A higher CD34 + cell dose correlates with better event-free survival after KIR-ligand mismatched cord blood transplantation for childhood acute myeloid leukemia

Although killer Ig-like receptor ligands (KIR-L) mismatch has been associated with alloreactive natural killer cell activity and potent graft-versus-leukemia (GVL) effect among adults with acute myeloid leukemia (AML), its role among children with AML receiving cord blood transplantation (CBT) has not been determined. We conducted a retrospective study using a nationwide registry of the Japanese Society for Transplantation and Cellular Therapy. Patients who were diagnosed with de novo non-M3 AML and who underwent their first CBT in remission between 2000 and 2021 at under 16 years old were included. A total of 299 patients were included; 238 patients were in the KIR-L match group, and 61 patients were in the KIR-L mismatch group. The cumulative incidence rates of neutrophil recovery, platelet engraftment, and acute/chronic graft-versus-host disease did not differ significantly between the groups. The 5-year event-free survival (EFS) rate was 69.8% in the KIR-L match group and 74.0% in the KIR-L mismatch group (p = 0.490). Stratification by CD34 + cell dose into four groups revealed a significant correlation between CD34 + cell dose and EFS in the KIR-L mismatch group (p = 0.006) but not in the KIR-L match group (p = 0.325). According to our multivariate analysis, KIR-L mismatch with a high CD34 + cell dose (≥ median dose) was identified as an independent favorable prognostic factor for EFS (hazard ratio = 0.19, p = 0.029) and for the cumulative incidence of relapse (hazard ratio = 0.09, p = 0.021). Our results suggested that higher CD34 + cell doses are crucial for achieving a potent GVL effect in the context of KIR-L-mismatched CBT.

The first case of hemorrhagic shock and encephalopathy syndrome with fulminant hypercytokinemia associated with pediatric COVID-19

BACKGROUND

Infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can lead not only to respiratory symptoms but also to neurologic symptoms with various levels of severity. After the worldwide prevalence of Omicron variant, severe neurological manifestations of coronavirus disease 2019 (COVID-19) such as febrile seizure, demyelinating disease, and cerebrovascular disease, have been reported. However, reports of acute encephalopathy in patients with COVID-19 are quite limited. Especially in terms of cytokine storm-inducing hemorrhagic shock and encephalopathy syndrome (HSES), there is no case reported related to COVID-19.

CASE PRESENTATION

We describe the case of an 8-year-old girl who presented with fatal HSES associated with pediatric SARS-CoV-2 infection. Status epilepticus occurs after the onset of fever and diarrhea and lasted for at least an hour. Unconsciousness was followed by circulatory failure and ultimately leading to death within 2 days after the fever onset. Analysis of forty-eight cytokines and chemokines measured in three consecutive serum samples revealed that interferon (IFN)-γ, interleukin (IL)-6, IL-10, IL-17A, tumor necrosis factor (TNF)-a, IL-8, Interferon gamma inducible protein (IP)-10, and Monocyte chemoattractant protein (MCP)-1, were increased within an hour after the onset of impaired consciousness.

CONCLUSION

Here, we describe a case of fatal fulminant encephalopathy with rapid progression because of HSES associated with COVID-19. High levels of cytokines and chemokines observed in this case may be because of the SARS-CoV-2-associated cytokine storm. This study is the first COVID-19-associated case of HSES.

High Plasma Presepsin Levels in Children With Hemophagocytic Lymphohistiocytosis

Presepsin is reported as a novel diagnostic and prognostic biomarker for sepsis, and its optimal cutoff value is reported to be 600 to 650 pg/mL. Three children were diagnosed with hemophagocytic lymphohistiocytosis (HLH). The cause of HLH was unknown in cases 1 and 2, while Epstein-Barr virus infection was the cause in case 3. The plasma presepsin levels at the diagnosis were 1020, 1080, and 3160 pg/mL in cases 1, 2, and 3, respectively. In case 1, the plasma level of presepsin decreased to 164 pg/mL on day 19 of her sickness, when symptoms improved. Follow-up plasma presepsin levels were missing for cases 2 and 3. No microbiological pathogens were detected in the blood cultures of any of the patients. Our cases suggest that plasma presepsin levels can be elevated in childhood HLH.

Infant case of severe immune thrombocytopenia caused by COVID-19 infection

Immune thrombocytopenia (ITP) is a common childhood acute autoimmune bleeding disorder caused by numerous viruses and characterized by isolated thrombocytopenia. Although cases of ITP caused by coronavirus disease 2019 (COVID-19) infection have been reported in adults, pediatric reports are limited. We present the case of a 1-year-old girl who developed COVID-19-infection-related ITP with a very low platelet count (0.0 × 104/μL). We searched for COVID-19-related pediatric ITP cases and found 10 other cases, with the majority having platelet counts of <1.0 × 104/μL. Although pediatric ITP cases caused by COVID-19 infection may be severe, further studies are needed.

Safety and efficacy of post-haematopoietic cell transplantation maintenance therapy with blinatumomab for relapsed/refractory CD19-positive B-cell acute lymphoblastic leukaemia: protocol for a phase I-II, multicentre, non-blinded, non-controlled trial (JPLSG SCT-ALL-BLIN21)

INTRODUCTION

Relapsed and refractory B-cell acute lymphoblastic leukaemia (R/R-B-ALL) is linked to a significant relapse rate after allogeneic haematopoietic cell transplantation (allo-HCT) in children, adolescents and young adults (CAYA). No standard treatment has been established to prevent relapse after allo-HCT for R/R-B-ALL, which is an unmet medical need. The administration of blinatumomab after allo-HCT is expected to enhance the antileukaemic effect on residual CD19-positive blasts by donor-derived CD3-positive T-cells.

METHODS AND ANALYSIS

The goal of this multicentre, open-label, uncontrolled, phase I-II clinical trial is to assess the safety and effectiveness of post-transplant maintenance therapy with blinatumomab for CAYA patients (25 years old or younger) with CD19-positive R/R-B-ALL who have received allo-HCT beyond first complete remission (CR) and have CR with haematological recovery between 30 and 100 days after allo-HCT. Eighty-five paediatric institutions in Japan are participating in this study. Forty-one patients will enrol within 2.25-year enrolment period and follow-up period is 1 year. The primary endpoints are the treatment completion rate for phase I study and the 1-year graft-versus-host disease-free/relapse-free survival rate for phase II study, respectively.

ETHICS AND DISSEMINATION

This research was approved by the Central Review Board at National Hospital Organization Nagoya Medical Center (Nagoya, Japan) on 21 January 2022 and was registered at the Japan Registry of Clinical Trials (jRCT) on 3 March 2022. Written informed consent is obtained from all patients and/or their guardians. The results of this study will be disseminated through peer-reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

jRCTs041210154.

Disease Progression of WHIM Syndrome in an International Cohort of 66 Pediatric and Adult Patients

Warts, hypogammaglobulinemia, infections, and myelokathexis (WHIM) syndrome (WS) is a combined immunodeficiency caused by gain-of-function mutations in the C-X-C chemokine receptor type 4 (CXCR4) gene. We characterize a unique international cohort of 66 patients, including 57 (86%) cases previously unreported, with variable clinical phenotypes. Of 17 distinct CXCR4 genetic variants within our cohort, 11 were novel pathogenic variants affecting 15 individuals (23%). All variants affect the same CXCR4 region and impair CXCR4 internalization resulting in hyperactive signaling. The median age of diagnosis in our cohort (5.5 years) indicates WHIM syndrome can commonly present in childhood, although some patients are not diagnosed until adulthood. The prevalence and mean age of recognition and/or onset of clinical manifestations within our cohort were infections 88%/1.6 years, neutropenia 98%/3.8 years, lymphopenia 88%/5.0 years, and warts 40%/12.1 years. However, we report greater prevalence and variety of autoimmune complications of WHIM syndrome (21.2%) than reported previously. Patients with versus without family history of WHIM syndrome were diagnosed earlier (22%, average age 1.3 years versus 78%, average age 5 years, respectively). Patients with a family history of WHIM syndrome also received earlier treatment, experienced less hospitalization, and had less end-organ damage. This observation reinforces previous reports that early treatment for WHIM syndrome improves outcomes. Only one patient died; death was attributed to complications of hematopoietic stem cell transplantation. The variable expressivity of WHIM syndrome in pediatric patients delays their diagnosis and therapy. Early-onset bacterial infections with severe neutropenia and/or lymphopenia should prompt genetic testing for WHIM syndrome, even in the absence of warts.

Impact of KIR-ligand mismatch on pediatric T-cell acute lymphoblastic leukemia in unrelated cord blood transplantation

BACKGROUND

Currently, allogeneic hematopoietic stem cell transplantation (allo-HSCT) is considered to be indicated for children and adolescents with high-risk or relapsed T-cell acute lymphoblastic leukemia (T-ALL); however, the outcomes are unsatisfactory. Killer cell immunoglobulin-like receptors (KIRs) are the main receptors on natural killer (NK) cells that play an important role in the graft-versus-leukemia effect after allo-HSCT. In allo-HSCT, when the recipient lacks a donor KIR-ligand (KIR-ligand mismatch in the graft-versus-host [GVH] direction), donor NK cells will be activated against recipient cells. KIR-ligand mismatch in the GVH direction improves outcomes after unrelated cord blood transplantation (UCBT) with acute myeloid leukemia, but the effect in T-ALL is unclear.

OBJECTIVE

We evaluated the impact of KIR-ligand mismatch in the GVH direction on the transplant outcomes of children and adolescents with T-ALL who received UCBT.

STUDY DESIGN

We conducted a retrospective study using a nationwide registry of the Japanese Society for Transplantation and Cellular Therapy. Patients diagnosed with T-ALL, aged 0-19 years, and underwent first UCBT between 1999 and 2017 were included.

RESULTS

A total of 91 patients were included in this study. In all, 23 (25.3%) percent of patients had KIR-ligand mismatch in the GVH direction. The 5-year leukemia-free survival (LFS) and overall survival (OS) rates after UCBT were 65.8% and 69.6%, respectively. In a multivariate analysis, KIR-ligand mismatch in the GVH direction was associated with a significant reduction in the relapse rate (hazard ratio [HR], 0.19; P = 0.002), resulting in better LFS (HR, 0.18; P = 0.010) and OS (HR, 0.26; P = 0.048) without increasing non-relapse mortality (NRM; HR, 1.90; P = 0.264). The cumulative incidence of GVH disease (GVHD) did not differ between patients with and without KIR-ligand mismatch (grade II-IV acute GVHD, 39.1% versus 36.8%, P = 0.648, grade III-IV acute GVHD, 13.0% versus 11.8%, P = 0.857, and chronic GVHD, 26.1% versus 22.9%, P = 0.736, respectively). Furthermore, acute and chronic GVHD were not associated with good patient outcomes. Notably, no relapse was observed in patients who received KIR-ligand mismatched UCBT in complete remission.

CONCLUSION

KIR-ligand mismatch in the GVH direction improved LFS and decreased relapse rates without increasing NRM in children and adolescents with T-ALL who received UCBT, which was not mediated by GVHD.

Title: Prognostic factors of children and adolescents with T-cell acute lymphoblastic leukemia after allogeneic transplantation

Acute lymphoblastic leukemia (ALL) is the most common cancer during childhood, and some high-risk patients with ALL require hematopoietic stem cell transplantation (HSCT). Mainly due to small patient numbers, studies focusing specifically on children and adolescents with T-cell ALL (T-ALL) are limited. Using a nationwide registry, we retrospectively analyzed data from patients under 20 years old who underwent their first HSCT for T-ALL between 2000 and 2018. As a result, total 484 patients were included, and their median follow-up period was 6.9 years after HSCT for survivors. While patients receiving HSCT at first complete remission (CR) showed relatively good 5-year leukemia free survival (5yLFS, 73.5%), once relapse occurred, their prognosis was much worse (44.4%) even if they attained second remission again (p < 0.001). Among patients receiving HSCT at CR1, grade II-IV acute graft versus host disease was associated with worse overall and LFS than grade 0-I (5yLFS 69.5% vs 82.1%, p = 0.026) mainly due to high non-relapse mortality. Among those patients, patients receiving related bone marrow transplantation, unrelated bone marrow transplantation, or unrelated cord blood transplantation showed similar survival (5yLFS, 73.2%, 76.3%, and 77.0%, respectively). For patients undergoing cord blood transplantation at CR1, total-body irradiation-based myeloablative conditioning was associated with better 5yLFS than other conditioning regimens (85.4% vs 62.2%, p = 0.044), as it reduced the risk of relapse. These results indicate that relapsed patients have much less chance of cure, and that identifying patients who require HSCT for cure and offering them HSCT with optimal settings during CR1 are crucial for children and adolescents with T-ALL. This article is protected by copyright. All rights reserved.

Low donor chimerism may be sufficient to prevent demyelination in adrenoleukodystrophy

Adrenoleukodystrophy (ALD) is a peroxisomal disorder characterized by white matter degeneration caused by adenosine triphosphate-binding cassette subfamily D member 1 (ABCD1) gene mutations, which lead to an accumulation of very-long-chain fatty acids (VLCFA). Hematopoietic stem cell transplantation (HSCT) is the most effective treatment; however, the ratio of donor-to-recipient cells required to prevent the progression of demyelination is unclear. The proband was diagnosed with the childhood cerebral form of ALD at 5 years of age based on the clinical phenotype, elevated plasma VLCFA levels, and pathogenic ABCD1 mutation c.293C>T (p.Ser98Leu). Soon after the diagnosis, he became bedridden. At 1 year of age, his younger brother was found to carry the same ABCD1 mutation; despite being asymptomatic, at 1 year and 9 months, head magnetic resonance imaging (MRI) showed high-signal-intensity lesions in the cerebral white matter. The patient underwent unrelated cord blood transplantation (UCBT) with a reduced conditioning regimen, which resulted in mixed chimerism. For 7 years after UCBT, the donor chimerism remained low (<10%) in peripheral blood and cerebrospinal fluid. However, even though a second HSCT was not performed, his neurological symptoms and brain MRI findings did not deteriorate. Our case suggests that even a small number of donor cells may prevent demyelination in ALD. This is an important case when considering the timing of a second HSCT.

Successful living donor liver transplantation for liver failure due to maternal T cell engraftment following cord blood transplantation in X-linked severe combined immunodeficiency disease: Case report

Maternal T cells from perinatal transplacental passage have been identified in up to 40% of patients with severe combined immunodeficiency (SCID). Although engrafted maternal T cells sometimes injure newborn tissue, liver failure due to maternal T cells has not been reported. We rescued a boy with X-linked SCID who developed liver failure due to engrafted maternal T cell invasion following living donor liver transplantation (LDLT) following unrelated umbilical cord blood transplantation (UCBT). After developing respiratory failure 3 weeks postpartum, he was diagnosed with X-linked SCID. Pathological findings showed maternal T cells engrafted in his liver and hepatic fibrosis gradually progressed. He underwent UCBT at 6 months, but hepatic function did not recover and liver failure progressed. Therefore, he underwent LDLT using an S2 monosegment graft at age 1.3 years. The patient had a leak at the Roux-en-Y anastomosis, which was repaired. Despite occasional episodes of pneumonia and otitis media, he is generally doing well 6 years after LDLT with continued immunosuppression agents. In conclusion, the combination of hematopoietic stem cell transplantation (HSCT) and liver transplantation may be efficacious, and HSCT should precede liver transplantation for children with X-linked SCID and liver failure.

Rapid blood cell recovery with immunosuppressive therapy combined with romiplostim in a patient with very severe hepatitis-associated aplastic anemia who underwent liver transplantation

Patients with hepatitis-associated aplastic anemia (HAA) who undergo living-donor liver transplantation (LDLT) have a poor prognosis with infections and bleeding complications. Rapid recovery of blood cells is critical for preventing these complications and improving the outcome. Immunosuppressive therapy (IST) combined with thrombopoietin receptor agonists is considered effective for aplastic anemia. However, there are no data on the benefits of adding thrombopoietin receptor agonists to IST for HAA. We present the case of a child with severe HAA who underwent LDLT, and who achieved rapid blood cell recovery with IST combined with romiplostim, a thrombopoietin receptor agonist. In addition, despite having undergone LDLT, the patient had no adverse events such as serious liver dysfunction or thrombosis. This case suggests that IST combined with thrombopoietin receptor agonists may be a promising treatment option for HAA patients undergoing LDLT.

Reduced leukemia relapse through cytomegalovirus reactivation in killer cell immunoglobulin-like receptor-ligand-mismatched cord blood transplantation

Cytomegalovirus (CMV) reactivation in cord blood transplantation (CBT) may result in the proliferation and maturation of natural killer (NK) cells. Similarly, a mismatch of the killer cell immunoglobulin-like receptor (KIR)-ligand induces NK cell activation. Therefore, if CMV reactivation occurs in the presence of KIR-ligand mismatch, it might improve CBT outcomes. We assessed the difference in the effect of CMV reactivation in the presence of KIR-ligand mismatch on disease relapse in the graft-versus-host direction. A total of 2840 patients with acute myeloid leukemia, acute lymphoblastic leukemia, myelodysplastic syndrome, and chronic myeloid leukemia were analyzed. Among those with a HLA-Bw4/A3/A11 (KIR3DL-ligand) mismatch, CMV reactivation up to 100 days following CBT had a favorable impact on relapse (18.9% vs. 32.9%, P = 0.0149). However, this effect was not observed in cases without the KIR3DL-ligand mismatch or in those with or without a HLA-C1/C2 (KIR2DL-ligand) mismatch. The multivariate analysis suggested that CMV reactivation had a favorable effect on relapse only in cases with a KIR3DL-ligand mismatch (hazard ratio 0.54, P = 0.032). Moreover, the interaction effect between CMV reactivation and KIR3DL-ligand mismatch on relapse was significant (P = 0.039). Thus, our study reveals the association between KIR-ligand mismatches and CMV reactivation, which will enhance CBT outcomes.

Hematopoietic Cell Transplantation with Reduced Intensity Conditioning Using Fludarabine/Busulfan or Fludarabine/Melphalan for Primary Immunodeficiency Diseases

PURPOSE

The purpose of our study was to compare the safety and efficacy of hematopoietic cell transplantation (HCT) using fludarabine (Flu)-based reduced intensity conditioning (RIC) with busulfan (BU) or melphalan (Mel) for primary immunodeficiency diseases (PID).

METHODS

We retrospectively analyzed transplant outcome, including engraftment, chimerism, immune reconstitution, and complications in 15 patients with severe combined immunodeficiency (SCID) and 27 patients with non-SCID PID. The patients underwent Flu-based RIC-HCT with BU (FluBU: 7 SCID, 16 non-SCID) or Mel (FluMel: 8 SCID, 11 non-SCID). The targeted low-dose BU with therapeutic drug monitoring was set to 30 mg hour/L for SCID.

RESULTS

The 2-year overall survival of all patients was 79.6% and that of patients with SCID in the FluBU and FluMel groups was 100% and 62.5%, respectively. In the FluBU group, all seven patients achieved engraftment, good immune reconstitution, and long-term survival. All five patients receiving umbilical cord blood transplantation achieved complete or high-level mixed chimerism and sufficient specific IgG production. In the FluMel group, six of eight patients achieved complete or high-level mixed chimerism. Viral reactivation or new viral infection occurred in one FluBU group patient and four FluMel group patients. In the non-SCID group, 10 of 11 patients (91%) who received FluMel achieved complete or high-level mixed chimerism but had variable outcomes. Patients with WAS (2/2 patients), NEMO deficiency (2/2 patients), and X-linked hyper IgM syndrome (2/3 patients) who received FluBU achieved complete or high-level mixed chimerism and long-term survival.

CONCLUSIONS

RIC-HCT with FluBU is a safe and effective strategy for obtaining high-level donor chimerism, immune reconstitution including B cell function, and long-term survival in patients with SCID. In patients with non-SCID PID, the results varied according to the subtype of the disease. Further prospective studies are required to optimize the conditioning regimen for non-SCID PID.

A Sliding Mode Controller Using an LS-SVM Model for a Water-Hydraulic Artificial Rubber Muscle

We describe a sliding mode controller design for an artificial rubber muscle driven by tap-water pressure. The hysteretic characteristics of this water-hydraulic artificial rubber muscle (WARM) often deteriorate its control accuracy. To cope with this complicated hysteresis, a modeling approach based on the least squares support vector machine (LS-SVM) with nonlinear kernel functions is first applied to a WARM. By employing this LS-SVM-based WARM model, a sliding mode controller is then derived for the WARM drive system. We verify the control performance of the proposed controller and compare its tracking accuracy with our previously developed controller through experiments.

Unrelated cord blood transplantation with myeloablative conditioning for pediatric acute lymphoblastic leukemia in remission: prognostic factors

The number of individuals undergoing unrelated cord blood transplantation (UCBT) has increased in recent years; however, information on prognostic factors is limited. We retrospectively analyzed data from 475 children and adolescents receiving UCBT with myeloablative conditioning for acute lymphoblastic leukemia (ALL) in complete remission (CR), based on a nationwide registry. In the total patient cohort, 5-year leukemia-free survival (LFS) and overall survival (OS) rates after UCBT were 61.1% and 67.7%, respectively. UCBT at first CR and UCBT after 2007 were associated with good survival, while grade II-IV acute graft-versus-host disease (GVHD) was associated with low relapse rate but did not affect survival. Analysis according to human leukocyte antigen (HLA) disparity revealed that tacrolimus-based GVHD prophylaxis resulted in higher OS and lower relapse rate and nonrelapse mortality (NRM) than cyclosporine-based GVHD prophylaxis in patients transplanted with 6/6 and ≤4/6 HLA-matched umbilical cord blood. Furthermore, grade II-IV acute GVHD was associated with good LFS and low relapse rate, without high NRM, in patients receiving 5/6 HLA-matched UCBT. These data indicate that prognostic factors for ALL differ depending on HLA disparity in UCBT.

Prevalence of germline GATA2 and SAMD9/9L variants in paediatric haematological disorders with monosomy 7

Monosomy 7 (-7) occurs in various types of paediatric myeloid disorders and has a poor prognosis. Recent studies have demonstrated that patients with germline gain-of-function SAMD9/9L variants and loss-of-function GATA2 variants are prone to developing myelodysplastic syndrome (MDS) associated with -7. However, the prevalence of the genetic variants among paediatric haematologic disorders with -7 is unknown. The present study screened germline variants of GATA2 and SAMD9/9L in 25 patients with various types of paediatric haematological disorders associated with -7. The diagnoses of the 25 patients included MDS (n = 10), acute myeloid leukaemia (AML) and myeloid sarcomas (n = 9), juvenile myelomonocytic leukaemia (n = 3) and other disorders (n = 3). Seven patients with a germline pathogenic GATA2 variant were found. For SAMD9/9L screening, next-generation sequencing was used to detect low-abundance variants and found four novel germline variants. Functional analysis revealed that three out of the four variants showed growth-restricting capacity in vitro and thus, were judged to be pathogenic. Cases with GATA2 mutation tended to be older, compared to those with SAMD9/9L mutations. In conclusion, GATA2 and SAMD9/9L were sequenced in 25 patients with paediatric haematologic disorders associated with -7, and 40% of them were found to have some pathogenic germline variants in the three genes.

Analysis of the BRAF and MAP2K1 mutations in patients with Langerhans cell histiocytosis in Japan

In Langerhans cell histiocytosis (LCH), somatic gene mutations in the mitogen-activated protein kinase pathway have been identified in more than 80% of cases in Western countries, in which mutually exclusive BRAF and MAP2K1 mutations are involved. Among them, BRAF V600E mutation is the major contributor (50-60%). In 59 patients (50 children and nine adults) with LCH (not including pulmonary LCH) in Japan, we first screened for BRAF V600E in all patients followed by target sequencing for other gene mutations in 17 of BRAF V600E-negative patients. As a result, BRAF V600E mutation was detected in 27/59 (46%) patients. We also identified BRAF mutations other than V600E in five and MAP2K1 mutations in nine patients. Thus, gene mutations in BRAF or MAP2K1 were identified in 41/44 (93%) of the fully tested patients. Regarding the correlation of clinical features and genotype in pediatric patients, we found that BRAF V600E mutation status was not correlated with sex, age at diagnosis, disease extent, response to first-line therapy, relapse, or CNS-related sequelae. Interestingly, MAP2K1 exon 2 in-frame deletion was related to the risk organ involvement; however, further studies are required to clarify the impact of these gene mutations on the clinical features of patients with LCH.

Whole-Genome Sequencing of the NARO World Rice Core Collection (WRC) as the Basis for Diversity and Association Studies

Genebanks provide access to diverse materials for crop improvement. To utilize and evaluate them effectively, core collections, such as the World Rice Core Collection (WRC) in the Genebank at the National Agriculture and Food Research Organization, have been developed. Because the WRC consists of 69 accessions with a high degree of genetic diversity, it has been used for >300 projects. To allow deeper investigation of existing WRC data and to further promote research using Genebank rice accessions, we performed whole-genome resequencing of these 69 accessions, examining their sequence variation by mapping against the Oryza sativa ssp. japonica Nipponbare genome. We obtained a total of 2,805,329 single nucleotide polymorphisms (SNPs) and 357,639 insertion-deletions. Based on the principal component analysis and population structure analysis of these data, the WRC can be classified into three major groups. We applied TASUKE, a multiple genome browser to visualize the different WRC genome sequences, and classified haplotype groups of genes affecting seed characteristics and heading date. TASUKE thus provides access to WRC genotypes as a tool for reverse genetics. We examined the suitability of the compact WRC population for genome-wide association studies (GWASs). Heading date, affected by a large number of quantitative trait loci (QTLs), was not associated with known genes, but several seed-related phenotypes were associated with known genes. Thus, for QTLs of strong effect, the compact WRC performed well in GWAS. This information enables us to understand genetic diversity in 37,000 rice accessions maintained in the Genebank and to find genes associated with different phenotypes. The sequence data have been deposited in DNA Data Bank of Japan Sequence Read Archive (DRA) (Supplementary Table S1).

Effects of Sulfonylureas on Periodontopathic Bacteria-Induced Inflammation

Interleukin-1β (IL-1β) is an inflammatory cytokine produced by monocytes/macrophages and is closely associated with periodontal diseases. The NLRP3 inflammasome is involved in IL-1β activation through pro-IL-1β processing and pyroptotic cell death in bacterial infection. Recently, glyburide, a hypoglycemic sulfonylurea, has been reported to reduce IL-1β activation by suppressing activation of the NLRP3 inflammasome. Therefore, we evaluated the possibility of targeting the NLRP3 inflammasome pathway by glyburide to suppress periodontal pathogen-induced inflammation. THP-1 cells (a human monocyte cell line) were differentiated to macrophage-like cells by treatment with phorbol 12-myristate 13-acetate and stimulated by periodontopathic bacteria, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, or Fusobacterium nucleatum, in the presence of glyburide. IL-1β and caspase-1 expression in the cells and culture supernatants were analyzed by Western blotting and enzyme-linked immunosorbent assay, and cell death was analyzed by lactate dehydrogenase assay. Stimulation of THP-1 macrophage-like cells with every periodontopathic bacteria induced IL-1β secretion without cell death, which was suppressed by the NLRP3 inhibitor, MCC950, and caspase-1 inhibitor, z-YVAD-FMK. Glyburide treatment suppressed IL-1β expression in culture supernatants and enhanced intracellular IL-1β expression, suggesting that glyburide may have inhibited IL-1β secretion. Subsequently, a periodontitis rat model was generated by injecting periodontal bacteria into the gingiva, which was analyzed histologically. Oral administration of glyburide significantly suppressed the infiltration of inflammatory cells and the number of osteoclasts in the alveolar bone compared with the control. In addition to glyburide, glimepiride was shown to suppress the release of IL-1β from THP-1 macrophage-like cells, whereas other sulfonylureas (tolbutamide and gliclazide) or other hypoglycemic drugs belonging to the biguanide family, such as metformin, failed to suppress IL-1β release. Our results suggest that pharmacological targeting of the NLRP3 pathway may be a strategy for suppressing periodontal diseases.

Serum and cerebrospinal fluid cytokines in children with acute encephalopathy

BACKGROUND

The pathogenesis of acute encephalopathy (AE) remains unclear, and a biomarker has not been identified.

METHODS

Levels of 49 cytokines and chemokines, including osteopontin (OPN), were measured in serum and cerebrospinal fluid (CSF) of children with AE (n = 17) or febrile convulsion (FC; n = 8; control group). The AE group included acute necrotizing encephalopathy (n = 1), acute encephalopathy with biphasic seizures and late reduced diffusion (AESD; n = 3), clinically mild encephalitis/encephalopathy with a reversible splenial lesion (MERS; n = 4), and unclassified acute encephalopathy (UCAE; n = 9) that does not meet the criteria of syndrome classification. Five individuals with AE had neurological sequelae or death (poor prognosis), whereas 12 were alive without neurological sequelae (good prognosis).

RESULTS

The CSF:serum ratios of OPN, CC chemokine ligand (CCL)4, and interleukin (IL)-10 were significantly higher in AE than in FC. The CSF levels of macrophage inhibitory factor (MIF) and leukemia inhibitory factor (LIF) were significantly higher in the poor-prognosis group than in the good-prognosis group. The CSF:serum ratios of OPN were significantly higher in AESD and in MERS than in FC. The CSF:serum ratios of MIF and OPN were higher in MERS than in UCAE or FC.

CONCLUSION

Our results suggest that microglia-related cytokines and chemokines such as OPN, MIF, and LIF could be novel biomarkers of AE, in addition to the previously reported IL-10 and CCL4, and that MIF and LIF may be markers of poor prognosis.

P1520 Aortic flow reversal caused by aortic regurgitation deteriorates renal function

Background

Chronic kidney disease is a growing public health problem. Renal dysfunction is known as a strong risk factor for cardiovascular disease and end-stage renal failure. The presence of pan-diastolic flow reversal in the abdominal aorta is a very specific sign of severe aortic regurgitation (AR). A higher aortic reverse/forward flow ratio is associated with lower intrarenal forward flow. However, the influence of AR on renal function has been poorly understood. We hypothesized that the aortic flow reversal reduces the renal artery forward flow and accordingly leads to renal dysfunction in patients with severe AR.

Methods

The study consisted of 21 consecutive patients (mean age 69 ± 11 years) with severe AR who underwent aortic valve replacement (AVR). We compared echocardiographic indices and the glomerular filtration rate (GFR) before and 603 ± 541 days after AVR.

Results

Blood pressure was 122 ± 16/54 ± 8 mmHg before AVR and 123 ± 16/76 ± 11 mmHg after AVR. After AVR, left ventricular (LV) end-diastolic dimension decreased from 57 ± 9 to 44 ± 5 mm and LV ejection fraction increased from 58 ± 12 to 60 ± 11 %. Estimated GFR significantly increased from 62.9 ± 18.9 to 71.8 ± 18.1 mL/min per 1.73 m2 after AVR (p = 0.003).

Conclusions An increase in aortic flow reversal caused by severe AR reduces forward flow into the kidney and thereby deteriorates renal function. This study demonstrated a key mediating role of central hemodynamic factors, particularly an exaggerated aortic flow reversal in renal dysfunction and severe AR.

Dysregulation of Epstein-Barr Virus Infection in Hypomorphic ZAP70 Mutation

Background

Some patients with genetic defects develop Epstein-Barr virus (EBV)-associated lymphoproliferative disorder (LPD)/lymphoma as the main feature. Hypomophic mutations can cause different clinical and laboratory manifestations from null mutations in the same genes.

Methods

We sought to describe the clinical and immunologic phenotype of a 21-month-old boy with EBV-associated LPD who was in good health until then. A genetic and immunologic analysis was performed.

Results

Whole-exome sequencing identified a novel compound heterozygous mutation of ZAP70 c.703-1G>A and c.1674G>A. A small amount of the normal transcript was observed. Unlike ZAP70 deficiency, which has been previously described as severe combined immunodeficiency with nonfunctional CD4+ T cells and absent CD8+ T cells, the patient had slightly low numbers of CD8+ T cells and a small amount of functional T cells. EBV-specific CD8+ T cells and invariant natural killer T (iNKT) cells were absent. The T-cell receptor repertoire, determined using next generation sequencing, was significantly restricted.

Conclusions

Our patient showed that a hypomorphic mutation of ZAP70 can lead to EBV-associated LPD and that EBV-specific CD8+ T cells and iNKT cells are critically involved in immune response against EBV infection.

Translocator protein 18kDa antagonist ameliorates stress-induced stool abnormality and abdominal pain in rodent stress models

BACKGROUND

Irritable bowel syndrome (IBS) is a functional gastrointestinal (GI) disorder characterized by abdominal pain and abnormal bowel habits, both of which are exacerbated by psychological stress. The translocator protein 18kDa (TSPO) is a marker of reactive gliosis in a number of central nervous system (CNS) diseases and responsible for many cellular functions, including neurosteroidogenesis. Although it has been reported that psychological stress disturbs neurosteroids levels, the pathophysiological relevance of TSPO in IBS is poorly understood.

METHODS

We examined the effects of a TSPO antagonist, ONO-2952, on stress-induced stool abnormality and abdominal pain in rats, and on anxiety-related behavior induced by cholecystokinin.

KEY RESULTS

Oral administration of ONO-2952 attenuated stress-induced defecation and rectal hyperalgesia in rats with an efficacy equivalent to that of a 5-HT₃ receptor antagonist. In addition, ONO-2952 suppressed cholecystokinin-induced anxiety-like behavior with an efficacy equivalent to that of psychotropic drugs. On the other hand, ONO-2952 did not affect spontaneous defecation, gastrointestinal transit, visceral nociceptive threshold, and neurosteroid production in non-stressed rats even at a dose 10 times higher than its effective dose in the stress models.

CONCLUSIONS AND INFERENCES

These results suggest that TSPO antagonism results in antistress action, and that ONO-2952 is a promising candidate for IBS without side effects associated with current treatment.

[Role of the sweet taste receptor in glucose metabolism: no sweets for diabetes?]

Type 2 diabetes is closely associated with our daily diets and has become a global health problem with increasing number of patients. Maintaining energy homeostasis is essentially required for the treatment of diabetes. Energy metabolism starts with taking in a meal. Nutrients including amino acids, fatty acids and glucose in the digest have been shown to act on the neuroendocrine cells in the gastrointestinal (GI) tract, and thereby play important roles in energy homeostasis. Therefore, the GI tract is now recognized as a sensor system for nutrient signals. Taste receptor type 1 member 2 (T1R2) is known to function as a co-receptor with T1R3 to detect sweet chemicals in the taste buds. It has been proposed that the T1R2/T1R3 receptor complex acts as sweet sensor in the intestine, and plays a pivotal role in sensing sugars and maintaining glucose homeostasis through incretin secretion. To clarify the physiological roles of T1R2 in glucose homeostasis, T1r2-lacZ knock-in/knock-out mice were generated. We found lacZ gene expression in the GI tract where T1r3 expression has been reported. Interestingly, the T1r2-lacZ knock-in mice showed impaired glucose tolerance on oral glucose challenge but not on intraperitoneal injection. However, the fasting glucose level in T1r2-lacZ knock-in mice was comparable to that in wild type mice. These results suggest an important role of the sweet taste receptor system in the intestine when stimulated by glucose. Therefore, the roles of T1R2 will be presented and the mechanism for metabolic homeostasis will be discussed.

Successful allogeneic bone marrow transplantation with reduced intensity conditioning regimen for a pediatric relapsed ALK positive anaplastic large cell lymphoma

Pediatric anaplastic large cell lymphoma (ALCL) is a chemosensitive malignancy, but about 30% of patients experience relapse. In most of these patients, a second complete remission is obtainable with salvage chemotherapy, though relapse free survival rates are as low as 30-60%. Herein, we report a 6-year-old boy with relapsed anaplastic lymphoma kinase (ALK) positive ALCL successfully treated with vinblastine monotherapy followed by allogeneic hematopoietic stem cell transplantation (allo-HSCT), with a reduced intensity conditioning (RIC) regimen, from his father. One HLA locus from the father was mismatched. The boy had neither severe graft-versus-host disease nor transplantation related complications. He is currently well and has remained disease free for 10 months, to date, since transplantation. Allo-HSCT with a RIC regimen may be a promising treatment strategy for relapsed ALK positive ALCL based on obtaining graft-versus lymphoma effects as well as reducing transplantation-related mortality.

Proton pump inhibitor after endoscopic resection for esophageal squamous cell cancer: multicenter prospective randomized controlled trial

BACKGROUND

Whether proton pump inhibitors (PPIs) relieve heartburn or precordial pain after endoscopic resection (ER) for esophageal squamous cell carcinoma (ESCC) remains unclear. The aim of this study was to investigate the efficacy of PPI therapy for these symptoms after ER for ESCC.

METHODS

We conducted a multicenter prospective randomized controlled trial among 15 hospitals in Japan. In total, 229 patients with cT1a ESCC were randomly assigned to receive PPI therapy for 5 weeks after ER (the PPI group, n = 115) or follow-up without PPI therapy (the non-PPI group, n = 114). The primary end point was the incidence of gastroesophageal reflux disease (GERD)-like symptoms after ER from a self-reported questionnaire (Frequency Scale for Symptoms of GERD). Secondary end points were ulcer healing rate at 5 weeks, incidence of pain, improvement rate of symptoms in those who started PPI therapy because of GERD-like symptoms in the non-PPI group, and adverse events.

RESULTS

No significant difference was observed in the incidence of GERD-like symptoms after ER between the non-PPI and PPI groups (30 % vs 34 %, respectively). No significant differences were observed in the ulcer healing rate at 5 weeks (84 % vs 85 %) and incidence of pain within 1 week (36 % vs 45 %). In nine of ten patients (90 %) who started PPI therapy because of GERD-like symptoms in the non-PPI group, PPI administration relieved GERD-like symptoms. No adverse events related to PPI administration were observed.

CONCLUSION

PPI therapy is not efficacious in reducing symptoms and did not promote healing of ulcers in patients undergoing ER for ESCC.

Dietary vitamin D3 improves postprandial hyperglycemia in aged mice

Type 2 Diabetes is closely associated with our daily diets and has become a global health problem with an increasing number of patients. Recent observational and randomized studies on vitamin D3 suggested that higher plasma 25-hydroxyvitamin D3 [25(OH)D3] concentrations and more vitamin D3 intake are associated with lower risk of type 2 diabetes, which is characterized by postprandial hyperglycemia due to inappropriate glucose stimulated insulin secretion (GSIS) and its age-dependent increase of onset. However, rapid action of dietary vitamin D3 on the postprandial glucose profile has not been analyzed. When vitamin D3 is orally ingested in mice aged 12-14 weeks during an oral glucose tolerance test (OGTT), the serum glucose profile was not changed. In contrast, when OGTT was performed with old mice aged 30-34 weeks, the glucose profile was dramatically improved with increased insulin secretion, suggesting that orally ingested vitamin D3 potentiated GSIS in aged mice. Interestingly, there was also a significant increase in plasma GLP-1 in these aged mice. Our results suggest that orally ingested dietary vitamin D3 in aged mice improves glucose metabolism as a GLP-1 enhancer.

Tumorigenic risk of human induced pluripotent stem cell explants cultured on mouse SNL76/7 feeder cells

The potential for tumor formation from transplanted human induced pluripotent stem cell (hiPSC) derivatives represents a high risk in their application to regenerative medicine. We examined the genetic origin and characteristics of tumors, that were formed when 13 hiPSC lines, established by ourselves, and 201B7 hiPSC from Kyoto University were transplanted into severe combined immune-deficient (SCID) mice. Though teratomas formed in 58% of mice, five angiosarcomas, one malignant solitary fibrous tumor and one undifferentiated pleomorphic sarcoma formed in the remaining mice. Three malignant cell lines were established from the tumors, which were derived from mitomycin C (MMC)-treated SNL76/7 (MMC-SNL) feeder cells, as tumor development from fusion cells between MMC-SNL and hiPSCs was negative by genetic analysis. While parent SNL76/7 cells produced malignant tumors, neither MMC-SNL nor MMC-treated mouse embryo fibroblast (MEF) produced malignant tumors. When MMC-SNL feeder cells were co-cultured with hiPSCs, growing cell lines were generated, that expressed genes similar to the parent SNL76/7 cells. Thus, hiPSCs grown on MMC-SNL feeder cells have a high risk of generating feeder-derived malignant tumors. The possible mechanism(s) of growth restoration and the formation of multiple tumor types are discussed with respect of the interactions between MMC-SNL and hiPSC.

Persistent fever and weight loss due to an interleukin-6-producing adrenocortical oncocytoma in a girl--review of the literature

Adrenocortical oncocytomas are rarely reported, occur almost exclusively in adults, and are mostly nonfunctional. Here, we report an interleukin-6 (IL-6)-producing adrenocortical oncocytoma in an 11-year-old girl presenting with fever, body weight loss, and increased levels of inflammatory markers and serum IL-6. Imaging studies revealed a 4-cm mass in the left adrenal gland. After complete resection, laboratory findings returned to normal. Histology was consistent with adrenocortical oncocytoma, and the tumor cells stained positive for IL-6.

CONCLUSION

IL-6-producing adrenocortical oncocytoma should be included in the differential diagnosis and imaging studies should be performed in patients presenting with persistent fever of unknown origin and high levels of inflammatory markers.

Roles for corticotropin-releasing factor receptor type 1 in energy homeostasis in mice

OBJECTIVE

Expression of corticotropin-releasing factor type 1 receptor (CRFR1) has been shown on pancreatic β cells, and its activation potentiates glucose-stimulated insulin secretion (GSIS). However, the roles of CRFR1 in energy metabolism beyond insulin release remain elusive.

MATERIALS/METHODS

We characterized the metabolic phenotypes of mice lacking CRFR1 (CRFR1KO mice) under conditions of energy excess.

RESULTS

When fed a normal diet, the glucose profile of CRFR1KO mice in response to a glucose tolerance test was similar to that of wild-type (WT) mice, while serum insulin levels were significantly lower in CRFR1KO mice, reflecting high insulin sensitivity in part due to very low glucocorticoid levels. Histology of the pancreas revealed islet hypoplasia in CRFR1KO mice, suggesting a role of CRFR1 in maintaining the β cell mass in a manner similar to incretins. In response to a high-fat diet, CRFR1KO mice showed insulin resistance, but serum insulin levels during glucose challenge remained at a low level, indicating defective GSIS. In addition, CRFR1KO mice showed resistance to diet-induced obesity and hepatic steatosis. Although total food intake was not different between CRFR1KO and WT mice, oxygen consumption was significantly increased in CRFR1KO mice. The increased energy expenditure may explain the lean phenotype of CRFR1KO mice under conditions of energy excess.

CONCLUSIONS

Our results suggest that CRFR1 plays important roles in whole body energy homeostasis, providing compelling evidence of the close relationship between energy homeostasis and the function of the hypothalamic-pituitary-adrenal axis.

Structures of the reaction products of the AZADO radical with TCNQF4 or thiourea

While an addition product was formed by the reaction of AZADO (2-azaadamantane N-oxyl) with TCNQF₄ (2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane), the reaction of AZADO with thiourea provided an inclusion compound, in which AZADO molecules are incorporated in cylindrical channels formed by thiourea molecules.

Successful treatment with pulse cyclophosphamide of a steroid-refractory hepatitic variant of liver acute graft-vs.-host disease in a child

A 13-yr-old boy with recurrent acute myeloid leukemia underwent HSCT using cells from an unrelated donor who matched all HLA antigens except one. Forty-two days later, the patient developed a steroid-refractory hepatitic variant of liver GVHD with peak ALT and T.Bil values of 1406 mU/mL and 10.4 mg/dL, respectively. He was successfully treated with pulse Cy (1000 mg/dose × one day) without a change in chimerism being observed or acquiring an infection. All immunosuppressant therapies could be discontinued 12 months after HSCT. Two yr after HSCT, the patient remains in CR without chronic GVHD. This single case report suggests that pulse Cy may be a promising therapy for steroid-refractory GVHD, especially hepatitic GVHD, but needs to be further tested in clinical trials.