Genetic characteristics and survival analysis of 27 cases of juvenile myelomonocytic leukemia / 中华儿科杂志

Objective: To investigate the genetic and genomic profiling of juvenile myelomonocytic leukemia (JMML) and factors affecting its survival rate. Methods: Clinical characteristics, cytogenetics, molecular biology results and survival status of children with 27 JMML cases admitted to the Hematology Department of Children's Hospital, Capital Institute of Pediatrics from December 2012 to December 2021 were analyzed retrospectively, and the outcomes of the children were followed up. Kaplan-Meier method was used for survival analysis. Univariate analysis was used for analyzing factors affecting the overall survival (OS) rates of patients who received hematopoietic stem cell transplantation (HSCT). Log-Rank test was used for comparison of survival curves. Results: Among 27 JMML cases, there were 11 males and 16 females. The age of disease onset was 28 (11,52) months. There are 20 cases of normal karyotype, 4 cases of monosomy 7, 1 case of trisomy 8,1 case of 11q23 rearrangement and 1 case of complex karyotype. A total of 39 somatic mutations were detected.Those involved in RAS signal pathway were the highest (64%(25/39)), among which PTPN11 mutation was the most frequent (44% (11/25)). A total of 17 cases (63%) received HSCT, 8 cases (30%) did not receive HSCT, and 2 cases (7%) lost follow-up. For children receiving transplantation, the follow-up time after transplantation was 47 (11,57) months. The 1-year OS rate of high-risk transplantation group (17 cases) and high-risk non transplantation group (6 cases) was (88±8)% and (50±20)% respectively, with a statistically significant difference (χ2=5.01, P=0.025). The 5-year OS rate of the high-risk transplantation group was (75±11)%. The survival time of those who relapsed or progressed to acute myeloid leukemia after transplantation was significantly shorter than that of those who did not relapse (χ2=6.80, P=0.009). The OS rate of patients with or without PTPN11 mutation was (81±12) % and (67±19)% respectively (χ2=0.85, P=0.356). Conclusions: The main pathogenesis involved in JMML is gene mutation related to RAS signaling pathway, and the most common driver gene of mutation is PTPN11. Allogeneic HSCT can significantly improve the survival rate of high-risk JMML patients. The recurrence or progression after transplantation was related to poor prognosis.

Analysis of Risk Factors for Cytomegalovirus Infection after Allogeneic Hematopoietic Stem Cell Transplantation / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To analyze the incidence of cytomegalovirus infection and related risk factors after allogeneic hematopoietic cell transplantation and to develop a rational strategy for the preemptive treatment of CMV infection.</p><p><b>METHODS</b>The clinical data of 398 patients undergoing allogeneic hematopoietic cell transplantation from December 2011 to December 2014 were analyzed retrospectively by using a Kaplan Meier analysis and Logistics model.</p><p><b>RESULTS</b>Out of 398 patients 233 developed post-transplant CMV infection (58.5%). Univariate analysis showed that HLA mismatch, ATG administration, acute graft versus host disease (aGVHD), using prednisone ≥ 1 mg/kg body weight or equivalent were associated with increase of CMV infection. Multivariate analysis showed that HLA mismatch (HR = 2.765, P = 0.000), ATG administration (HR = 3.866, P = 0.000), using prednisone ≥ 1 mg/kg body weight or equivalent (HR = 4.767, P = 0.000) also were associated with increase of CMV infection.</p><p><b>CONCLUSION</b>HLA mismatch, ATG administration, using prednisone ≥ 1 mg/kg are risk factors for CMV reaction.</p>

Application of Cytotoxic T-Lymphocytes for the Treatment of Cytomegalovirus Infection in Hematopoietic Stem Cell Transplantation / 中国实验血液学杂志

Human cytomegalovirus (HCMV) infection, a common complication, remains a major risk factor related with patient death after hematopoietic stem cell transplantation (HSCT). Cytotoxic T lymphocytes (CTL) which is crucial to control HCMV infection, can prevent or treat HCMV infection safely and effectively after adoptive infusion. Many studies have been focussed on exploring different methods for preparation of CTL. The method of using antigen presenting cells to stimulate peripheral blood mononuclear cells is simple to operate, easy to conduct large-scale clinical trials. Isolation of CTL from donor-derived PBMC by peptide-tetramer or INF-γ antibody requires a large volume of peripheral blood and high cost for preparation. Third-party CTL can provide an "off-the-shelf" product, but the problem of HLA-mismatch still would be solved. In addition, the clinical efficacy and safety of different methods also vary. This article reviews and compares the current methods to generate CTL and efficacy of the cells after infusions.

Establishment of Humanized Mouse Model by Using Transplantation of Mobilized Peripheral Blood Stem Cells / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the hematopoietic reconstitution in immunodeficiency NPG(TM) mice after transplantation of G-CSF-mobilized peripheral blood CD34(+) hemopoietic stem cells.</p><p><b>METHODS</b>CD34(+) cells were isolated from peripheral blood stem cells (PBSC) by magnetic activated cell sorting (MACS), and then were transplanted into NPG(TM) mice irradiated with sublethal dose of X ray by marrow cavity transplantation. The hemogram of mice after transplantation for 2, 4 weeks was observed; human cell populations (CD45(+), CD19(+)) in the peripheral blood of mice were dynamically analyzed by flow cytometry (FCM) at 4, 6, 8, 10 and 12 weeks after transplantation. Until the planned harvest at the 12 week after transplantation, the CD45(+), CD19(+) level in bone marrow, liver, spleen from each mouse were detected by flow cytometry; the expression of human Alu gene in the bone marrow cell of mouse was detected by PCR.</p><p><b>RESULTS</b>The purity of CD34(+) cells accounted for 96.3%; after irradiation, the nucleated cells and megalokaryocytes in the marrow cavity of NPG mice were reduced significantly or were lost, and reached the myeloablative effect. At week 4 after transplantation, components of blood cells in peripheral blood of transplanted mice were recovered to the level before irradiation; all the mice survived, human CD45(+), CD19(+) cells were found by FCM in the peripheral blood of all the surviving mice in transplantation group at week 4, 6, 8, 10, 12 after the transplantation; at the 12th week, the human Alu gene could be detected in the bone marrow of all the mice in transplantation group.</p><p><b>CONCLUSION</b>The human-mouse chimeric model is successfully established in irradiation-induced NPG mouse by transplantation of CD34(+) HSC from G-CSF-mobilized peripheral blood via marrow cavity.</p>