[Relationship between Effect of Induction Chemotherapy and Prognosis in AML Patients].

OBJECTIVE: To explore the relationship between effect of induction chemotherapy and prognosis in acute myeloid leukemia (AML) patients. METHODS: The clinical data of 146 adult AML patients treated in Affiliated Hospital of Chifeng University from March 2015 to March 2018 were enrolled and retrospectively analyzed. Day 14 bone marrow biopsy (D14BM) cellularity and blast proportion, daily peripheral blood blast (PBB) clearance rate, time to PBB clearance and etc. were primarily observed after induction chemotherapy. All the patients were divided into Non-relapse survival group, Relapse survival group, Non-relapse death group and Relapse death group according to survival and recurrence situation during 2-year follow-up. The survival of the patients was analyzed by Kaplan-Meier. Univariate analysis of prognostic factors were performed by ordinal Logistic regression, and ROC curve was used to assess the prediction efficiency of those factors for the 2-year overall survival (OS) and relapse of the patients. RESULTS: A total of 138 patients were included since 8 cases failed to be assessed clinically. Their 2-year OS rate was 65.94%. Age of the patients in Non-relapse survival group was lower than that in Relapse death group. The D14BM cellularities in Non-relapse survival group and Relapse survival group were lower than those in Relapse death group (P<0.05). Daily PBB clearance rates in Non-relapse survival group and Relapse survival group were higher than those in Non-relapse death group and Relapse death group (P<0.05). There was a statistical difference among the four groups in the number of cycles of induction chemotherapy (P<0.05). The survival rate within 2 years in the patients with D14BM cellularity≤10% was higher than that in patients with cellularity >10%, while it was higher in patients with daily PBB clearance rate >20% than those with clearance rate≤20% (P<0.05). Age (HR=1.102, P=0.000), D14BM cellularity (HR=1.252, P=0.000) and the cycles of induction chemotherapy≥3 (HR=1.703, P=0.000) were the risk factors affecting the prognosis of AML patients, while daily PBB clearance rate was a protective factor (HR=0.799, P=0.000). The AUC of age, daily PBB clearance rate and D14BM cellularity in predicting 2-year OS of AML patients was 0.738, 0.817 and 0.807, respectively, whereas in predicting relapse within 2 years it was 0.691, 0.647 and 0.711, respectively. There was no statistical difference among the three factors in the sensitivity of 2-year OS (68.11%, 85.12%, 74.49%) and 2-year relapse (50.00%, 64.13%, 61.60%) (P>0.05). CONCLUSION: Bone marrow biopsy results and PBB clearance rate are related to prognosis in AML patients, which can offer certain predictive value in assessing 2-year OS of patients.

[Distribution of compact bone mesenchymal stem cells in lung tissue and bone marrow of mouse].

This study was aimed to investigate the distribution of compact bone mesenchymal stem cells(MSC) marked with lentiviral plasmid pGC FU-RFP-LV in lung tissue and bone marrow of mouse. The MSC were infected by lentivirus with infection efficiency 78%, the infected MSC were injected into BALB/c mice via tail veins in concentration of 1×10(6) /mouse. The mice were randomly divided into 4 group according to 4 time points as 1, 2, 5 and 7 days. The lung tissue and bone marrow were taken and made of frozen sections and smears respectively in order to observed the distributions of MSC. The results indicated that the lentiviral infected MSC displayed phenotypes and biological characteristics which conformed to MSC by immunophenotyping analysis and induction differentiation detection. After the MSC were infected with optimal viral titer MOI = 50, the cell growth no significantly changed; the fluorescent microscopy revealed that the distributions of MSC in bone marrow on day 1, 2, 5 and 7 were 0.50 ± 0.20, 0.67 ± 0.23, 0.53 ± 0.14, 0.33 ± 0.16; those in lung tissue were 0.55 ± 0.15, 0.47 ± 0.13, 0.29 ± 0.13, 0.26 ± 0.08. It is concluded that the distribution of MSC in lung tissue reaches a peak on day 1, while distribution of MSC in bone marrow reaches a peak on day 2. The distribution of mouse MSC relates with RFP gene expression and implantation of MSC in lung tissue and bone marrow.

[Research progress on immunologic mechanisms of mesenchymal stem cells for treatment of graft-versus-host disease].

Mesenchymal stem cells (MSC) are the non-hematopoietic stem cells with a multi-differentiation potentials, which has a low immunogenicity and immune regulation ability. MSC immune regulation ability is particularly important, such as MSC can inhibit the activation and proliferation of T, B lymphocytes, NK cells and dendritic cells (DC). Meanwhile, MSC is able to reconstruct the human hematopoietic microenvironment, improving the successful rate of hematopoietic stem cell transplantation. Graft versus host disease (GVHD) is the main factor causing hematopoietic stem cell transplantation-related mortality. Based on the above mentioned properties, MSCs are used to treat autoimmune diseases and GVHD, recently. Therefore, deep exploration of the cellular immune mechanisms of MSC to treat GVHD is particularly important. This review focuses on progress of research related to treatment of GVHD by MSC immune mechanisms and briefly summarizes the status of the clinical studies.

Detection of a CD4+CD8-CD3- cell subpopulation during the differentiation of cord blood CD34+ cells into T cells in vitro.

INTRODUCTION: Umbilical cord blood contains relatively abundant primitive CD34(+) hematopoietic progenitor cells which can differentiate into T lymphocytes ex vivo MATERIALS AND METHODS: In this study, thymic stromal cells (TSCs) were isolated from aborted fetuses and a monolayer culture system was established. Highly-purified CD34(+) cells from umbilical cord blood were cultured on the TSCs after limiting-dilution. The cells were then harvested and evaluated for CD4, CD8, and CD3 expression at different time points. CD4(+)CD8(-)CD3(-) lymphoid progenitor cells that could differentiate into mature T lymphocytes were observed after 15 days when a cocktail of cytokines, including Flt-3 ligand, stem cell factor, interleukin (IL)-12, and IL-2, was added. RESULTS: These results thus show that CD4(+)CD8(-)CD3(-) cells can be derived from CD34(+) cells in vitro when cultured on TSCs. CONCLUSIONS: We showed that CD4(+)CD8(-)CD3(-) cells can be derived from highly purified CD34(+) cells on TSCs during T-cell lymphopoiesis in vitro.