Single-Cell Transcriptomic Analysis of Epstein-Barr Virus-Associated Hemophagocytic Lymphohistiocytosis.

Epstein-Barr virus (EBV) infection can lead to infectious mononucleosis (EBV-IM) and, more rarely, EBV-associated hemophagocytic lymphohistiocytosis (EBV-HLH), which is characterized by a life-threatening hyperinflammatory cytokine storm with immune dysregulation. Interferon-gamma (IFNγ) has been identified as a critical mediator for primary HLH; however, the detailed role of IFNγ and other cytokines in EBV-HLH is not fully understood. In this study, we used single-cell RNA sequencing to characterize the immune landscape of EBV-HLH and compared it with EBV-IM. Three pediatric patients with EBV-HLH with different backgrounds, one with X-linked lymphoproliferative syndrome type 1 (XLP1), two with chronic active EBV disease (CAEBV), and two patients with EBV-IM were enrolled. The TUBA1B + STMN1 + CD8 + T cell cluster, a responsive proliferating cluster with rich mRNA detection, was explicitly observed in EBV-IM, and the upregulation of SH2D1A-the gene responsible for XLP1-was localized in this cluster. This proliferative cluster was scarcely observed in EBV-HLH cases. In EBV-HLH cases with CAEBV, upregulation of LAG3 was observed in EBV-infected cells, which may be associated with an impaired response by CD8 + T cells. Additionally, genes involved in type I interferon (IFN) signaling were commonly upregulated in each cell fraction of EBV-HLH, and activation of type II IFN signaling was observed in CD4 + T cells, natural killer cells, and monocytes but not in CD8 + T cells in EBV-HLH. In conclusion, impaired responsive proliferation of CD8 + T cells and upregulation of type I IFN signaling were commonly observed in EBV-HLH cases, regardless of the patients' background, indicating the key features of EBV-HLH.

Assessment of patients' characteristics associated with the efficacy and safety of oral valganciclovir treatment for infants with symptomatic congenital cytomegalovirus disease.

INTRODUCTION: Insurance coverage for oral valganciclovir (VGCV) began in Japan in April 2023 on the basis of results, including our clinical trials for symptomatic congenital cytomegalovirus (CMV) disease. The VGCV treatment is available throughout Japan, so clinicians must consider the likelihood of hearing improvement and the possibility of neutropenia before dosing. MATERIALS AND METHODS: We performed a substudy of an investigator-initiated, single-arm, prospective, multicenter, clinical trial in which 24 infants with symptomatic congenital CMV disease were orally administered 16 mg/kg VGCV twice daily for 6 months as an intervention. We examined the infants' baseline characteristics associated with improved hearing impairment or a severely reduced neutrophil count. RESULTS: Of the 24 patients, 4 had normal hearing on assessment of their ear with the best hearing. Hearing impairment improved in 14 patients and did not respond to VGCV treatment in 6 patients at the 6-month hearing assessment. CMV DNA levels in plasma at baseline were higher in patients in whom hearing did not respond to treatment. A neutrophil count <500/mm3 occurred in 5 (21%) patients for the first 6 weeks and in 8 (33%) patients for the first 6 months. A neutrophil count at screening and the lowest neutrophil count over the 6 months showed the highest correlation (r = 0.477, p = 0.019). CONCLUSIONS: Infants with a low plasma viral load at screening tend to have an improvement in hearing impairment. Clinicians should be aware of neutropenia during VGCV treatment particularly in patients with a low neutrophil count during screening.

Analysis of Cytokine Profiles in Pediatric Myocarditis Multicenter Study.

Acute myocarditis (AM) is an inflammatory disease of the heart muscle that can progress to fulminant myocarditis (FM), a severe and life-threatening condition. The cytokine profile of myocarditis in children, especially in relation to fulminant myocarditis, is not well understood. This study aims to evaluate the cytokine profiles of acute and fulminant myocarditis in children. Pediatric patients diagnosed with myocarditis were included in the study. Cytokine levels were measured using a multiplexed fluorescent bead-based immunoassay. Statistical analysis was performed to compare patient characteristics and cytokine levels between FM, AM, and healthy control (HC) groups. Principal component analysis (PCA) was applied to cytokine groups that were independent among the FM, AM, and HC groups. The study included 22 patients with FM and 14 with AM patients. We identified four cytokines that were significantly higher in the FM group compared to the AM group: IL1-RA (p = 0.002), IL-8 (p = 0.005), IL-10 (p = 0.011), and IL-15 (p = 0.005). IL-4 was significantly higher in the AM group compared to FM and HC groups (p = 0.006 and 0.0015). PDGF-AA, and VEGF-A were significantly lower in the FM group than in the AM group (p = 0.013 and <0.001). Similar results were obtained in PCA. Cytokine profiles might be used to differentiate pediatric FM from AM, stratify severity, and predict prognosis. The targeted therapy that works individual cytokines might provide a potential treatment for reducing the onset of the FM and calming the condition, and further studies are needed.

A GIRL WITH ADENOVIRUS TYPE 2 INDUCED INTERSTITIAL PNEUMONITIS ACUTELY EXACERBATED WITH PRIMARY HUMAN HERPESVIRUS 7 INFECTION.

We encountered a previously healthy 3-year-old girl with interstitial pneumonitis that initially developed due to human adenovirus type 2 infection and exacerbated by primary human herpesvirus 7 infection. A comprehensive serum biomarker analysis showed patterns that differed by viral infection, suggesting that respiratory and lymphotropic viral infections might have different pathophysiology in interstitial pneumonitis.

Association between aspirin dose and outcomes in patients with acute Kawasaki disease: a nationwide retrospective cohort study in Japan.

This study aimed to identify the appropriate dose of aspirin to be prescribed to patients with acute Kawasaki disease (KD). Using a Japanese national inpatient database, we identified patients with KD treated with intravenous immunoglobulin between 2010 and 2021.The outcomes included the occurrence of coronary artery abnormalities and intravenous immunoglobulin resistance, length of hospital stay, and medical costs. Restricted cubic spline functions were performed to examine the association between aspirin dose and the outcomes. Data of 82,109 patients were extracted from the database. Non-linear associations were observed between aspirin dose and the outcomes. In comparison with an aspirin dose of 30 mg/kg/day, the odds ratio (95% confidence interval) for coronary artery abnormalities was 1.40 (1.13-1.75) at 5 mg/kg/day. An aspirin dose of ≥ 30 mg/kg/day did not significantly change the odds ratio for coronary artery abnormalities. Intravenous immunoglobulin resistance was significantly lower at a dose of 60 mg/kg/day or higher. CONCLUSION:  The results showed no significant association between aspirin escalation over standard-dose and coronary artery abnormalities in patients with acute KD. High-dose aspirin showed the potential to reduce hospital stay and medical costs without increasing complications. WHAT IS KNOWN: • Aspirin is used as a standard treatment together with intravenous immunoglobulin for acute Kawasaki disease (KD). However, few studies have shown the most effective dosage of aspirin to prevent coronary artery abnormalities (CAAs). WHAT IS NEW: • There was no significant association between aspirin dose escalation and CAAs in patients with acute KD.

Development of recombinant rotavirus carrying herpes simplex virus 2 glycoprotein D gene based on reverse genetics technology.

Vaccine development for herpes simplex virus 2 (HSV-2) has been attempted, but no vaccines are yet available. A plasmid-based reverse genetics system for Rotavirus (RV), which can cause gastroenteritis, allows the generation of recombinant RV containing foreign genes. In this study, we sought to develop simian RV (SA11) as a vector to express HSV-2 glycoprotein D (gD2) and evaluated its immunogenicity in mice. We generated the recombinant SA11-gD2 virus (rSA11-gD2) and confirmed its ability to express gD2 in vitro. The virus was orally inoculated into suckling BALB/c mice and into 8-week-old mice. Serum IgG and IgA titers against RV and gD2 were measured by ELISA. In the 8-week-old mice inoculated with rSA11-gD2, significant increases in not only antibodies against RV but also IgG against gD2 were demonstrated. In the suckling mice, antibodies against RV were induced, but gD2 antibody was not detected. Diarrhea observed after the first inoculation of rSA11-gD2 in suckling mice was similar to that induced by the parent virus. A gD2 expressing simian RV recombinant, which was orally inoculated, induced IgG against gD2. This strategy holds possibility for genital herpes vaccine development.

The electrophysiological index can effectively predict subsequent coronary artery aneurysm in children with Kawasaki disease.

Objectives: The Gunma score is used to predict the severity of Kawasaki disease (KD), including coronary artery aneurysm (CAA) as a cardiac complication, in Japan. Additionally, the characteristic ratio of ventricular repolarization (T-peak to T-end interval to QT interval [Tp-e/QT]) on a surface electrocardiogram reflects myocardial inflammation. This study aimed to determine whether the Tp-e/QT can be used to predict CAA in children with KD. Methods: We analyzed chest surface electrocardiograms of 112 children with KD before receiving intravenous immunoglobulin therapy using available software (QTD; Fukuda Denshi, Tokyo, Japan). Results: The Tp-e/QT (lead V5) was positively correlated with the Gunma score (r=0.352, p<0.001). The Tp-e/QT was larger in patients with CAA (residual CAA at 1 month after onset) than in those without CAA (0.314±0.026 versus 0.253±0.044, p=0.003). A receiver operating characteristic curve analysis was performed to assess whether the Gunma score and Tp-e/QT could predict subsequent CAA. The area under the curve of the Gunma score was 0.719 with the cutoff set at 5 points. The area under the curve of the Tp-e/QT was 0.892 with a cutoff value of 0.299. The fit of the prediction models to the observed probability was tested by the Hosmer-Lemeshow test with calibration plots using Locally weighted scatterplot smoothing (LOESS) fit. The Gunma score (p=0.95) and Tp-e/QT (p=0.95) showed a good fit. Conclusions: The Tp-e/QT is a useful biomarker in predicting coronary aneurysm complications in KD.

Serological analysis of severe acute respiratory syndrome coronavirus 2 infection in children with Kawasaki disease.

Multisystem inflammatory syndrome in children (MIS-C) was reported as a severe complication of coronavirus disease 2019; an infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and was suggested to be associated with Kawasaki disease (KD) in terms of severe systemic inflammation and mucocutaneous symptoms. Because severe gastrointestinal symptoms and systemic shock are more frequently observed with MIS-C, patients with mild MIS-C might have been diagnosed with KD. In this study, titers of IgG antibodies against the SARS-CoV-2 S (S-IgG) and N proteins (N-IgG) were measured in 99 serum samples collected from patients with KD treated between January 2020 and December 2021 to evaluate the relationship between KD and SARS-CoV-2 infection. S-IgG were detected in only one patient out of 99 patients. This patient had coronavirus disease 2019 (COVID-19) 10 months before KD onset, and was unlikely MIS-C. According to characters of S-IgG and N-IgG, the patients was unlikely infected with SARS-CoV-2 just before the onset of KD. In addition to this study, the 26th Nationwide Survey and previous studies showed an association between KD and SARS-CoV-2 to be unlikely. In conclusion, SARS-CoV-2 infection was not observed in patients with KD until Delta predominance in Japan by the method of detecting SARS-CoV-2 IgG.

Medical records as screening tools for child death review in Japan.

BACKGROUND: Although many child death review (CDR) systems have been developed in Japan, the optimal system is still being identified. The aim of this study is to identify the etiologies of child deaths and to propose a screening method for initiating the CDR process in Japan. METHODS: Clinical medical records (CMRs) in hospitals and autopsy records were surveyed for cases of deaths of children aged less than 15 years between 2014 and 2016 in Aichi Prefecture, Japan. The data were analyzed in three steps, and the findings were compared with the vital statistics. RESULTS: Of the 695 children whose death certificates were submitted to Aichi Prefecture, 590 could be traced to pediatric care hospitals. The distribution of causes of death was slightly different from the vital statistics, with 11.5% dying of extrinsic causes and 19.7% dying of unknown causes. Maltreatment was suspected in 64 cases, which was much higher than that in government statistics. Overall, 158 (26.8%) deaths were considered preventable. The number of unnatural deaths, which might be screened in, was calculated as 172 (29.2%) in the vital statistics, whereas the survey of CMRs revealed that 241 (40.8%) to 282 (47.8%) should be screened in. CONCLUSIONS: Surveying CMRs in hospitals may be a suitable method to detect and screen deaths to start the CDR process in Japan.

Association between residents' scholarly activities and publication requirement policy.

BACKGROUND: Scholarship is recognized as important in residency training worldwide. The Japan Pediatric Society (JPS) enacted a reform in 2017 to require publication of an article as a prerequisite for taking the board certification test, with the goal of increasing scholarly activity. METHODS: The purpose of this study was to provide a detailed description of the trends in residents' scholarly activities related to the JPS reform. A secondary analysis was performed on the cross-sectional database of pediatrics residents who took the certification test in 2015-2018. RESULTS: The enrolled participants were 2399 residents of which 79.7% passed the test. Publication of any type of article increased significantly (21%-22% to 100%; 0.1 to 0.3/person-year) after the implementation of the JPS reform, whereas academic presentations did not (89% to 91%; 1.2 to 1.3/person-year), both in terms of the percentage of the number of those who created them and the average rate of research production. Not only Japanese articles (11%-13% to 49%-53%; 0.04 to 0.15-0.17/person-year) or case reports (10%-14% to 51%-52%; 0.03-0.05 to 0.16-0.17/person-year), but also English articles (4%-5% to 15%-16%; 0.01-0.02 to 0.05/person-year) and original articles (5% to 11%-17%; 0.01 to 0.03-0.05/person-year) increased significantly. The number of each type of article publication was correlated with success in the board certification test (odds ratio 1.5-1.8). CONCLUSIONS: Scholarly activities of pediatrics residents were enhanced by the JPS implementation of the article requirement policy, which is crucial to fostering a scholarly culture. The most efficient measures to promote scholarship need to be persistently investigated.

Similarities in rotavirus vaccine viral shedding and immune responses in pairs of twins.

Objectives: Intestinal rotavirus (RV) vaccine replication and host immune response are suggested to be affected by several factors, including maternal antibodies, breastfeeding history, and gut microbiome, which are thought to be similar in pairs of twins. The aim of this study was to determine whether viral shedding from the fecal RV vaccine strain Rotarix® (RV1) and IgG and IgA responses to RV show similarity in pairs of twins. Methods: Quantitative reverse transcription polymerase chain reaction specific to RV vaccine strain RV1 was used to monitor fecal RV1 viral shedding. RV IgG and IgA titers were measured using an in-house enzyme-linked immunosorbent assay. Fecal RV1 viral shedding and immune responses were compared between twins and singletons with mixed effects and fixed effects models. Results: A total of 347 stool and 54 blood samples were collected from four pairs of twins and twelve singletons during the observation period. Although the kinetics of fecal RV1 viral shedding and immune responses differed among vaccinated individuals, they appeared to be similar within twin pairs. RV shedding after the first dose (P=0.049) and RV IgG titers during the entire observation period (P=0.015) had a significantly better fit in the fixed effect model that assumed that twins have the same response versus the model that assumed that twins have a different response. Conclusions: The similarity of RV vaccine viral replication in intestine and host immune responses in twin pairs was demonstrated using statistical analysis.

Case report: A case of severe retropharyngeal edema after COVID-19 successfully treated with intravenous immunoglobulin.

Multisystem inflammatory syndrome in children (MIS-C) has been widely reported, mainly in Western countries. The clinical features of MIS-C and Kawasaki disease are similar. The latter is common in Asian countries, including Japan. Meanwhile, the incidence of MIS-C seems to be low in Japan. Retropharyngeal edema is relatively common in older patients with Kawasaki disease and has been reported in a few patients with MIS-C. We describe a case of severe retropharyngeal edema after coronavirus disease 2019 (COVID-19) that improved quickly with high-dose of intravenous immunoglobulin treatment. Onset of retropharyngeal edema was 3 weeks after COVID-19. The patient received appropriate intravenous antibiotics for 5 days, but his symptoms worsened. Therefore, we suspected that his retropharyngeal edema was caused by suspected MIS-C even though he did not have the typical clinical symptoms of suspected MIS-C such as gastrointestinal symptoms and shock. Retropharyngeal edema was refractory to antibiotic therapy but lessened quickly with high-dose immunoglobulin therapy, without other typical clinical manifestations of MIS-C, suggesting that early immunoglobulin therapy might prevent the progression of MIS-C.

Changes in trends of pediatric ß- and γ-herpesvirus infections during the COVID-19 pandemic: A single-center observational study.

Nonpharmaceutical interventions (NPIs) to control COVID-19 have decreased the incidence of many pediatric infectious diseases. The epidemiology of ß- and γ-herpesvirus infections might have been affected by NPIs. The aim of this study was to elucidate changes in trends in ß- and γ-herpesvirus infections and complex febrile seizures (cFS) of viral etiology before and during the COVID-19 pandemic. Between April 2017 and March 2021, febrile children aged ≤5 years were enrolled. Detection of EBV, CMV, HHV-6B, and HHV-7 DNA in serum was performed using real-time PCR. The epidemiology of viral infections and cFS were compared between the prepandemic and pandemic periods. During the observation period, 1432 serum samples were collected. The mean number of febrile children decreased during the pandemic period, but the number of patients with HHV-6B infection increased from 35 (9.3% of all febrile children) per year before the pandemic to 43 (15.5%) during the pandemic. The change in the proportion of patients with primary HHV-6B infection was 6.50% (95% confidence interval [CI], 2.05%-11.3%; p = 0.0047). The mean number of patients with cFS decreased during the pandemic period, but the number of patients with HHV-6B-associated cFS was stable throughout the observation period. Therefore, the change in proportion of patients with cFS caused by primary HHV-6B infection was 49.5% (95% CI, 12.2%-60.5%; p = 0.0048). The disease burden of primary HHV-6B infection among patients in the emergency room remained unchanged, with a significant increase in the relative proportion after the COVID-19 pandemic began.

Future Perspective for ALK-Positive Anaplastic Large Cell Lymphoma with Initial Central Nervous System (CNS) Involvement: Could Next-Generation ALK Inhibitors Replace Brain Radiotherapy for the Prevention of Further CNS Relapse?

Central nervous system (CNS) involvement in anaplastic large cell lymphoma (ALCL) at diagnosis is rare and leads to poor prognosis with the use of the standard ALCL99 protocol alone. CNS-directed intensive chemotherapy, such as an increased dose of intravenous MTX, increased dose of dexamethasone, intensified intrathecal therapy, and high-dose cytarabine, followed by cranial irradiation, has been shown to improve survival in this population. In this paper, the authors describe a 14-year-old male with an intracranial ALCL mass at onset who received CNS-directed chemotherapy followed by 23.4 Gy of whole-brain irradiation. After the first systemic relapse, the CNS-penetrating ALK inhibitor, alectinib, was applied; it has successfully maintained remission for 18 months without any adverse events. CNS-penetrating ALK inhibitor therapy might prevent CNS relapse in pediatric ALK-positive ALCL. Next-generation ALK inhibitors could be introduced as a promising treatment option, even for primary ALCL with CNS involvement, which could lead to the omission of cranial irradiation and avoid radiation-induced sequalae. Further evidence of CNS-penetrating ALK inhibitor combined therapy for primary ALK-positive ALCL is warranted to reduce radiation-induced sequalae in future treatments.

Retrospective immunohistochemical analysis of human cytomegalovirus infection in the placenta and its association with fetal growth restriction.

Objectives: Fetal human cytomegalovirus (HCMV) infection might be involved in fetal growth restriction (FGR). Maternal serostatus and the prevalence of congenital HCMV infection are affected by various factors, such as socioeconomic status and ethnicity. Therefore, the prevalence of congenital HCMV-related FGR should be examined in each region. Methods: Seventy-eight cases of FGR with delivery between January 2012 and January 2017 at Fujita Health University Hospital were studied. Twenty-one non-FGR cases were also included as a control group. Placental sections obtained from the FGR and control cases were immunostained with two primary antibodies for detecting immediate early antigens. Results: Nineteen placental samples from FGR cases with another etiology were excluded. Finally, 59 placental samples from FGR cases of unknown etiology were included in the pathological analysis. Four of 59 (6.8%) placental samples were positive for HCMV antigen. All four positive cases were stained with the M0854 antibody, and there were no positive case with the MAB810R antibody. Neither maternal nor infantile clinical features were different between the HCMV-positive and -negative FGR cases. A pathological examination showed a hematoma in three of four cases and infarction in two of four cases. Conclusions: HCMV antigen was detected in 6.8% of placental samples obtained from FGR cases without an obvious etiology. No remarkable maternal or neonatal clinical features discriminated HCMV-related FGR from FGR due to other causes. Vasculitis and inflammation might play important roles in the pathogenesis of HCMV-related FGR.

Dry loop-mediated isothermal amplification assay for detection of SARS-CoV-2 from clinical specimens.

Objectives: To establish a point-of-care test for coronavirus disease 2019 (COVID-19), we developed a dry loop-mediated isothermal amplification (LAMP) method to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA. Methods: We carried out reverse transcription (RT)-LAMP using the Loopamp SARS-CoV-2 Detection kit (Eiken Chemical, Tokyo, Japan). The entire mixture, except for the primers, is dried and immobilized inside the tube lid. Results: To determine the specificity of the kit, 22 viruses associated with respiratory infections, including SARS-CoV-2, were tested. The sensitivity of this assay, determined by either a real-time turbidity assay or colorimetric change of the reaction mixture, as evaluated by the naked eye or under illumination with ultraviolet light, was 10 copies/reaction. No LAMP product was detected in reactions performed with RNA from any pathogens other than SARS-CoV-2. After completing an initial validation analysis, we analyzed 24 nasopharyngeal swab specimens collected from patients suspected to have COVID-19. Of the 24 samples, 19 (79.2%) were determined by real-time RT-PCR analysis as being positive for SARS-CoV-2 RNA. Using the Loopamp SARS-CoV-2 Detection kit, we detected SARS-CoV-2 RNA in 15 (62.5%) of the 24 samples. Thus, the sensitivity, specificity, positive predictive value, and negative predictive values of the Loopamp 2019-CoV-2 detection reagent kit were 78.9%, 100%, 100%, and 55.6%, respectively. Conclusions: The dry LAMP method for detecting SARS-CoV-2 RNA is fast and easy to use, and its reagents can be stored at 4°C, solving the cold chain problem; thus, it represents a promising tool for COVID-19 diagnosis in developing countries.

Trend in the Numbers of Hospitalized Patients With Varicella, Herpes Zoster, and Ischemic Stroke in Japanese Individuals <20 Years of Age Before and After Implementation of Universal Varicella Vaccination.

Several studies have shown an association between varicella-zoster virus infection and ischemic stroke. We analyzed the trends in the numbers of patients with varicella, herpes zoster and ischemic stroke before and after the universal vaccination program using a Japanese database of hospitalized patients. The number of patients with varicella decreased but those of herpes zoster and ischemic stroke did not change.

Analysis of the reliability of rapid diagnostic tests for varicella, including breakthrough cases.

In the era of universal varicella vaccination, diagnosis of varicella is challenging, especially for breakthrough cases. We sought to clarify the reliability of direct varicella-zoster virus (VZV) loop-mediated isothermal amplification (LAMP) and DermaQuick® VZV using the immunochromatography technique as rapid diagnostic tests for varicella. In addition, the usefulness of saliva as a sample type for direct LAMP was investigated. Among the 46 enrolled patients with suspected VZV infection, 31 patients (67.3%) were positive for the nucleic acid test based on real-time PCR from skin swab samples. Direct LAMP of skin swabs was positive in 29 (63.0%) of 46 patients. DermaQuick® VZV was positive in 25 (54.3%) of 46 patients. VZV DNA was detected in only 48.4% of oral swabs with the direct LAMP method. With real-time polymerase chain reaction (PCR) as the standard for diagnosing varicella, the sensitivity and specificity of DermaQuick® VZV were 80.7% and 100%, respectively. The sensitivity and specificity of direct LAMP from skin swabs were 93.6% and 100%, respectively. The sensitivity and specificity of real-time PCR for DNA extracted from oral swabs were 74.2% and 93.3%, respectively. Thus, oral swab samples are not suitable for breakthrough varicella diagnosis. Although DermaQuick® VZV is considered the most convenient point-of-care test for varicella, its sensitivity and specificity were lower than those of direct VZV LAMP.

Acute and Postacute Clinical Characteristics of Coronavirus Disease 2019 in Children in Japan.

BACKGROUND: The clinical features of coronavirus disease 2019 (COVID-19) in children have been changing because of the emergence and rapid spread of variants of concern (VOC). The increase in cases infected with VOC has brought concern with persistent symptoms after COVID-19 in children. This survey aimed to analyze the clinical manifestations and persistent symptoms of pediatric COVID-19 cases in Japan. METHODS: We analyzed the clinical manifestations of pediatric COVID-19 cases reported between February 2020 and April 2022 in Japan, using a dedicated database updated voluntarily by the members of the Japan Pediatric Society. Using the same database, we also analyzed persistent symptoms after COVID-19 in children who were diagnosed between February 2020 and November 2021. RESULTS: A total of 5411 and 1697 pediatric COVID-19 cases were included for analyzing clinical manifestations and persistent symptoms, respectively. During the Omicron variant predominant period, the percentage of patients with seizures increased to 13.4% and 7.4% in patient groups 1-4 and 5-11 years of age, respectively, compared with the pre-Delta (1.3%, 0.4%) or Delta period (3.1%, 0.0%). Persistent and present symptoms after 28 days of COVID-19 onset were reported in 55 (3.2%). CONCLUSIONS: Our survey showed that the rate of symptomatic pediatric COVID-19 cases increased gradually, especially during the Omicron variant predominant period, and a certain percentage of pediatric cases had persistent symptoms. Certain percentages of pediatric COVID-19 patients had severe complications or prolonged symptoms. Further studies are needed to follow such patients.

Transport and Golgi organization 2 deficiency with a prominent elevation of C14:1 during a metabolic crisis: A case report.

Mutations in transport and Golgi organization 2 homolog (TANGO2) have recently been described as a cause of an autosomal recessive syndrome characterized by episodes of metabolic crisis associated with rhabdomyolysis, cardiac arrhythmias, and neurodegeneration. Herein, we report a case of a one-and-a-half-year-old Japanese girl, born to nonconsanguineous parents, who presented with metabolic crisis characterized by hypoglycemia with hypoketonemia, rhabdomyolysis, lactic acidosis, and prolonged corrected QT interval (QTc) at the age of 6 months. Acylcarnitine analysis during the episode of crisis showed prominent elevation of C14:1, suggesting very-long-chain acyl-CoA dehydrogenase (VLCAD) deficiency. In addition, worsening rhabdomyolysis was observed after intravenous administration of L-carnitine. VLCAD deficiency was initially suspected; however, the enzyme activity in lymphocytes was only mildly decreased at the gene carrier level, and no mutation in the VLCAD gene (ADADVL) was detected. Subsequently, acylcarnitine analysis was nonspecific at 17-h fasting and almost normal during the stable phase. Eventually, a trio whole-exome sequencing revealed a compound heterozygous variant of two novel variants in the TANGO2 gene, a missense variant, and a deletion of exon 7. This is the first case of TANGO2 deficiency in Asians. Our case suggests that elevated C14:1 may be seen in severe metabolic crises and that the use of L-carnitine should be avoided during metabolic crises.