Chimeric antigen receptor T cell immunotherapy(CAR-T)has achieved a significant breakthrough in hematologic malignancies.On the contrary, the application of CAR-T in solid tumor, including pediatric solid tumor, is confronted with numerous barriers.Pre-clinical experiments and clinical trials point out that several reasons account for the consequence: rare and heterogeneous targets; limited lifetime of CAR-T in vivo as a result of T cell exhaustion; inadequate infiltration of tumor sites due to steric hindrance; side effects of treatment.Based on the above problems, this review will summarize the research progression of different targets, the choice of immune cells, inhibitory tumor microenvironment, and countermeasures for side effects, so as to provide several new explorable directions for improving the treatment effect.

Objective:To investigate the clinical characteristics, treatment process and prognosis of children with severe side effects after chimeric antigen receptor T cell immunotherapy(CAR-T), so as to provide evidence for timely intervention after CAR-T treatment.Methods:From June 1, 2015 to May 31, 2020, children with cytokine release syndrome(CRS)or immune cell related neurotoxicity syndrome(ICANS)who were treated with CAR-T therapy in our hospital and revealed severe effects transferred to PICU were included in the study, and their clinical course and multiple laboratory examination data were systematically analyzed.Results:Seventeen children showed CRS reaction and entered PICU after CAR-T therapy.The most common clinical symptoms were respiratory distress(13 cases) and circulatory disorder(10 cases), of which 7 cases were complicated with severe ICANS.Serum interferon -γ(IFN-γ)and interleukin-6(IL-6)levels significantly increased after CAR-T cell infusion, reaching the peak at (5.1±1.6)days.The serum levels of IFN-γ and IL-6 in children with severe CRS were significantly higher than those in children with mild CRS(all P<0.05). The level of serum IL-6 in children with high tumor load was significantly higher than that in children with low tumor load( P<0.05). The mortality rate of children with elevated level of serum TNF-α was higher(5/5 vs.3/11, P<0.05). Children with severe CRS were more likely to develop grade 4 ICANS(4/4 vs.0/3, P<0.05). The mortality rate of children with oxygenation index(P/F value)<200 mmHg(1 mmHg=0.133 kPa) was higher(5/5 vs.2/12, P<0.05). The vasoactive inotropic score[ M( Min, Max)] in the death group was significantly higher than that in survival group[29.5(14.0, 50.0) vs.1.5(0, 25.0), Z=8.000, P=0.027]. Conclusion:Serum IL-6 and IFN-γ are crucial causes of CRS.High tumor load is one of the factors causing high level of serum inflammatory factors.Respiration and circulation systems are the most frequently involved systems.Therefore, the evaluation indexes of these two systems can help us judge the prognosis of children.

As a disruptive therapeutic technique, chimeric antigen receptor T-cell (CAR-T)immunotherapy has achieved a revolutionary breakthrough in pediatric patients with relapsed/refractory acute lymphoblastic leukemia(ALL). Using genetic engineering technology, T lymphocytes can be modified to express CAR on the surface, which then target tumor-specific antigens and exert cytotoxic effects against tumor cells.However, CAR-T therapy may cause some serious adverse reactions, of which the most common and noticeable is cytokine release syndrome(CRS). Inappropriate medical management of CRS will lead to severe complications and can be even life-threating.In this review, we mainly discuss the progress of CRS in the CAR-T therapy of children ALL from the aspects of the mechanism, clinical manifestations, grading systems and clinical treatment.

Neuroblastoma is the most common extra-cranial malignant tumor in childhood. About 50% of the children have widespread metastatic diseases at initial diagnosis and the outcomes are poor. Chimeric antigen receptor (CAR) is a kind of genetically engineered receptors usually generated by extracellular antigen recognition region, spacer, transmembrane domain and intracellular endodomain. The antigen recognition region joining heavy and light chain variable regions of a monoclonal antibody with a linker to form a single-chain variable fragment (scFv) which can bind to tumor-associated antigens and lead to anti-tumor activity in an MHC-unrestricted manner. In this review, the recent advances and applications of CAR-T cell in neuroblostoma are reviewed and the application-related problems and possible solving strategies are discussed.

Objective To investigate the incidence of the ETV6/RUNX1 fusion gene among Chinese pediatric patients with B-ALL and its effect on the prognosis. Methods A total of 723 patients with B-ALL from January 1, 2007 to December 31, 2014 were enrolled in this study. All patients were detected ETV6/RUNX1 fusion gene by FISH. Clinical data and ETV6/RUNX1 were combined to analyze the clinical prognosis. Results Among the 723 patients, 151 were with ETV6/RUNX1 positive B-ALL, accounting for approximately 20.89%(151/723) of B-precursor cases;91 patients were with recurrence, including 10 patients with ETV6/RUNX1 positive B-ALL, and the recurrence rate of ETV6/RUNX1 positive B-ALL was 10.99%(10/91). Among 10 recurrent patients with ETV6/RUNX1 positive B-ALL, 9 patients relapsed more than 300 days later after diagnosis, while the recurrence times among the patients with ETV6/RUNX1 negative was very different. Although the recurrence times between the two groups showed no signiifcant difference (P?=?0.09), the recurrence times of ETV6/RUNX1 positive patients were mainly found at the end of clinical chemotherapy, while the recurrence time of ETV6/RUNX1 negative patients were mainly at maintaining chemotherapy period, there was a signiifcant difference between the distribution of recurrence time (P?

ObjectiveTo clarify the characteristics and clinical signiifcance of the NOTCH1 mutations in childhood T-cell acute lymphoblastic leukemia (T-ALL).MethodsAmplify and sequence the heterodimerization (HD) domain and the pro-line-glutamicacid-serine-threonine (PEST) domain of theNOTCH1 gene in 28 T-ALL children, in order to explore the frequency, position and type of the mutations as well as their reletions with prognosis.ResultsIn 28 children with T-ALL, 15 cases (51.57%) had been identiifed theNOTCH1 mutations, all of which were heterozygous mutations. The lymphoblast counts in peripher-al blood and bone marrow in theNOTCH1 mutant group at admission were signiifcantly higher than in the non-mutant group (P<0.05). The 1-year remission rate in the 28 children with T-ALL was 75% (21/28), including 80% (12/15) in mutant group in which 3 patients relapsed and all of them died (1-year mortality 20%) and 69.20% (9/13) in non-mutant group in which 4 patients relapsed but all survived (1-year mortality 0%).ConclusionsThe children with T-ALL had a high incidence of NOTCH1 mu-tations at various sites. In addition, the patients withNOTCH1 mutations had more severe disease at diagnosis, better short-term prognosis and poor outcome with salvage therapy after relapse.

OBJECTIVETo enrich our national database with data of rare diseases by analyzing molecular diagnosis and hematopoietic stem cell transplantation (HSCT) in children with inherited bone marrow failure syndromes (IBMFS).

METHODNext-generation sequencing (NGS)-based genetic diagnosis panel was applied for the clinical diagnosis and management of IBMFS. Retrospective analysis was performed on clinical and genetic data of 17 consecutive children who received HSCT over a long time interval (November. 2005-June 2015).

RESULTThree patients were diagnosed only by clinical manifestation before 2012. After that NGS-based genetic diagnosis panel was used to identify IBMFS-related genes in 12/14.IBMFS patients (except two Diamond-Blackfan anemia (DBA) patients). Two Fanconi anemia (FA) patients were confirmed to be new variations through family-genotype-analysis and 3 families accepted prenatal diagnosis to avoid birth of affected fetuses. Seventeen IBMFS patients (10 FA,5 DBA and 2 dyskeratosis congenital (DKC)) were treated with HSCT from matched sibling donors (n=2), matched unrelated donors (n=8) or mismatched unrelated donors (n=7). The source of stem cells for transplantation included peripheral blood (n=12) and cord blood (n=5). With regard to the conditioning regimens, FA and DKC patients received fludarabine-based reduced intensity conditioning, while DBA patients received classical busulfan-based myeloablative conditioning. Median age at the time of HSCT was 36 months (7-156 months). The number of infused mononuclear cells and CD34⁺ cells was (10.6 ± 6.7) × 10⁸ and (5.9 ± 7.0) × 10⁶ per kilogram of recipient body weight, respectively. The median number of days to neutrophil recovery was 13 days after HSCT (range: 10-19 days). Platelet recovery was faster in the PBSCT group than in the CBT group ((16.3 ± 6.0) days vs. (30.0 ± 17.1) days,t=-2.487,P=0.026). During a median follow-up of 17 months (range: 2-114 months), except one FA patient who was transplanted with HLA-matched unrelated cord blood (CB) died from pneumonia and heart failure because of engraftment failure, other 16 children are alive after the successful HSCT. The failure-free survival rate of the patients three years after HSCT was 94%.

CONCLUSIONNGS-based molecular diagnosis technology and effective HSCT have significantly facilitated the treatment of children with IBMFS in our country, and our national database about this rare disease is to be further exploited.

Anemia, Aplastic ; Anemia, Diamond-Blackfan ; therapy ; Bone Marrow Diseases ; Child ; Dyskeratosis Congenita ; therapy ; Fanconi Anemia ; therapy ; Fetal Blood ; Hematopoietic Stem Cell Transplantation ; Hemoglobinuria, Paroxysmal ; diagnosis ; genetics ; therapy ; Humans ; Retrospective Studies ; Siblings ; Survival Rate ; Transplantation Conditioning ; Unrelated Donors ; Vidarabine ; analogs & derivatives ; therapeutic use

OBJECTIVEThe exact mechanisms of defect closure in patients with perimembranous ventricular septal defect (PMVSD) remain unknown. We hypothesized that the expression of urokinase type plasminogen activator (uPA) and plasminogen activator inhibitor-1 (PAI-1) may mediate extracellular matrix (ECM) remodeling in aneurysms.

METHODSeven normal heart tricuspid septal leaflet and 33 aneurysms were collected in Shanghai Renji Hospital and Shanghai Children's Medical Center from January 2008 to June 2010. Immunohistochemical expression of uPA and PAI-1 in 4 normal heart valvular tissues and 15 aneurysms was detected with immunohistochemical methods. The expression of uPA and PAI-1 mRNA in 3 normal heart valvular tissues and 7 aneurysms was studied by real time fluorescent PCR; the protein expression of uPA and PAI-1 in 4 normal heart valvular tissues and 11 aneurysms was tested with Western blotting.

RESULTThe surface of the aneurysms were completely covered by endothelial cells. Two types of granulation tissue, myxoid and fibrous, were associated with the aneurismal formation. uPA were recognized predominantly in valvar interstitial cells (VICs) which located mainly in regions adjacent to the endothelium and smooth muscle cells of blood vessels. PAI-1 was found in both VICs which located mainly in granulation tissue and endothelial cells. Nine aneurysms expressed a higher uPA activity than 4 normal valvular tissues ((74.6±11.8)% vs. (49.5±7.4)%; t = 3.87, P = 0.003) and six aneurysms expressed a low uPA activity ((10.3±3.1)% vs. (49.5±7.4)%; t=11.78, P=0.000) and a high PAI-1 activity ((55.2±1.7)% vs. (50.8±3.8)%; t=2.55, P=0.034) using immunohistochemical methods. uPA / PAI-1 ratio of protein expression tested by Western blot was 0.88±0.22 in four normal heart vavular tissues; five aneurysms expressed high uPA activity and low PAI-1 activity and uPA/PAI-1 ratio was 4.26±2.04; while the other 6 cases expressed low uPA activity and high PAI-1 activity and uPA/PAI-1 ratio was 0.30±0.07; the difference among the three groups was statistically significant (P<0.05). The rate of uPA/PAI-1 in relative copy of mRNA expression among normal heart valvular tissue, high uPA expressed aneurysms and low uPA expressed aneurysms are also significantly different (2.14±0.17 vs. 0.45±0.04; 2.14±0.17 vs. 4.38±1.41, P<0.05) respectively.

CONCLUSIONThe expression of uPA and PAI-1 in VICs suggests that interactions among these molecules contribute to the aneurysm formation and development. This provides a potential mechanism for defect closure in patients with PMVSD.

Aneurysm ; pathology ; Blotting, Western ; China ; Endothelial Cells ; cytology ; Extracellular Matrix ; metabolism ; Granulation Tissue ; pathology ; Heart Septal Defects, Ventricular ; pathology ; Humans ; Immunohistochemistry ; Plasminogen Activator Inhibitor 1 ; metabolism ; RNA, Messenger ; Urokinase-Type Plasminogen Activator ; metabolism

Objectives To investigate the correlation between single nucleotide polymorphisms (SNP) in interleu-kin-15 (IL-15) and treatment response in childhood acute lymphoblastic leukemia (ALL). Methods Genomic DNA samples extracted from remission bone marrow cells of ALL patients were genotyped by MassArray. Five SNPs (rs10519612, rs10519613, rs17007695, rs17015014 and rs35964658) in IL-15 and their association to minimal residual disease (MRD) status in the end of induction therapy were studied. Results SNP rs17007695 was associated with the early response in children with ALL(P=0.049) and the incidence of positive MRD after induction therapy in CC genotype carriers was 1.8 times more than that in TT genotype carriers. Haplotype analysis of these five SNPs showed that the frequency of haplotype CACGG in MRD positive group was 2.1 times higher than that in MRD negative group (P=0.035). Conclusions IL-15 gene polymorphism was associated with the early treatment response in Han Chinese children with acute lymphoblastic leuke-mia.

This study investigated the intracellular localization of asparagine synthetase (ASNS) in the relation with chemoresistance in leukemia. pIRES-GFP-ASNS-Flag/Neo expression vector was transiently tansfected into SK-N-MC cells and 297T cells respectively. Immunofluorescence and Western blot analysis were performed for cellular localization of ASNS respectively. U937 cells were treated with L-asparaginase for 48 h and examined for endogenous ASNS expression on plasma membrane by immunofluorescence staining. Immunofluorescence staining showed that the transiently expressed ASNS was partly localized on transfected-SK-N-MC cell surface. Moreover, Western blotting exhibited that ASNS expressed both in cytosol and on plasma membrane of transfected-293T cells. Immunofluorescence staining with anti-ASNS-specific monoclonal antibody revealed that endogenous ASNS was localized on the plasma membrane of U937 cells, except for its distribution in the cytosol. In addition, ASNS exhibited a higher expression on plasma membrane after treatment with L-asparaginase as compared with the untreated cells. It was concluded that the subcellular translocation of ASNS may play an important role in L-asparaginase resistance in leukemia cells.