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.

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.

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.

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.

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.

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.

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.

Correlation of cytomegalovirus viral load between whole blood and plasma of congenital cytomegalovirus infection under valganciclovir treatment.

BACKGROUND: Congenital cytomegalovirus (CMV) infection (cCMV) can cause sensorineural hearing loss and neurodevelopmental disabilities in children. Oral valganciclovir (VGCV) therapy has been reported to improve long-term audiological and neurodevelopmental outcomes in patients with cCMV. The levels of CMV DNA in whole blood have been monitored in previous studies. However, quantitative methods using whole blood have not been standardized. Recently, the plasma viral load has been standardized and widely used in CMV-associated diseases. METHODS: CMV viral loads in whole blood and plasma were serially measured in 24 patients with a confirmatory diagnosis of cCMV during oral VGCV therapy using an in-house real-time PCR assay. Plasma samples were assayed using the Cobas 6800 system (Roche Diagnostics) in addition to an in-house assay. RESULTS: Plasma CMV viral loads were remarkably decreased at the end of therapy compared to before therapy. A significant correlation of CMV levels between whole blood and plasma was observed (Spearman's ρ = 0.566). The levels of CMV DNA before therapy were significantly correlated with the period of decreasing the viral loads to below the detection limit, not only in whole blood (Spearman's ρ = 0.901) but also in plasma (Spearman, ρ = 0.804). Finally, CMV viral loads between the in-house assay and commercially available standardized assay in 75 plasma samples with positive PCR results for CMV were compared; a significant correlation was observed between the results of both assays. CONCLUSIONS: There was a significant correlation between the two assays (Spearman, ρ = 0.882), suggesting that CMV plasma viral loads measured by the standardized assay are widely used to monitor the levels of CMV DNA in patients with cCMV during oral VGCV therapy.

Anti-N-methyl-D-aspartate receptor encephalitis with concurrent human herpes virus-6A deoxyribonucleic acid detection: An autopsy case.

We report an autopsy case of anti-N-methyl-D-aspartate (NMDA) receptor (NMDAR) encephalitis with concurrent human herpes virus-6 (HHV-6) A deoxyribonucleic acid (DNA) detection in cerebrospinal fluid (CSF). A 38-year-old previously healthy Japanese man presented with a generalized seizure. Brain magnetic resonance imaging (MRI) findings were unremarkable, but CSF revealed pleocytosis. On Day 11, HHV-6 DNA was detected in CSF, and IgG antibodies against the NR1 subunit of the NMDAR (GluN1) were subsequently detected. Since HHV-6 encephalitis was initially suspected, the patient was treated with foscarnet and ganciclovir, but the HHV-6A copy number increased from 200 (Day 22) to 2000 copies/mL (Day 47), and the therapy was ineffective. As typical symptoms of anti-NMDAR encephalitis developed, we changed the patient's treatment to combat anti-NMDAR encephalitis. He was repeatedly treated with first-line immunotherapy, and GluN1 antibody titer decreased. He was not treated with second-line immunotherapy because of recurrent infections; he died on Day 310. Postmortem examinations did not show systemic tumors. Microscopic examination of the brain revealed only severe neuronal rarefaction in the hippocampal cornu ammonis (CA) 3-4 areas with gliosis. Early initiation of aggressive immunotherapy may be required in a refractory case of anti-NMDAR encephalitis, even with HHV-6A DNA detection, because the significance of this concurrent detection in autoimmune encephalitis remains unclear.

Systemic herpes simplex virus infection in a child with eczema herpeticum.

Eczema herpeticum (EH) is a disseminated cutaneous infection with herpes simplex virus (HSV) that develops in patients with atopic dermatitis. The kinetics and clinical significance of HSV viremia in EH are poorly understood. Herein, we report HSV DNAemia in a child with EH 12 months after the completion of chemotherapy for Hodgkin lymphoma.

Endogenization and excision of human herpesvirus 6 in human genomes.

Sequences homologous to human herpesvirus 6 (HHV-6) are integrated within the nuclear genome of about 1% of humans, but it is not clear how this came about. It is also uncertain whether integrated HHV-6 can reactivate into an infectious virus. HHV-6 integrates into telomeres, and this has recently been associated with polymorphisms affecting MOV10L1. MOV10L1 is located on the subtelomere of chromosome 22q (chr22q) and is required to make PIWI-interacting RNAs (piRNAs). As piRNAs block germline integration of transposons, piRNA-mediated repression of HHV-6 integration has been proposed to explain this association. In vitro, recombination of the HHV-6 genome along its terminal direct repeats (DRs) leads to excision from the telomere and viral reactivation, but the expected "solo-DR scar" has not been described in vivo. Here we screened for integrated HHV-6 in 7,485 Japanese subjects using whole-genome sequencing (WGS). Integrated HHV-6 was associated with polymorphisms on chr22q. However, in contrast to prior work, we find that the reported MOV10L1 polymorphism is physically linked to an ancient endogenous HHV-6A variant integrated into the telomere of chr22q in East Asians. Unexpectedly, an HHV-6B variant has also endogenized in chr22q; two endogenous HHV-6 variants at this locus thus account for 72% of all integrated HHV-6 in Japan. We also report human genomes carrying only one portion of the HHV-6B genome, a solo-DR, supporting in vivo excision and possible viral reactivation. Together these results explain the recently-reported association between integrated HHV-6 and MOV10L1/piRNAs, suggest potential exaptation of HHV-6 in its coevolution with human chr22q, and clarify the evolution and risk of reactivation of the only intact (non-retro)viral genome known to be present in human germlines.

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.

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 of steroid administration with larger coronary artery abnormalities in patients with Kawasaki disease.

We sought to elucidate the risk profiles of patients with Kawasaki disease who developed coronary artery abnormalities through a retrospective analysis with special reference to steroid treatment. Demographics of the patients were obtained from medical records, and characteristics of the coronary artery abnormalities were evaluated by echocardiography and coronary angiography, which included number, location, size, and length of coronary artery abnormalities (we evaluated by cardiac catheterisation with the American Heart Association classification with segments). We divided the patients into two groups based on steroid use and compared their characteristics and the complications of coronary artery abnormalities and cardiac events. A total of 29 patients were diagnosed with coronary artery abnormalities by echocardiography and coronary angiography during the study period (24 male; median age, 24 months [range: 2-84 months]). Eighteen patients were treated with aspirin and intravenous immunoglobulin (63%, non-steroid group), whereas 11 received aspirin and intravenous immunoglobulin plus steroids (37%, steroid group). No significant differences were found in the number and location of coronary artery abnormalities between the steroid and non-steroid groups. However, the size and number of segments for coronary artery abnormalities were significantly larger and shorter, respectively, in the steroid group (z-score: non-steroid group 6.3 versus steroid group 8.7; p < 0.01). The coronary artery abnormality segments under steroid use were also shorter (non-steroid group versus steroid group, two segments versus one segment; p = 0.02). Coronary artery abnormality size was larger in patients who used steroids than that of non-steroids. This study showed that steroid use significantly affected coronary artery abnormality size in patients with Kawasaki disease. However, cardiac complications from coronary artery abnormalities and cardiac events were comparable between the steroid and non-steroid groups. Further prospective, multicentre studies are needed to confirm these findings.

Dynamics of salivary human herpesvirus-6 and -7 shedding in pregnant women.

Reactivation of Betaherpesvirinae (Human herpesvirus 6A: HHV-6A, -6B, HHV-7) may be associated with mental illness and host fatigue. This study aimed to determine whether viral reactivation, measured by monitoring salivary viral DNA load, can be used to monitor depression in pregnant and postpartum women. Saliva samples were collected from 64 pregnant women at five points of observation periods. The HHV-6- and HHV-7-specific qPCRs were carried out to measure viral DNA load. When HHV-6 DNA was detected in saliva, nested PCR was used to discriminate between HHV-6A and -6B. In both viruses, a significant correlation was observed between detection frequency and viral DNA load in saliva. In the low-shedding group, HHV-6 DNA was significantly higher in the third trimester (p < 0.0001), the time of delivery (p = 0.0003), 1 month after birth (p = 0.0023) compared with the first trimester, and HHV-7 was at the time of delivery (p = 0.0277) and 1 month after birth (p = 0.0235). Most of the detected HHV-6 DNAs in saliva were HHV-6B. Both viral DNA loads were significantly lower (HHV-6: p = 0.0101, HHV-7: p = 0.0044) in the subjects with abnormal Edinburgh Postnatal Depression Scale (EPDS) scores. The detection rate and viral DNA load of both viruses in saliva increased after the third trimester. Salivary virus DNA shedding was significantly lower in subjects with an abnormal EPDS score.

Detection of human herpesviruses in cerebrospinal fluids collected from patients suspected of neuroinfectious diseases.

The full spectrum of human herpesviruses (HHV)-associated neuroinfectious diseases in immunocompetent adults remains unclear. Hence, we sought to elucidate the epidemiology and clinical features of these diseases. The study subjects were patients over 16 years old suspected of neuroinfectious diseases who underwent spinal tap performed by neurologists in our university hospital between April 2013 and March 2018. The presence of seven HHV DNAs in cerebrospinal fluid (CSF) was determined by real-time PCR. HHV DNAs were detected in 33 (10.2%) of the 322 patients. The most frequently detected herpesvirus was varicella zoster virus (VZV) (19 patients), followed by HHV-6 (four patients), herpes simplex virus (HSV)-1 (three patients), HSV-2 (three patients), and Epstein-Barr virus (two patients). HHV DNAs were detected in CSF collected from patients with various neuroinfectious diseases, including myelitis, peripheral neuritis, encephalitis, and meningitis. All patients with HSV-1 DNA had encephalitis, whereas all patients with HSV-2 DNA had meningitis. Eleven of the 19 patients with VZV DNA had meningitis. Patients with VZV-associated encephalitis (median age, 80 years) were significantly older than non-encephalitis patients (median age, 60.5 years) (P = 0.046). Although post-herpetic neuralgia was observed in seven (54%) of the 13 patients with VZV and without encephalitis, no such neurological sequela was observed in the four encephalitis patients. In conclusion, HHVs were associated with approximately 10% of neuroinfectious diseases in this cohort. VZV was the most common pathogen, probably due to the large number of VZV meningitis patients. In addition, patients with VZV-associated meningitis were significantly younger than patients with VZV-associated encephalitis.

Death review of children receiving medical care at home.

BACKGROUND: Children receiving home medical care need special attention to prevent unexpected death. The aim of this study was to clarify the factors contributing to death in children receiving home medical care from the child death review database. METHODS: Children receiving home medical care were enrolled from the child death review database from 2014 to 2016 in Aichi prefecture, Japan, with a population of one million children. Types of medical care and factors contributing to death were examined. RESULTS: Of the 631 children who died, 40 children (6%) were receiving home medical care (21: tracheostomy; 19: ventilator; 26: suctioning of naso-oral secretions; 19: oxygen inhalation; 32: tube feeding; 6: urethral catheterization; and 1: peritoneal dialysis). The death rate was 50 times that in the general population of children. Ten children had contributory factors that seemed to be preventable. In four children, the families could not replace the tracheostomy tubes during an accident. In three, oxygen saturation or ventilator alarms were not set appropriately. In two, an oxygen cylinder became empty. One child fell down from a seat in a car. CONCLUSIONS: Improvement of devices and correct guidance to caregivers may reduce the death rate in children receiving home medical care. IMPACT: Children receiving home medical care, such as tracheostomy care, mechanical ventilation, or tube feeding, need special attention to prevent unexpected death. In this population-based child death review, 6% of children received home medical care, and it was estimated that 1 of 100 children receiving home medical care died per year. One-quarter of the deaths could be preventable by caregiver education or development of devices.

Association between intravenous immunoglobulin dose and outcomes in patients with acute Kawasaki disease.

The most effective dosage of intravenous immunoglobulin (IVIG) to prevent coronary artery abnormalities (CAAs) in patients with acute Kawasaki disease (KD) remains unknown. This study aimed to identify the appropriate dose of IVIG to be administered to patients with acute KD, using a national inpatient database in Japan. We used the Diagnostic Procedure Combination database to identify KD patients treated with IVIG between 2010 and 2020. The primary outcome was the proportion of CAAs upon discharge. Secondary outcomes included IVIG resistance, length of stay, and medical costs. Data from 88,223 patients were extracted from the database. We found a U-shaped association between IVIG dose and the proportion of CAA, with the bottom of the curve at approximately 2.0 g/kg; the odds ratio (95% confidence interval [CI]) was 1.34 (1.26-1.43) for 1.8 g/kg and 1.80 (1.29-2.51) for 2.4 g/kg with reference to 2.0 g/kg for CAA. Similarly, IVIG dose had a U-shaped association with the proportion of IVIG resistance, with the bottom of the curve at approximately 2.0 g/kg; the odds ratio (95% CI) was 1.39 (1.36-1.42) for 1.8 g/kg and 8.95 (8.15-9.83) for 2.4 g/kg with reference to 2.0 g/kg for IVIG resistance. Additionally, IVIG dosage was found to have U-shaped associations with the length of stay and medical costs, with the bottom of the curve at approximately 2 g/kg.   Conclusions: IVIG with a dose of 2 g/kg was considered appropriate for the initial treatment of KD. What is Known: • For treatments of acute Kawasaki Disease (KD), IVIG has been the most recommended to reduce fever early and prevent complications of CAAs. Few studies have shown the most effective dosage of IVIG to be administered to prevent CAAs. What is New: • 2 g/kg intravenous immunoglobulin was considered appropriate for the initial treatment of Kawasaki disease.

An atypical case of Kawasaki disease with severe pneumonia in a neonate.

BACKGROUND: Kawasaki disease (KD) is an acute, febrile, systemic vasculitis of unknown etiology that primarily affects the coronary arteries and generally occurs at around 1 year of age. Although the diagnosis of KD is generally not difficult, it is challenging in cases of incomplete KD lacking characteristic clinical manifestations. The incidence of incomplete KD is higher in infants younger than 6 months of age. Pneumonia is an extremely rare complication of KD and can be misinterpreted as atypical pneumonia rather than KD. Herein, we report a neonate with atypical KD and severe pneumonia who required mechanical ventilation. CASE PRESENTATION: Japanese one-month-old infant had only fever and rash on admission (day 1), and he was transferred to the intensive care unit for severe pneumonia on day 2. Although pneumonia improved following intensive care, he was diagnosed with KD on day 14 because of emerging typical clinical manifestations such as fever, bulbar nonexudative conjunctival injection, desquamation of the fingers, and coronary artery aneurysm. KD symptoms improved after three doses of intravenous immunoglobulin plus cyclosporine. However, small coronary aneurysms were present at the time of discharge. In a retrospective analysis, no pathogens were detected by multiplex real-time PCR in samples collected at admission, and the serum cytokine profile demonstrated prominent elevation of IL-6 as well as elevation of neopterin, sTNF-RI, and sTNF-RII, which suggested KD. CONCLUSIONS: The patient's entire clinical course, including the severe pneumonia, was caused by KD. As in this case, neonatal KD may exhibit atypical manifestations such as severe pneumonia requiring mechanical ventilation.