[The Role of NK Cells in Allogeneic Hematopoietic Stem Cell Micro-Transplantation for Acute Myeloid leukemia].

OBJECTIVE: To explore the role of NK cells in allogeneic hematopoietic stem cell micro-transplantation(MST) in the treatment of patients with acute myeloid leukemia(AML). METHODS: Data from 93 AML patients treated with MST at our center from 2013-2018 were retrospectively analyzed. The induction regimen was anthracycline and cytarabine combined with peripheral blood stem cells transplantation mobilization by granulocyte colony stimulating factor (GPBSC), followed by 2-4 courses of intensive treatment with medium to high doses of cytarabine combined with GPBSC after achieving complete remission (CR). The therapeutic effects of one and two courses of MST induction therapy on 42 patients who did not reach CR before transplantation were evaluated. Cox proportional hazards regression analysis was used to analyze the impact of donor NK cell dose and KIR genotype, including KIR ligand mismatch, 2DS1, haplotype, and HLA-Cw ligands on survival prognosis of patients. RESULTS: Forty-two patients received MST induction therapy, and the CR rate was 57.1% after 1 course and 73.7% after 2 courses. Multivariate analysis showed that, medium and high doses of NK cells was significantly associated with improved disease-free survival (DFS) of patients (HR=0.27, P =0.005; HR=0.21, P =0.001), and high doses of NK cells was significantly associated with improved overall survival (OS) of patients (HR=0.15, P =0.000). Donor 2DS1 positive significantly increases OS of patients (HR=0.25, P =0.011). For high-risk patients under 60 years old, patients of the donor-recipient KIR ligand mismatch group had longer DFS compared to the nonmismatch group (P =0.036); donor 2DS1 positive significantly prolonged OS of patients (P =0.009). CONCLUSION: NK cell dose, KIR ligand mismatch and 2DS1 influence the therapeutic effect of MST, improve the survival of AML patients.

Hematopoietic stem cell microtransplantation in patients aged over 70 with acute myeloid leukemia: a multicenter study.

In the era of molecular targeted drugs, elderly patients with acute myeloid leukemia (AML) are still very difficult to treat, especially those older than 70 years. The decline in immune function leads to serious infection and disease recurrence. The microtransplant treatment regimen (MST) chemotherapy combined with allogeneic hematopoietic stem cell infusion is a new cell therapy regimen. The aim of this MST study was to improve the survival of elderly patients by graft versus leukemia action and improving T-cell immune function. From May 2012 to July 2020, one hundred and eleven patients aged 70 to 88 years with de novo AML were analyzed retrospectively. After induction chemotherapy, patients whom complete remission (CR) was achieved were given another 2 cycles of postremission therapy. The MST groups were given allogeneic stem cell infusion after each chemotherapy cycle. CR, leukemia-free survival, and overall survival (OS) were compared between groups. Additionally, the immune function and the T cell receptor (TCR) library of T cells were detected and analyzed. The MST group exhibited an encouragingly high CR rate (63.8%), even in high-risk patients (54%), and this rate was significantly higher than that in the chemotherapy alone group. The 1-year OS of MST patients was 57.7%, and it was 55.9% in the high-risk group. It was only 37.3% in the chemotherapy alone group. Higher numbers of naive T cells were found in the MST population than in the chemotherapy alone group. More updated T-cell clones were observed in MST patients by T-cell receptor repertoire analysis with a next-generation sequencing methodology. These results suggest that MST is a safe and practical regimen conducive to longer-term survival in patients of a highly advanced age with AML. Furthermore, it has broad clinical value in the recovery of immune function in elderly patients.

Donor Selection in HLA-Mismatched Hematopoietic Stem Cell Microtransplantation for Acute Myeloid Leukemia.

To remedy the lack of human leukocyte antigen (HLA)-matched donors and address the problems bedeviling traditional allogeneic hematopoietic stem cell transplantation which induces the resultant graft-versus-host disease, we designed a scheme called HLA-mismatched hematopoietic stem cell microtransplantation (MST) for patients with acute myeloid leukemia (AML), where encouraging results were achieved. In providing answers to such questions as how to select the donors of MST and which factors were involved in the outcome of MST. One hundred thirty-one AML patients from four centers with lower or standard risk of prognosis after complete remission were given three courses of MST: high dose of cytarabine plus infusion of granulocyte colony-stimulating factor mobilized peripheral blood stem cells from HLA-mismatched donors. Leukemia-free survival (LFS) and overall survival were compared, with respect to gender difference, number of HLA-matched loci, killer cell immunoglobulin-like receptor (KIR), and ligand mismatch between donors and recipients. Median LFS of recipients with different KIR ligands from those of donors was found to be significantly higher than that of recipients having identical ligands with donors (P < 0.05). The mean LFS was statistically different between recipients whose donors had HLA-C1/C2 ligand and those whose donors had C1/C1 or C2/C2 ligand (P < 0.05). The following factors were found to promote long-term survival: female recipients of male donors' stem cell, and donors with different KIR ligands from recipients.

Comparative study of micro-transplantation from HLA fully mismatched unrelated and partly matched related donors in acute myeloid leukemia.

Micro-transplantation (MST) by chemotherapy, combined with granulocyte colony-stimulating factor-mobilized peripheral blood stem cell (GPBSC) infusion, from an HLA partial matched related donor has shown some encouraging effective therapy for acute myeloid leukemia (AML). However, the outcome of human leukocyte antigen (HLA) fully mismatched unrelated donor-derived MST in such patients is still unknown. In the present study, we compared the efficacy of HLA fully mismatched unrelated donor-derived MST, and partly matched related donor-derived MST, in AML of 126 patients from two centers in China, These patients, aged 16 to 65 years, were given three or four courses of MST, which consisted of a high dosage cytarabine followed by GPBSC from unrelated donor or related donor. There was a statistically significant difference in 3-year leukemia-free survival (LFS) and 3-year overall survival (OS) between the unrelated and the related group. The non-treatment-related mortality (NRM) rates of patients, and other adverse complications, were no different in the two groups. In conclusion, unrelated donor-derived MST is believed to be a safe treatment, with efficacy similar to or higher than related donor-derived MST. This result provides support for the potential of MST for expanding the donor selection. However, the specific mechanism of action needs further study.

HLA-Mismatched Microtransplant in Older Patients Newly Diagnosed With Acute Myeloid Leukemia: Results From the Microtransplantation Interest Group.

IMPORTANCE: The outcome of older patients with acute myeloid leukemia (AML) remains unsatisfactory. Recent studies have shown that HLA-mismatched microtransplant could improve outcomes in such patients. OBJECTIVE: To evaluate outcomes in different age groups among older patients with newly diagnosed AML who receive HLA-mismatched microtransplant. DESIGN, SETTING, AND PARTICIPANTS: This multicenter clinical study included 185 patients with de novo AML at 12 centers in China, the United States, and Spain in the Microtransplantation Interest Group. Patients were divided into the following 4 age groups: 60 to 64 years, 65 to 69 years, 70 to 74 years, and 75 to 85 years. The study period was May 1, 2006, to July 31, 2015. EXPOSURES: Induction chemotherapy and postremission therapy with cytarabine hydrochloride with or without anthracycline, followed by highly HLA-mismatched related or fully mismatched unrelated donor cell infusion. No graft-vs-host disease prophylaxis was used. MAIN OUTCOMES AND MEASURES: The primary end point of the study was to evaluate the complete remission rates, leukemia-free survival, and overall survival in different age groups. Additional end points of the study included hematopoietic recovery, graft-vs-host disease, relapse rate, nonrelapse mortality, and other treatment-related toxicities. RESULTS: Among 185 patients, the median age was 67 years (range, 60-85 years), and 75 (40.5%) were female. The denominators in adjusted percentages in overall survival, leukemia-free survival, relapse, and nonrelapse mortality are not the sample proportions of observations. The overall complete remission rate was not significantly different among the 4 age groups (75.4% [52 of 69], 70.2% [33 of 47], 79.1% [34 of 43], and 73.1% [19 of 26). The 1-year overall survival rates were 87.7%, 85.8%, and 77.8% in the first 3 age groups, which were much higher than the rate in the fourth age group (51.7%) (P = .004, P = .008, and P = .04, respectively). The 2-year overall survival rates were 63.7% and 66.8% in the first 2 age groups, which were higher than the rates in the last 2 age groups (34.2% and 14.8%) (P = .02, P = .03, P < .001, and P < .001, respectively). The 1-year cumulative incidences of nonrelapse mortality were 10.2%, 0%, 3.4%, and 26.0% in the 4 age groups and 8.1% in all patients. The median times to neutrophil and platelet recovery were 12 days and 14 days after induction chemotherapy, respectively. Five patients had full or mixed donor engraftment, and 30.8% (8 of 26) of patients demonstrated donor microchimerism. Two patients (1.1%) developed severe acute graft-vs-host disease. CONCLUSIONS AND RELEVANCE: Microtransplant achieved a high complete remission rate in AML patients aged 60 to 85 years and higher 1-year overall survival in those aged 60 to 74 years.

[Biological characteristics of Microvesicles Derived from Bone Marrow Mesenchymal Stem Cells and Their Capacities Supporting ex vivo Expansion of Hematopoietic Stem Cells].

OBJECTIVE: To explore the biological characteristics of microvesicles(MV) derived from bone marrow mesenchymal stem cells (BM-MSC) and their capability supporting ex vivo expansion of hematopoietic stem cells(HSC). METHODS: The MV from cultured BM-MSC supernatant were isolated by multi-step differential velocity contrifugation; the morphological characteristics of MV were observed by electron microscopy with negative staining of samples; the protein level in MV was detected by using Micro-BCA method; the surface markers on MV were analyzed by flow cytometry. The peripheral blood HSC(PB-HSC) were isolated after culture and mobilization; the experiment was diveded into 2 group: in MV group, the 10 mg/L MV was given, while in control group, the same volume of PBS was given; the change of PB-HSC count was observed by cell counting; the change of surface markers on PB-HSC was detected dynamically by flow cytometry; the cell colony culture was used to determin the function change of PB-HSC after co-culture with MV. RESULTS: MSC-MVs are 20-100 nm circular vesicles under electron microscope. About 10 µg protein could be extracted from every 1×106 MSC. The flow cytometry showed that CD63 and CD44 were positive with a rate of 96.0% and 50.2%, while the HLA-DR, CD34, CD29 and CD73 etc were negative. When being co-cultured with GPBMNC for 2 days, the cell number of MV groups was 1.49±0.15 times of the control group (P>0.05). When being co-cultured for 4 days, the cell number of MV groups was 2.20±0.24 times of the control group(P<0.05). The CD34+ cell number of MV groups was 1.76±0.30 times the control group after culture for 2 day and 1.95±0.20 times after culture for 4 day. CONCLUSION: The MV has been successfully extracted from MSC culture supernatant by multi-step differential velocity centrifugation. MSC-MV can promote HSC expansion in vitro.

[Biological Characteristics of Microvesicles Secreted by Human Peripheral Blood Hematopoietic Stem Cells].

OBJECTIVE: To investigate the effects of microvesicles(MV) isolated from human peripheral blood hematopoietic stem cells(PB-HSC) on immune regulation and hematopoiesis. METHODS: PB-HSCs were separated by density-gradient centrifugation and cultrued. The supernatants of PB-HSC at 48 h were harvested for isolation and purification of MV by using ultracentrifugation. The electron microscopy was used to observe the morphology of MV. The protein level in MV was quantified through bicinchoninic acid(BCA) protein assay. Flow cytometry was used to detect the immunophenotype of MV. Human peripheral blood mononuclear cells(PB-MNC) were isolated from healthy donor and treated with isolated MV. After being co-cultured for 12 h, confocal microscopy was used to observe the action mode of MV on PB-MNC. After being co-cultured for 48 h, the levels of IL-2, IL-6, IL-8, IL-10, IFN-γ and TNF-α were detected by ELISA. Flow cytometry was used to detect the changes of T cell subsets and the activation of T cell subsets as well as intracellular cytokine staining after co-culture for 48 h. The methylcellulose was used to assess the hematopoiesis-supportive function of MV as well as co-cultured supernatants. RESULTS: The eletron microscopy revealed that MV were elliptical membrane vesicles. The protein amount in MV ranges from 29 to 110 µg. Flow cytometry showed that MV expressed mix markers on the surface, especially highly expressed MV specific marker CD63(85.86%) and hematopoietic stem cell marker CD34(33.52%). After being co-cultured for 12 h, confocal microscopy showed that MV were merged with PB-MNC. After being co-cultured for 48 h, ELISA showed that the secretion of cytokines IL-6,IL-8, IL-10 as well as TNF-α was increased while the level of IL-2 and IFN-γ was not changed much. The results of flow cytometry showed that there was no significant change in T cell subsets and T cell activation. Staining of intracellular factor showed that IL-8 was increased significantly in CD11c+ cells. The colony-forming experiments revealed that MV and the co-cultured supernatants could facilitate the colony formation. CONCLUSION: MV isolated from PB-HSC have immune-regulatery function and can prornote hematopoiesis.

[Significance of Monitoring Minimal Residual Disease by Flow Cytometry in Acute Leukemia Patients Underwent Nonmyeloablative Allo-HSCT].

OBJECTIVE: To explore the value of dynamically monitoring minimal residual disease (MRD) by flow cytometry before and after non-myeloablative allo-HSCT (NST) for prediction of acute leukemia(AL) relapse after transplantation. METHODS: The clinical data of 51 AL patients underwent NST were analyzed retrospectively in Department of Hematology of Affiliated Hospital of Academy of Military Medical Sciences from January 2011 to December 2015. All AL patients achieved the morphologic complete remission of bone marrow before transplantation. The bone marrow samples were collected for monitoring of MRD within 35 days before transplant, every month till 3 months after transplant, every 3 months till 24 months after transplant, and then every 6 months after 2 years of transplant. According to the MRD cutoff value of 0.2%, the AL patients were divided into high level MRD group (18 cases) which was defined as MRD≥0.2% after transplantantion at least for 1 time, and low level MRD group (33 cases) which was defined as MRD<0.2% after transplant all the time. 2 year cumulative relapse rate in 2 groups were compared. RESULTS: Two-year relapse rates were 6.1% and 50% in low-level MRD group and high-level MRD group post NST(P=0.001)respectively. Multivariate analysis indicated that the risk of relapse in high level MRD group was 5.84 times of low level MRD group(P=0.036). MRD≥0.2% post transplant was an independent risk factor for leukemia relapse post NST. The mortality rate was 81.8% and 46.3%(P<0.05) in relapse and non-relapse groups respectively. CONCLUSION: Dynamically monitoring MRD by FCM is a crucial tool for early relapse estimation of acute leukemia in adult patients after allogeneic nonmyeloablative hematopoietic stem cell transplantation. MRD≥0.2% after transplant can be used as a early valuable evidence for predicting relapse and guiding active medical intervention.

[Effect of Infusion of Recipient Spleen Cells at Different Time after Murine Haploidentical Hematopoietic Stem Cell Transplantation on Graft Versus Host Disease].

OBJECTIVE: To explore the effect of infusing G-CSF mobilized recipient spleen cells at different time after haploidentical stem cell transplantation(HSCT) on graft-versus-host disease (GVHD) in mice and its possible mechanism. METHODS: Forty mice after HSCT were randomly divided into 4 groups (n=10): GVHD positive control group (control group), 1st d recipient cell infusion group after transplantation (+1 d group), 4th d recipient cell infusion group after transplantation(+4 d group), 7th d recipient cell infusion group after transplantation(+7 d group). The mice in control group were injected the normal saline of same equivalent with experimental group which were given the same amount of G-CSF-mobilized recipient spleen cells. The general manifestation and pathological change of GVHD were observed. The expression changes of CD3+CD4+, CD3+CD8+ cell subsets and FasL in peripheral blood were detected by flow cytometry. RESULTS: The incidence of GVHD was significantly decreased in +4 d group and the median survival time was longer than 60 days, which was significantly higher than that of control group (24 d), +1 d group (21 d), +7 d group (28 d). (P<0.01, P<0.01, P<0.01). The Fasl expression of peripheral blood T lymphocytes in +4 d group were significantly lower than that in the other 3 groups(P<0.05). CONCLUSION: The +4 d infusion of G-CSF mobilized recipient spleen cells on 4th day after haploidentical HSC transplantation can inhibit the expression of FasL in donor T lymphocytes, and significantly reduce the incidence of GVHD.

[Establishment of Mouse Model of H-2 Haploidentical Hematopoietic Stem Cell Transplantation from Double Donors].

OBJECTIVE: To establish a new mouse model of H-2 haploidentical stem cell transplantation from double donors (DHSCT) and compare with conventional haploidentical hematopoietic stem cell transplantation (HSCT) so as to alleviate transplant-related complications. METHODS: The recipients CB6F1 of conventional HSCT group were pretreated by 8 Gy total body irradiation(TBI), and received 3×107 donor (male C57) spleen mononuclear cells (spMNC) mobilized by G-CSF within 2 hours after TBI. Recipients CB6F1 of D-HSCT groups accepted 2 Gy TBI, and received total 12×107 spMNC mobilized by G-CSF from 2 donors within 2 hours after TBI, each donor donated 6×107 cells. According to the different strains and sex of donors, DHSCT were divided into 3 groups: in group A, the stem cells were from male C57 and female BALB/c; in group B, stem cells were from male C57 and male BALB/c, while the stem cells in group C were from male C57 and male C3H. Hematopoietic reconstruction, engraftment, GVHD and survival were observed among these 4 groups. RESULTS: The nadir of white blood cell count after conventional HSCT were lower than 1×109/L and lasted for 3 to 5 days, while not less than 3×109/L after D-HSCT among either group A, B or C. The complete chimerism (CC) in conventional HSCT group was achieved quickly within only 1 week in peripheral blood. Mixed chimerism (MC) in peripheral blood was found within the first week after DHSCT among either group A, B or C, and transformed into stable CC within the second week eventually. Both GVHD morbidity and mortality of conventional HSCT were 100% at 34th day after transplantation.Among DHSCT groups,the overall GVHD morbidity and mortality at 34th day after transplant were 49.6% and 50%(P<0.01,P<0.05), respectively,and 60.4% and 81.2% at 50th day after transplant. Overall survival of 50 days was 50.9% that indicated a long survival in such mice DHSCT. The differences of hematopoietic reconstruction, donor cell engraftment, GVHD incidence, GVHD mortality and OS were not statistically significant among group A, B and C(P>0.05). CONCLUSION: A new mouse model of H-2 haploidentical peripheral blood stem cell transplantation from double donors (DHSCT) has been successfully established by reducing conditioning intensity and increasing graft cell numbers from double haploidentical donors without GVHD prophylaxis. DHSCT successfully achieved stable complete chimerism, less GVHD morbidity and mortality and longer OS without hematopoietic suppression. This study provides experimental evidence for clinical application of HLA haploidentical peripheral blood stem cell transplantation from double donors.

The long-term outcome of reduced-intensity allogeneic stem cell transplantation from a matched related or unrelated donor, or haploidentical family donor in patients with leukemia: a retrospective analysis of data from the China RIC Cooperative Group.

This study compared 6-year follow-up data from patients undergoing reduced-intensity conditioning (RIC) transplantation with an HLA-matched related donor (MRD), an HLA-matched unrelated donor (MUD), or an HLA-haploidentical donor (HID) for leukemia. Four hundred and twenty-seven patients from the China RIC Cooperative Group were enrolled, including 301 in the MRD, 79 in the HID, and 47 in the MUD groups. The conditioning regimen involved fludarabine combined with anti-lymphocyte globulin and cyclophosphamide. Graft-versus-host disease (GVHD) prophylaxis was administered using cyclosporin A (CsA) and mycophenolate mofetil (MMF). Four hundred and nineteen patients achieved stable donor chimerism. The incidence of stage II-IV acute GVHD in the HID group was 44.3 %, significantly higher than that in the MRD (23.6 %) and MUD (19.1 %) groups. The 1-year transplantation-related mortality (TRM) rates were 44.3, 17.6, and 21.3, respectively. Event-free survival (EFS) at 6 years in the HID group was 36.7 %, significantly lower than that of the MRD and MUD groups (59.1 and 66.0 %, P < 0.001 and P = 0.001, respectively). For advanced leukemia, the relapse rate of the HID group was 18.5 %, lower than that of the MRD group (37.5 %, P = 0.05), but the EFS at 6 years was 31.7 and 30.4 % (P > 0.05), respectively. RIC transplantation with MRD and MUD had similar outcome in leukemia which is better than that with HID. RIC transplantation with HID had lower relapsed with higher TRM and GVHD rate, particularly in advanced leukemias. RIC transplantation with MRD and MUD had similar outcomes in leukemia and they were better than those with HID. RIC transplantation with HID had a lower relapse rate but higher TRM and GVHD rates, particularly in cases of advanced leukemia.

[Features of Immunophenotypes and Characteristics of Molecular Biology and Cellular Genetics of AML Patients with CD4 and CD7 Expression].

OBJECTIVE: To explore the features of immunophenotypes and the characteristics of molecular biology and cellular genetics of AML patients with CD7 and CD4 expression. METHODS: The immunophenotypical markers of AML cells were detected by multiple parameter flow cytometry; the expression of WT1, MDK, ETO, PML-RaRa and BCR-ABL were detected by RT-PCR; and cellular features were analyzed by R-band in 304 patients. The patients were divided into three groups according to their immunophenotypes: AML with CD7 expression (CD7 group), AML with CD4 expression(CD4 group) and AML without CD7 and CD4 expression (common AML group). RESULTS: The expression rate and level of HLA-DR in CD7 group were higher than those in the common AML group, and the expression rate of CD33 and CD34 was higher than that in the other two groups. The expression rate and level of CD15, CD64 in the CD4 group were higher than those in the other 2 groups, and the expression rate and level of CD33 were higher than those in the common AML group. WT1 expression in the CD7 group was lower than that in the common AML group. PML-RaRa was not detected in the CD7 group. AML with co-expression of CD4 or CD7 showed more normal karyotype. (15;17) was not found in AML with CD7 expression. CONCLUSION: AML cells with CD7 expression originate from precursor cells and are blocked in the early phase of hematological development; AML cells with CD4 expression originate from more mature stage of hematological devevelopment and with CD33, CD64 and CD15 high expression; AML cells with CD7 and CD4 expression are characterized by no-specific change of cellular genetics. According to the expression level and intesity of CD4 and CD7, and together with other specific lineage markers, the MRD in AML patients can be quantitatively detected.

[Expression of WT1 Gene in Bone Marrow of Patients with Acute Myeloid Leukemia and Its Influence on Prognosis].

OBJECTIVE: To investigate the expression level of WT1 gene in bone marrow of patients with acute myeloid leukemia (AML) and its relationship with prognosis. METHODS: The copy numbers of WT1 and internal reference gene in bone marrow samples from 75 newly diagnosed AML patients were detected by using real-time quantitative PCR. The gene WT1 expression level was determined by the ratio of the copy numbers of WT1 to reference gene. And the clinical characteristics, the complete remission (CR) rate after induction chemotherapy, 2-year overall survival (OS) rate and event-free survival (EFS) rate were calculated and analysed. RESULTS: The expression level of WT1 did not significantly correlate with common clinical parameters such as age, sex, molecular abnormality, FAB classification and risk stratification. The CR rate in the high WT1 expression group before treatment was 65.4%, which was lower than that of 93.9% in the low expression group (χ2=8.25, P<0.01). The 2-year overall survival rate and event-free survival rate of the two groups were statistically significantly different (P<0.05), and the OS and EFS rates in high WT1 expression group were lower than those in low expression group. After the induction chamotheropy for about 1, 3 month and 6 months, the 2-year OS rate significantly increased in patients with decrease of WT1 gene expression level by one log or more (P<0.05). CONCLUSION: The expression level of WT1 gene in bone marrow may be an effective marker to evaluate therapy efficacy and prognosis for AML patients (non APL).

[Characteristics and Prognosis of 24 Cases of Primary Acute Myeloid Leukemia with Trisomy 8].

OBJECTIVE: To explore the clinical features and prognosis of primary acute myeloid leukemia (AML) with trisomy 8. METHODS: The clinical data of 24 cases diagnosed as primary AML with trisomy 8 were collected. The clinical characteristics such as sex, age, subtype of FAB, blood routine and bone marrow blast at the first visit were analyzed and the relationship of the characteristics with CR rate and the prognosis was explored. RESULTS: 12 out of 24 AML patients were diagnosed as M5 (50%), while M2, M3, M4 and M6 had 3 cases, respectively (12.5%); one case did not receive the chemotherapy. 23 cases received 1-2 cycles of standard induction chemotherapy. Among them 3 cases of M3 achieved complete response (CR) and survived until the last following up with 100% 5-year OS rate. Among 20 cases of non-M3, 12 cases achieved CR1 (60%), 4 cases achieved partial response (PR) (20%), 4 cases did not respond (NR); 5 cases relapsed in follow-up for 3 years after CR1 (41.7%), 3 cases achieved CR2 after re-induction chemotherapy, and 2 cases remained NR. Among 20 cases of non-M3, 1 case failed to be followed-up after diagnosis within 1 month. The mean follow-up time of 19 cases was 26.2 (1.5-84) months, 9 cases died (6 cases of M5, 1 case of M4 and 2 cases of M2), who achieved PR and NR, or relapsed after CR1; the 3-year DFS and OS were 21%, 31.5% respectively. 2 cases of non-M3 accepted allo-HSCT with HLA-matched sibling donor and kept disease-free survival until the last following up, and survived for 58 and 66 months respectively. Except for 3 cases of M3, 2 cases received allo-HSCT and the cases without chemotherapy, the other 18 cases with initial WBC count less than 10×10(9)/L had OS and DFS longer than those of 10 cases with initial WBC count no less than 10×10(9)/L (P<0.05, P<0.01). The OS of 10 cases with CR1 was longer than OS of those cases without CR1 (P<0.01). CONCLUSION: The incidence of trisomy 8 in M5 is higher than the other AML subtypes, and the prognosis of M5 is poor. The initial WBC count above 10×10(9)/L is a high-risk factor. M3 with trisomy 8 and RARA gene has a very good prognosis. Trisomy 8 may increase the risk of primary AML except for M3, so allo-HSCT with HLA-matched sibling donor should be carried out as much as possible after CR1. The gene mutation of FLT3, MLL, HOX11, C-kit, NPM1 may possess an important significance on prognosis.

A Study of Human Leukocyte Antigen Mismatched Cellular Therapy (Stem Cell Microtransplantation) in High-Risk Myelodysplastic Syndrome or Transformed Acute Myelogenous Leukemia.

UNLABELLED: The treatment outcomes of myelodysplastic syndrome (MDS) and transformed acute myelogenous leukemia (tAML) remain very unsatisfactory. We designed a combination of human leukocyte antigen (HLA)-mismatched hematopoietic stem cell microtransplantation (MST) with chemotherapy for patients with MDS and tAML and evaluated its effects and toxicity. Patients were between 13 and 79 years old. Patients with MDS (n=21) were given HLA-mismatched MST combined with decitabine and cytarabine; patients with tAML (n=22) were given HLA-mismatched MST combined with decitabine and cytarabine, and also mitoxantrone. Patients in complete remission (CR) also received MST plus decitabine and medium-dose cytarabine chemotherapy without graft-versus-host disease (GVHD) prophylaxis. The overall response rate of the patients with MDS was significantly higher than that of those with tAML (81% vs. 50%; p=.03). The CR rates were 52.4% and 36.4% in the two groups, respectively. There was no difference in the cytogenetic CR rate between the MDS and tAML groups (85.7% vs. 70%, respectively; p=.7). The 24-month overall survival of the patients with MDS was significantly higher than that of the patients with tAML (84.7% and 34.1%, respectively; p=.003). The median recovery times of neutrophils and platelets were, respectively, 14 and 17 days in the patients with MDS, and 16 and 19 days in those with tAML. The treatment-related mortality rates were 4.8% and 18.2%, respectively, in the MDS and tAML groups (p=.34). No GVHD was observed in any patient. Microtransplantation combined with decitabine and chemotherapy may provide a novel, effective, and safe treatment for high-risk MDS and tAML. SIGNIFICANCE: Microtransplantation (MST) refers to regular chemotherapy combined with granulocyte colony-stimulating factor-mobilized peripheral blood stem cell infusion of human leukocyte antigen-mismatched donor cells without using immunosuppressive agents. It aims to support hematopoietic recovery and perform graft-versus-leukemia (GVL) effects but differs from traditional allogeneic stem cell transplantation because the rate of donor cell chimerism is low and there is and no graft-versus-host disease (GVHD) risk. Thus, a trial was designed to evaluate the safety and efficacy of MST in patients with myelodysplastic syndrome and those with transformed acute myelogenous leukemia. Higher complete remission and cytogenetic complete response rates were observed, and the treatment improved disease progress-free survival, sped hematopoietic recovery, and avoided GVHD.

[Efficacy of Nonmyeloablative Allogeneic Hematopoietic Stem Cells for 14 Case of Severe Acquired Aplastic Anemia].

OBJECTIVE: To investigate the therapeutic efficacy of nonmyeloablative allogeneic hematopoietic stem cells transplantation for severe acquired aplastic anemia (SAA). METHODS: Fourteen patients with severe acquired aplastic anemia received nonmyeloablative allogeneic hematopoietic stem cells transplantation from HLA matched sibling donors, among them 8 cases were dagnosed as SAA-I, 6 cases were diagnosed as SAA-II. The conditioning regimen consisted of fludarabine (FIUD), cyclophosphamide (CTX) and anti-thymocyte globulin (ATG/ALG). The prophylaxis for graft-versus-host disease (GVHD) was performed with cyclosporine (CsA) combined with mycophenolate mofetil (MMF) or tacrolimus (FK506). RESULTS: All the patients gained a quick successfully engraftment of donor hametopoietic cells. The mean recovery time for neutrophil and platelet was 9 d and 13 d respectively. All the patients have acquired a full donor chimerism before 14 d. There were only 2 cases of GVHD: one out of them was acute skin GVHD (grade I) at day 70 after transplantation and the other was chronic liver GVHD (grade I) in 1 years after transplantation, the GVHD more than degree II did not coccur in all patients, 9 patients with bacterial and fungal mixed infection and (or) virus infection were observed, and improved after anti-infection therapy. The median follow-up time were 54.5 months (ranged between 5-144 months), and 12 patients remain disease-free survival currently, only 2 patients died of fungal infectin. CONCLUSION: Transplantation of nonmyeloablative allogeneic hematopoietic stem cell is safe and effective for the treatment of severe acquired aplastic, but the prevention, treatment and monitoring of infection need to be enhance.

[Clinical efficacy of switching to 2nd generation of tyrosine kinase inhibitor on CML patients at poor responses to imatinib].

OBJECTIVE: This study was to investigate the timing and clinical efficacy of switching to the 2nd generation of tyrosine kinase inhibitor (TKI) for CML patients at poor response to imatinib (dissatifed efficacy or intolerance). METHODS: The therapeatic efficacy and side reaction of switched 2nd TKI in patients with newly diagnsed CML-CP who poorly responded to imatinib were observed, anong them 3 cases were intolerant, 6 cases did not acquire satisfied efficacy. RESULTS: After switching to 2nd generation TKI, 3 patients with intolerance achieved complete cytogenetic remission (CCyR) in 3 months, and major molecular remission (MMR) in 3-6 months. All of them achieved optimal efficacy according to European Leukemia Network (ELN), but the pleural effusion appeared in 1 case after use of 2nd generation of TKI for 3 months, and the dadatinib was stoped temporally, and the curative efficacy still was maintained. Among 6 cases with poor efficacy by treatment with imatinib, 2 cases with BCR/ABL mutation progressed after switching 2nd generation of TKI, out of them 1 case with poor tolerance progeressed to the accelerated phase, but was cured by haploidentical allogeneic hematopoictic stem cell transplantation, 1 case progressed to blastic crisis and died of serious infection; the another 4 cases achieved MMR in 3-12 months after using 2nd generation of TKI, and maintained CMR for 12-36 months. CONCLUSION: CML-CP patients without the optimal response to imatinib should be treated by switching to 2nd generation of TKI as soon as possible, and thereby patients may acquired satisfactory therapentic efficacy.

[Establishment and identification of a H-2 completely mismatched microtransplantation model of leukemia mouse].

This study was purposed to establish and identify a H-2 completely mismatched microtransplantation model of leukemia mouse. The recipients were female BALB/c mice, while donors were male C57BL/6J mice. Recipients were inoculated intravenously with 1×10(6) of WEHI-3 cells, a cell line of myelomonocytic leukemia. Donors received 100 µg/kg G-CSF mobilization through hypodermic injection, every 12 hours, and it last 5 days. Chemotherapy regimens was MA (mitoxantrone+cytarabine), and it last 4 days. Recipients were given chemotherapy conditioning without GVHD prophylaxis after inoculation of leukemic cells for 2 days, and within 8 hours after last chemotherapy received donor mobilized spleen mononuclear cells (sMNC). The number of sMNC was (3, 6, 12) ×10(7), respectively. The early death rate, recovery level of WBC in peripheral blood and leukemia load were compared between chemotherapy and microtransplantation groups. The donor chimerism was detected by RT-PCR. From the clinical manifestation and pathological features, the GVHD in recipients was evaluated. The results showed that the early mortality in chemotherapy group was 25%, meanwhile those in the (3, 6, 12)×10(7) groups were 16.67%, 8.33%, 8.33%, respectively. The(3, 6)×10(7) groups has a stronger hematopoietic recovery capability than that in chemotherapy and 12×10(7) groups (P < 0.05) . There were more leukemic cells in chemotherapy mice than that in microtransplantation mice (P < 0.01) , and (12, 6)×10(7) groups had lower leukemia load than that in 3×10(7) group (P < 0.05) . No signs of GVHD were observed in microtransplantation mice. The donor microchimerism could be discovered at eraly 2 weeks after donor cell transfusion. It is concluded that a H-2 completely mismatched microtransplantation model of leukemia mouse has been successfully established, and it will provide a experimental base for studying microtransplantation in clinic.

[Risk factors analysis of cytomegalovirus infection after nonmyeloablative allogeneic peripheral blood stem cell transplantation].

The aim of this study was to analyze the risk factors of cytomegalovirus (CMV) infection and CMV disease after nonmyeloablative allogeneic hematopoietic stem cell transplantation(NST) and develop a rational strategy for the diagnosis, monitoring and preemptive treatment of CMV infection. The Clinical data of 80 patients undergoing NST from November 2009 to November 2012 in the hospital 307 were retrospectively analyzed. The cytomegalovirus load in peripheral blood of patients was detected by using RT-PCR. The results indicated that the incidence of CMV infection was 77.5% (62/80), and the median time for the positive CMV-DNA firstly detected by RT-PCR was day 35 (17-133) after NST. The total of 100-day cumulative incidence of CMV disease was 11.3%(9/80) after early preemptive therapy. Both univariate and multivariate analysis showed thymoglobulin (ATG) used in preconditioning regimen, other herpesvirus infection and fungal infection in medical history before NST were the risk factors of CMV infection after NST.Univariate analysis revealed that CMV viremia and ATG used in preconditioning regimen were the risk factors for CMV disease, while the same result was not found in the multivariate analysis.The incidence of CMV infection in patients with II-IV grade of aGVHD was 91.3%,while the incidence of CMV infection in patients with 0-1 grade of aGVHD was 71.9% (P = 0.06), it seems that II-IV grade of aGVHD was not the risk factor of CMV infection for NST. It is concluded that the ATG used in preconditioning regimen may increase the incidence of both CMV infection and CMV disease after NST. CMV infection easily accompanies by other herpesvirus infection and fungal infection.Therefore other herpesvirus infection and fungal infection should be attentively monitored and prevented after trans-plantation.

[Different changes of serum cytokines following HLA-identical and HLA haploidentical non-myeloablative allogeneic hematopoietic stem cell transplantation].

This study was aimed to investigate the expression difference of serum cytokines in 20 patients receiving HLA-identical nonmyeloablative allogeneic hematopoietic stem cell transplantation (iNAHSCT) and HLA-haploidentical nonmyeloablative allogeneic hematopoietic stem cell transplantation (hiNAHSCT). IL-2, IL-4, IL-6, IL-10, TNF-α, γ-IFN and IL-17 were detected by flow cytometric bead array before and on week 1, 2, 4 after transplantation respectively. The results showed that the IL-2 level was found to be up-regulated at week 1 and 2 after transplantation in iNAHSCT group and in hiNAHSCT group respectively, but there was no difference between these two groups (P > 0.05). The γ-IFN levels was up-regulated at week 4 after transplantation in above-mentioned two groups, but no difference was found between these two groups. The IL-4 level increased at week 2 and 1 after transplantation in iNAHSCT and hiNAHCT groups respectively, but the IL-4 level in iNAHSCT group was higher than that in hiNAHSCT group. The IL-6 level rose at week 1 and 2 after transplant in above mentioned groups respectively, and reached to peak level at week 4 after transplantation, but IL-6 level in hiNAHSCT was higher than that in iNAHSCT group (P < 0.02). The IL-10 level was up-regulated at week 1 and 2 in iNAHSCT and hiNAHSCT groups respectively, but the IL-10 level in iNAHSC was higher than that in hiNAHSCT group. The TNF-α level was up-regulated at week 1 in hiNAHSCT group, but at week 2 in iNAHSCT group after transplantation. The TNF-α level in hiNHASCT group was higher than that in iNAHSCT group (P < 0.01). The IL-17 level was up-regulated at week 1 and week 4 after transplantation in hiNAHSCT and iNAHSCT groups respectively, the IL-17 level in hiNAHSCT group was high as compared with that in iNAHSCT group. It is concluded that the serum cytokine levels are obviously up-regulated in iNAHSCT and hiNHASCT groups, and reach to peak level at week 4 after transplantation. The IL-6, TNF-α and IL-17 level up-regulated significantly in hiNAHSCT group, but the IL-4 and IL-10 level up-regulated significantly in iNAHSCT.