Genome-wide assessment of genetic risk loci for childhood acute lymphoblastic leukemia in Japanese patients

Not available.

Rejuvenated iPSC-derived GD2-directed CART Cells Harbor Robust Cytotoxicity Against Small Cell Lung Cancer

Small cell lung cancer (SCLC) is exceptionally aggressive, with limited treatment options. Disialoganglioside (GD2) is highly expressed on SCLC and is considered a good target for chimeric antigen receptor (CAR) T cells (CART). Although GD2-directed CARTs (GD2-CART) exhibit cytotoxicity against various GD2-expressing tumors, they lack significant cytotoxicity against SCLC. To enhance cytotoxicity of GD2-CARTs against SCLC, we introduced GD2-CAR into induced pluripotent stem cells (iPSC)-derived rejuvenated cytotoxic T lymphocytes (GD2-CARrejT). GD2-CARrejTs acted much more strongly against SCLC cells than did GD2-CARTs both in vitro and in vivo. Single-cell RNA sequencing elucidated that levels of expression of TIGIT were significantly lower and levels of expression of genes associated with cytotoxicity were significantly higher in GD2-CARrejTs than those in GD2-CARTs. Dual blockade of TIGIT and programmed death-1 (PD-1) increased the cytotoxicity of GD2-CARTs to some extent, suggesting that low TIGIT and PD-1 expression by GD2-CARrejTs is a major factor required for robust cytotoxicity against SCLC. Not only for robust cytotoxicity but also for availability as "off-the-shelf" T-cell therapy, iPSC-derived GD2-CARrejTs are a promising novel treatment for SCLC.

SIGNIFICANCE

This research introduces iPSC-derived rejuvenated GD2-CARTs (GD2-CARrejT) as a novel approach to combat SCLC. Compared with conventional GD2-CARTs, GD2-CARrejTs with reduced TIGIT and PD-1 expression demonstrate robust cytotoxicity against SCLC and would be a promising therapy for SCLC.

Severely obese 14-year-old boy with central sleep apnea several years after head trauma

Central sleep apnea (CSA) is rare in older children. Although CSA mostly arises from neurological diseases such as Chiari malformation, the frequency of CSA is significantly higher in obese children. Herein, we describe the case of a 14-yr-old boy who presented with CSA secondary to severe obesity and a history of traumatic lateral medullary syndrome at 8 yr of age. Polysomnography revealed severe sleep apnea syndrome with apnea-hypopnea index of 41.4 per hour and central apnea index of 8.9 per hour. Magnetic resonance imaging of the head showed no new brainstem or cerebellar infarcts; however, old changes in the cerebellar infarction persisted. Obesity is primarily associated with obstructive sleep apnea. However, obesity can result in CSA through pharyngeal collapse and the reduction of oxygen reserves caused by reduced thoracic volume, which suppresses respiratory center stimulation. Because the respiratory center disorder owing to head injury sequelae improved after the acute stage, obesity was deemed the cause of CSA in this case. Hence, children with severe obesity may require CSA monitoring.

Ligand-based, piggyBac-engineered CAR-T cells targeting EGFR are safe and effective against non-small cell lung cancers

Epidermal growth factor receptor (EGFR) is overexpressed in various cancers, including non-small cell lung cancer (NSCLC), and in some somatic cells at a limited level, rendering it an attractive antitumor target. In this study, we engineered chimeric antigen receptor (CAR)-T cells using the piggyBac transposon system, autologous artificial antigen-presenting cells, and natural ligands of EGFR. We showed that this approach yielded CAR-T cells with favorable phenotypes and CAR positivity. They exhibited potent antitumor activity against NSCLC both in vitro and in vivo. When administered to tumor-bearing mice and non-tumor-bearing cynomolgus macaques, they did not elicit toxicity despite their cross-reactivity to both murine and simian EGFRs. In total we tested three ligands and found that the CAR candidate with the highest affinity consistently displayed greater potency without adverse events. Taken together, our results demonstrate the feasibility and safety of targeting EGFR-expressing NSCLCs using ligand-based, piggyBac-engineered CAR-T cells. Our data also show that lowering the affinity of CAR molecules is not always beneficial.

Erratum: Ligand-based, piggyBac-engineered CAR-T cells targeting EGFR are safe and effective against non-small cell lung cancers

[This corrects the article DOI: 10.1016/j.omto.2023.100728.].

Myeloid/natural killer (NK) cell precursor acute leukemia as a distinct leukemia type

Myeloid/natural killer (NK) cell precursor acute leukemia (MNKPL) has been described on the basis of its unique immunophenotype and clinical phenotype. However, there is no consensus on the characteristics for identifying this disease type because of its rarity and lack of defined distinctive molecular characteristics. In this study, multiomics analysis revealed that MNKPL is distinct from acute myeloid leukemia, T cell acute lymphoblastic leukemia, and mixed-phenotype acute leukemia (MPAL), and NOTCH1 and RUNX3 activation and BCL11B down-regulation are hallmarks of MNKPL. Although NK cells have been classically considered to be lymphoid lineage-derived, the results of our single-cell analysis using MNKPL cells suggest that NK cells and myeloid cells share common progenitor cells. Treatment outcomes for MNKPL are unsatisfactory, even when hematopoietic cell transplantation is performed. Multiomics analysis and in vitro drug sensitivity assays revealed increased sensitivity to l-asparaginase and reduced levels of asparagine synthetase (ASNS), supporting the clinically observed effectiveness of l-asparaginase.

Tests of Light-Lepton Universality in Angular Asymmetries of B^{0}→D^{*-}ℓν Decays

We present the first comprehensive tests of the universality of the light leptons in the angular distributions of semileptonic B^{0}-meson decays to charged spin-1 charmed mesons. We measure five angular-asymmetry observables as functions of the decay recoil that are sensitive to lepton-universality-violating contributions. We use events where one neutral B is fully reconstructed in ϒ(4S)→BB[over ¯] decays in data corresponding to 189  fb^{-1} integrated luminosity from electron-positron collisions collected with the Belle II detector. We find no significant deviation from the standard model expectations.

Precise Measurement of the D_{s}^{+} Lifetime at Belle II

We measure the lifetime of the D_{s}^{+} meson using a data sample of 207  fb^{-1} collected by the Belle II experiment running at the SuperKEKB asymmetric-energy e^{+}e^{-} collider. The lifetime is determined by fitting the decay-time distribution of a sample of 116×10^{3} D_{s}^{+}→ϕπ^{+} decays. Our result is τ_{D_{s}^{+}}=(499.5±1.7±0.9)  fs, where the first uncertainty is statistical and the second is systematic. This result is significantly more precise than previous measurements.

Search for a τ^{+}τ^{-} Resonance in e^{+}e^{-}→μ^{+}μ^{-}τ^{+}τ^{-} Events with the Belle II Experiment

We report the first search for a nonstandard-model resonance decaying into τ pairs in e^{+}e^{-}→μ^{+}μ^{-}τ^{+}τ^{-} events in the 3.6-10  GeV/c^{2} mass range. We use a 62.8  fb^{-1} sample of e^{+}e^{-} collisions collected at a center-of-mass energy of 10.58 GeV by the Belle II experiment at the SuperKEKB collider. The analysis probes three different models predicting a spin-1 particle coupling only to the heavier lepton families, a Higgs-like spin-0 particle that couples preferentially to charged leptons (leptophilic scalar), and an axionlike particle, respectively. We observe no evidence for a signal and set exclusion limits at 90% confidence level on the product of cross section and branching fraction into τ pairs, ranging from 0.7 to 24 fb, and on the couplings of these processes. We obtain world-leading constraints on the couplings for the leptophilic scalar model for masses above 6.5  GeV/c^{2} and for the axionlike particle model over the entire mass range.

Measurement of CP Violation in B^{0}→K_{S}^{0}π^{0} Decays at Belle II

We report a measurement of the CP-violating parameters C and S in B^{0}→K_{S}^{0}π^{0} decays at Belle II using a sample of 387×10^{6}  BB[over ¯] events recorded in e^{+}e^{-} collisions at a center-of-mass energy corresponding to the ϒ(4S) resonance. These parameters are determined by fitting the proper decay-time distribution of a sample of 415 signal events. We obtain C=-0.04_{-0.15}^{+0.14}±0.05 and S=0.75_{-0.23}^{+0.20}±0.04, where the first uncertainties are statistical and the second are systematic.

SARS-CoV-2-Associated Multisystem Inflammatory Syndrome in Children (MIS-C): A Case Report from Iraq

The novel coronavirus disease (COVID-19) continues to evolve. Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2)-associated multisystem inflammatory syndrome in children (MIS-C) is a rare post-COVID-19 complication that affects children with critical outcomes. Few MIS-C reports were available from Arab-Asian ethnicities. We here describe a presentation mimicking a head injury overlapping the manifestations of MIS-C in a child from Iraq. A 10-year-old boy presented with blunt trauma in a shock-like status, and a head injury was suspected. Since he was febrile two days before the trauma, another pathology was assumed. Imaging and laboratory evaluations were performed, and after excluding gross neurosurgical etiology, he was initially treated as a toxic shock syndrome. Meanwhile, he was deteriorating with continuous fever, impaired consciousness, and seizure on the following day. Although not considered initially, close monitoring with a multidisciplinary approach and serial investigations revealed that the child met the criteria of MIS-C. SARS-CoV-2 IgG was shown to be high, while the RT-PCR of COVID-19 was negative. Once he received immunoglobulin and methylprednisolone, he improved dramatically. In conclusion, this report aimed to increase awareness about MIS-C among health workers and emphasized the need for a multidisciplinary team approach in Iraq due to the importance of timely treatment.

Epidemiological and therapeutic profiles of lung cancer patients in the Hokushin Region Japan: a retrospective hospital administrative database study

OBJECTIVE

This study was performed to validate the epidemiology, initial treatment, and clinical practice of lung cancer patients in the Hokushin region, Japan.

METHODS

We retrospectively surveyed data of 5503 newly diagnosed and registered lung cancer patients in 22 principal hospital-based cancer registries in Hokushin region linked with health insurance claims data for registered patients between 2016 and 2017.

RESULTS

The patients consisted of 3677 (66.8%) men and 1826 (33.2%) women with a mean (range) age of 72.2 (27-103) years). Diagnoses were small cell lung cancer (n = 512, 9.4%), squamous cell carcinoma (n = 1083, 19.7%), and non-squamous non-small cell lung cancer (NSCLC; n = 3906, 70.9%). The population with stage I disease in Toyama prefecture (41.1%) was smaller than in the other three prefectures associated with reduced selection of initial surgical therapy and increased frequencies of stage IV disease (33.2%) and best supportive care (18.6%). Initial chemotherapy for stage IV non-squamous NSCLC consisted of tyrosine kinase inhibitors in 39.3% of cases for EGFR and 4% of cases for ALK-positive non-squamous NSCLC, followed by platinum compounds (25.9%) non-platinum compounds (12.9%), and immune checkpoint inhibitors (10.2%). Carboplatin was the commonly prescribed first-line cytotoxic chemotherapeutic agent (65.4% of patients under 75 years and in 96.7% of patients over 75 years).

CONCLUSION

This study revealed real-world data on epidemiological and treatment status in lung cancer in four prefectures in Hokushin region, Japan. Simultaneous analysis of nationwide registry and insurance data could provide valuable insights for the development of lung cancer screening and medical treatment strategies. In addition, the comparative data analysis with other lesions or countries will be useful for evaluating the differences in clinical practice of cancer managements.

Test of Light-Lepton Universality in the Rates of Inclusive Semileptonic B-Meson Decays at Belle II

We present the first measurement of the ratio of branching fractions of inclusive semileptonic B-meson decays, R(X_{e/μ})=B(B→Xeν)/B(B→Xμν), a precision test of electron-muon universality, using data corresponding to 189  fb^{-1} from electron-positron collisions collected with the Belle II detector. In events where the partner B meson is fully reconstructed, we use fits to the lepton momentum spectra above 1.3  GeV/c to obtain R(X_{e/μ})=1.007±0.009(stat)±0.019(syst), which is the most precise lepton-universality test of its kind and agrees with the standard-model expectation.

Familial and lifestyle factors related to physical activity in elementary school students: a cross-sectional study based on a nationally representative survey in Japan

PURPOSE

The decrease in physical activity (PA) among children has become a global concern. Since the analysis of sociodemographic factors as determinants of exercise habits has been inconclusive, this study investigated the factors related to participation in organized sports and moderate-to-vigorous PA (MVPA) levels.

METHODS

Cross-sectional data from the Sports-Life Survey conducted in 2019 by the Sasagawa Sports Foundation were used. Data on the gender, age, grade, annual household income, family members, and lifestyle habits of elementary school children as well as information on participation in organized sports and MVPA were collected by written questionnaires. Multiple logistic regression models were applied to calculate the adjusted odds ratio and 95% confidence interval for the association of each variable with participation in organized sports and frequent MVPA (≥ 60 min/day for ≥ 5 days/week).

RESULTS

A total of 1,197 participants were included in the analysis. Whereas 1,053 (88.2%) students expressed a like for PA, only 725 students (60.8%) actually took part in organized sports. Organized sports participation was significantly associated with gender, grade, population density, household income, daily breakfast, lower screen time, and frequent exercise with parents (all P < 0.05). We observed that 12.3% of participants met the frequent MVPA level, which was significantly related to lower screen time and exercise habits with parents (both P < 0.05).

CONCLUSIONS

Social and family factors may be strong determinants of engagement in PA among Japanese elementary school-aged children. Parental involvement appears particularly important for promoting PA among youths.

Search for an Invisible Z^{'} in a Final State with Two Muons and Missing Energy at Belle II

The L_{μ}-L_{τ} extension of the standard model predicts the existence of a lepton-flavor-universality-violating Z^{'} boson that couples only to the heavier lepton families. We search for such a Z^{'} through its invisible decay in the process e^{+}e^{-}→μ^{+}μ^{-}Z^{'}. We use a sample of electron-positron collisions at a center-of-mass energy of 10.58 GeV collected by the Belle II experiment in 2019-2020, corresponding to an integrated luminosity of 79.7  fb^{-1}. We find no excess over the expected standard-model background. We set 90%-confidence-level upper limits on the cross section for this process as well as on the coupling of the model, which ranges from 3×10^{-3} at low Z^{'} masses to 1 at Z^{'} masses of 8  GeV/c^{2}.

Comprehensive genetic analyses of childhood acute leukemia in Iraq using next-generation sequencing

Background

Molecular analyses in hematological malignancies provide insights about genetic makeup. Probable etiological factors in leukemogenesis could also be disclosed. Since genetic analyses are still primitive in Iraq, a country of repeated wars, we conceived of performing next-generation sequencing (NGS), to disclose the genomic landscape of acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) among a cohort of Iraqi children.

Methods

Dried blood samples were collected from Iraqi children with ALL (n=55), or AML (n=11), and transferred to Japan where NGS was done. Whole-exome, whole-genome, and targeted gene sequencings were performed.

Results

Somatic point mutations and the copy number variations among Iraqi children with acute leukemia were comparable with those in other countries, and cytosine-to-thymine nucleotide alterations were dominant. Strikingly, TCF3-PBX1 was the most recurrent fusion gene (22.4%) in B-cell precursor ALL (B-ALL), and acute promyelocytic leukemia (AML-M3) was subtyped in 5 AML cases. Additionally, a high frequency of RAS signaling pathway mutations was detected in children with B-ALL (38.8%), along with 3 AML cases that carried oncogenic RAS.

Conclusions

Apart from disclosing the high frequency of TCF3-PBX1, NGS confirmed our previous finding of recurrent RAS mutations in Iraqi childhood acute leukemia. Our results suggest that the biology of Iraqi childhood acute leukemia is in part characteristic, where the war-aftermath environment or geography might play a role.

Search for Lepton-Flavor-Violating τ Decays to a Lepton and an Invisible Boson at Belle II

We search for lepton-flavor-violating τ^{-}→e^{-}α and τ^{-}→μ^{-}α decays, where α is an invisible spin-0 boson. The search uses electron-positron collisions at 10.58 GeV center-of-mass energy with an integrated luminosity of 62.8  fb^{-1}, produced by the SuperKEKB collider and collected with the Belle II detector. We search for an excess in the lepton-energy spectrum of the known τ^{-}→e^{-}ν[over ¯]_{e}ν_{τ} and τ^{-}→μ^{-}ν[over ¯]_{μ}ν_{τ} decays. We report 95% confidence-level upper limits on the branching-fraction ratio B(τ^{-}→e^{-}α)/B(τ^{-}→e^{-}ν[over ¯]_{e}ν_{τ}) in the range (1.1-9.7)×10^{-3} and on B(τ^{-}→μ^{-}α)/B(τ^{-}→μ^{-}ν[over ¯]_{μ}ν_{τ}) in the range (0.7-12.2)×10^{-3} for α masses between 0 and 1.6  GeV/c^{2}. These results provide the most stringent bounds on invisible boson production from τ decays.

Targeting FLT3-specific chimeric antigen receptor T cells for acute lymphoblastic leukemia with KMT2A rearrangement

CD19-specific chimeric antigen receptor T (CAR T) immunotherapy is used to treat B-cell malignancies. However, antigen-escape mediated relapse following CAR T therapy has emerged as a major concern. In some relapsed cases, especially KMT2A rearrangement-positive B-acute lymphoblastic leukemia (KMT2A-r B-ALL), most of the B-cell antigens are lost via lineage conversion to the myeloid phenotype, rendering multi-B-cell-antigen-targeted CAR T cell therapy ineffective. Fms-related tyrosine kinase-3 (FLT3) is highly expressed in KMT2A-r B-ALL; therefore, in this study, we aimed to evaluate the antitumor efficacy of CAR T cells targeting both CD19 and FLT3 in KMT2A-r B-ALL cells. We developed piggyBac transposon-mediated CAR T cells targeting CD19, FLT3, or both (dual) and generated CD19-negative KMT2A-r B-ALL models through CRISPR-induced CD19 gene-knockout (KO). FLT3 CAR T cells showed antitumor efficacy against CD19-KO KMT2A-r B-ALL cells both in vitro and in vivo; dual-targeted CAR T cells showed cytotoxicity against wild-type (WT) and CD19-KO KMT2A-r B-ALL cells, whereas CD19 CAR T cells demonstrated cytotoxicity only against WT KMT2A-r B-ALL cells in vitro. Therefore, targeting FLT3-specific CAR T cells would be a promising strategy for KMT2A-r B-ALL cells even with CD19-negative relapsed cases.

Factors Affecting Day-to-Day Variations in Tacrolimus Concentration among Children and Young Adults Undergoing Allogeneic Hematopoietic Stem Cell Transplantation

Tacrolimus is widely used as prophylaxis for graft-versus-host disease (GVHD) in allogeneic stem cell transplantation (allo-HSCT). It has a narrow therapeutic index range; high tacrolimus concentrations are associated with toxicity, whereas low concentrations are associated with an increased risk of GVHD. Although dose adjustments based on therapeutic drug monitoring are performed, unexpected large variations in tacrolimus concentration are sometimes encountered. The available evidence suggests that the factors affecting tacrolimus concentration are not fully understood. This study was aimed primarily at investigating the factors affecting day-to-day variations in tacrolimus concentration in children and young adults who received continuous tacrolimus infusion after allo-HSCT. The secondary objective was to identify the factors causing large variations (>20%) in tacrolimus concentrations. This retrospective cohort study comprised 123 consecutive pediatric and young adult patients (age <25 years) who received continuous i.v. tacrolimus infusion after allo-HSCT at Shinshu University Hospital, Matsumoto, Japan, between January 2009 and December 2021. To compare day-to-day variations in tacrolimus concentration without consideration of the tacrolimus dose, 2 consecutive days when the tacrolimus dose was not changed were selected from between the first post-allo-HSCT day of a tacrolimus concentration >7 ng/mL and day 28 post-allo-HSCT. Subsequently, information for the subsequent 24 hours was collected along with the tacrolimus concentrations and hematocrit values. Tacrolimus concentration was determined using whole blood samples. Tacrolimus concentrations were significantly higher in patients who received red blood cell concentrate (RCC) transfusions (P < .0001) and methotrexate (P = .0162), patients with persistent fever (P = .0056), and patients with a decline in fever (P = .0003). In contrast, tacrolimus concentrations were significantly lower in patients who received platelet concentrate (PC) transfusions (P < .0001), who redeveloped fever (P = .0261), and who had a replaced tacrolimus administration route set (P = .0008). Variations in tacrolimus concentration were significantly correlated with variations in hematocrit (r = .556; P < .0001). Body weight (P < .0001), RCC transfusion (P < .0001), methotrexate use (P = .0333), persistent fever (P = .0150), and decline in fever (P = .0073) were associated with a sharp increase in tacrolimus concentration. In contrast, body weight (P < .0001), PC transfusion (P = .0025), and replacement of the tacrolimus administration route set (P = .0025) were associated with a sharp decrease in tacrolimus concentration. RCC and PC transfusions, fever, methotrexate administration, and replacement of the tacrolimus administration route set were independent factors affecting day-to-day variations in tacrolimus concentration. In addition to these factors, low body weight was a risk factor for both sharp increases and decreases in tacrolimus concentration. These findings suggest the need for better control of tacrolimus concentration using whole blood samples.

Intensification of treatment with vinca alkaloid does not improve outcomes in pediatric patients with Langerhans cell histiocytosis: results from the JPLSG LCH-12 study

Chemotherapy with cytarabine, vincristine (VCR), and prednisolone has achieved low mortality rates in pediatric patients with Langerhans cell histiocytosis (LCH). However, relapse rates remain high, making event-free survival (EFS) rates unsatisfactory. A nationwide clinical trial, LCH-12, tested a modified protocol in which the early maintenance phase was intensified with increasing dosages of VCR. Patients newly diagnosed with multifocal bone (MFB) or multisystem (MS) LCH and aged < 20 years at diagnosis were enrolled between June 2012 and November 2017. Of the 150 eligible patients, 43 with MFB were treated for 30 weeks and 107 with MS LCH were treated for 54 weeks. One patient with MS LCH died of sepsis during the induction phase. The 3-year EFS rates among patients with MFB LCH, risk organ (RO)-negative MS LCH, and RO-positive MS LCH were 66.7% (95% confidential interval [CI], 56.5-77.0%), 66.1% (95% CI 52.9-76.4%), and 51.1% (95% CI 35.8-64.5%), respectively, similar to previously observed rates. EFS rates were significantly lower in patients with disease activity scores > 6 than in those with scores ≤ 6. The strategy that included more intense treatment with VCR was not effective. Other strategies are required to improve outcomes in patients with pediatric LCH.

Observation of e^{+}e^{-}→ωχ_{bJ}(1P) and Search for X_{b}→ωϒ(1S) at sqrt[s] near 10.75 GeV

We study the processes e^{+}e^{-}→ωχ_{bJ}(1P) (J=0, 1, or 2) using samples at center-of-mass energies sqrt[s]=10.701, 10.745, and 10.805 GeV, corresponding to 1.6, 9.8, and 4.7  fb^{-1} of integrated luminosity, respectively. These data were collected with the Belle II detector during special operations of the SuperKEKB collider above the ϒ(4S) resonance. We report the first observation of ωχ_{bJ}(1P) signals at sqrt[s]=10.745  GeV. By combining Belle II data with Belle results at sqrt[s]=10.867  GeV, we find energy dependencies of the Born cross sections for e^{+}e^{-}→ωχ_{b1,b2}(1P) to be consistent with the shape of the ϒ(10753) state. These data indicate that the internal structures of the ϒ(10753) and ϒ(10860) states may differ. Including data at sqrt[s]=10.653  GeV, we also search for the bottomonium equivalent of the X(3872) state decaying into ωϒ(1S). No significant signal is observed for masses between 10.45 and 10.65  GeV/c^{2}.

piggyBac-transposon-mediated CAR-T cells for the treatment of hematological and solid malignancies

Since the introduction of the use of chimeric antigen receptor T-cell therapy (CAR-T therapy) dramatically changed the therapeutic strategy for B cell tumors, various CAR-T cell products have been developed and applied to myeloid and solid tumors. Although viral vectors have been widely used to produce genetically engineered T cells, advances in genetic engineering have led to the development of methods for producing non-viral, gene-modified CAR-T cells. Recent progress has revealed that non-viral CAR-T cells have a significant impact not only on the simplicity of the production process and the accessibility of non-viral vectors but also on the function of the cells themselves. In this review, we focus on piggyBac-transposon-based CAR-T cells among non-viral, gene-modified CAR-T cells and discuss their characteristics, preclinical development, and recent clinical applications.

Immature Platelet Fraction and Its Kinetics in Neonates

Thrombocytopenia is a common abnormality encountered in the neonatal period, and immature platelet fraction (IPF) may be an informative indicator of thrombopoiesis; however, data on IPF in neonates are scarce. To define reference intervals (RIs) and factors affecting IPF in neonates, we measured the IPF of 533 consecutive neonates. With a multiple regression analysis of 330 newborns with normal platelet counts at birth, premature delivery, neonatal asphyxia, intrauterine infection, chromosomal abnormalities, and respiratory disorders were identified as independent factors for IPF%. The RIs of IPF% and absolute IPF value in neonates were determined to be 1.3% to 5.7% and 3.2 to 14.5×10 9 /L, respectively. On day 14 after birth, IPF% increased to twice the value at birth and thereafter returned to the previous value on day 28. Reticulocyte counts, in contrast, were the lowest at day 14. IPF% was increased in 16 thrombocytopenic patients with various clinical conditions, especially those with immune-mediated thrombocytopenia. IPF in neonates may be evaluated essentially based on the same RIs as in adults, although some precautions must be taken when evaluating IPF in neonates in the first 2 weeks of life. IPF may be useful for evaluating thrombopoiesis and thrombocytopenia in neonates.

Pulmonary veno-occlusive disease after respiratory syncytial virus infection in a post hematopoietic stem cell transplantation patient

Background

Pulmonary veno-occlusive disease (PVOD) is a rare but fatal complication of hematopoietic stem cell transplantation (HSCT). Although literature on PVOD post-HSCT is scarce, a recent study has indicated that this condition may be underestimated. Respiratory syncytial virus (RSV) is a common respiratory pathogen that causes common cold in healthy individuals but may lead to severe lower respiratory infection accompanied by respiratory distress in infants and immunocompromised individuals, such as post-HSCT patients. However, little is known about the relationship between PVOD and RSV infections.

Case report

A 4-year-old boy was diagnosed with metastatic neuroblastoma and underwent intensive chemotherapy, autologous HSCT, and allogeneic cord blood transplantation (CBT). He experienced PVOD on day 194 following CBT after displaying upper respiratory symptoms and positive RSV antigen test results approximately one month prior. Pathological examination of a lung biopsy specimen revealed lung injury suspected to be associated with viral infection in addition to PVOD-related findings, suggesting that RSV infection might have contributed to the onset of PVOD.

Conclusions

The patient's clinical history and histological findings indicated that RSV could have triggered the development of PVOD under potential endothelial damage caused by HSCT and other prior treatments. Common respiratory viral infections, such as RSV infection, may evoke the development of PVOD.

Basophil activation test for allergic and febrile non-haemolytic transfusion reactions among paediatric patients with haematological or oncological disease

BACKGROUND AND OBJECTIVES

Allergic transfusion reactions (ATRs) and febrile non-haemolytic transfusion reactions (FNHTRs) are common, although their mechanisms remain unclear. Immunoglobulin E (IgE)-mediated type I hypersensitivity may be involved in the pathogenesis of ATR. A basophil activation test (BAT) may help elucidate this process.

MATERIALS AND METHODS

The BAT was based on peripheral blood samples from paediatric patients with a haematological or oncological disease and on samples of residual blood products transfused in each case. Dasatinib was used to evaluate whether basophil activation was mediated by an IgE-dependent pathway.

RESULTS

Twenty-seven patients with and 19 patients without ATR/FNHTR were included in this study, respectively. The median BAT values associated with ATR- (n = 41) and FNHTR-causing (n = 5) blood products were 22.1% (range = 6.1%-77.0%) and 27.8% (range = 15.2%-47.8%), respectively, which were higher than the median value of 8.5% (range = 1.1%-40.9%) observed in blood products without a transfusion reaction. Dasatinib suppressed basophil activity. BAT values were comparable in patients with ATR regardless of severity. Meanwhile, BAT values analysed with blood products non-causal for ATR/FNHTR were higher in patients with ATR/FNHTR than in those without.

CONCLUSION

The IgE-mediated type I hypersensitivity may be involved in the pathogenesis of ATR and FNHTR. BAT analyses may help elucidate the underlying mechanisms and identify patients at risk.

[Immune cell therapy for acute myeloid leukemia]

Recently, a series of new approvals or expanded indications for small-molecule drugs indicated for acute myeloid leukemia (AML) has occurred. Small-molecule drugs greatly improve AML treatment options and contribute to prolonged prognosis; however, drug resistance is inevitable with long-term use. New modalities that have immune cell therapy should be developed using chimeric antigen receptor (CAR)-T cells which is one of the most promising next-generation cancer therapies for hematological cancers, and with awaited practical application in AML. Although CAR-T cell development that targets various AML-related antigens has progressed so far, products close to practical use have remained unavailable globally due to the AML-specific drug discovery challenges. This article will review the clinical development of CAR-T cells and discuss the developmental issues in AML from the viewpoint of target antigen characteristics and on-target/off-tumor toxicity.

Skin and soft tissue infections in adolescent chronic myeloid leukemia under dasatinib treatment

Although skin complications are common adverse events from tyrosine kinase inhibitors (TKIs) for the treatment of chronic myeloid leukemia (CML), no reports have focused on skin and soft tissue infections (SSTIs) associated with TKI use. We herein present five episodes of SSTIs in three CML patients under dasatinib treatment. All patients were adolescents and had been receiving dasatinib for more than 4 years. In contrast, none of 41 adult CML patients experienced SSTIs in a retrospective analysis. Our findings suggest that long-term dasatinib treatment in adolescent patients may be associated with the increased risk of SSTIs.

Abstract 5570: Development of piggyBac transposon-mediated HER2-CAR-T cells for the treatment of solid tumors

Background: Although chimeric antigen receptor (CAR)-T therapies have achieved remarkable success in the treatment of hematologic malignancies, the outcome for patients with solid tumors remains poor. There are several reasons behind this, including exhaustion of CAR-T cell, poor homing and penetration in the tumor, and the lack of persistence in the immunosuppressive tumor microenvironment. To solve these problems, we have developed HER2-CAR-T cells (BP2301) using the piggyBac (PB) transposon-based gene transfer system.

Methods and Results: Second generation HER2-CAR construct plus PB transposase were introduced into autologous peripheral blood mononuclear cells (PBMC) by electroporation. These cells were activated with UV-inactivated genetically-engineered antigen presenting autologous PBMC (AP cells) expressing HER2, CD80, and 4-1BBL, and propagated for 14 days to obtain the final product (BP2301). BP2301 exhibited dominant fraction of less exhausted stem cell memory-like T cells (Tscm), which could be associated with antitumor efficacy. BP2301 showed robust in vitro killing activity against HER2+ tumor cells even after multiple rounds of cancer cell challenge, suggesting the long-term functionality without immune-exhaustion. In a xenograft murine model of rhabdomyosarcoma cell line (SJCRh30), a single intravenous administration of BP2301 (5 × 106 CAR-positive cells) eradicated the tumor, and mice treated with BP2301 rejected the second tumor establishment owing to the in vivo expansion of BP2301.

Conclusion: BP2301 has demonstrated potent anti-tumor activity in vitro and in vivo. We have established a GMP manufacturing process for BP2301, completed non-clinical safety and efficacy studies, and plan to launch an investigator-initiated phase 1 clinical trial to evaluate the safety and efficacy of BP2301 in HER2-expressing sarcoma and gynecologic malignancies in the second quarter of 2022.

Citation Format: Koichiro Shioya, Tomio Matsumura, Yuta Ohira, Naomi Komatsuzaki, Manaka Shinagawa, Miyuki Tanaka, Shigeki Yagyu, Yozo Nakazawa, Lilin Zhang. Development of piggyBac transposon-mediated HER2-CAR-T cells for the treatment of solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5570.

Intraoperative Placement of an Absorbable Spacer Prior to Radiation Therapy for a Malignant Peripheral Nerve Sheath Tumor

A 7-year-6-month-old female was diagnosed with a pelvic malignant peripheral nerve sheath tumor and lymph node metastases. Tumorectomy was performed after four cycles of chemotherapy. A 33-mm cystic lesion was observed around the left iliac muscle after three cycles of postoperative chemotherapy, and proton beam therapy (PBT) was recommended. She was referred for absorbable spacer (AS) placement. The left ovarian appendage (OA) was resected due to the direct tumor infiltration. The right OA was fixed to the uterosacral ligament. The AS was fixed to the lateral pelvis. The PBT (70.3 Gy relative biological effectiveness) was performed successfully with the AS, and she also had the reproducing possibility due to prevention of severe irradiation damage of the right OA. AS eliminated the surgical removal of spacers and enabled us high-dose PBT for residual tumor without severe irradiation damage including infertility.

ADC Level is Related to DWI Reversal in Patients Undergoing Mechanical Thrombectomy: A Retrospective Cohort Study

BACKGROUND AND PURPOSE

In patients with ischemic stroke, DWI lesions can occasionally be reversed by reperfusion therapy. This study aimed to ascertain the relationship between ADC levels and DWI reversal in patients with acute ischemic stroke who underwent recanalization treatment.

MATERIALS AND METHODS

We conducted a retrospective cohort study in patients with acute ischemic stroke who underwent endovascular mechanical thrombectomy with successful recanalization between April 2017 and March 2021. DWI reversal was assessed through follow-up MR imaging approximately 24 hours after treatment.

RESULTS

In total, 118 patients were included. DWI reversal was confirmed in 42 patients. The ADC level in patients with reversal was significantly higher than that in patients without reversal. Eighty-three percent of patients with DWI reversal areas had mean ADC levels of ≥520 × 10^-6 mm²/s, and 71% of patients without DWI reversal areas had mean ADC levels of <520 × 10^-6 mm²/s. The mean ADC threshold was 520 × 10^-6 mm²/s with a sensitivity and specificity of 71% and 83%, respectively. In multivariate analysis, the mean ADC level (OR, 1.023; 95% CI, 1.013-1.033; P < .0001) was independently associated with DWI reversal. Patients with DWI reversal areas had earlier neurologic improvement (NIHSS at 7 days) than patients without reversal areas (P < .0001).

CONCLUSIONS

In acute ischemic stroke, the ADC value is independently associated with DWI reversal. Lesions with a mean ADC of ≥520 × 10^-6 mm²/s are salvageable by mechanical thrombectomy, and DWI reversal areas regain neurologic function. The ADC value is easily assessed and is a useful tool to predict viable lesions.

A retrospective survey of patients who discontinued participation in the JPLSG HLH-2004 clinical trial

Although clinical trials have reported an improvement in the prognosis of hemophagocytic lymphohistiocytosis (HLH), current treatment outcomes are unsatisfactory, especially in severe cases. Most clinical trial patients with severe disease discontinue participation due to complications associated with HLH or treatment-related toxicity. A retrospective survey of patients who discontinued participation in the JPLSG HLH-2004 clinical trial was conducted to review the detailed course of these cases to optimize HLH treatment and supportive care. Findings in these patients were compared with those of 45 patients who completed the protocol treatment. The 3 year overall survival rate of patients who completed treatment was 86.7%, versus 50.7% for those who did not complete treatment. Incidence of serious adverse events, such as infections, coagulopathy, and posterior reversible encephalopathy syndrome, during the initial 8 weeks of treatment was much higher in patients who did not complete treatment than in patients who completed treatment. To improve overall outcomes of patients with HLH, it is important to not only optimize HLH-directed therapy but also provide appropriate supportive care.

Relationship between allergic transfusion reactions and allergic predisposition among pediatric patients with hematological/oncological disease

BACKGROUND

Allergic transfusion reactions (ATRs) manifest frequently as transfusion reactions, and their onset may be related to a patient's allergic predisposition. Moreover, although pediatric patients with hematological/oncological disease are more susceptible to ATRs, the relationship between allergic predisposition and ATRs remains to be fully clarified.

STUDY DESIGN AND METHODS

Patients who were diagnosed with pediatric hematological/oncological disease and received transfusion at the study institutions were included. We determined patient background information related to their allergy history, measured the levels of allergen-specific immunoglobulin E (IgE) using sera obtained on diagnosis, and analyzed their associations with ATR onset.

RESULTS

Of the 363 patients analyzed, 144 developed ATRs. Multivariate analysis identified cases with high basophils in the peripheral blood, and Dermatophagoides pteronyssinus- and egg white-specific IgEs were involved in the development of ATR in all age groups. Meanwhile, a history of food allergies, and positivity for Japanese cypress- and D. pteronyssinus-specific IgEs were risk factors for developing ATRs in the <5 years age group. Moreover, patients aged 5-<10 years with a history of asthma, allergic rhinitis, pollinosis, or atopic dermatitis, and those aged ≥10 years with positivity for dog dander-specific IgE were at risk for developing ATRs.

CONCLUSION

The allergic constitution of patients plays a role in ATR onset even in pediatric hematological/oncological diseases. Therefore, advance confirmation of a patient's allergic constitution may partly predict the onset of ATRs. However, since multiple allergic predispositions within complex mechanisms may be involved in the onset of ATRs, further verification is required.

PiggyBac Transposon-Mediated CD19 Chimeric Antigen Receptor-T Cells Derived From CD45RA-Positive Peripheral Blood Mononuclear Cells Possess Potent and Sustained Antileukemic Function

The quality of chimeric antigen receptor (CAR)-T cell products, namely, memory and exhaustion markers, affects the long-term functionality of CAR-T cells. We previously reported that piggyBac (PB) transposon-mediated CD19 CAR-T cells exhibit a memory-rich phenotype that is characterized by the high proportion of CD45RA⁺/C-C chemokine receptor type 7 (CCR7)⁺ T-cell fraction. To further investigate the favorable phenotype of PB-CD19 CAR-T cells, we generated PB-CD19 CAR-T cells from CD45RA⁺ and CD45RA⁻ peripheral blood mononuclear cells (PBMCs) (RA⁺ CAR and RA⁻ CAR, respectively), and compared their phenotypes and antitumor activity. RA⁺ CAR-T cells showed better transient gene transfer efficiency 24 h after transduction and superior expansion capacity after 14 days of culture than those shown by RA⁻ CAR-T cells. RA⁺ CAR-T cells exhibited dominant CD8 expression, decreased expression of the exhaustion marker programmed cell death protein-1 (PD-1) and T-cell senescence marker CD57, and enriched naïve/stem cell memory fraction, which are associated with the longevity of CAR-T cells. Transcriptome analysis showed that canonical exhaustion markers were downregulated in RA⁺ CAR-T, even after antigen stimulation. Although antigen stimulation could increase CAR expression, leading to tonic CAR signaling and exhaustion, the expression of CAR molecules on cell surface after antigen stimulation in RA⁺ CAR-T cells was controlled at a relatively lower level than that in RA⁻ CAR-T cells. In the in vivo stress test, RA⁺ CAR-T cells achieved prolonged tumor control with expansion of CAR-T cells compared with RA⁻ CAR-T cells. CAR-T cells were not detected in the control or RA⁻ CAR-T cells but RA⁺ CAR-T cells were expanded even after 50 days of treatment, as confirmed by sequential bone marrow aspiration. Our results suggest that PB-mediated RA⁺ CAR-T cells exhibit a memory-rich phenotype and superior antitumor function, thus CD45RA⁺ PBMCs might be considered an efficient starting material for PB-CAR-T cell manufacturing. This novel approach will be beneficial for effective treatment of B cell malignancies.

Clinical Courses of IKAROS and CTLA4 Deficiencies: A Systematic Literature Review and Retrospective Longitudinal Study

IKAROS and CTLA4 deficiencies are inborn errors of immunity and show similar clinical phenotypes, including hypogammaglobulinemia and autoimmune diseases (ADs). However, the differences in clinical features and pathogenesis of these are not fully understood. Therefore, we performed systematic literature reviews for IKAROS and CTLA4 deficiencies. The reviews suggested that patients with IKAROS deficiency develop AD earlier than hypogammaglobulinemia. However, no study assessed the detailed changes in clinical manifestations over time; this was likely due to the cross-sectional nature of the studies. Therefore, we conducted a retrospective longitudinal study on IKAROS and CTLA4 deficiencies in our cohort to evaluate the clinical course over time. In patients with IKAROS deficiency, AD and hypogammaglobulinemia often develop in that order, and AD often resolves before the onset of hypogammaglobulinemia; these observations were not found in patients with CTLA4 deficiency. Understanding this difference in the clinical course helps in the clinical management of both. Furthermore, our results suggest B- and T-cell-mediated ADs in patients with IKAROS and CTLA4 deficiencies, respectively.

Dual-antigen targeted iPSC-derived chimeric antigen receptor-T cell therapy for refractory lymphoma

We generated dual-antigen receptor (DR) T cells from induced pluripotent stem cells (iPSCs) to mitigate tumor antigen escape. These cells were engineered to express a chimeric antigen receptor (CAR) for the antigen cell surface latent membrane protein 1 (LMP1; LMP1-CAR) and a T cell receptor directed to cell surface latent membrane protein 2 (LMP2), in association with human leucocyte antigen A24, to treat therapy-refractory Epstein-Barr virus-associated lymphomas. We introduced LMP1-CAR into iPSCs derived from LMP2-specific cytotoxic T lymphocytes (CTLs) to generate rejuvenated CTLs (rejTs) active against LMP1 and LMP2, or DRrejTs. All DRrejT-treated mice survived >100 days. Furthermore, DRrejTs rejected follow-up inocula of lymphoma cells, demonstrating that DRrejTs persisted long-term. We also demonstrated that DRrejTs targeting CD19 and LMP2 antigens exhibited a robust tumor suppressive effect and conferred a clear survival advantage. Co-operative antitumor effect and in vivo persistence, with unlimited availability of DRrejT therapy, will provide powerful and sustainable T cell immunotherapy.

Cellular congenital mesoblastic nephroma detected by prenatal MRI: a case report and literature review

Congenital mesoblastic nephroma (CMN) is a rare tumor, yet it is the most frequently diagnosed renal neoplasm in the first 3 months of life. CMN reports with prenatal magnetic resonance imaging (MRI) are scarce. Our aims were to describe a case with fetal MR imaging along with other findings, and to review the literature concerned with prenatal MRI detection of CMN. Upon routine ultrasound (US) examination of a 36-week pregnant woman, a fetal abdominal mass was disclosed. Prenatal MRI revealed a large, well-circumscribed renal mass of solid and cystic components, not invading the adjacent tissues, but compressing normal renal parenchyma of the lower pole of the left kidney. Thus, a low malignant renal tumor was considered. After Cesarean delivery, imaging including US and computerized tomography (CT) scan was performed on the apparently healthy boy and verified the prenatal MRI finding. Accordingly, left nephrectomy was performed at the age of 12 days. The pathology confirmed CT results of the solid and cystic components of the mass, in addition to the necrotic and hemorrhagic constitution. Cellular CMN was diagnosed, and ETV6 gene rearrangement was demonstrated by FISH analysis. No recurrence was detected within the 40 months follow-up after the operation. Our report described a rare and seldomly detected renal tumor in utero with the aid of MRI and reviewed the few related reports in the literature in which MRI was performed prenatally. This report also highlights the need for prenatal MRI as a complementary tool to US in cases with suspected fetal renal mass and recommends its use for carefully managing the possible risks during the perinatal period.

[Current status and future perspective of CAR T-cell therapy for acute myeloid leukemia]

For over a decade, various chimeric antigen receptor (CAR)-modified T-cells targeting myeloid antigens have been researched and developed overseas for relapsed/refractory acute myeloid leukemia (AML). However, none of them is domestically and internationally nearing approval. Clinical trial results on CAR T-cells targeting LeY, CD33, NKG2D ligands, CD38, or CD123 have been reported; however, they have not shown significant clinical benefit. More recently, several promising studies in CLL1 CAR T-cells have been reported in China, which attracted attention. We started a first-in-human clinical trial of GMR CAR T-cells in patients with CD116-positive myeloid neoplasms, particularly AML and juvenile myelomonocytic leukemia, in 2021. CAR T-cells can be a promising and practical treatment option for patients with relapsed/refractory AML.

[A first-in-human clinical trial of piggyBac transposon-mediated GMR CAR-T cells against CD116-positive acute myeloid leukemia and juvenile myelomonocytic leukemia]

Although several types of chimeric antigen receptor (CAR)-modified T cells (CAR-T cells) targeting myeloid antigens have been developed for acute myeloid leukemia (AML) globally, significant clinical benefits have not yet been reported. Furthermore, CAR-T cells targeting juvenile myelomonocytic leukemia (JMML) have not yet been developed. All JMML cells and 63-83% of AML cells express granulocyte macrophage-colony stimulating factor (GM-CSF) receptor (GMR, CD116/CD131 complex). Therefore, we created ligand-based CAR-T cells targeting GMR using the piggyBac transposon system. We further redesigned the CAR construct by optimizing the affinity of the antigen-binding region and length of the spacer region. The GMR CAR-T cells with a mutated GM-CSF at residue 21 (E21K) and a G4S spacer showed superior antitumor effects in the human AML-xenograft model. Safety tests revealed that the toxicity of GMR CAR-T cells was restricted to normal monocytes. Based on the promising results of the nonclinical study, we started a first-in-human clinical trial of GMR CAR-T cells in patients with CD116-positive AML and JMML in 2021.

Cancer among children, adolescents and young adults in the Hokushin region, Japan, between 2010 and 2015

Adolescents and young adults with cancer encounter age-related challenges. Cancer treatment and support are not always tailored to the needs of each patient due to difficulty in the collection of accurate data. The present study aimed to investigate cancer among children and adolescents and young adults in the four adjacent prefectures of Japan (Toyama, Ishikawa, Fukui and Nagano) by analyzing data from a unique regional cancer database. We retrieved and analyzed the data of pediatric and adolescent and young adult patients aged between 0 and 39 years at cancer diagnosis (including carcinoma in situ), which was registered in the Hokushin Ganpro database between 2010 and 2015. A total of 5718 cases (1571 males and 4147 females) were identified during this period. The overall male-to-female ratio was 1:2.6. There was no distinct difference in the number of cancer cases per 100 000 population between males and females until 19 years of age. The difference became more pronounced after 20 years of age. The number of cancer cases (per 100 000 population) in the 0-14-, 15-19-, 20-29- and 30-39-year age groups was estimated to be 13.4, 14.5, 44.0 and 101.5, respectively. Carcinomas were the most common type of cancer in the adolescents and young adults (15-39 years) population (74%), whereas they were not the predominant cancer type in the pediatric (0-14 years) population. Although further research is needed to understand the needs of adolescents and young adults with cancer, we believe that our findings will help guide efforts to improve the management strategy for adolescents and young adults with cancer.