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Objective: To construct a novel chimeric antigen receptor T (CAR-T) cell targeting CD138 and to investigate its cytotoxicity against myeloma cells. Methods: The hybridoma strain that can stably secrete the CD138 monoclonal antibody (mAb) was prepared and obtained through monoclonal antibody screening technology. The hybridoma strain cells were intraperitoneally injected into mice to produce ascites containing monoclonal antibodies, which were then collected and purified to obtain pure CD138 mAb. Further examinations were performed to assess the biological characteristics of CD138 mAb. The variable region sequence of this antibody was amplified through reverse transcription polymerase chain reaction and was used as the antigen recognition domain of CD138 CAR, which was subsequently expressed on the surface of T cells by lentiviral infection. Flow cytometry was employed to assess the phenotype of CD138 CAR-T cells. In vitro cytotoxicity and degranulation assays were performed to evaluate their antitumor effects. Results: ① We successfully prepared anti-human CD138 antibody hybridoma cell lines and screened a hybridoma cell strain, 5G2, which could persistently and stably secrete the anti-CD138 antibody. ② The purified CD138 (5G2) mAb can especially recognize CD138(+) cells with a binding affinity constant (K(D)) of 6.011×10(-9) mol/L and showed no significant binding activity with CD138(-) cells. ③The variable region sequence of the CD138 (5G2) antibody was obtained using molecular cloning technology, and CD138 (5G2) CAR was successfully constructed and expressed on T cells through lentivirus infection and, concurrently, demonstrated effective binding to recombinant human CD138 protein.④ The proliferation of T cells transduced with the CD138 (5G2) CAR was highly efficient. The phenotype analysis revealed that CD138 (5G2) CAR-T cells exhibited a greater tendency to differentiate into central memory T cells and memory stem T cells, with a reduced proportion of terminally differentiated effector memory subsets. ⑤CD138 (5G2) CAR-T cells demonstrated specific cytotoxicity against CD138(+) myeloma cell line H929, whereas CD138(-) cell line K562 remained unaffected. The percentage of residual H929 cells was (12.92±8.02) % after co-culturing with CD138 (5G2) CAR-T cells, while (54.25±15.79) % was left in the Vector-T group (E∶T=1∶2; P <0.001). ⑥Results of degranulation assays demonstrated a significant activation of CD138 (5G2) CAR-T cells after co-culture with the H929 cell line, whereas no significant activation was observed in Vector-T cells [ (25.78±3.35) % vs (6.13±1.30) %, P <0.001]. ⑦After co-culturing with CD138(+) cells, CD138 (5G2) CAR-T cells exhibited a significant increase in cytokine secretion compared to the Vector-T group [interleukin-2: (1 697.52±599.05) pg/ml vs (5.07±1.17) pg/ml, P <0.001; interferon-γ: (3 312.20±486.38) pg/ml vs (9.28±1.46) pg/ml, P <0.001; and tumor necrosis factor-α: (1 837.43±640.49) pg/ml vs (8.75±1.65) pg/ml, P <0.001]. However, no significant difference was observed in cytokine secretion levels between the two groups after co-culturing with CD138(-) cells. Conclusion: This study successfully prepared a novel monoclonal antibody against CD138, and CAR-T cells constructed with the antigen recognition domain derived from this 5G2 mAb demonstrated effective antitumor activity against myeloma cells. This can be used as a new option for the detection of the CD138 antigen and proposes a novel strategy for multiple myeloma immunotherapy.

Objective: To construct a novel dual-specific antibody targeting human CD123 (CD123 DuAb) and study its effects in acute myeloid leukemia (AML) . Methods: Based on the variable region of the CD123 monoclonal antibody independently developed at our institution, the CD123 DuAb expression plasmid was constructed by molecular cloning and transfected into ExpiCHO-S cells to prepare the antibody protein. Through a series of in vitro experiments, its activation and proliferation effect on T cells, as well as the effect of promoting T-cell killing of AML cells, were verified. Results: ① A novel CD123 DuAb plasmid targeting CD123 was successfully constructed and expressed in the Expi-CHO eukaryotic system. ②The CD123 DuAb could bind both CD3 on T cells and CD123 on CD123(+) tumor cells. ③When T cells were co-cultured with MV4-11 cells with addition of the CD123 DuAb at a concentration of 1 nmol/L, the positive expression rates of CD69 and CD25 on T cells were 68.0% and 44.3%, respectively, which were significantly higher than those of the control group ( P <0.05). ④Co-culture with CD123 DuAb at 1 nmol/L promoted T-cell proliferation, and the absolute T-cell count increased from 5×10(5)/ml to 3.2×10(6)/ml on day 9, and CFSE fluorescence intensity decreased significantly. ⑤ With the increase in CD123 DuAb concentration in the culture system, T-cell exhaustion and apoptosis increased. When the CD123 DuAb was added at a concentration of 1 nmol/L to the culture system, the proportion of CD8(+) PD-1(+) LAG-3(+) T cells was 10.90%, and the proportion of propidium iodide (PI) (-) Annexin Ⅴ(+) T cells and PI(+) Annexin Ⅴ(+) T cells was 18.27% and 11.43%, respectively, which were significantly higher than those in the control group ( P <0.05). ⑥ The CD123 DuAb significantly activated T cells, and the activation intensity was positively correlated with its concentration. The expression rate of CD107a on T cells reached 16.05% with 1 nmol/L CD123 DuAb, which was significantly higher than that of the control group ( P <0.05). ⑦The CD123 DuAb promoted cytokine secretion by T cells at a concentration of 1 nmol/L, and the concentration of IFN-γ and TNF-α in the supernatant of the co-culture system reached 193.8 pg/ml and 169.8 pg/ml, respectively, which was significantly higher than that of the control group ( P <0.05). ⑧When CD123 DuAb was added at a concentration of 1 nmol/L to the co-culture system of T cells and CD123(+) tumor cells, the killing intensity of T cells significantly increased, and the residual rates of CD123(+) MV4-11 cells, CD123(+) Molm13 cells, and CD123(+) THP-1 cells were 7.4%, 6.7%, and 14.6% on day 3, respectively, which were significantly lower than those in the control group ( P <0.05) . Conclusion: In this study, a novel CD123 DuAb was constructed and expressed. In vitro experiments verified that the DuAb binds to CD123(+) tumor cells and T cells simultaneously, promotes T-cell activation and proliferation, and facilitates their anti-leukemia effect, which provides a basis for further clinical research.

Objective: This study aimed to explore the application of interaction-dependent fucosyl-biotinylation (FucoID), a chemical biology-based proximity labeling technique, in capturing tumor antigen-specific T cells and its clinical value in chronic myelogenous leukemia (CML) . Methods: Flow cytometry and fluorescence microscopy were employed to evaluate the experimental parameters for FucoID in CML. Peripheral blood samples were obtained from 14 newly diagnosed CML patients in the chronic phase. These samples underwent flow cytometry-based sorting and were subsequently labeled with FucoID to facilitate the isolation of tumor cells and T cells, followed by the immunophenotypic identification of tumor antigen-specific T cells. Finally, the diagnostic and therapeutic potential of FucoID in CML was assessed. Results: Initially, the experimental parameters for FucoID in CML were established. The proportion of CD3(+) T cells in patients was (8.96±6.47) %, exhibiting a marked decrease compared with that in healthy individuals at (38.89±22.62) %. The proportion of tumor-specific antigen-reactive T cells was (3.34±4.49) %, which demonstrated interpatient variability. In addition, the proportion of tumor-specific antigen-active T cells in CD4(+) T cells was (3.95±1.72) %, which was generally lower than the proportion in CD8(+) T cells at (5.68±2.18) %. Compared with those in tumor-specific antigen-nonreactive T cells, CCR7(-)CD45RA(-) effector memory T cells and CCR7(-)CD45RA(+) effector T cells were highly enriched in tumor-specific antigen-reactive T cells. Moreover, the intensity of tumor immune reactivity in patients exhibited a significant correlation with white blood cell count (WBC) and hemoglobin (HGB) levels in peripheral blood, while no such correlation was observed with other clinical baseline characteristics. Conclusion: The combination of FucoID and flow cytometry enables the rapid identification and isolation of tumor antigen-specific T cells in CML. The successful application of this method in CML and the implications of our findings suggest its potential clinical value in the field of hematologic malignancies.

Objective: To investigate the effect of the AML1-ETO (AE) fusion gene on the biological function of U937 leukemia cells by establishing a leukemia cell model that induces AE fusion gene expression. Methods: The doxycycline (Dox) -dependent expression of the AE fusion gene in the U937 cell line (U937-AE) were established using a lentivirus vector system. The Cell Counting Kit 8 methods, including the PI and sidanilide induction, were used to detect cell proliferation, cell cycle-induced differentiation assays, respectively. The effect of the AE fusion gene on the biological function of U937-AE cells was preliminarily explored using transcriptome sequencing and metabonomic sequencing. Results: ①The Dox-dependent Tet-on regulatory system was successfully constructed to regulate the stable AE fusion gene expression in U937-AE cells. ②Cell proliferation slowed down and the cell proliferation rate with AE expression (3.47±0.07) was lower than AE non-expression (3.86 ± 0.05) after inducing the AE fusion gene expression for 24 h ( P <0.05). The proportion of cells in the G(0)/G(1) phase in the cell cycle increased, with AE expression [ (63.45±3.10) %) ] was higher than AE non-expression [ (41.36± 9.56) %] ( P <0.05). The proportion of cells expressing CD13 and CD14 decreased with the expression of AE. The AE negative group is significantly higher than the AE positive group ( P <0.05). ③The enrichment analysis of the transcriptome sequencing gene set revealed significantly enriched quiescence, nuclear factor kappa-light-chain-enhancer of activated B cells, interferon-α/γ, and other inflammatory response and immune regulation signals after AE expression. ④Disorder of fatty acid metabolism of U937-AE cells occurred under the influence of AE. The concentration of the medium and short-chain fatty acid acylcarnitine metabolites decreased in cells with AE expressing, propionyl L-carnitine, wherein those with AE expression (0.46±0.13) were lower than those with AE non-expression (1.00±0.27) ( P <0.05). The metabolite concentration of some long-chain fatty acid acylcarnitine increased in cells with AE expressing tetradecanoyl carnitine, wherein those with AE expression (1.26±0.01) were higher than those with AE non-expression (1.00±0.05) ( P <0.05) . Conclusion: This study successfully established a leukemia cell model that can induce AE expression. The AE expression blocked the cell cycle and inhibited cell differentiation. The gene sets related to the inflammatory reactions was significantly enriched in U937-AE cells that express AE, and fatty acid metabolism was disordered.

Objective: To investigate the prognostic significance of interferon regulatory factor 9 (IRF9) expression and identify its role as a potential therapeutic target in acute promyelocytic leukemia (APL) . Methods: The gene expression profile and survival data applied in the bioinformatic analysis were obtained from The Cancer Genome Atlas and Beat acute myeloid leukemia (AML) cohorts. A dox-induced lentiviral system was used to induce the expression of PML-RARα (PR) in U937 cells, and the expression level of IRF9 in U937 cells treated with or without ATRA was examined. We then induced the expression of IRF9 in NB4, a promyelocytic leukemia cell line. In vitro studies focused on leukemic phenotypes triggered by IRF9 expression. Results: ①Bioinformatic analysis of the public database demonstrated the lowest expression of IRF9 in APL among all subtypes of AML, with lower expression associated with worse prognosis. ②We successfully established a PR-expression-inducible U937 cell line and found that IRF9 was downregulated by the PR fusion gene in APL, with undetectable expression in NB4 promyelocytic cells. ③An IRF9-inducible NB4 cell line was successfully established. The inducible expression of IRF9 promoted the differentiation of NB4 cells and had a synergistic effect with lower doses of ATRA. In addition, the inducible expression of IRF9 significantly reduced the colony formation capacity of NB4 cells. Conclusion: In this study, we found that the inducible expression of PR downregulates IRF9 and can be reversed by ATRA, suggesting a specific regulatory relationship between IRF9 and the PR fusion gene. The induction of IRF9 expression in NB4 cells can promote cell differentiation as well as reduce the colony forming ability of leukemia cells, implying an anti-leukemia effect for IRF9, which lays a biological foundation for IRF9 as a potential target for the treatment of APL.

Objective: To investigate the effect of CD33-targeted bi-specific and tri-specific T-cell engagers on T-cell proliferation and explore their cytotoxicity on leukemia cells. Methods: The CD33-targeted bi-specific T-cell engager (CD33-BiTE) and tri-specific T-cell engager (CD33-TriTE) expression vectors were successfully constructed and expressed through a eukaryotic cell expression system. CD33-BiTE and CD33-TriTE were purified by affinity chromatography. The effects of CD33-BiTE and CD33-TriTE on T cells were analyzed through in vitro experiments. Results: ① CD33-BiTE and CD33-TriTE were successfully constructed and purified and could compete with flow cytometry antibodies for binding to the target cells. ② After 12 days of co-culture with CD33-BiTE and CD33-TriTE, the number of human T cells were expanded to 33.89±19.46 and 81.56±23.62 folds, respectively. CD33-TriTE induced a stronger proliferation of T cells than CD33-BiTE ( P <0.05) . ③ Both CD33-BiTE and CD33-TriTE induced specific dose-dependent cytotoxicity on CD33(+) leukemia cells. ④ Compared to CD33-TriTE, leukemia cells were prone to express PD-L1 when co-cultured with T cells and CD33-BiTE. CD33-TriTE induced powerful cytotoxicity on leukemia cells with high PD-L1 expression. Conclusion: CD33-BiTE and CD33-TriTE expression vectors were constructed, and fusion proteins were expressed in eukaryotic cells. Our results support the proliferative and activating effects of BiTE and TriTE on T cells. Compared to that of CD33-BiTE, CD33-TriTE induced a stronger proliferative effect on T cells and a more powerful cytotoxicity on leukemia cells with high PD-L1 expression.

Objective: To compare the efficacy of two induction regimens, namely, idarubicin combined with cytarabine (IA) versus the combination of homoharringtonine, daunorubicin, and cytarabine (HAD) , in adult patients with newly diagnosed de novo acute myeloid leukemia (AML) . Methods: From May 2014 to November 2019, 199 patients diagnosed with AML receiving either the IA or HAD regimens were assessed for overall survival (OS) , relapse-free survival (RFS) , as well as the CR rate and the MRD negative rate after induction therapy. The differences in prognosis between the two induction therapy groups was assessed according to factors, including age, white blood cell (WBC) count, NPM1 mutation, FLT3-ITD mutation, 2017 ELN risk stratification, CR(1) transplantation, and the use of high-dose cytarabine during consolidation therapy, etc. Results: Among the 199 patients, there were 104 males and 95 females, with a median age of 37 (15-61) years. Ninety patients received the IA regimen, and 109 received the HAD regimen. Comparing the efficacy of the IA and HAD regimens, the CR rates after the first induction therapy were 71.1% and 63.3%, respectively ( P =0.245) , and the MRD negative rates after the first induction therapy were 53.3% and 48.6%, respectively ( P =0.509) . One patient in the IA group and two in the HAD group died within 60 days after induction. The two-year OS was 61.5% and 70.6%, respectively ( P =0.835) , and the two-year RFS was 51.6% and 57.8%, respectively ( P =0.291) . There were no statistically significant differences between the two groups. Multivariate analysis showed that the ELN risk stratification was an independent risk factor in both induction groups; CR(1) HSCT was an independent prognostic factor for OS and RFS in the IA patients and for RFS in the HAD patients but not for OS in the HAD patients. Age, WBC level, NPM1 mutation, and FLT3-ITD mutation had no independent prognostic significance. Conclusion: The IA and HAD regimens were both effective induction regimens for AML patients.

Objective: To construct chimeric antigen receptor (CAR) T cells targeting CD52 (CD52 CAR-T) and validate the effect of CD52 CAR-T cells on CD52-positive leukemia. Methods: A second-generation CD52-targeting CAR bearing 4-1BB costimulatory domain was ligated into a lentiviral vector through molecular cloning. Lentivirus was prepared and packaged by 293 T cells with a four-plasmid system. Fluorescein was used to label cell surface antigens to evaluate the phenotype of CD52 CAR-T cells after infection. Flow cytometry and ELISA were used to evaluate the specific cytotoxicity of CD52 CAR-T cells to CD52-positive cell lines in vitro. Results: ①A pCDH-CD52scFv-CD8α-4-1BB-CD3ζ-GFP expressing plasmid was successfully constructed and used to transduce T cells expressing a novel CD52-targeting CAR. ②On day 6, CD52-positive T cells were almost killed by CD52-targeted CAR-T post lentivirus transduction [CD52 CAR-T (4.48 ± 4.99) %, vs Vector-T (56.58±19.8) %, P =0.011]. ③T cells transduced with the CAR targeting CD52 showed low levels of apoptosis and could be expanded long-term ex vivo. ④The CD52 CAR could promote T cell differentiation into central and effector memory T cells, whereas the proportion of T cells with a CD45RA(+) effector memory phenotype were reduced. ⑤CD52 CAR-T cells could specifically kill CD52-positive HuT78-19t cells but had no killing effect on CD52-negative MOLT4-19t cells. For CD52 CAR-T cells, the percentage of residual of HuT78-19t cells was (2.66±1.60) % at an the E:T ratio of 1∶1 for 24 h, while (56.66±5.74) % of MOLT4-19t cells survived ( P <0.001) . ⑥The results of a degranulation experiment confirmed that HuT78-19t cells significantly activated CD52 CAR-T cells but not MOLT4-19t cells[ (57.34±11.25) % vs (13.06± 4.23) %, P <0.001]. ⑦CD52 CAR-T cells released more cytokines when co-cultured with HuT78-19t cells than that of vector-T cells [IFN-γ: (3706±226) pg/ml, P <0.001; TNF-α: (1732±560) pg/ml, P <0.01]. Conclusions: We successfully prepared CD52 CAR-T cells with anti-leukemia effects, which might provide the foundation for further immunotherapy.

Objective: To evaluate the efficacy and toxicity profiles of idarubicin, cytarabine, and cyclophosphamide (IAC) in relapse/refractory acute myeloid leukemia (AML) . Methods: This study was a prospective, randomized controlled clinical trial with the registration number NCT02937662. The patients were randomly divided into two groups. The experimental group was treated with an IAC regimen, and the regimen of the control group was selected by doctors according to medication experience. After salvage chemotherapy, allogeneic hematopoietic stem cell transplantation (allo-HSCT) was conducted as far as possible according to the situation of the patients. We aimed to observe the efficacy, safety, and toxicity of the IAC regimen in relapse/refractory AML and to explore which is the better regimen. Results: Forty-two patients were enrolled in the clinical trial, with a median age of 36 years (IAC group, 22 cases and control groups, 20 cases) . ①The objective response rate was 71.4% in the IAC group and 40.0% in the control group ( P =0.062) ; the complete remission (CR) rate was 66.7% in the IAC group and 40.0% in the control group ( P =0.121) . The median follow-up time of surviving patients was 10.5 (range:1.7-32.8) months; the median overall survival (OS) was 14.1 (range: 0.6-49.1) months in the IAC group and 9.9 (range: 2.0-53.8) months in the control group ( P =0.305) . The 1-year OS was 54.5% (95% CI 33.7%-75.3%) in the IAC group and 48.2% (95% CI 25.9%-70.5%) in the control group ( P =0.305) , with no significant difference between these two regimens. ②The main hematologic adverse events (AEs) were anemia, thrombocytopenia, and neutropenia. The incidence of grade 3-4 hematologic AEs in the two groups was 100% (22/22) in the IAC group and 95% (19/20) in the control group. The median time of neutropenia after chemotherapy in the IAC group and control group was 20 (IQR: 8-30) and 14 (IQR: 5-50) days, respectively ( P =0.023) . ③The CR rate of the early relapse (relapse within 12 months) group was 46.7% and that of the late relapse (relapse after 12 months) group was 72.7% ( P =0.17) . The median OS time of early recurrence was 9.9 (range:1.7-53.8) months, and that of late recurrence patients was 19.3 (range: 0.6-40.8) months ( P =0.420) , with no significant differences between the two groups. The 1-year OS rates were 45.3% (95% CI 27.2%-63.3%) and 66.7% (95% CI 40.0%-93.4%) , respectively ( P =0.420) . Survival analysis showed that the 1-year OS rates of the hematopoietic stem cell transplantation group and non-hematopoietic stem cell transplantation group were 87.5% (95% CI 71.2%-100%) and 6.3% (95% CI 5.7%-18.3%) , respectively. The OS rate of the hematopoietic stem cell transplantation group was significantly higher than that of the non-hematopoietic stem cell transplantation group ( P <0.001) . Conclusion: The IAC regimen is a well-tolerated and effective regimen in relapsed/refractory AML; this regimen had similar efficacy and safety with the regimen selected according to the doctor's experience for treating relapsed/refractory AML. For relapsed/refractory patients with AML, allogeneic hematopoietic stem cell transplantation should be attempted as soon as possible to achieve long-term survival.

Objective: To retrospectively analyze the data of Chinese patients with newly diagnosed acute promyelocytic leukemia (APL) to preliminarily discuss the clinical and cytogenetic characteristics. Methods: From February 2004 to June 2020, patients with newly diagnosed APL aged ≥ 15 years who were admitted to the Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Science & Peking Union Medical College were chosen. Clinical and laboratory features were retrospectively analyzed. Results: A total of 790 cases were included, with a male to female ratio of 1.22. The median age of the patients was 41 (15-76) years. Patients aged between 20 and 59 predominated, with 632 patients (80%) of 790 patients classified as low and intermediate risk and 158 patients (20%) of 790 patients classified as high risk. The white blood cell, platelet, and hemoglobin levels at diagnosis were 2.3 (0.1-176.1) ×10(9)/L, 29.5 (2.0-1220.8) ×10(9)/L, and 89 (15-169) g/L, respectively, and 4.8% of patients were complicated with psoriasis. The long-form type of PML-RARα was most commonly seen in APL, accounting for 58%. Both APTT extension (10.3%) and creatinine>14 mg/L (1%) are rarely seen in patients at diagnosis. Cytogenetics was performed in 715 patients with newly diagnosed APL. t (15;17) with additional chromosomal abnormalities were found in 155 patients, accounting for 21.7%; among which, +8 was most frequently seen. A complex karyotype was found in 64 (9.0%) patients. Next-generation sequencing was performed in 178 patients, and 113 mutated genes were discovered; 75 genes had an incidence rate>1%. FLT3 was the most frequently seen, which accounted for 44.9%, and 20.8% of the 178 patients present with FLT3-ITD. Conclusions: Patients aged 20-59 years are the most common group with newly diagnosed APL. No obvious difference was found in the ratio of males to females. In terms of risk stratification, patients divided into low and intermediate risk predominate. t (15;17) with additional chromosomal abnormalities accounted for 21% of 715 patients, in which +8 was most commonly seen. The long-form subtype was most frequently seen in PML-RARα-positive patients, and FLT3 was most commonly seen in the mutation spectrum of APL.

Objective: This study aimed to create a type of CAR-T cells that targets LMP1 antigen and study its immunotherapeutic effect on LMP1-positive hematological malignancies. Methods: To generate LMP1 CAR-T cells, a plasmid expressing LMP1 CAR was created using molecular cloning technology, and T cells were infected with LMP1 CAR lentivirus. The effects of LMP1 CAR-T cells on specific cytotoxicity against LMP1-positive tumor cell lines infected with the EB virus had been confirmed. Results: ① LMP1 protein expressing on EB virus-positive lymphoma cells surface was verified. ② The LMP1 CAR-expressing plasmid was created, and LMP1 CAR-T cells were obtained by infecting T cells with a lentivirus packaging system, with an infection efficiency of more than 80% . ③LMP1 CAR-T cells have a 4∶1 effect-to-target ratio in killing LMP1-positive lymphoma cells. The killing effect of LMP1 CAR-T cells on Raji cells was enhanced after 48 h of coculture, but there was no significant killing effect on Ramos, which are LMP1-negative lymphoma cells. ④After coculture with LMP1-positive lymphoma cells at a ratio of 1∶1 for 5 h, the degranulation effect was enhanced. The proportion of CD107a(+) T cells in the LMP1 CAR-T cell treatment group was significantly higher than that in the vector-T cell group [ (13.25±2.94) % vs (1.55±0.05) % , t =3.972, P =0.017]. ⑤After coculture with LMP1-positive lymphoma cells, the proportion of CD69(+) and CD25(+) T cells in the LMP1 CAR-T cell group was significantly higher than that in vector-T cell group [ (7.40±0.41) % vs (3.48±0.47) % , t =6.268, P =0.003; (73.00±4.73) % vs (57.67±2.60) % , t =2.842, P =0.047]. ⑥After coculture with LMP1-positive lymphoma cells, cytokine secretion in the LMP1 CAR-T cell group was higher than that in the vector-T cell group [interferon-gamma: (703±73) ng/L vs (422±87) ng/L, t =2.478, P =0.068; tumor necrosis factor-alpha: (215±35) ng/L vs (125±2) ng/L, t =2.536, P =0.064]. Conclusion: In this study, we found that the LMP1 protein is only found on the surface of the EBV-positive tumor cell. Simultaneously, we created an LMP1 CAR-expressing plasmid and obtained LMP1 CAR-T cells by infecting T cells with a lentivirus packaging system. Furthermore, we demonstrated that LMP1 CAR-T cells could specifically kill LMP1-positive tumor cells in vitro. The degranulation and activation effects of LMP1 CAR-T cells were enhanced after coculture with LMP1-positive tumor cells, indicating a potential clinical application.

Objective: To investigate the effect of genetic polymorphisms of TPMT*2 rs1800462, TPMT*3B rs1800460, TPMT*3C rs1142345, and NUDT15 rs116855232 on the tolerance of 6-mercaptopurine (6-MP) therapy in adult acute lymphoblastic leukemia (ALL) . Methods: A total of 216 adult patients who were diagnosed with ALL and treated with cyclophosphamide, cytarabine, and 6-MP [complementary and alternative medicine (CAM) regimen] from September 2015 to December 2019 were included. Polymorphisms were detected by TaqMan SNP Genotyping Assay. Combined with clinical data, the influence of genetic polymorphism on the tolerance of 6-MP in the treatment of ALL was analyzed. Results: Among the 216 patients, 185 (85.65%) patients had B-ALL and 31 (14.35%) patients had T-ALL. 216 (100%) patients had CC genotype for both TPMT*2 rs1800462 and TPMT*3B rs1800460. The number of TT and TC genotypes for TPMT*3C rs1142345 was 209 (96.76%) and 7 (3.24%) , respectively. The allele frequency was 1.62% for TPMT*3C rs1142345. The number of CC, CT, and TT genotypes for NUDT15 rs116855232 was 166 (76.85%) , 48 (22.22%) , and 2 (0.93%) , respectively. The allele frequency was 12.04% for NUDT15 rs116855232. The TPMT*3C rs1142345 mutant group (TC+CC genotype) had less transfusion volume of packed red blood cell than the wild group (CC genotype) ( P =0.036) , and the mutant group (TC+CC genotype) had a higher risk to develop hepatotoxicity (increased aspartate aminotransferase) than the wild group (CC genotype) ( OR =9.559, 95% CI 1.135-80.475, P =0.038) . The durations of white blood cells (WBC) <1×10(9)/L and absolute neutrophil count (ANC) <0.5×10(9)/L in the NUDT15 rs116855232 mutation group (CT+TT genotype) were longer than that in the wild group (CC genotype) ( P =0.005, P =0.007) , and the transfusion volume of apheresis-derived platelets in the mutant group (CT+TT type) was greater than that in the wild group (CC genotype) ( P =0.014) . Conclusion: Genetic polymorphism of TMPT and NUDT15 has an effect on the tolerance of 6-MP in the treatment of adult ALL. Detecting genotypes of patients with ALL before treatment helps to optimize the dosage of 6-MP, which may help shorten the bone marrow suppression duration and reduce blood transfusion volume.

Objective: To investigate the long term efficacy and side effects of a donor-derived CD19 chimeric antigen receptor (CAR) T-cell (HI19α-4-1BB-ζ CAR-T) therapy in the treatment of patients with relapsed B-cell acute lymphoblastic leukemia (B-ALL) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) . Methods: A total of 9 subjects with relapsed B-ALL post allo-HSCT received donor-derived CD19 CAR-T therapy from July 2017 to May 2020. All subjects were infused with donor CD3-positive T cells after lymphodepletion chemotherapy, and a median dose of CAR-T cells was 1.79 (range, 0.86-3.53) ×10(6)/kg. Results: ①All subjects achieved complete remission and MRD-negative at 28-42 d post CAR-T cells infusion. ②Cytokine releasing syndrome (CRS) occurrd in all subjects and was grade 3 in 2, grade 2 in 4, grade 1 in 3 cases respectively. Four subjects developed immune effector cell-associated neurotoxicity syndrome (ICANS) , which was grade 2 in 1, grade 1 in 3. One subject developed grade IV acute graft-versus-host disease (GVHD) , and side effects were all controllable. ③Four subjects relapsed at a median period of 8.6 (4.6-19.3) months, 2 subjects died of disease progression after receiving chemotherapy and another one also died of disease progression 14 months after a second transplant, only 1 subject achieved complete remission after CD22 CAR-T cell therapy. Until last follow-up date, 6 subjects were leukemia-free and achieved complete donor chimerism. The estimated 1-year and 2-year leukemia-free survival (LFS) rate was 63.5% and 50.8%, with a median LFS of 18.1 months. ④After a median follow-up of 25.1 (range, 6.9-36.7) months, the estimated 2-year and 2.5-year OS rate were 87.5% and 52.5%, respectively. Conclusion: The donor-derived CD19 CAR-T cell therapy obtain a high remission rate in relapsed B-ALL patients post allo-HSCT with tolerable side effects, half subjects survived more than 2 years without disease recurrence, though long-term efficacy requires further observation. Chinese Clinical Trial Registry: ChiCTR1900025419.

Objective: To investigate the safety and efficacy of venetoclax with low-dose cytarabine (LDAC) in Chinese patients with acute myeloid leukemia (AML) who are unable to tolerate intensive induction chemotherapy. Methods: Adults ≥ 18 years with newly diagnosed AML who were ineligible for intensive chemotherapy were enrolled in this international, randomized, double-blind, placebo-controlled trial. Globally, patients ( n =211) were randomized 2∶1 to either venetoclax with LDAC or placebo with LDAC in 28-d cycles, with LDAC on days 1-10. The primary endpoint was OS; the secondary endpoints included response rates, event-free survival, and adverse events. Results: A total of 15 Chinese patients were enrolled (venetoclax arm, n =9; placebo arm, n =6) . The median age was 72 years (range, 61-86) . For the primary analysis, the venetoclax arm provided a 38% reduction in death risk compared with the placebo[hazard ratio ( HR ) , 0.62 (95% CI 0.12-3.07) ]. An unplanned analysis with an additional 6 months of follow-up demonstrated a median OS of 9.0 months for venetoclax compared with 4.1 months for placebo. The complete remission (CR) rates with CR with incomplete blood count recovery (CRi) were 3/9 (33%) and 0/6 (0%) , respectively. The most common non-hematologic adverse effects (venetoclax vs placebo) were hypokalemia[5/9 (56%) vs 4/6 (67%) ], vomiting[4/9 (44%) vs 3/6 (50%) ], constipation[2/9 (22%) vs 4/6 (67%) ], and hypoalbuminemia[1/9 (11%) vs 4/6 (67%) ]. Conclusion: Venetoclax with LDAC demonstrated meaningful efficacy and a manageable safety profile in Chinese patients consistent with the observations from the global VIALE-C population, making it an important treatment option for patients with newly diagnosed AML who are otherwise ineligible for intensive chemotherapy.

Objective: To prepare a novel tri-specific T cell engager (19TriTE) targeting CD19 antigen, and to investigate its immunotherapeutic effect on CD19-positive hematological malignancies. Methods: 19TriTE was constructed by molecular cloning technology and successfully expressed through the eukaryotic expressing system. The effects of 19TriTE on the proliferation and activation of T cells, as well as the specific cytotoxicity against CD19 positive tumor cell lines were verified. Results: ①19TriTE expressing plasmid was constructed and successfully expressed through the eukaryotic expressing system. ②19TriTE can specifically bind to T cells and Nalm6 cells, with equilibrium dissociation constants of 19.21 nmol/L and 11.67 nmol/L, respectively. ③The expression rates of CD69 positive T cells and CD25 positive T cells were 35.4% and 49.8% respectively, when 2 nmol/L 19TriTE were added in the co-culture system, which were significantly higher than those in the control group. ④19TriTE can significantly promote the proliferation of T cells. The absolute count of T cells expanded from the initial one million to 74 million with an 74 fold increase at the concentration of 1 nmol/L on day 12. ⑤19TriTE can significantly mediate T cells killing of CD19 positive target cells in a dose-dependent manner. At the concentration of 10 nmol/L, the target cells lysis reached 50%. ⑥Degranulation experiment verified that 19TriTE can activate T cells in the presence of CD19 positive target cells, and the activation of T cells positively correlated with the dose of 19TriTE. ⑦When 19TriTE fusion protein co-cultured with T cells and target cells overexpression RFP and luciferase genes respectively, 19TriTE can notably mediate T cells killing of CD19 positive target cells through fluorescent microscope or bioluminescence imaging technology. Conclusion: In this study, we successfully constructed and expressed 19TriTE fusion protein and verified that it can effectively activate T cells and promote their proliferation in vitro. At the same time, it can bind to CD19 positive target cells and T cells, as well as enhance T cells anti-leukemia effect in vitro, providing the foundation for further clinical research.

Objective: This study evaluates the efficacy and safety of dasatinib combined with a multi-agent chemotherapy regimen of Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph(+) ALL) patients. Methods: This prospective, single-arm, and open clinical study enrolled 30 adult Ph(+) ALL patients who were newly diagnosed and treated from January 2016 to April 2018 in the center of this study. Standard induction chemotherapy was given for 4 weeks. However, dasatinib (100 mg/d) was continuously administered from day 8 until the end of the whole therapy in the induction therapy. Patients who are available for allogeneic or autologous stem cell transplantation (SCT) received transplantation when the disease was evaluated as complete remission. Results: All 30 patients achieved hematological complete remission (HCR) after the induction chemotherapy, and 70.0% (21/30) of them achieved the accumulated molecular complete remission (MCR) . The patients were followed up with a median follow-up time of 37.8 months (32.0-46.6) . The 3 year overall survival (OS) and 3 year hematological relapse-free survival (HRFS) were 68.1% and 61.6%, respectively. Moreover, 63.3% and 43.3% of the patients achieved molecular major remission and MCR, respectively. Consequently, 60.0% of the patients achieved MCR until 6 months. The patients who achieved MCR within 6 months had superior OS ( P =0.004) , HRFS ( P =0.049) , and event-free survival (EFS; P =0.001) . Fifteen patients (50.0%) received SCT at the first HCR. However, HRFS ( P =0.030) and EFS ( P =0.010) in the SCT group were better than those in the chemotherapy group. Conclusions: The regimen of dasatinib combined with a multi-agent chemotherapy was proven safe and effective in the treatment of newly diagnosed adult Ph(+) ALL patients. Clinical trial registration: ClinicalTrials.gov, NCT02523976.

Objective: To investigate the clinical characteristics, etiology, and prognosis of familial acute myeloid leukemia (AML) with germline CEBPA mutation and improve the understanding of familial leukemia. Methods: The age of onset, clinical characteristics, outcome, and prognosis of a family of patients with AML were investigated, and the family tree of the cases was displayed. Bone marrow and oral mucosal cells were collected from the proband, and peripheral blood was collected from the relatives of the proband. Gene mutation was detected by gene sequencing technology. Results: A total of 10 patients in this family were diagnosed with acute leukemia, including 4 males and 6 females, with a median age of 9 (3-48) years. Of the 10 patients, six died. Among them, 4 patients did not receive treatment, 1 patient survived 3 years after chemotherapy and died of relapse, and one patient died 2 years after receiving traditional Chinese medicine and supportive treatment. Four patients are alive. One patient has survived 15 years through chemotherapy, and three patients have survived with chemotherapy combined with hematopoietic stem cell transplantation, and the survival time was 6, 9, and 28 months at the end of follow-up. Gene sequencing was performed on proband and 8 relatives of the proband, and 5 were found to have the germline CEBPA TAD p.G36Afs*124 mutation. Among the 5 individuals with confirmed CEBPA mutation, 4 were diagnosed with AML, and 1 had not developed disease during follow-up. Conclusion: AML with germline CEBPA gene mutation mostly occurs in children and young adults, with complete or nearly complete penetrance. With active treatment, most of the patients have a favorable prognosis.

Objective: This study aimed to explore the efficacy and safety of rituximab combined with short-course and intensive regimens in the treatment of adult patients with Burkitt leukemia. Methods: The clinical data of 11 Burkitt leukemia patients in our hospital from January 30, 2006, to September 12, 2018, were collected. The clinical details, complete remission (CR) rate, overall survival (OS) , relapse-free survival (RFS) , and adverse events were evaluated. Results: The median age of 11 patients was 34 (15-54) years, of which six were males and five were females (M∶F, 1.2∶1) . The median white blood cell (WBC) count was 12.28 (2.21-48.46) ×10(9)/L, and the median blast percent of peripheral blood and bone marrow were 40% (3%-76%) and 84.0% (29.5%-94.5%) , respectively. Ten patients were administered with rituximab combined with a short-course and intensive regimens, and two patients underwent autologous hematopoietic stem cell transplantation following consolidation chemotherapy. The CR rate after one cycle of induction therapy was 100%, the four-year OS was 90%, and RFS was 90%. Out of the ten treated patients, only one patient suffered from tumor lysis syndrome during the induction chemotherapy. Consequently, renal function recovered after hemodialysis and other treatments. The regimen is safe with no treatment-related deaths. Conclusions: Rituximab combined with short-course and intensive chemotherapy regimens is effective and well-tolerated in adult Burkitt leukemia.

Objective: To analyze the influence of CD19 isoforms to the efficacy of CD19/CD3 Bispecific T-cell Engager (BiTE) antibody, and explore the resistance mechanism of BiTE immunotherapy. Methods: Semi-quantitative RT-PCR (qRT-PCR) was used to detect the expression of CD19 mRNA isoforms before and after BiTE treatment in a patient with CD19(+) B cell acute lymphoblastic leukemia (ALL) . CD19 isoforms were analyzed by Sanger sequencing. Flow cytometry and transcriptome sequencing were performed to analyze the expression of cell lineage specific molecules before and after BiTE treatment. Results: The expression of CD19 isoform with exon 2 deletion was identified at diagnosis. After relapsed and treatment of BiTE antibody, the patient did not achieve remission and CD19 antigen on leukemic cells turned negative detected by flow cytometry after BiTE treatment. However the expression ratio of CD19 isoform with exon 2 deletion was not increased. Flow cytometry phenotype and transcriptome sequencing confirmed that no linage switching developed, which suggested the expression of CD19 isoform caused by exon alternative splicing and lineage switching was not related to CD19 epitope loss in this patient. This patient achieved complete remission by sequential administration of self-developed CD22 CAR-T and CD19 CAR-T after disease progression. Conclusion: Targeting or combining an alternative antigen specific CAR-T may be a promising treatment option after losing CD19 expression in relapsed ALL.

Objective: To analyze the clinical manifestations and laboratory features in patients with myeloid neoplasms complicated with clonal T large granular lymphocyte (T-LGL) proliferation. Methods: The clinical data of 5 patients with myeloid neoplasms complicated with clonal T-LGL proliferation from November 2017 to November 2018 in Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College were analyzed retrospectively. Results: The median age was 60 years old. All patients had a history of abnormal peripheral blood cell counts for over 6 months. The absolute lymphocyte count in peripheral blood was less than 1.0×10(9)/L. In addition to the typical T-LGL phenotype, the immunophenotype was heterogenous including CD4(+)CD8(-) in 2 patients, the other 3 CD4(-)CD8(+). Four patients were αβ type T cells, the other one was γδ type. STAT3 mutation was detected in 1 patient by next-generation sequencing, the other 4 cases were negative. Conclusions: Clonal T-LGL proliferation with myeloid neoplasm develops in an indolent manner, mainly in elderly patients. Hemocytopenia is the most common manifestation. The diagnosis of T-LGL proliferation does not have specific criteria, that it should be differentiated from other T cell proliferative disorders, such as T-cell clones of undetermined significance. STAT3 or STAT5b mutation may help distinguish.

Objective: To construct a new CD123- specific chimeric antigen receptor in order to provide a foundation for immunotherapy of CD123 positive leukemia. Methods: A hybridoma strain (6E11) capable of stably secreting CD123 antibody was obtained by a monoclonal screening technique, and the hybridoma cells were expanded and injected intraperitoneally to the pretreated Balb/c mice. Ascites was collected and purified to obtain the monoclonal antibody (mAb) . The affinity and specificity of 6E11 mAb were measured. The variable regions of the heavy and light chains of the 6E11 mAb were cloned by RT-PCR from the 6E11 mouse hybridoma. We generated a new CD123 specific chimeric antigen receptor with a scFv fragment derived from 6E11 antibody, designated as 6E11 CAR. T cells were transduced with lentiviral supernatant from 293T cells transfected with 6E11 CAR plasmid to generate 6E11 CAR-T cells. The specific cytotoxicity of 6E11 CAR-T against CD123(+) acute myeloid leukemia (AML) cell lines and primary AML cells in vitro were evaluated by co-culture experiments, degranulation experiments and cytokine releasing assay. Results: ① A hybridoma cell line 6E11 stably secreting anti-human CD123 antibody was developed and its variable region sequences were obtained. ② The 6E11 mAb has high affinity for CD123 protein (Kd value: 2.1 nmol/L) . The 6E11 mAb specifically recognizes CD123(+) cell line THP-1 cells and does not respond to CD123(-) cell line Jurkat cells. ③ 6E11 CAR-T cells were successfully generated with a CAR expression rate higher than 60%. ④ 6E11 CAR-T cells could specifically kill CD123(+) MV4-11 cell line but had no killing effect on the CD123(-) K562 cell line. Compared with vector-T cells, 6E11 CAR-T cells have higher killing rate to MV4-11 cells[ (98.60±1.20) % vs (20.28±6.74) %, P <0.001]. ⑤ MV4-11 cells activated 6E11 CAR-T cells significantly but not Vector-T cells[ (26.33±3.30) % vs (1.17±0.06) %, P <0.001]. ⑥ 6E11 CAR-T cells released more cytokines than vector-T cells when co-cultured with MV4-11[IL-2: (92.90±1.51) pg/ml vs (6.05±3.41) pg/ml, P <0.001; TNF-α: (1 407.20±91.95) pg/ml vs (7.86±0.85) pg/ml, P <0.001; IFN-γ: (5 614.60±170.17) pg/ml vs (8.42±2.70) pg/ml, P <0.001]. The IFN-γ, IL-2 and TNF-α in the 6E11 CAR-T group were similar to those in the Vector-T group when co-cultured with K562. ⑦ 6E11 CAR-T cells could be activated by bone marrow mononuclear cells (BMMNC) derived from CD123(+) AML patients and effectively kill these BMMNC cells from CD123(+) AML patients. Conclusion: 6E11 hybridoma cell line can stably secrete highly specific monoclonal antibodies against human CD123, which can be used to detect the expression of human CD123. It can also be used to target human CD123 protein in tumor immunotherapy. CD123 CAR-T cells with 6E11 Ig variable region sequence have specific anti-leukemic activity in vitro, which may provide a new option for further clinical research of AML.

Objective: To investigate the clinical characteristics, diagnosis, treatment and prognosis of therapy-related myeloid neoplasms (t-MNs) after successful treatment for acute promyelocytic leukemia (APL) . Methods: Clinical data of 4 patients, diagnosed as t-MNs secondary to APL at Hematology Hospital of Chinese Academy of Medical Sciences from October 2012 to January 2019, were collected retrospectively. T-MNs related literature was reviewed. Results: The 4 cases were all females, with the median age 42 (range 40-53) years old at the diagnosis of APL. Regarding the induction and consolidation regimens, 3 patients received all-trans retinoid acid (ATRA) and arsenic trioxide (ATO) combined with anthracycline/anthraquinone and/or cytosine. One patient only received ATRA and other auxiliary drugs. Alkylating agents were not administrated. The 4 patients developed t-MNs 40 to 43 months after complete remission (CR) of APL, including 1 case of therapy-related myelodysplastic syndrome (t-MDS) and 3 cases of acute myeloid leukemia (t-AML) . The PML-RARα fusion genes were all negative when t-MNs developed. The three patients with t-AML were treated with 3 to 4 re-induction regimens, one of whom underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) after complete remission (CR) . One patient with t-MDS received hypomethylating agents. After a median follow-up of 54.5 (48-62) months, 2 patients with t-AML died, the median overall survival after t-MN was 12 (5-18) months. From 1989 to 2018, a total of 63 t-MN cases were reported in the literature. Therefore, 67 cases were analyzed when four patients in our center were added, including 27 males and 40 females with median age 52.5 (15-76) years. The median latency was 39 (12-126) months and the median overall survival after diagnosis of t-MN was 10 (1-39) months. Conclusions: Although rare, t-MNs may occur after successful control of APL. There are no existing guidelines for prevention and treatment of t-MNs, which have very poor prognosis. If cytopenia or other abnormalities of peripheral blood cells develop after 3 years of APL, t-MNs should be considered as a differential diagnosis.

Objective: To investigate the clinic-pathological features, diagnosis and treatment of 8p11 myeloproliferative syndrome (EMS) . Methods: Five patients diagnosed as EMS from Jan 2014 to May 2018 at Blood Disease Hospital, Chinese Academy of Medical Sciences were enrolled. The clinical manifestations, laboratory characteristics, treatment and outcome of these patients were summarized. Results: The peripheral blood leukocyte count of 5 patients with EMS increased significantly, accompanied with an elevated absolute eosinophils value (the average as 18.89×10(9)/L) . The hypercellularity of myeloid cells was common in bone marrow, always with the elevated proportion of eosinophils (the average as 17.24%) , but less than 5% of blast cells. The chromosome karyotype of the 5 cases differed from each other, but presenting with the same rearrangement of FGFR1 gene by fluorescence in situ hybridization technology. The average interval between onset and diagnosis was 4.8 months with a median survival of only 14 months. Conclusion: EMS was a rare hematologic malignancy with poor prognosis and short survival. It was commonly to be misdiagnosed. Analysis of cytogenetics and molecular biology were helpful for early diagnosis.

Objective: To construct the BCMA-CAR using the B-cell maturation antigen (BCMA) specific ligand APRIL as antigen binding region and to validate the effect of BCMA-CAR modified T cells (BCMA-CAR-T) on myeloma cells. Methods: The BCMA-CAR was constructed using the BCMA specific ligand APRIL as antigen binding domain and 4-1BB as the costimulatory domain. The specific cytotoxicity against BCMA(+) myeloma cell lines and primary multiple myeloma (MM) cells in vitro were evaluated. In addition, BCMA(+) myeloma xenograft mouse model was established to assess the anti-tumor effect of BCMA-CAR-T cell therapy in vivo. Results: BCMA-CAR-T cells could specifically kill BCMA(+) myeloma cell lines (For BCMA-CAR-T cells, BCMA(+) cells are almost undetectable in the E∶T ratio of 1∶4) and MM patients' bone marrow mononuclear cells (the proportion of residual cells in BCMA-CAR-T and vector-T groups was 16.0% vs 66.85%, P =0.003) with significant degranulation (CAR-T and vector-T cells cocultured with MM1.S, H929 and U266 had degranulation levels of 33.30% vs 5.62%, 16.97% vs 2.95% and 25.87% vs 2.97%, respectively, P <0.001) and cytokines release ( P <0.01) in vitro. In a human BCMA(+) myeloma xenograft mouse model, BCMA-CAR-T cells could significantly prolong the survival of mice (The median survival time of mice treated with BCMA-CAR-T and vector-T cells was 87.5 days and 67.5 days, respectively, P <0.001) . Conclusion: The ligand-based BCMA-CAR-T cells could be a promising strategy for BCMA(+) multiple myeloma treatment.

Objective: To compare the time of the recovery of neutrophils or leukocytes by pegylated recombinant human granulocyte stimulating factor (PEG-rhG-CSF) or common recombinant human granulocyte stimulating factor (rhG-CSF) in the myelosuppressive phase after induction chemotherapy in newly diagnosed acute myeloid leukemia (AML) patients. At the same time, the incidences of infection and hospitalization were compared. Methods: A prospective randomized controlled trial was conducted in patients with newly diagnosed AML who met the enrollment criteria from August 2014 to December 2017. The patients were randomly divided into two groups according to a 1:1 ratio: PEG-rhG-CSF group and rhG-CSF group. The time of neutrophil or leukocyte recovery, infection rate and hospitalization interval were compared between the two groups. Results: 60 patients with newly diagnosed AML were enrolled: 30 patients in the PEG-rhG-CSF group and 30 patients in the rhG-CSF group. There were no significant differences in age, chemotherapy regimen, pre-chemotherapy ANC, WBC, and induction efficacy between the two groups ( P >0.05) . The median time (range) of ANC or WBC recovery in patients with PEG-rhG-CSF and rhG-CSF were 19 (14-35) d and 19 (15-26) d, respectively, with no statistical difference ( P =0.566) . The incidences of infection in the PEG-rhG-CSF group and the rhG-CSF group were 90.0%and 93.3%, respectively, and there was no statistical difference ( P =1.000) . The median days of hospitalization (range) was 20.5 (17-49) days and 21 (19-43) days, respectively, with no statistical difference ( P =0.530) . Conclusions: In AML patients after induction therapy, there was no significant difference between the application of PEG-rhG-CSF and daily rhG-CSF in ANC or WBC recovery time, infection incidence and hospitalization time.

Objective: To investigate the application values of immunophenotypic analysis and molecular genetics in the diagnosis of acute promyelocytic leukemia (APL) . Methods: The retrospective analyses of flow cytometric (FCM) immunophenotypic anyalysis, chromosome karyotype and chromosome fluorescence in situ hybridization (FISH) of 798 outpatient or hospitalization APL patients referred to our hospital between May 2012 and December 2017 were performed to further study the application values of FCM and molecular genetics in the diagnosis of APL. Results: The sensitivity and specificity of FCM were 91.9% and 98.7% respectively. The typical characteristic immunophenotype for APL was as of follows: a high SSC, absence of expression of cluster differntiation (CD) CD34 and HLA-DR, and expression or stronger expression of CD33, consistent expression of CD13, CD9, CD123, expression of CD56, CD7, CD2 (sometimes) . The rest 10% of the cases harbored atypical APL phenotypes, generally accompanied by CD34 and/or HLA-DR expression, decreased SSC and often accompanied by CD2 expression, it was difficult to definitively diagnose APL by this FCM phenotype, and their diagnoses depended on the results of genetics or molecular biology tests. Compared with normal individuals, complex karyotypes APL with t (15;17) translocation, other variant translocations and variant t (11;17) , t (5;17) had no significant differences in terms of their FCM phenotypes. Conclusions: FCM could rapidly and effectively diagnose APL. Despite the fact that complex karyotypes with various additional chromosomal abnormalities were detected in approximately one third of APL cases in addition to the pathognomonic t (15;17) (q22;q21) , they had no observable impact on the overall immunophenotype. Molecular and genetic criteria were the golden criteria for the diagnosis of APL. About 10% of immunophenotyping cases relied on molecular genetics for diagnosis.

Objective: To analyze the clinical, laboratory characteristics and prognosis of adult early T-cell precursor acute lymphoblastic leukemia (ETP-ALL). Methods: The clinical data of 13 adult ETP-ALL patients from January 2009 to March 2017 were retrospectively analyzed and compared with non-ETP ALL patients. Results: 13 ETP-ALL patients (17.3%) were identified in 75 adult T-ALL patients, the median age of the patients was 35 years old (15 to 49 years) and 10 patients were male (76.9%). ETP-ALL patients had lower WBC count, LDH level, blasts in peripheral blood, lower incidence of thymic mass and higher PLT count compared to non-ETP ALL patients. The CR rate after one course induction chemotherapy for ETP-ALL and non-ETP ALL patients was 33.3% and 90.1%, respectively ( χ (2)=26.521, P <0.001). The median overall survival(OS) was 11.33 (95% CI 0-28.46) and 25.69 (95% CI 11.98-39.41) months, respectively. The 3-year OS was 41.7% and 40.7%, respectively ( P =0.699). The median event free survival (EFS) was 1.51 (95% CI 1.23-1.79) and 21.36 (95% CI 4.67-38.04) months, respectively. The 3-year EFS was 16.7% and 39.5%, respectively ( P =0.002). The 3-year relapse free survival (RFS) was 53.0% and 52.0%, respectively ( P =0.797). Multivariate analysis revealed that CNSL and allo-HSCT were independent risk factors affecting OS of T-ALL and ETP-ALL didn't affect the prognosis of T-ALL. Conclusion: To our knowledge, this study is the first report on characteristics and prognosis of adult ETP-ALL patients in China. At total of 13 T-ALL patients (17.3%) were classified as having ETP-ALL. These patients had a lower leukemia burden and lower CR rate after one course induction compared to non-ETP ALL patients. Allo-HSCT can improve the prognosis of ETP-ALL.

Objective: To evaluate the impact of KIT D816 mutation on the salvage therapy in relapsed acute myeloid leukemia (AML) with t(8;21) translocation. Method: The characteristics of the first relapsed AML with t(8;21) translocation from 10 hospitals were retrospectively collected, complete remission (CR(2)) rate after one course salvage chemotherapy and the relationship between KIT mutation and CR(2) rate was analyzed. Results: 68 cases were enrolled in this study, and 30 cases (44.1%) achieved CR(2). All patients received KIT mutation detection, and KIT D816 mutation was identified in 26 cases. The KIT D816 positive group had significantly lower CR(2) compared with non-KIT D816 group (23.1% vs 57.1%, χ (2)=7.559, P =0.006), and patients with longer CR(1) duration achieved significantly higher CR(2) than those with CR(1) duration less than 12 months (74.1% vs 31.9%, χ (2)=9.192, P =0.002). KIT D816 mutation was tightly related to shorter CR(1) duration. No significant difference of 2 years post relapse survival was observed between KIT D816 mutation and non-KIT D816 mutation group. Conclusion: KIT D816 mutation at diagnosis was an adverse factor on the salvage therapy in relapsed AML with t(8;21) translocation, significantly related to shorter CR1 duration, and can be used for prediction of salvage therapy response. KIT D816 mutation could guide the decision-making of salvage therapy in relapsed AML with t(8;21) translocation.

Objectives: To investigate the influence of duration of antibiotic therapy on the prognosis of patients with AML who had Gram-negative bloodstream infection during consolidation chemotherapy. Methods: Data were collected retrospectively from 591 patients enrolled from the registered "A Phase III study on optimizing treatment based on risk stratification for acute myeloid leukemia, ChiCTR-TRC-10001202" treatment protocol between September 2010 and January 2016 in different treatment cycles. Results: A total of 119 episodes of Gram-negative bloodstream infection occurred during consolidation chemotherapy. Excluding the 5 episodes in which fever lasted longer than 7 days, 114 episodes of infection were analyzed. The median neutrophil count was 0 (0-5.62)×10(9)/L, median neutropenia duration was 9 (3-26) days, median interval of antibiotics administration was 7 (4-14) days. Logistic regression analysis showed that there is no significant difference on 3-day recurrent fever rate and reinfection by the same type bacteria between antibiotics administration ≤7 days or >7 days (1.2% vs 3.0%, P =0.522, OR =0.400, 95% CI 0.024-6.591; 18.5% vs 21.2%, P =0.741, OR =0.844, 95% CI 0.309-2.307). Propensity score analysis confirmed there was no significant difference on same pathogen infection rate between antibiotics application time ≤ 7 days or >7 days ( P =0.525, OR =0.663, 95% CI 0.187-2.352). No infection associated death occurred within 7 or 30 days in both groups. Conclusion: Discontinuation of therapy until sensitive antibiotics treated for 7 days does not increase the recurrent fever rate and the infection associated death rate. Indicating that, for AML who had Gram-negative bloodstream infection during consolidation chemotherapy, short courses of antibiotic therapy is a reasonable treatment option when the infection is controlled.

Objective: To investigate the spectrum of gene mutations in adult patients with B-acute lymphoblastic leukemia (B-ALL), and to analyze the influences of different gene mutations on prognosis. Methods: DNA samples from 113 adult B-ALL patients who administered from June 2009 to September 2015 were collected. Target-specific next generation sequencing (NGS) approach was used to analyze the mutations of 112 genes (focused on the specific mutational hotspots) and all putative mutations were compared against multiple databases to calculate the frequency spectrum. The impact of gene mutation on the patients' overall survival (OS) and recurrence free survival (RFS) was analyzed by the putative mutations through Kaplan-Meier, and Cox regression methods. Results: Of the 113 patients, 103 (92.0%) harbored at least one mutation and 29 (25.6%) harbored more than 3 genes mutation. The five most frequently mutated genes in B-ALL are SF1, FAT1, MPL, PTPN11 and NRAS. Gene mutations are different between Ph + B-ALL and Ph - B-ALL patients. Ph - B-ALL patients with JAK-STAT signal pathway related gene mutation, such as JAK1/JAK2 mutation showed a poor prognosis compared to the patients without mutation (OS: P =0.011, 0.001; RFS: P =0.014,<0.001). Patients with PTPN11 mutation showed better survival than those without mutation, but the difference was not statistically significant ( P value > 0.05). Besides, in Ph + B-ALL patients whose epigenetic modifications related signaling pathway genes were affected, they had a worse prognosis (OS: P =0.038; RFS: P =0.047). Conclusion: Gene mutations are common in adult ALL patients, a variety of signaling pathways are involved. The frequency and spectrum are varied in different types of B-ALL. JAK family gene mutation usually indicates poor prognosis. The co-occurrence of somatic mutations in adult B-ALL patients indicate the genetic complex and instability of adult B-ALL patients.

Objective: To analyze the clinical and laboratory characteristics, and prognosis of adult acute myeloid leukemia (AML) patients with MLL gene rearrangements. Methods: The medical records of 92 adult AML patients with MLL gene rearrangements from January 2010 to December 2016 were retrospectively analyzed. Results: 92 cases (6.5%) with MLL gene rearrangements were identified in 1 417 adult AML (Non-M(3)) patients, the median age of the patients was 35.5 years (15 to 64 years old) with an equal sex ratio, the median WBC were 21.00(0.42-404.76)×10(9)/L, and 78 patients (84.8%) were acute monoblastic leukemia according to FAB classification. Eleven common partner genes were detected in 32 patients, 9 cases (28.1%) were MLL/AF9(+), 5 cases (15.6%) were MLL/AF6(+), 5 cases (15.6%) were MLL/ELL(+), 2 cases (6.3%) were MLL/AF10(+), 1 case (3.1%) was MLL/SETP6(+), and the remaining 10 patients' partner genes weren't identified. Of 92 patients, 83 cases with a median follow-up of 10.3 (0.3-74.0) months were included for the prognosis analysis, the complete remission (CR) rate was 85.5% (71/83), the median overall survival (OS) and relapse free survival (RFS) were 15.4 and 13.1 months, respectively. Two-year OS and RFS were 36.6% and 29.5%, respectively. Of 31 patients underwent allogeneic hematopoietic stem-cell transplantation (allo-HSCT), two-year OS and RFS for patients received and non-received allo-HSCT were 57.9% and 21.4%, 52.7% and 14.9%, respectively ( P <0.001). Among patients with partner genes tested, 9 of 32 cases (28.1%) were MLL/AF9(+), the median follow-up was 6.0(4.1-20.7) months. 3 patients with MLL/AF9 underwent allo-HSCT. 23 cases (71.9%) were non- MLL/AF9(+), the median follow-up was 7.8 (0.3-26.6) months. 14 patients (60.1%) with non-MLL/AF9 underwent allo-HSCT. One-year OS for patients with MLL/AF9 and non-MLL/AF9 were 38.1% and 55.5%, respectively ( P =0.688). Multivariate analysis revealed that high WBC ( RR =1.825, 95% CI 1.022-3.259, P =0.042), one cycle to achieve CR ( RR =0.130, 95% CI 0.063-0.267, P <0.001), post-remission treatment with allo-HSCT ( RR =0.169, 95% CI 0.079-0.362, P <0.001) were independent prognostic factors affecting OS. Conclusions: AML with MLL gene rearrangements was closely associated with monocytic differentiation, and MLL/AF9 was the most frequent partner gene. Conventional chemotherapy produced a high response rate, but likely to relapse, allo-HSCT may have the potential to further improve the prognosis of this group of patients.

Objective: To investigate the impact and mechanism of NPM1 gene expression on acute myeloid leukemia (AML) cell lines. Methods: Human AML cell line U937 and HL-60 cells were transfected with NPM1 plasmid to establish stable clones, and the high NPM1 protein expression (NPM1(hi)) clones were screened by Western blot. The cell proliferation was assayed by methylthiazolyl tetrazolium bromide (MTT) , cell cycle and cell apoptosis by flow cytometric, cell colony formation by microscope count, the molecular pathways related to cell cycle by Western blot. The expression of NPM1 gene in primary AML bone marrow mononuclear cells (BMMC) was investigated by RQ-PCR. Results: ①The proliferation of NPM1(hi) U937 and HL-60 cells was similar with that of control cells (4.68±1.28 vs 3.89±0.81, 3.34±0.37 vs 2.68±0.29, P >0.05) . ②The percentage of S phase in NPM1(hi) U937 and HL-60 cells was higher than that in control cells[ (50.22±3.42) % vs (39.78±3.80) %, (59.01±3.27) % vs (43.94±2.08) %, P <0.05]. ③The anti-apoptosis capacity and colony formation abilities of NPM1(hi) U937 cells increased than that of control cells[ (68.8±10.2) % vs (48.7±3.22) %, and (772.7±24.0) vs (652.3±16.5) , P <0.05], but the above abilities of NPM1(hi) HL60 cells were similar with that of control cells. ④ The expressions of CDK4, Cyclin D1, Cyclin D2 and Cyclin E in NPM1(hi) leukemia cells were higher than that of control cells, but the expression of Cyclin D3 was lower. ⑤The NPM1 expression levels in AML patients with favorable cytogenetic prognosis were lower than that of patients with intermediate prognosis. Conclusions: NPM1 protein could promote more cells to enter S phase, enhance the ability of antiapoptosis and colony formation in AML cell lines. The quantitative level of NPM1 may predict the cytogenetic risk of AML patients.

Objective: To investigate the feasibility of multiplex real-time RT-PCR with fluorescent probes in early screening of Ph-like acute lymphoblastic leukemia (ALL) and analyze the clinical feature and prognos. Method: A total of 118 adult B-ALL patients diagnosed between October 2010 and March 2016 were enrolled in this study. Multiplex RT-PCR was used to detect the Ph-like ALL related fusion gene and CRLF2 expression in 58 BCR-ABL and MLL rearrangement negative patients. The clinical features, treatment response and prognosis were analyzed in Ph-like fusion gene positive and/or CRLF2 over-expression patients. Result: Among 58 patients, 9 patients (9/58, 15.5%) showed Ph-like ALL related fusion genes positive and 10 patients (10/58, 17.2%) showed CRLF2 over-expression. There were statistical differences in age, WBC count, immunophenotypes, cytogenetics and risk stratification among Ph-like fusion gene positive or CRLF2 over-expression patients, Ph(+) patients, MLL(+) patients and B-other patients. The 2-year overall survival rates were 65%, 47%, 64% and 74% respectively among these four groups ( P =0.043) . The 2-year relapse free survival rates were 51%, 39%, 62% and 70% respectively among these four groups ( P =0.010) . Conclusion: Routine screening of Ph-like ALL by multiplex RTPCR is feasible.

Objective: To investigate the effect and mechanism of all-trans retinoic acid (ATRA) on leukemic cell line U937 cells with NPM1 mutation. Methods: Human acute myeloid leukemia cell line U937 was explored, NPM1 mutated (A type) plasmids were transfected into U937 to form stable clones A1 and A2, which were identified by Western blot and Co-immunoprecipitation. The cell proliferation was measured by methylthiazolyl tetrazolium bromide (MTT) ; cell cycle and cell apoptosis were explored by flow cytometric; cell colony formation was measured by microscope count, the molecular pathways related to cell proliferation were measured by Western blot. Results: ①The cell proliferations of mutant A1 and A2 were inhibited significantly by 52.6% and 35.8% ( P <0.05) , respectively under ATRA exposure. ②The percentages of G(0)/G(1) stage of mutant A1 and A2 increased by 20.1% and 35.8%, respectively under ATRA exposure. ③All the U937 leukemic cells were inhibited under ATRA exposure; the decreased percentages of vector, wild-type and mutant NPM1 cells were 32.7%, 57.9% and 90.9% respectively. ④p-ERK decreased obviously after ATRA exposure in NPM1 mutated leukemic cells. ⑤More mutant NPM1 cells inclined to apoptosis under the exposure of ATRA and cytotoxic drugs than cytotoxic drugs alone, meanwhile more cells apoptosis occurred when ATRA was administrated after cytotoxic drugs exposure. Conclusions: ATRA could inhibit cell proliferation and colony formation, blocked the cell cycle in the G(0)/G(1) stage accompanied by the significant reduction of p-ERK in U937 leukemic cells with NPM1 mutation. Besides, ATRA could synergize with drugs to suppress the leukemic cells survival more effectively when ATRA was administered after the cytotoxic drugs exposure in U937 leukemic cells with NPM1 mutation.

Objective: To investigate the impact of minimal residual disease (MRD) by multiparameter flow cytometry (MPFC) during aplasia on efficacy and prognosis of de novo acute myeloid leukemia (AML) (non M(3)) patients. Methods: The MRD data by 8-color MPFC during aplasia (day 14-15 of induction therapy) in 85 de novo AML (non M(3)) patients and the MRD impact on efficacy and prognosis were retrospectively analyzed. Results: Data of 85 patients, including 42 males (49.4%) and 43 females (50.6%) , were collected, with a median age of 35 (15-54) years. The median MRD by MPFC during aplasia was 0.58% (0-81.11%) , and 70 (82.4%) patients achieved complete remission (CR) after first induction chemotherapy. The cutoff of MRD by receiver operating characteristic (ROC) analysis was 2.305% (Se= 0.867, Sp=0.800) . The CR rate after one course was significantly higher in patients with MRD<2.305% [96.6% (56/58) ]than in patients with MRD≥2.305%[51.9% (14/27) ] ( χ (2)=22.348, P <0.001) ; no significant difference with respect to relapse-free survival rate ( χ (2)=1.08, P =0.299) or overall survival rate ( χ (2)=0.42, P =0.516) could be demonstrated for the comparison of the two groups. Multivariates analysis showed MRD divided by 2.305% was the only independent prognostic factor for CR after one course ( OR = 21.560, 95% CI 4.129-112.579, P <0.001) . Conclusion: Flow cytometric MRD divided by 2.305% during aplasia could be a predictor of efficacy after first induction therapy in AML patients.

Objective: To probe the potential utility of Wilms tumor 1 (WT1) as a marker of minimal residual disease (MRD) in acute myeloid leukemia (AML) to estimate the relapse-predicting cut-off value. Methods: Quantitative assessment of bone marrow WT1 mRNA level was preformed using real-time quantitative reverse transcription polymerase chain reaction (RQ-RT-PCR) assay. The expression levels of WT1 dynamically measured with RQ-RT-PCR were retrospectively analyzed in 121 AML cases (not including acute promyelocytic leukemia) achieving complete remission (CR) after induction therapy followed by consolidation therapy. By comparing WT1 levels of patients with different post-therapy outcomes, the investigators used the receiver operating characteristic (ROC) curve to determine WT1 threshold so as to predict their clinical relapses. Then prognoses and the significance of intervention were analyzed between WT1 positive and negative patients according to the cut-off value of WT1. Results: According to ROC curve, WT1 level higher than 2.98% predicted the possibility of relapse. For simplicity and clinical application, 3.00% was used as the cut-off value of WT1 level for relapse. WT1 levels in 41 patients at diagnosis were detected, meanwhile 3 patients whose WT1 levels at diagnosis below 3.00% were excluded, then the median WT1 level of the rest 38 patients at diagnosis was 44.09% (range 7.19%-188.06%) . The median WT1 level in remission was 0.48% (352 samples, range 0-8.41%) . The median WT1 level at diagnosis was higher than that in remission. Excluding the 3 patients with WT1 level at diagnosis under 3.00%, the relapse rate of WT1 positive group (>3.00% during consolidation phase and follow-up) and WT1 negative group (≤3.00%) was 70.0% (14/20) and 12.2% (12/98) respectively ( P <0.001) . The median time from WT1 positivity to clinical relapse was 58 days. Conclusions: WT1 expression level above 3.00% was associated with markedly high risk of relapse, which could be as a useful marker for monitoring MRD following consolidation therapy.

Objective: To evaluate the efficacy and safety of generic imatinib (Genike, Chiatai Tianqing Pharmaceutical Group Co., Ltd.) and imatinib (Glevic, Novartis, Switzerland) in newly diagnosed patients with chronic myeloid leukemia in chronic phase (CML-CP) . Methods: A retrospective study of 323 CML-CP patients (205 in Glivec treatment group and 118 in Genike group) who were ≥ 18 years old receiving imatinib monotherapy over the period of June 2013 to March 2016 was done to compare the differences of cytogenetics, molecular curative effect, survival, and adverse reactions between the two groups. The beginning dosage of imatinib was 400mg per day. There was no statistically difference between the two groups of patients on baseline. Results: ①The median duration of imatinib treatment was 13 (0.5-36) months in Glevic group and 11 (1-31) months in Genike group. ②The rate of complete hematological remission (CHR) had no statistically difference between Glivec and Genike treatment groups[98% (201/205) vs 97.5% (115/118) , χ (2)=0.123, P =0.725]. ③Cumulative rates of major cytogenetic responses (MCyR) at 3, 6 and 12 months after imatinib treatment in Gleevec and Genike groups were (59.7±3.5) % vs (79.8±3.1) %, (89.2±2.6) % vs (59.1±4.7) %, (80.3±4.1) % vs (87.1±4.3) %, respectively, the difference was not statistically significant ( χ (2)=0.084, P =0.772) . Cumulative rates of complete cytogenetic response (CCyR) at 3, 6 and 12 months after imatinib treatment in Gleevec and Genike groups were (32.9±3.4) % vs (58.3±3.7) %, (87.4±3.0) % vs (35.2±4.5) %, (64.8±4.8) % vs (87.3±4.7) %, respectively, the difference was not statistically significant ( χ (2)=0.660, P =0.417) . ④Cumulative rates of major molecular responses at 6, 12 months after imatinib treatment in Glevic and Genike groups were (24.9±3.3) % vs (57.0±4.1) %, (16.3±4.0) % vs (55.3±7.7) %, respectively, there was no statistical significance ( χ (2)=1.617, P =0.204) . Cumulative rates of molecular response 4.5 (MR4.5) at 12 months after imatinib treatment in Glevic and Genike groups were (14.9±3.2) % vs (8.1±2.1) % ( χ (2)=3.628, P =0.057) , respectively. ⑤At a median follow-up of 12 months, the difference of progression-free survival (PFS) in Glevic and Genike groups had no statistical significance[ (96.6±1.4) % vs (93.3±2.5) %, χ (2)=2.293, P =0.130]. The difference of event-free survival (EFS) had no statistical significance, either[ (95.6±1.5) % vs (93.3±2.4) %, χ (2)=2.124, P =0.145]. ⑥Genike was well tolerated in patients with CML-CP and had no statistically significant difference in adverse events compared with Glevic group. Conclusion: There were no statistically significant differences in efficacy and safety between Glevic and Genike treatment in newly diagnosed patients with CML-CP.

Objective: To evaluate the incidence of invasive fungal infections (IFI) and usage of intravenous antifungal drugs during remission induction chemotherapy in patients with acute myeloid leukemia (AML) under primary antifungal prophylaxis with posaconazole. Methods: Clinical records from newly diagnosed AML patients above 15 years old in one single center from February 2014 to January 2016 were retrospectively reviewed and analyzed, excluding acute promyelocytic leukemia. The incidence of IFI and usage of intravenous antifungal drugs were investigated between control group (not receiving any broad spectrum antifungal prophylaxis) and treatment group (receiving posaconazole as primary prophylaxis). Results: A total of 147 newly diagnosed AML patients were enrolled. Of them, 81 received prophylaxis with posaconazole, and 66 did not receive broad-spectrum antifungal treatment. 7 IFI occurred in posaconazole group, and all were possible cases; 19 IFI occurred in control group (3 proven, 4 probable, 12 possible). The incidence of IFI was significantly lower in treatment group than that in control group (8.6% vs 28.8%, χ (2)=10.138, P =0.001). Usage of intravenous antifungal drugs was significantly decreased in posaconazole group (18.5% vs 50.0%, χ (2)=16.390, P <0.001). Conclusion: Prophylaxis with posaconazole coulf prevent IFI and reduce usage of intravenous antifungal drugs significantly during remission induction chemotherapy in AML patients.

Objective: To analyze the clinical features and prognosis of acute lymphoblastic leukemia patients with immunophenotype of CD10(-)pre-B (CD10(-) pre B-ALL) . Methods: 6 adult cases with CD10(-) pre B-ALL immunophenotypes were analyzed retrospectively, related literatures were reviewed to clarify these kind of patients' clinical features and prognosis. Results: CD10(-) pre B-ALL occurred in 1.5% of ALL, 1.8% of B-ALL and 11.5% of pre B-ALL respectively. All the 6 patients were male with the median age as 33.5 years old, the median white blood cells was 101.78×10(9)/L, MLL-AF4 fusion transcripts were evident in all cases. Complete remission (CR) was achieved in 5 patients after first induction chemotherapy, 1 patient failed to respond to induction therapy, and got CR after 3 courses of chemotherapy. 2 patients underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) in CR(1), 1 patient relapsed in the short term and underwent allo-HSCT in CR(2). 1 patient was still waiting for allo-HSCT. Of the 2 patients who didn't receive transplantation, 1 died following a relapse, the other remained to be in CR. Conclusions: CD10(-) pre B-ALL was a rare but distinct subtype in adult ALL characterized by male dominance, high onset white blood cells and MLL rearrangement rate. Conventional chemotherapy produced a high response rate but more likely relapse, allo-HSCT may have the potential to improve the prognosis of these patients.

Objective: To investigate the clinical significance and prognosis factors of acute myeloid leukemia (AML) with FLT3 mutation-internal tandem duplication (FLT3-ITD) and provide more evidence for prognosis evaluation in AML with FLT3-ITD. Methods: The clinical characteristics and outcomes of 98 AML with FLT3-ITD were analyzed. Results: In patients with FLT3-ITD positive AML, the median of WBC and peripheral blood blast at initial diagnosis were 58.2 (0.3-461.8) ×10 9 /L and 42.2 (0-397.1) ×10 9 /L, respectively. The complete remission (CR) rate after one course induction therapy was 60.6% in 71 patients with intermediate or adverse risk. The primary refractory rate was 26.8% in 71 patients with intermediate or adverse risk. The lower number of peripheral blood blast was a favorable factor to achieve CR after one course induction therapy ( P =0.009). CR after one course ( HR =0.395, 95% CI 0.183-0.85, P =0.001) and allo-transplantation in CR 1 ( HR =0.180, 95% CI 0.043-0.752, P =0.018) favored longer relapse-free survival (RFS). CR after one course ( HR =0.251, 95% CI 0.121-0.523, P < 0.001) and lower number of peripheral blood blast ( HR =0.219, 95% CI 0.088-0.545, P =0.003) favored longer overall survival (OS) in AML with FLT3-ITD. Conclusion: FLT3-ITD positive AML with lower number of peripheral blood blast has a relative favorable prognosis. CR after one course and allotransplantation in CR 1 are important strategy to improve prognosis in AML with FLT3-ITD.

Objective: To explore the efficacy and prognostic factors of imatinib(IM)combined with chemotherapy for BCR-ABL gene positive acute lymphoblastic leukemia(ALL). Methods: A total of 209 BCR-ABL + ALL patients treated with imatinib plus chemotherapy from April 2003 to August 2015 were enrolled in the study, and 106 patients underwent hematopoietic stem cell transplantation(HSCT). Results: The complete remission(CR)rate was 97.9% in newly diagnosed patients. WBC≥100×10 9 /L at diagnosis was a poor factor for overall survival(OS)( P =0.043). Without HSCT, not achieved CR within 4 weeks in the first cycle induction chemotherapy and complete molecular remission(CMR)not achieved during the treatment were adverse factors for OS( P <0.001, P =0.009, P <0.001, respectively), as well as for relapse free survival(RFS)( P <0.001, <0.001 and <0.001, respectively). Of the 106 patients who underwent allo-HSCT or auto-HSCT, there was no statistically significant difference on the OS and RFS. There was no significant difference on OS in patients treated with imatinib or not in the induction chemotherapy, but the former showed higher 5-year RFS rate(37.0% vs 24.0%, P =0.005). The survival of the patients who took tyrosine kinase inhibitors(TKIs)regularly and continuously was the best(40 patients changed to other TKI due to relapse/unsatisfactory decrease in transcription level/occurrence of mutation), followed by those who interrupted TKIs during the bone marrow suppression, those who took TKIs irregularly the worst. The 5- year OS rates among three groups were 46.0%, 28.0% and 17.0%, respectively( P =0.004). The 5- year EFS rates among three groups were 38.0%, 28.0% and 17.0%, respectively( P <0.001). Conclusion: TKIs plus chemotherapy followed by HSCT improved the prognosis of the patients with BCR-ABL + ALL patients. It is important to administer TKIs regularly and continuously to improve the outcome of BCR-ABL + ALL patients.

Objective: To explore the cytogenetic and prognostic significance of monosomal karyotype (MK) in adult patients with acute myeloid leukemia (AML)., Methods: From September 2002 to November 2014 in Blood Diseases Hospital, Chinese Academy of Medical Sciences, 97 cases with AML were enrolled, including 96 cases within unfavorable cytogenetic category and an MK case within the intermediate category. The clinical data of MK-positive cases and unfavorable risk MK-negative cases were analyzed., Results: There were 31 MK cases, accounting for 2.5% of the AML patients treated at the same period. Thirty of them were complex aberrant karyotypes defined as showing three or more clonal abnormalities and classified into adverse group based on SWOG criteria. The rest one of these 31 MK was intermediate risk according to SWOG criteria. Among MK cases, the most frequent monosomal chromosome were -17, -5, -7, -21, -8, -22. In 96 cytogenetic unfavorable AML cases, the median OS period was 6.1 months for MK, the median OS period did not reach for non-MK AML (P=0.001). And the median relapse free survival (RFS) period was 3.1 and 18.6 months for MK and non-MK AML (P<0.001), respectively. Both overall survival (OS) and RFS varied significantly between MK and non-MK categories. In 49 complex karyotype AML cases, the median OS was 6.1 and 10.8 months for MK and non-MK AML (P=0.088), respectively. And the median RFS was 3.1 and 8.6 months for MK and non-MK AML (P=0.009), respectively. The RFS varied significantly between MK and non-MK categories., Conclusion: Most MK patients were complex karyotype in cytogenetic unfavorable group. Within unfavorable or complex karyotype categories, MK-positive cases had a more adverse prognosis than MK-negative cases.

Objective: To compare the efficacy and toxicities of combining homoharringtonine (HHT)±daunorubicin (DNR) with all-trans-retinoic acid (ATRA) based therapy and DNR plus ATRA based therapy in newly diagnosed low/intermediate risk acute promyelocytic leukemia (APL)., Methods: A total of 96 newly diagnosed patients with APL were randomized to HHT group, DNR group and HHT+ DNR group prospectively. The complete remission (CR) rate, the overall survival (OS) and event-free survival (EFS) of three groups were analyzed., Results: There were 31 patients in HHT group, 33 patients in DNR group and 32 patients in HHT+ DNR group. The baseline characteristics of three groups were similar. No patient died during induction therapy. The morphologic CR rate was 100.0%. The median time to peak WBC counts in HHT+DNR group (4 days, range: 1-23 days) was significantly shorter than that in HHT group (9 days, range: 1-27 days) (P=0.008) and DNR group (7 days, range: 1-27 days) (P=0.240). There was no difference among three groups about the incidence of differentiation syndrome, the median interval to achieve CR, peak WBC counts and transfusions (P >0.05). All patients achieved complete molecular remission (CMR) during consolidation therapy. The interval to achieve CMR was no significantly difference among three groups (P >0.05). The 3-year OS rates for HHT group, DNR group and HHT+DNR group were 95.0%, 100.0% and 91.0%, respectively (P=0.595). The 3-year EFS rates for three groups were 93.0%, 90.0% and 85.0% (P=0.382). No difference was found in the incidence of adverse events among three groups (P >0.05)., Conclusions: Similar to DNR plus ATRA based therapy, HHT plus ATRA based induction and consolidation therapy should be one of highly-efficient treatment options for newly diagnosed APL. Clinical trial registration Chinese Clinical Trial Registry, ChiCTR-TRC-12002628.