Development of a precision tumor bone metastasis model by a magnetic micro-living-motor system.

An ideal bone metastasis animal model is critical and fundamental for mechanistic research and following development of new drug and treatment. Caudal artery (CA) injection allows bone metastasis in the hindlimb, while in-depth targeted and quantitative studies of bone metastasis require a new model to overcome its limitations. Here, we developed a targeted, quantitative, and highly consistent method for the modeling of bone metastasis with cell-based magnetic micro-living-motor (MLM) system created by effectively combining Fe3O4-PDA-Au with biosafety. The MLM system can achieve efficient migration, target site colonization and control tumorigenesis in bone precisely with the application of a magnetic field. In vivo, day 3 post cell injection, tumor bone metastasis signals were observed locally in the injected femur among 82.76% mice of the MLM group as compared to the 56.82% in the CA group, and the signal intensity was 45.1 and 95.9 times stronger than that in the left and right lower limbs of the CA group, respectively. Post-injection day 28, metastasis in vital organs was reduced by approximately 90% in the MLM group compared to the CA group. Our innovative use of the MLM system in the field of tumor modeling opens a new avenue for exploring the mechanisms of tumor bone metastasis, recurrence and drug resistance.

A universal dual-mode hydrogel array based on phage-DNA probe for simultaneous rapid screening and precisely quantitative detection of Escherichia coli O157:H7 in foods by the fluorescent/microfluidic chip electrophoresis methods.

Rapid and specific detection of virulent bacterial strains is a great challenge for food safety regarding large amounts of contaminated samples. Herein, a dual-mode hydrogel array biosensor was constructed to simultaneously rapidly screen and precisely quantitatively detect virulent Escherichia coli O157:H7 (E. coli O157:H7) based on a novel DNA-modified phage probe. First, E. coli O157:H7 was incubated with alginate to form the E. coli O157:H7/hydrogel premix complex. Subsequently, hydrogel formation by cross-linking upon the addition of calcium ions and phages for E. coli O157:H7 modified with a DNA primer (phage-DNA) was added to the alginate hydrogel. The DNA on the complex could trigger rolling circle amplification (RCA) to form a phage probe containing a long-chain DNA skeleton (phage@RCA-DNA). The RCA-DNA was then hybridized with the complementary DNA (cDNA) to form double-stranded DNA fragments (phage@RCA-dsDNA), which could be stained by the SYBR Green dye to emit visual green fluorescence (FL) and determined by a smartphone for rapid screening. Meanwhile, the unreacted cDNA in the supernatant could be quantitatively detected by microfluidic chip electrophoresis (MCE). The signal decrement was also proportional to the bacterial concentration. The detection limit values of E. coli O157:H7 were 50 CFU mL-1 by the FL signal and 6 CFU mL-1 by the MCE signal. The two results could be mutually corrected to decrease the false-positive results. This assay was also employed to detect virulent Salmonella Typhimurium (S. Typhimurium) using the corresponding S. Typhimurium phage@RCA-DNA probe. All these results demonstrated that the universal bioassay was suitable for simultaneous rapid screening and precisely quantitative detection of virulent bacterial strains.

Nestin+ Mesenchymal Stromal Cells Fibrotic Transition Mediated by CD169+ Macrophages in Bone Marrow Chronic Graft-versus-Host Disease.

Chronic graft-versus-host disease (cGVHD) involves multiple organs, but little is known about bone marrow (BM) alterations caused by cGVHD. In mice and humans, we found that cGVHD is associated with BM fibrosis resulting in T cell infiltration, IgG deposition, and hematopoietic dysfunction. Macrophages and Nestin+ mesenchymal stromal cells (MSCs) participated in the process of BM fibrosis during BM cGVHD development. BM macrophage numbers were significantly increased in mice and humans with BM fibrosis associated with cGVHD. Amplified macrophages produced TGF-ß1, which recruited Nestin+ MSCs forming clusters, and Nestin+ MSCs later differentiated into fibroblasts, a process mediated by increased TGF-ß/Smad signaling. TLR4/MyD88-mediated activation of endoplasmic reticulum (ER) stress in macrophages is associated with fibrosis by increasing Nestin+ MSC migration and differentiation into fibroblasts. Depletion of macrophages by clodronate-containing liposomes and inhibition of ER stress by 4-phenylbutyric acid reversed BM fibrosis by inhibiting fibroblast differentiation. These studies provide insights into the pathogenesis of BM fibrosis during cGVHD development.

Wilms' tumor 1 expression combined with genetic mutations for prognostic assessment in MDS.

Overexpression of Wilms' tumor (WT1) is frequently observed in myelodysplastic syndrome (MDS), which has been proposed as a prognostic marker. However, the prognostic role of WT1 expression in different contexts remains to be fully elucidated. We retrospectively assessed the relationships between WT1 levels and preexisting prognostic factors to further investigate its prognostic role under different contexts. In our study, WT1 expression was positively correlated with WHO 2016 classification and IPSS-R stratification. Lower WT1 expression was found in relation to TET2, TP53, CD101, or SRSF2 mutations, while mutant NPM1 patients possessed higher level. Notably, WT1 overexpression maintained its inferior prognostic effect on overall survival (OS) in TP53-wild patients but not in TP53-mutated group. In multivariate analysis, higher WT1 expression was a risk factors for OS in EB patients without TP53 mutations. Overall, WT1 expression was useful to predict prognosis for MDS and its prognostic role was impacted by some gene mutations.

Magnetically empowered bone marrow cells as a micro-living motor can improve early hematopoietic reconstitution.

BACKGROUND AIMS: Bone marrow-derived hematopoietic stem cell transplantation/hematopoietic progenitor cell transplantation (HSCT/HPCT) is widely used and one of the most useful treatments in clinical practice. However, the homing rate of hematopoietic stem cells/hematopoietic progenitor cells (HSCs/HPCs) by routine cell transfusion is quite low, influencing hematopoietic reconstitution after HSCT/HPCT. METHODS: The authors developed a micro-living motor (MLM) strategy to increase the number of magnetically empowered bone marrow cells (ME-BMCs) homing to the bone marrow of recipient mice. RESULTS: In the in vitro study, migration and retention of ME-BMCs were greatly improved in comparison with non-magnetized bone marrow cells, and the biological characteristics of ME-BMCs were well maintained. Differentially expressed gene analysis indicated that ME-BMCs might function through gene regulation. In the in vivo study, faster hematopoietic reconstitution was observed in ME-BMC mice, which demonstrated a better survival rate and milder symptoms of acute graft-versus-host disease after transplantation of allogeneic ME-BMCs. CONCLUSIONS: This study demonstrated that ME-BMCs serving as MLMs facilitated the homing of HSCs/HPCs and eventually contributed to earlier hematopoietic reconstitution in recipients. These data might provide useful information for other kinds of cell therapies.

[Apoptosis of Megakaryocytic Leukemia Cell Line Meg-01 Induced by TSP-1 Via CD36/Caspase-3].

OBJECTIVE: To investigate the effect of thrombospondin-1 (TSP-1) on apoptosis of human megakaryocytic leukemia cell line Meg-01 and its possible mechanism. METHODS: The expression of CD36 antigen in Meg-01 cells was detected by flow cytometry and immunocytochemistry. Meg-01 cells were cultured for 48 hours with TSP-1 and CD36 antibody FA6-152 at different concentrations. The early apoptosis and activity of caspase-3 were detected by flow cytometry. The effect of TSP-1 on the growth and differentiation of megakaryocytes was investigated by cell counting and CFU-MK culture. RESULTS: The flow cytometry and immunocytochemistry showed that CD36 antigen was expressed on the surface of Meg-01 cells. TSP-1 (5 µg/ml) inhibited the growth of Meg-01 cells, but had unobvious effect on M-07e cells. After addition of CD36 antibody FA6-152 (5, 10, and 25 µg/ml), the inhibition effect of TSP-1 was significantly reduced. TSP-1 (2.5, 5, and 7.5 µg/ml) increased the positive expression of Annexin V (P<0.01) and caspase-3 activity (P<0.01), which indicated that TSP-1 had a significant effect on inducing apoptosis. After addition of CD36 antibody FA6-152 (25 µg/ml), the apoptosis induced by TSP-1 in Meg-01 cells was significantly reduced. TSP-1 (5, 10, and 25 µg/ml) could significantly inhibit the formation of CFU-MK in mouse bone marrow cells, while ß-TG could not. CD36 antibody FA6-152 (25 µg/ml) could significantly reduce the inhibition of TSP-1 on CFU-MK. CONCLUSION: TSP-1 may induce apoptosis of megakaryocytic leukemia cell line Meg-01 cells via CD36/caspase-3, which provides a potential new drug development and treatment target for clinical treatment of megakaryocytic leukemia.

[Clinical Characteristics and Prognosis of Elderly Patients with Medium and High risk Myelodysplastic Syndrome].

OBJECTIVE: To investigate the clinical characteristics and prognosis of patients with medium and high risk myelodysplastic syndrome (MDS). METHODS: 97 MDS patients above the age of 60 treated in Nanfang Hospital, Southern Medical University from February 2011 to August 2020 were enrolled. The clinical characteristics and prognosis of the MDS patients with medium risk, high risk or very high risk based on IPSS-R category were retrospectively analyzed. According to the difference of treatment regimes, the patients were divided into the transplantation group, chemotherapy group and other treatment group, and the efficacy among the patients in the 3 groups were analyzed. RESULTS: MDS with excess blast (MDS-EB) in the elderly patients with medium and high risk MDS were the most common, 47.4% of the patients with abnormal chromosome karyotypes, and 23.7% with complex karyotypes (≥3). 97.3% of the patients showed at least one gene mutation, and TP53 mutations were detected in nearly 20% of the patients with medium and high risk. Multivariate analysis showed that IPSS-R category and treatment regimes were the factors affecting the prognosis of elderly patients with medium and high risk MDS. The median overall survival (OS) time of the patients in the 3 groups showed significant difference (P=0.012), and the median OS of the patients in the transplantation group was significantly longer than that in the chemotherapy group and other group (P=0.003,P=0.014,respectively), while there was no significant difference in median OS between chemotherapy group and other treatment group (P=0.685). CONCLUSION: Elderly MDS patients with medium and high risk can benefit from allogeneic hematopoietic stem cell transplantation, which will prolong their OS.

[Correlation between U2AF1 Gene Mutation Characteristics and Clinical Manifestations and Prognosis in Patients with Myelodysplastic Syndrome].

OBJECTIVE: To investigate the correlation between U2AF1 gene mutation and clinical manifestations and prognosis in patients with myelodysplastic syndromes (MDS). METHODS: The clinical data of 203 MDS patients who accepted Next Generation Sequencing (NGS) was retrospectively analyzed in Nanfang Hospital, Southern Medical University from December 2012 to October 2019. According to whether the patients had U2AF1 gene mutation, the patients were divided into U2AF1 mutated group and non-mutated group, and the relationship between gene mutation characteristics and clinical manifestations and prognosis was analyzed. Then according to the difference of the mutation site of U2AF1, the patients in U2AF1 mutated group were divided into U2AF1S34 mutated group and U2AF1Q157/R156 mutated group, and the correlation between gene mutation characteristics and prognosis was analyzed. RESULTS: The incidence of U2AF1 mutation in MDS patients was approximately 11.3% (23/203), and the mutation frequency of U2AF1 allele was 32.5%. The male ratio in U2AF1 mutated group was significantly higher than that in U2AF1 non-mutated group (P=0.001). There was no patient who had complex karyotypes or TP53 gene mutation in U2AF1 mutated group. There were no significant differences in ages, blood parameters, bone marrow blasts, WHO 2016 classification, IPSS-R category, chromosomal abnormalities like del(5q), -7/del(7q), del(20q), +8, and gene mutation like ASXL1, DNMT3A, RUNX1, SF3B1, and SRSF2 mutation between U2AF1 mutated group and the non-mutated group. Compared with the non-mutated group, there was no significant difference in the overall survival time (P=0.377), the time of acute myeloid leukemia (AML) transformation (P=0.681), and the response rate to hypome- thylating agents in U2AF1 mutated group (P=0.556). Besides, no differences were observed in sex, diagnosis age, WHO 2016 classification, IPSS-R category, blood parameters, overall survival time, and AML transformation time between U2AF1S34 mutated group and U2AF1Q157/R156 mutated group. CONCLUSION: The U2AF1 gene mutation dose not affect the survival time, AML transformation time, and response rate to hypomethylating agents in MDS patients. Besides, there are no statistical differences in the clinical characteristics and prognosis of MDS patients between U2AF1S34 mutated group and U2AF1Q157/R156 mutated group. Transplantation shows no significant benefit for patients with U2AF1 mutation.

Effect of dissolved organic matter on adsorption of sediments to Oxytetracycline: An insight from zeta potential and DLVO theory.

To reveal the adsorption mechanism of sediment to antibiotics with the presence of dissolved organic matter (DOM), batch experiments were carried out by oxytetracycline (OTC) on sediments with decayed plants (PDOM) and composted chicken manure (MDOM), and the zeta potential in the system before and after adsorption was measured. Results showed that the PDOM promoted the adsorption process, while the MDOM inhibited the adsorption. Adding PDOM, the change of zeta potential (Δζ) increased by 40.08% for first terrace sediments (FT) and 63.98% for riverbed sediments (RB), respectively; meanwhile, MDOM decreased by 20.04% for FT and 28.39% for RB, respectively. The results of kinetic fitting models of replacing the adsorption amount with Δζ were consistent with the initial. It indicated that there was a positive correlation between the adsorption amount and Δζ, and the zeta potential can be used to quickly judge the degree of adsorption process. The Derjaguin-Landau-Verwey-Overbeek (DLVO) theory describes the interactions of sediment particles. In terms of adsorption amount, zeta potential (absolute value) and total interaction energy all followed the order: RB > FT, RB-PDOM > FT-PDOM, and RB-MDOM > FT-MDOM. The more negative the zeta potential is, the better the dispersion of the particles is. Stronger repulsion is more conducive to adsorbing positively charged OTC. The site energy distribution theory further explained that the distribution of adsorption site in the various states of sediments increased while adding the PDOM and decreased while adding the MDOM.

Why some donors are more willing to donate platelets? ----a qualitative study on 25 regular platelet donors in Guangzhou, China.

BACKGROUND: Since 1998, China has gradually moved toward voluntary uncompensated blood donation. In some cities, the shortage of platelets has been noticeably severe. Mutual assistance that collects blood from one's family and social networks is a potential solution. The measure, however, turned out problematic. There are donors who choose to donate platelets over whole blood without compensations, and donate platelets directly to blood banks instead of via the mutual assistance system. This study explores reasons behind their choices qualitatively. METHODS: This report is based on data conducted from January to February 2018; 25 uncompensated regular platelet donors were interviewed. The blood component donation service team in Guangzhou facilitated the data collection process and referred prospectively eligible blood donors to our research team. The interviews took about 30 min to two hours to complete. The qualitative data were analyzed by using the software ATLAS.ti 8. RESULTS: Platelet donation takes a much long time than whole blood donation and requires complicated processes. It may also cause discomfort as the other blood components are returned to the body, causing physical and psychological distress due to worries about contamination. Thus, platelet donation tends to involve higher time and psychological costs than whole blood donation. Yet, it has short collection intervals that allows for more frequent donations, and urgency of a severer shortage than whole blood. Hence, regular platelet donors may feel higher significance in platelet donation than whole blood donation, with the belief that more lives would be saved. Some whole blood donors thus switched to become platelet donors. Mutual assistance blood donation was not chosen by the participants for platelet donation, because such donations may exert moral pressure to both the donors and recipients. Furthermore, "acquaintance" has been loosely defined; the system has sometimes been manipulated to become profit-making monetary transactions. It hence failed. CONCLUSIONS: The practice of platelet donation reinforces the understanding that blood donation is a gift giving process performed among strangers. A safe and sustainable voluntary blood supply can only be secured in the absence of monetary transactions and moral pressure.

[Detection Rate of Central Nervous System Leukemia Can Be Improved by Cell Preservation Solution].

OBJECTIVE: To investigate whether cell preservation solution can prolong the survival time of leukemia cells and increase the survival rate, so as to improve the detection rate of central nervous system leukemia. METHODS: Kasumi cells were added into cerebrospinal fluid (CSF) supernatant with or without cell preservation solution to compare cell viability and biological characteristics at different time point. Wright Giemsa staining was used to compare cell morphology; cell counting, CCK-8 method, and trypan blue staining were used to compare the cell number, and flow cytometry was used to compare the cell viability. The expression of AML-ETO tumor fusion gene was detected by fluorescence quantitative RT-PCR. RESULTS: At different time points (8 h and 24 h), the survival, molecular biological characteristics and RT-PCR result of the cells in CSF with cell preservation solution were significantly better than those in normal cerebrospinal fluid. CONCLUSION: Cell preservation solution can effectively improve the survival time and survival rate of leukemic cells, thereby increase the detection rate of CNS leukemia.

The Adsorptive Removal of Fluoride from Aqueous Solution by Modified Sludge: Optimization Using Response Surface Methodology.

The sludge from the water supply plant was investigated to remove fluoride ions from the water. To improve the adsorption ability, the original sludge sample was treated with fuel oxidation, pyrolysis, hydrochloric acid, and sulphuric acid methods, and hydrochloric acid treatment improved the adsorption capacity of the sludge on the fluoride in water significantly, with a maximum adsorption capacity to 140 mg/kg. The adsorption experimental data was the well fitted pseudo-first-order model and the Langmuir isotherms model. SEM images and XRD patterns of the adsorbent were recorded to get a better insight into the adsorption process. The effect of three variables, hydrochloric acid treated sludge (HWS) dose, pH, and initial fluoride concentration were studied using a Box-Behnken statistical experimental design. The model of the adsorption and optimum conditions was investigated using the response surface methodology. The optimum removal efficiency of fluoride can reach 81.153% under the optimum condition: HWS dose of 14.10 g/L and pH value at 6.12. The effect of co-existing anions and the removal efficiency from the water were also studied. The results suggest that sludge from the water supply plant can be reused as a coagulant for the removal of fluoride from poor quality water.

Minimization of the perianal infection rate of hematological malignancies with agranulocytosis by quality control circle activity and patient-hospital-student win-win concept.

Objective The agranulocytosis-associated perianal infection (PI) rate ranges from 60% to 100% among patients with hematopoietic malignancies. In this study, we assessed the efficacy of a quality control circle (QCC) to minimize the PI rate. Methods Among 274 patients with severe immunodeficiency (agranulocytosis of ≥2 weeks) in our bone marrow transplantation center, the PI rate was 17.20%. A QCC was established following the 10 steps of the plan-do-check-act (PDCA) model; this was scientifically supported by culturing the bacterial colony from patients' perianal skin to determine the sanitization effect and interval time. Because a warm aqueous solution of potassium permanganate is recommended for sanitization, the bacterial colony culture was also used to determine the proper drug concentration, water temperature, and soaking time. All procedures were standardized. Patients, hospital staff, and medical students were enrolled into the QCC team based on the patient-hospital-student (PHS) win-win concept. Results After establishment of the PDCA model, the PI rate among 253 patients decreased from 17.20% to 5.93% and remained at 5.25% during the following year. The medical expenses and length of hospital stay consequently decreased. Conclusion The QCC and PHS win-win concept can reduce the PI rate and promote medical quality.

Autoimmune hematological diseases following haploidentical donor hematopoietic stem cell Transplant compared with matched sibling and unrelated donor.

Autoimmune hematological diseases (AHDs) occur more frequently than other autoimmune complications after allogeneic hematopoietic stem cell transplantation (allo-HSCT) and are often refractory to treatment. This study was to analyze the incidence and risk factors of AHDs as well as their response to treatment . Four hundred and forty-five adult malignant hematopoietic disorders underwent allo-HSCT were enrolled in this retrospective study, including 124 haploidentical donor (HRD), 140 unrelated donor (MUD) and 181 HLA-matched sibling donor (MSD) transplants. Twelve patients developed AHDs, including 6 autoimmune hemolytic anemia and 6 Evans syndrome. Evans syndrome all occurred in HRD transplants. The 3-year cumulative incidence of AHDs was 4.0 ± 1.3%, and HRD had higher incidence than MUD (8.7 ± 3.0% vs 1.8 ± 1.2%, P = 0.012) and MSD (8.7 ± 3.0% vs 3.5 ± 2.6%, P = 0.004 ). The steroids combined with Cyclosporine A were acted as the first line treatment, and the response rate was 73%. No patients experienced recurrence at a median follow up of 313 days after stopping treatment. HRD transplants (vs MUD: HR, 5.87; CI, 1.24 to 27.73; p = 0.026 and vs MSD: HR, 7.70; CI, 1.63 to 36.44; P = 0.010) and concurrent chronic graft versus host disease (HR, 3.76; CI, 1.18 to 11.92; P = 0.025) were risk factors for AHDs.

Upfront treatment with the first and second-generation tyrosine kinase inhibitors in Ph-positive acute lymphoblastic leukemia.

The treatment of Ph-positive acute lymphoblastic leukemia (Ph+ ALL) has entranced tyrosine kinase inhibitors (TKIs) era. Currently both imatinib and dasatinib are registered as the front-line treatment for Ph+ ALL, and the other 2nd-generation TKIs are suggested as an alternative for those who failed the first-line treatment. However, it remains unclear who could benefit from the 2nd-generation TKIs as the first-line treatment for Ph+ ALL. In this study we compared the efficacy and safety of the 1st and 2nd-generation TKIs in the front-line treatment of Ph+ ALL and found a trend toward better disease-free survival (DFS) in the 2nd-generation TKIs group, though no significant difference in early response and long-term survival between the two groups. Furthermore, subgroup analysis showed that if allogeneic hematopoietic stem cell transplantation (allo-HSCT) was incorporated as consolidation, the 2nd-generation TKIs benefited patients with better DFS and overall survival (OS). The two generation TKIs were well tolerated. Higher incidence of acquiring T315I mutation was observed in the patients relapsed on the 2nd-generation TKIs. These findings suggested front-line treatment of Ph+ ALL with the 2nd-generation TKIs might benefit patients with better survival when allo-HSCT was incorporated as consolidation therapy; meanwhile, the higher incidence of T315I mutation in patients relapsed on the 2nd-generation TKIs deserved further attention.

Rituximab-based treatments followed by adoptive cellular immunotherapy for biopsy-proven EBV-associated post-transplant lymphoproliferative disease in recipients of allogeneic hematopoietic stem cell transplantation.

To improve prognosis of post-transplant lymphoproliferative disease (PTLD), a sequential therapeutic strategy that rituximab-based treatments followed by donor lymphocyte infusion (DLI) or autologous EBV-specific cytotoxic T lymphocytes (EBV-CTL) for biopsy-proven EBV-associated PTLD in recipients of allogeneic hematopoietic stem cell transplantation was designed. 84 patients with EBV-PTLD were enrolled in this prospective study. After two cycles of the rituximab-based treatments, 68 of 84 patients (81% [95% CI 71-88]) responded and 52 (62% [51-72]) had CRs. This increased to 73 of 77 patients (95% [87-98]) with completion of sequential cell infusions, and 70 of 77 (91% [82-96]) achieved CRs after DLI or autologous EBV-CTL infusion. 22 patients experienced acute GVHD (aGVHD) (grade I in 5 and grade II in 13, grade III in 4) and 13 chronic GVHD (limited cGVHD in 7 and extensive cGVHD in 6) in 62 patients undergoing a median of three doses of DLI. The incidences of GVHD were similar between DLI and EBV-CTL group (aGVHD 35% vs. 33%, p = 0.876; cGVHD 21% vs. 13%; p = 0.503). EBV-CTL activity after the rituximab-based treatments did not change, while increased after cell infusions and reached its maximum in the 3rd or 6th month after EBV-CTL or DLI treatment, respectively. The 5-y cumulative incidence of PTLD relapse was 4.5% ± 3.3%. The 5-y overall survival (OS) and progression-free survival (PFS) after PTLD were 70.7% ± 5.2% and 68.9% ± 5.3%, respectively. Rituximab-based treatments combined with adoptive cellular immunotherapy might elevate CR rates and reduce relapse of PTLD after allo-HSCT.

[Sclerodermatous chronic graft-versus-host disease after hematopoietic stem cell transplantation: incidence, clinical characteristics and risk factors].

OBJECTIVE: To investigate the incidence and risk factors of sclerodermatous chronic graft-versus-host disease (ScGVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT). METHODS: The clinical data of 259 patients undergoing allo-HSCT in Nanfang Hospital between January, 2012 and December, 2014 were analyzed. RESULTS: Chronic GVHD following allo-HSCT occurred in 134 (51.7%) cases, among whom 22 patients showed sclerodermatous features at a median of 12.5 months (range 4-28 months) after the transplantation. The overall incidence of ScGVHD was 8.49% (22/259) in the recipients and 16.4% (22/134) in those with cGVHD. Univariate analysis showed that the conditioning regimen with total body irradiation (P=0.031), GVHD prophylaxis with MMF (P=0.046), presence of chronic GVHD (P=0.008), and donor lymphocyte infusion (P=0.001) were all closely associated with the occurrence of ScGVHD. Multivariate analysis identified chronic GVHD (RR=3.512, 95%CI: 1.235-9.987, P=0.018) and donor lymphocyte infusion (RR=5.217, 95%CI: 1.698-16.029, P=0.004) as the independent risk factors of ScGVHD. CONCLUSION: ScGVHD following allo-HSCT is not a common complication, and cGVHD and donor lymphocyte infusion are the independent risk factors for ScGVHD.

[Sorafenib as salvage therapy in refractory relapsed acute myeloid leukemia with positive FLT3 mutation].

OBJECTIVE: To analyze the effect of sorafenib as salvage therapy used before and/or after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in refractory relapsed FLT3-positive acute myeloid leukemia (AML). METHODS: A total of 16 patients with refractory relapsed FLT3-positive AML, including 10 refractory relapsed pre-transplantation and 6 relapsed after allo-HSCT, were enrolled in this retrospective study. Sorafenib treatment protocols included sorafenib in combination with chemotherapy inducing remission, and sorafenib monotherapy as mauntenance treatment after complete remission (CR). RESULTS: Thirteen of the 16 patients achieved CR after one or two courses of induction therapy, including 7 refractory relapsed pre-transplantation and 6 relapsed after allo-HSCT. With a median follow up of 472 (range, 59-1569) days post-transplantation, 12 patients survived and 4 died. Causes of death included leukemia relapse (n=3) and acute graft-versus-host disease (n=1). The 2-year overall and disease-free survival post-transplantation of the 16 patients were (75.0±10.8) % and (50.5±13.7) % respectively. The main side effect of sorafenib was the skin rash. The incidence of rash was lower in the patients used sorafenib pre-transplantation than those post-transplantation (30.0% vs 75.0%, P=0.043). CONCLUSION: Sorafenib used as salvage therapy befor and/or after transplantation for refractory relapsed FLT3-positive AML could reduce the relapse rate and improve the survival.

Sequential intensified conditioning followed by prophylactic DLI could reduce relapse of refractory acute leukemia after allo-HSCT.

The major obstacle is leukemia relapse for refractory leukemia undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). We previously introduced a strategy of sequential intensified conditioning and early rapid immunosupressant withdrawal for refractory leukemia undergoing allo-HSCT, with 5-year overall survival (OS) and 3-year relapse rate of 44.6% and 33.3%. To reduce leukemia relapse, prophylactic donor lymphocyte infusion (DLI) was administered based on our historical strategy. A total of 153 refractory advanced acute leukemia patients were enrolled in this prospective study. According to the availability of donor lymphocytes and the criteria for DLI, 144 patients surviving day +60 were divided into two groups (80 DLI versus 64 non-DLI). The relapse rate was less and OS was better in patients receiving DLI than in those not receiving DLI (22.7% vs 33.9%, P=0.048; 58.1% vs 54.9%, P=0.043). The non-relapse mortality (NRM) was similar between DLI and non-DLI groups (P=0.104). Overall, the 5-year overall and disease-free survival post-transplantation were 51.1%±5.7% and 49.2%±5.3%. The 5-year relapse rate and NRM were 27.3%±4.4% and 29.7%±5.3%. Multivariate analysis revealed that lower bone marrow blasts on day 0, DLI and chronic graft-versus-host disease were associated with less relapse and better OS. The strategy of sequential intensified conditioning followed by early immunosupressant withdrawal and DLI could reduce relapse of refractory acute leukemia after allo-HSCT and improve survival.