 28 months. Seven patients (50%) had type 2 mutations of CALR. No patient had mutations in the other candidate genes. There was no statistical differences in age, gender, hemoglobin, WBC, neutrophil and platelet counts, percentage of circulating blast, overall survival and leukemia transformation between patients with and without CALR mutation. Conclusion Our study documented that Chinese pediatric patients with PMF in our cohort had its own clinical characteristics and poor outcome. CALR mutations were detected in 50% of our pediatric patients with PMF. Based on our study, CALR mutations screening could be used as molecular marker for diagnosis of pediatric patients with PMF. Pediatr Blood Cancer 2014;61:2256–2262. © 2014 Wiley Periodicals, Inc.

To evaluate the copy number variations (CNVs) in pediatric ETV6/RUNX1 gene positive acute lymphoblastic leukemia(ALL) and its correlation with clinical features and prognosis.Totally 141 children (14 years of age) with newly diagnosed ETV6/RUNX1 positive ALL in Institute of Hematology and Blood Diseases Hospital, were included from January 2006 to November 2012. The CNVs were analyzed by multiplex ligation-dependent probe amplification (MLPA). The survival rate between the patients with CNVs were explored. Overall survival (OS) and event-free survival (EFS) were estimated by the Kaplan-Meier method and compared with the log-rank test.Among the 141 cases, 55.3% (n=78) were boys and 44.7% (n=63) were girls and the median age was 4 (1-13) years. The estimated 5-year DFS rate for the patients was (84±4)%. The estimated 5-year OS rate for the patients was (85±4)%. Ninety-five patients were tested MLPA. CNVs were detected in 73 cases (76.8%). CNVs of genes EBF1(15.8%), CDKN2A/2B(18.9%), PAX5(21.1%), ETV6(54.8%), BTG1(10.5%) were detected in more than 10% of the patients. Among the 95 patients, EBF1 deletions were found in 9 patients and EBF1 amplifications were found in 6 patients; 5-year recurrence-free survival (RFS) was statistically significant among 3 groups (χ(2)=9.809, P=0.007) . PAX5 deletions were found in 13 patients and PAX5 amplifications were found in 7 patients; the difference in 5-year RFS was statistically significant between 3 groups(χ(2)=7.622, P=0.022). ETV6 deletions were found in 39 patients and ETV6 amplifications were found in 13 patients; the difference in 5-year RFS was statistically significant among the 3 groups (χ(2)=11.045, P=0.004).The CNVs had prognostic relevance in ETV6/RUNX1 positive ALL.

Diamond-Blackfan anemia (DBA) is an inherited bone marrow failure syndrome characterized by a paucity of erythroid progenitors. We summarized the clinical and genetic features of 104 DBA patients in a single-center retrospective study in China. Data of DBA patients who received consultations at our center from 2003 to 2015 were analyzed retrospectively. Genes encoding 10 ribosomal proteins (RPs) and GATA1 were sequenced for mutation detection. Our cohort was composed of 65 males and 39 females. Congenital malformations were observed in 19 patients. Mutations of the RP genes were detected in 58.3 % patients. Twenty different mutations were first reported. Thirty-four patients received prednisone combined with CsA therapy, and improvement was observed in 20 cases. During follow-up for a median 39 months, 33.7 % of the patients achieved remission, 41.3 % of the patients were persistently transfusion independent, 21.7 % of the patients were transfusion dependent, and three patients died. The patient group with detected mutations had a younger age of disease onset, a higher malformation rate, and tended to have a lower remission rate and a higher transfusion-dependence rate. Prednisone in combination with cyclosporine A can be a second-line choice for DBA patients. Differences were detected between DBA patients with and without detectable mutations in the genes studied.

To identify ikaros family zinc finger1 (IKZF1) deletion in patients with pediatric B cells-acute lymphoblastic leukemia (B-ALL) without reproducible chromosomal abnomalities and further investigate its value in this part of patients' pathogenesis and prognosis.The study was approved by the institutional review board of the authors' hospital and informed consent was obtained from the patients and/or their legal guardians. Data of 96 children with B-ALL patients without reproducible cytogenetic abnormalities whose bone marrows specimens were enough for DNA extraction for the detection were retrospectively selected. All the patients were diagnosed and systematically treated according to CCLG-ALL2008 in our hospital from April 2008 to April 2013. The 96 patients were divided into two groups according to the result of IKZF1's detection by multiplex ligation-dependent probe amplification (MLPA): The cases that with any of eight exons of IKZF1 deleted were entered into"Group with IKZF1 deletion"otherwise entered"Group without IKZF1 deletion". Disease free survival (DFS), event-free survival (EFS) and overall survival (OS) were compared between the two groups.Nineteen out of 96 B-ALL patients without reproducible cytogenetic abnormalities had IKZF1 deletion (20%). Three of 19 patients with IKZF1 deletions of the whole gene; ten of 19 patients with IKZF1 deletions of exon 1; 4 of 19 patients with IKZF1 deletions of exons 4-7; one of 19 patients with IKZF1 deletions of exons 2-7 and one of 19 patients with IKZF1 deletions of exons 1-6. Whose white blood cell (WBC) ≥ 50 × 10(9)/L inIKZF1 diletion group was more than whthout IKZF1 deletion group(42% vs. 13%, P=0.004). Patients with IKZF1 deletions had a lower 3-year DFS (0.67 ± 0.13 vs. 0.93 ± 0.04, P=0.001); EFS (0.67 ± 0.13 vs. 0.90 ± 0.04, P = 0.012) and OS(0.79 ± 0.09 vs. 0.96 ± 0.02, P=0.010) compared to those without IKZF1 deletions. Excluding the influence of sex, age, WBC count at diagnosis, cerebrospinal fluid state and prednisone response IKZF1 deletion still affected the patients' DFS, EFS and OS ( P0.05 for all comparisons).Some of pediatric B-cell precursor ALL without reproducible cytogenetic abnormalities had been detected to have IKZF1 deletion; IKZF1 deletion is an independent poor prognostic factor in these patients.

A new noncentrosymmetric polyborate, Ba(2)[B(6)O(9)(OH)(4)], has been synthesized under a hydrothermal condition. The polyborate contains chiral layers constructed by two kinds of helical chains and also form new B(18)O(42) circles based on B(3)O(8) units [(3: Δ+2T)]. One kind of Ba atom locates in the cavity surrounded by the B(11)O(11) ring within the anion layer, and the other kind of Ba atom inserts between two adjacent layers. UV-vis diffuse reflectance spectroscopy demonstrates that the compound has a cutoff edge below 190 nm and has a large second-harmonic generation (SHG) effect, which is approximately 3 times that of KH(2)PO(4) (KDP) and is type-I phase matchable.

Eight novel lanthanide−organic frameworks, [Ln(CDA)] (Ln = Pr (1), Nd (2), Sm (3), CDA = 4-hydroxypyran-2,6-dicarboxylate), [Ho(CDA)(H2O)] (4), [Pr(HCDA)(C2O4)0.5(H2O)2] (5), [Lu(CDA)Ba2(C2O4)2(H2O)2]·0.25CH3OH (6), [Dy(HCAM)2(CAM)Ba2(H2O)9.75]·7.625H2O ((7), CAM = 4-hydroxypyridine-2,6-dicarboxylate), [Sm2(CAM)4Ba3(H2O)2] (8), have been synthesized under hydrothermal conditions. They were structurally characterized by single-crystal X-ray diffraction. Compounds 1−3 are isostructural and display novel three-dimensional (3D) architectures, and compound 4 features a two-dimensional (2D) double-layer structure. The structural divergence between 1−3 and 4 may originate from a lanthanide contraction effect. By increasing the temperature during the synthesis of 1, CDA was partly decomposed into oxalate ions, and as a result, compound 5 with a 3D framework different from that of 1 was obtained. The Lu-based compound isostructural to 4 has not been obtained so far under synthetic conditions similar to that of 1−4...

Hepatitis E is chronic in immunocompromised patients with HIV infection, organ transplant, or radiation and chemotherapy. General cases are not chronic. Fifty-five cases were collected and followed up for 4-14 years. It was found that chronic hepatitis E is more common in males, but a high degree of inflammatory activity and fibrosis was not evident. After 4-14 years of follow-up observation, cirrhosis or liver cancer did not appear. This is significantly different from the hepatitis B and C viruses. We speculated that the chronic mechanism in the general patients with hepatitis E might be different from that of immunocompromised cases.

Background Early treatment responses are important prognostic factors in childhood T-cell acute lymphoblastic leukemia (T-ALL) patients. The predictive values of early treatment responses in Chinese childhood T-ALL patients were still unknown. Methods From January 2003 to December 2012, 74 consecutive patients aged ≤15 years with newly diagnosed T-ALL were treated with BCH-2003 protocol or CCLG-2008 protocol in the Department of Pediatric, Institute of Hematology and Blood Diseases Hospital in China. Predictive values of early treatment responses, including prednisone response, bone marrow morphology at day 15 and day 33 during induction chemotherapy, and minimal residual disease (MRD) monitored by flow cytometry after induction therapy (time point 1, TP1) and before consolidation therapy (time point 2, TP2), were analyzed. Results The 5-year event free survival (EFS) and overall survival (OS) rates for these patients were 62.5 % (SE, 6.4) and 62.7 % (SE, 6.6), respectively. Prednisone poor responder was strongly associated with increased chance of induction failure (14.8 %) and decreased survival rate (5 year EFS rate, 51.1 % (SE, 10.5)). Patients with ≥25 % blast cells in bone marrow at day 15 were more likely to have an inferior outcome. 93.2 % of the T-ALL patients achieved complete remission at day 33 while patients with resistant disease all died of disease progression. MRD ≥10−2 at TP1 or MRD ≥10−3 at TP2 was significantly related to dismal prognosis. Risk groups classified by MRD at two time points could stratify patients into different groups: 29.0 % of the patients were MRD standard risk (MRD

To estimate the significance of the adjustment of acute lymphoblastic leukemia (ALL) risk group by monitoring minimal residual disease(MRD).Totally 285 children ALL patients who were diagnosed and systematically treated according to CCLG-2008 in Institute of Hematology and Blood Diseases Hospital, CAMS and PUMC, from April 2008 to August 2011 were prospectively selected. Among these cases, 62.8% (n = 179) were boys and 37.2% (n = 106) were girls and the median age was 5.3(0.5-14.0). The patients who were at high-risk group initially were excluded. The grouping of cases: the patients were divided into two groups according to the dates of initial diagnosis. Group I had 126 patients who were initially diagnosed between April 2008 and December 2009 in whom therapeutic regimen was not adjusted by reassignment of risk group by MRD. Group II had 159 patients who were initially diagnosed between January 2010 and August 2011 whose therapeutic regimen was adjusted by reassignment of risk group by MRD at specific time (33rd day of induction chemotherapy and 12 weeks after the beginning of chemotherapy). MP-FCM Coulter FC-500 was used in the detection of MRD.Among these 285 patients, 94.0% (n = 268) were diagnosed as B-lineage acute lymphoblastic leukemia and 6.0% (n = 17) were T-lineage acute lymphoblastic leukemia. In group I, 61.9% (n = 78) patients belonged to low-risk group, 38.1% (n = 48) median-risk; in group II, before the adjustment, the rates of the low-risk group and median-risk group were 68.6% (n = 109) and 31.4% (n = 50) , respectively, while after the adjustment they were altered to 53.5% (n = 85) and 39.6% (n = 63) , furthermore 6.9% (n = 11) patients went into the high-risk group. Both groups were followed up for 2.5 years after their diagnoses, the disease of 7.4% (n = 21) patients relapsed, and the rates of two groups were 12.7% (n = 16) and 3.1% (n = 5) respectively, P = 0.009. The rate of serious infection (such as sepsis, pulmonary infection) of all these patients was 32.3% (92/285) , there was no significant difference between the two groups [28.6% (36/126) vs.35.2% (56/159) , P = 0.392]. The mortality of all these patients was 6.7% (19/285) , and that of group I was higher than that of group II [10.3% (13/126) vs. 3.8% (6/159) , P = 0.044]. The 2.5 years overall survival (OS), event-free survival (EFS) and disease-free survival (DFS) of group I were all lower than those of group II in Kaplan-Meier survivorship analysis (all P0.05). The two groups were followed up for 2.5 years after their diagnoses, after elimination of the confounding influence of sex, age, FAB subtype, WBC count, ratio of blast cells in bone marrow at diagnosed, chromosome karyotype and fusion gene, reassignment of risk group by MRD was used to calculate the OS, EFS and DFS of ALL patients (all P0.05). After the adjustment the risk group was more significant in the assessment of prognosis.The reassignment of risk group in low and median risk groups children with acute lymphoblastic leukemia by MRD did not increase the rate of serious infection but could reduce the relapse rate and mortality, and was beneficial to increase the patients' OS, EFS and DFS.

Colorless block crystals of the title compound are hydrothermally prepared from aqueous mixtures of Pb(NO3)2 and LiOOH (autoclave, 200 °C, 72 h, 92% yield).