Corrigendum: Down-Regulated FOXO1 in Refractory/Relapse Childhood B-Cell Acute Lymphoblastic Leukemia.

[This corrects the article .].

Down-Regulated FOXO1 in Refractory/Relapse Childhood B-Cell Acute Lymphoblastic Leukemia.

Background: Acute lymphoblastic leukemia (ALL) is the most common pediatric cancer, with an overall prevalence of 4/100,000, accounting for 25-30% of all childhood cancers. With advances in childhood ALL treatment, the cure rate for childhood ALL has exceeded 80% in most countries. However, refractory/relapsed ALL remains a leading cause of treatment failure and subsequent death. Forkhead box O1 (FOXO1) belongs to the forkhead family of transcription factors, but its role in B-cell ALL (B-ALL) has not been determined yet. Procedures: RNA sequencing was applied to an ALL case with induction failure (IF) to identify the possible genetic events. A cytokine-dependent growth assay in Ba/F3 cells was used to test the leukemic transformation capacity of MEIS1-FOXO1. The propidium iodide (PI) staining method was used to evaluate the effect of MEIS1-FOXO1 on cycle distribution. FOXO1 transactivity was examined using a luciferase reporter assay. FOXO1 mRNA expression levels were examined using real-time quantitative PCR among 40 children with B-ALL treated with the CCCG-ALL-2015 protocol. Association analysis was performed to test the correlation of FOXO1 transcription with childhood B-ALL prognosis and relapse in a series of GEO datasets. An MTT assay was performed to test the drug sensitivity. Results: In this ALL case with IF, we identified a novel MEIS1-FOXO1 fusion gene. The transactivity of MEIS1-FOXO1 was significantly lower than that of wild-type FOXO1. MEIS1-FOXO1 potentiated leukemia transformation and promoted Ba/F3 cell cycle S-phase entry. Low FOXO1 transcription levels were found to be strongly associated with unfavorable ALL subtype, minimal residual disease (MRD) positivity, and relapse. Lower FOXO1 expression was associated with prednisone and cyclophosphamide resistance. Conclusions: Low FOXO1 transcription was associated with high-risk stratification and relapse in children with B-ALL, probably due to multi-drug resistance.

Successful Anti-CLL1 CAR T-Cell Therapy in Secondary Acute Myeloid Leukemia.

Secondary acute myeloid leukemia (sAML) is a high-risk AML evolving from heterogenous prior hematological disorders. Compared to de novo AML, sAML has even worse responses to current therapy and thus is associated with lower remission rates, inferior overall survival (OS) and higher relapse rates. Many efforts have been devoted to improving the overall but with limited success, and novel strategy is thus highly needed. Recent research has identified that CLL1 is highly expressed on AML leukemia stem cells and blasts cells but not on normal hematopoietic stem cells. In this case report, we treated a secondary AML patient with anti -CLL1 CAR-T therapy and achieved morphological, immunophenotypic and molecular complete remission for over 10 months. Although only one successful case is presented here, the anti-CLL1 CAR T-cells should be considered as another treatment option for secondary AML in the future.

DNA methylation markers in the diagnosis and prognosis of common leukemias.

The ability to identify a specific type of leukemia using minimally invasive biopsies holds great promise to improve the diagnosis, treatment selection, and prognosis prediction of patients. Using genome-wide methylation profiling and machine learning methods, we investigated the utility of CpG methylation status to differentiate blood from patients with acute lymphocytic leukemia (ALL) or acute myelogenous leukemia (AML) from normal blood. We established a CpG methylation panel that can distinguish ALL and AML blood from normal blood as well as ALL blood from AML blood with high sensitivity and specificity. We then developed a methylation-based survival classifier with 23 CpGs for ALL and 20 CpGs for AML that could successfully divide patients into high-risk and low-risk groups, with significant differences in clinical outcome in each leukemia type. Together, these findings demonstrate that methylation profiles can be highly sensitive and specific in the accurate diagnosis of ALL and AML, with implications for the prediction of prognosis and treatment selection.

On the forming mechanism of the cleaning airflow of pulse-jet fabric filters.

To reveal the formation mechanism of a pulse-jet airflow's cleaning effect in a filter bag, a theoretical model is built by using the theory of the gas jet and unitary adiabatic flow according to given specifications and dimensions of the bags and resistance characteristics of the cloth and dust layer. It is about the relationship between cleaning system structure and operating parameters. The model follows the principle that the flow and kinetic energy of jet flow injected into a filter bag should be consistent with the flow of cleaning airflow in the bag and the pressure drop flowing through the filter cloth and dust layer. The purpose of the model is to achieve the peak pressure of cleaning airflow, which dominates the effect of the pulse-jet cleaning process. The cleaning system structure includes air pressure in the nozzle, structure and size of nozzle, exit velocity of nozzle, jet distance, and diameter of jet cross section. Based on the condition of the cleaning system structure and operating parameters established by using the theoretical model, Fluent software is applied to carry out a numerical simulation of the jet airflow field at the nozzle's outlet, jet airflow field between nozzle and bag top, and cleaning airflow field in the filter bag. Experimental results are used to verify the reliability of the theoretical model. They are obtained in a pilot-scale test filter with a single bag, with length 2 m and in general full-scale dimensions of the cleaning system. The results show that when any rectification measure is not installed at the bag opening, the cross-sectional area covered by the jet gas is hardly sufficient to cover the entire area of the bag opening. A large portion of the gases injected into the filter bag will overflow reversely upward from the edge due to pressure differences between the upper area and lower area inside the bag opening. This led to a serious shortage of the cleaning airflow and ar limited increase in static pressure. When a venturi-type rectifier tube is installed at the bag opening, the jet flow is converted to funnel flow for which the cross-section velocity distribution is more uniform at the throat of the rectifier tube due to the guided effects of the upper tapered pipe. Then it is transited to stressful flow below the bag opening via rectified effects of the lower dilated pipe. The results show that the gap between the static pressure of gas in the bag and the expected value is significantly reduced. The theoretical value of the nozzle diameter is enlarged to compensate for two aspects of adverse effects of cleaning airflow and energy. This is because the flow is not a purely free-form jet from the nozzle to the entrance of the rectifier tube and because the gas suffers from local resistance while flowing through the rectifier tube. The numerical simulation and experiment show that the peak pressure of cleaning airflow in the filter bag is able to reach the expected value. The results confirm that the mechanism of the pulse-jet cleaning airflow and the calculation method of the pulse-jet cleaning system structure and operating parameters offered in this study are correct. The study results provide a scientific basis for designing the system of pulse-jet fabric filters. IMPLICATIONS: Pulse-jet cleaned fabric filters are commonly used for air pollution control in many industries. Pulse-jet cleaning is widely used for this purpose as it enables frequent cleaning while the filter is operating. However, the theoretical system of the forming mechanism of the pulse-jet cleaning has not formed so far. This indicates the theoretical model plays an important role in designing effective pulse-jet cleaned fabric filters.

Diagnosis and treatment of neoplastic post-transplant lymphoproliferative disorder following hematopoietic stem cell transplant in ß-thalassemia: A pediatric case report.

INTRODUCTION: Post-transplant lymphoproliferative disorder (PTLD) is the most common form of lymphoproliferation in childhood and is associated with significant morbidity and mortality. In this report we reviewed the case of a pediatric patient who experienced PTLD after allogeneic hematopoietic stem cell transplantation (HSCT) from a human leukocyte antigen (HLA)-identical sibling. METHODS: The clinical characteristics, diagnosis, and treatment of PTLD after sibling HSCT in a 4-year-old boy with severe ß-thalassemia was retrospectively reviewed. RESULTS: Medical records revealed the patient developed a fever and superficial lymphadenopathy and soft palate enlargement 8 months post-HSCT. Pathologic diagnosis indicated non-Hodgkin lymphoma (B-cell type), which resulted in a reduced dose of immunosuppressant and the initiation of chemotherapy (administered according to the BFM95 protocol for 2 courses; 4 courses of rituximab therapy was also administered). Currently, the patient has been disease-free for over 3 years. There are no specific guidelines for the treatment of PTLD. The status of stem cell implantation after transplantation, and graft versus host disease should be evaluated jointly, and rituximab therapy and chemotherapy with BFM-95 may be used for treatment of pediatric PTLD after HSCT. CONCLUSION: The current case represents a unique opportunity to review a pediatric patient with ß-thalassemia. The successful treatment of post-transplant non-Hodgkin B lymphoma may help other physicians in the management of similar pediatric cases.

[Liver and heart iron deposition status in patients with ß thalassemia major: a multicenter study].

OBJECTIVE: To observe the status of iron deposition in patient with ß thalassemia major, and to formulate appropriate treatment strategies. METHOD: The data of status of transfusion and chelation in 135 patients aged from 6 years and 4 months to 17 years and 11 months with ß thalassemia major were collected and analyzed. Serum ferritin levels were determined and cardiac and hepatic iron deposition was determined using MRI T2(*) technology. RESULT: Of the 135 cases studied, 66 were male, and 69 were female, their average age was 12.1 years. Serum ferritin (SF) was determined for 111 cases, it varied from 1 086.8 µg/L to 15 011.5 µg/L. Among them, 16 cases had SF level <2 000 µg/L (14.5%) , in 41 cases SF were between 2 000 and 4 000 µg/L (36.0%) ;in 54 cases SF >4 000 µg/L (48.7%) . Liver MRI T2(*) results showed that in only 8 cases (5.9%) iron content in the liver was in normal range, 19 cases (14.9%) showed mild liver iron deposition;34 (25.2%) moderate and 74 (54.8%, the youngest one was only 6 years and 4 months of age) had severe iron deposition respectively. Cardiac MRI T2(*) showed that in 89 cases (65.9%) iron content in the heart was in normal range;19 cases (14.1%) had mild cardiac iron deposition and 27 (20.0%) presented severe iron deposition (the youngest one was only 9 years and 3 months of age) . SF level was obviously related to liver and cardiac iron deposition (MRI T2(*)) r and P value were -0.284, 0.003 and -0.374, 0.000 respectively. In 108 cases regular transfusion and chelation were delayed due to financial problem. The late and insufficient dosage administered and irregular chelation caused the higher SF level and the severe iron deposition. CONCLUSION: The survival status of ß thalassemia major in China is worrisome. Majority of them had not received regular transfusion and chelation. Liver and cardiac iron deposition occur early and had a high incidence.

[Influence of total nucleated cell dose on the efficacy of cord blood transplantation].

OBJECTIVE: To study the influence of cord blood total nucleated cell (TNC) dose on the efficacy of cord blood transplantation in children. METHODS: Thirty-four children with hematological disease received cord blood transplantation. They were assigned to 3 groups according to the infused TNC dose: TNC>10 x 10(7)/kg (n=7), 10 x10(7)/kg>TNC> or =7 x 10(7)/kg (n=9) and TNC<7 x 10(7)/kg (n=18). The rates of graft and rejection of hematopoietic stem cells and the efficacy of transplantation were examined in the three groups. RESULTS: All 7 children in the group infused with TNC >10 x 10(7)/kg got a long-term stable engraftment. The median time of absolute neutrophil count >0.5 x 10(9)/L was 14.8 days (range 12-20 days) and platelets >50 x10(9)/L was 52.3 days (range 26-86 days). They survived in a disease-free state. Of the 9 children in the group infused with TNC between 10 x 10(7)/kg and 7 x 10(7)/kg, 7 got engraftment. The median time of absolute neutrophil count >0.5 x 10(9)/L was 16.4 days (range 11-30 days) and platelets >50 x 10(9)/L was 63.7 days (range 34-140 days). Four children got a long-term stable engraftment and survived in a disease-free state. Two children with beta-thalassemia major had secondary rejection after engraftment and autologous hematopoitic recovery. One child died after engraftment and one child died in the early period after transplantation. Of the 18 children in the group infused with TNC<7 x 10(7)/kg, 16 children got engraftment. The median time of absolute neutrophil count >0.5 x 10(9)/L was 19.5 days (range 10-29 days) and platelets >50 x 10(9)/L was 70.1 days (range 41-116 days). Eight children had a long-term stable engraftment and survived in a disease-free state. Two children with beta-thalassemia major had secondary rejection after engraftment and autologous hematopoitic recovery. Six children died after engraftment. Two children had graft failure. CONCLUSIONS: TNC dose is an important influencing factor for hematopoietic stem cell engraftment in cord blood transplantation. An increased TNC dose may improve the success of cord blood transplantation.

[Haploidentical hematopoietic stem cell transplantation for beta-thalassemia major in children].

OBJECTIVE: Hematopoietic stem cell transplantation is currently a unique curative therapy for beta-thalassemia major. However, only 30% of patients have HLA-identical siblings to serve as donors. This study investigated the feasibility of hematopoietic stem cell transplantation from HLA mismatched related donors for beta-thalassemia major in children. METHODS: Between November 2001 and November 2007, 10 patients with beta-thalassemia major at median ages of 4.4 years (range:1.6-9.4 years) received 11 transplantations from their haploidentical donors, either HLA mismatched sibling umbilical cord bloods (n=6) or parents marrows (n=4) or sibling marrow (n=1). The conditioning regiment included fludarabine (100 mg/m2), busulfan (16 mg/kg), cyclophosphamide (200 mg/kg) and antithymocyte globulin. RESULTS: Of the 10 patients, 6 (60%) had sustained engraftment and red blood cell transfusion independence; 2 patients showed transient engraftment but rejected the graft quickly; 1 patients had no evidence of engraftment and developed aplastic anemia; 1 patient who received two transplantations had no evidence of engraftment and developed persistent aplastic anemia. All eight engrafted patients showed grade I to III acute graft-versus-host disease (GVHD), and only one developed limited skin chronic GVHD. The probability of overall and disease-free survival was 90% and 60%, respectively, with a median follow-up duration of 57.1 months (range: 2.5 to 85.1 months). CONCLUSIONS: Haploidentical stem cell transplantation is an alternative option for children with beta-thalassemia major, particularly when a matched sibling donor is not available.

[Relationship between cellular immune function during conditioning and graft rejection in patients with beta-thalassemia major].

OBJECTIVE: To analyze the relationship between cell-mediated immune function during conditioning and graft rejection in patients with beta-thalassemia major. METHODS: Allogeneic hematopoietic stem cell transplantation was performed in 25 children with beta-thalassemia major and 11 with acute leukemia group. The percentages of T lymphocytes and natural killer (NK) cells in peripheral blood of these patients were detected with dual color immunofluorescence on day -10 (before conditioning) and day -5 (after conditioning), and the relationship between the cellular immune function and graft rejection was analyzed. RESULTS: All the patients with acute leukemia showed engraftment. The rate of graft rejection was 34.8% in the patients with beta-thalassemia major. Compared with the leukemic patients, the patients with beta-thalassemia showed significantly increased percentage of CD3(+)CD8(+) T lymphocytes before and after the conditioning (P<0.05). The percentage of CD3(-)CD56(+) NK cells increased significantly in patients with beta-thalassemia major after the conditioning (P<0.05), but decreased markedly after conditioning in the leukemic patients (P<0.05). In patients with beta-thalassemia major and graft rejection, the CD3(-)CD56(+) cell phenotype was predominant after conditioning but remained unchanged in those with engraftment. CONCLUSION: CD3(-)CD56(+) NK cells are probably associated with graft rejection in patients with beta-thalassemia major, and may serve as an index for predicting graft rejection following allogeneic hematopoietic stem cell transplantation.