Pediatric acute disseminated encephalomyelitis following asymptomatic coronavirus disease 2019.

After the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epidemic emerged, the virus spread rapidly worldwide, and outbreaks continued to occur intermittently. Here, we present the case of a 5-year-old boy with acute disseminated encephalomyelitis (ADEM) and initial symptoms of dysphoria and pain in the right lower extremity. Around the time of this episode, the patient exhibited no fever or respiratory symptoms. Brain magnetic resonance imaging (MRI) revealed multiple T2-weighted image/fluid-attenuated inversion recovery high-signal areas bilaterally subcortical to the deep white matter, corpus callosum, and bilateral basal ganglia. MRI of the cervical and thoracic regions indicated a long lesion with continuous T2WI high signal intensity in the central gray matter. Serum aquaporin-4 antibody and serum myelin oligodendrocyte glycoprotein antibody tests were negative and positive, respectively. A polymerase chain reaction test using nasopharyngeal swab fluid upon admission was positive for SARS-CoV-2. Patients with severe coronavirus disease 2019 (COVID-19) in the acute phase may show central nervous system symptoms. There have been no previous reports of ADEM in the subacute phase of COVID-19, lacking symptoms in the acute phase, as in the present case. Notably, ADEM can develop in the subacute phase of asymptomatic COVID-19 infection.

Silent spinal epidural abscess due to facet joint arthritis.

Spinal epidural abscess (SEA) is an abscess that forms between the dura mater and vertebrae. SEA is characterized by back pain and neuropathy associated with fever, of which early diagnosis and treatment are necessary to avoid irreversible neurological sequelae. However, its diagnosis is often difficult because specific symptoms are rarely present in the early stages of the disease. A 25-month-old boy, healthy by nature and free of risk factors, was referred and admitted for fever symptoms only, without back pain or neurological symptoms. We focused on the residual activation of the coagulation-fibrinolytic system, which was contrary to the response to therapy, and were able to establish a diagnosis of SEA. After the initiation of antibiotics, the patient responded well to treatment and made a mild recovery without the need for surgical intervention. To date, there are no reported cases of SEA with only febrile symptoms without localized spinal cord tenderness. SEA is easily overlooked and should be considered in the differential diagnosis of pediatric fever of unknown origin. Although imaging studies have drawbacks, such as radiation exposure and sedation, they should be immediately performed if SEA is suspected.

Evaluation of the association of birth order and group childcare attendance with Kawasaki disease using data from a nationwide longitudinal survey.

Background: Kawasaki disease (KD) is a form of pediatric systemic vasculitis. Although the etiology remains unclear, infections have been identified as possible triggers. Children with a later birth order and those who attend childcare are at a higher risk of infections due to exposure to pathogens from their older siblings and other childcare attendees. However, longitudinal studies exploring these associations are limited. Thus, we aimed to elucidate the relationship between birth order, group childcare attendance, and KD, using a nationwide longitudinal survey in Japan. Methods: In total, 36,885 children born in Japan in 2010 were included. The survey used questionnaires to identify hospitalized cases of KD. We evaluated the relationship between birth order classification, group childcare attendance, and KD prevalence every year, from 6 to 66 months of age. For each outcome, odds ratios (ORs), and 95% confidence intervals (CIs) were estimated after adjusting for child factors, parental factors, and region of residence. Results: Children with higher birth orders were more likely to be hospitalized with KD at 6-18 months of age (second child OR: 1.77, 95% CI: 1.25-2.51; third child OR: 1.70, 95% CI: 1.08-2.65). This trend was stronger for children who did not attend group childcare (second child OR: 2.51, 95% CI: 1.57-4.01; third child OR: 2.41, 95% CI: 1.30-4.43). An increased risk of KD hospitalization owing to the birth order was not observed in any age group for children in the childcare group. Conclusions: Children with higher birth orders were at high risk for hospitalization due to KD at 6-18 months of age. The effect of birth order was more prominent among the children who did not attend group childcare.

Respiratory pathogen trends in patients with Kawasaki disease during the COVID-19 pandemic and respiratory syncytial virus epidemic in Japan.

BACKGROUND: Although the etiology of Kawasaki disease (KD) remains unknown, the most common view is that an infectious agent triggers the activation of the inflammatory cascade in predisposed children. The coronavirus disease 2019 (COVID-19) pandemic has led to the establishment of infection control measures, which reduced the overall incidence of respiratory infections; however, a resurgence of respiratory syncytial virus (RSV) infection occurred in the summer of 2021. This study aimed to examine the relationship between respiratory pathogens and KD during the COVID-19 pandemic and the RSV epidemic in Japan between 2020 and 2021. METHODS: We retrospectively reviewed the medical charts of pediatric patients with KD or respiratory tract infection (RTI) admitted to National Hospital Organization Okayama Medical Center between December 1, 2020, and August 31, 2021. All patients with KD and RTI underwent multiplex polymerase chain reaction testing upon admission. We classified patients with KD into the three subgroups-pathogen-negative, single pathogen-positive, and multi-pathogen-positive-and compared their laboratory data and clinical features. RESULTS: This study enrolled 48 patients with KD and 269 with RTI. Rhinovirus and enterovirus were the most prevalent pathogens in both patients with KD and RTI (13 [27.1%] and 132 patients [49.1%], respectively). The clinical characteristics of the pathogen-negative KD group and the pathogen-positive KD group at diagnosis were similar; however, the pathogen-negative group tended to receive additional treatment, such as multiple courses of intravenous immunoglobulin, intravenous methylprednisolone, infliximab, cyclosporine A, and plasmapheresis, more frequently. The number of patients with KD remained stable when RTI was not prevalent but increased following the surge in RTI with RSV. CONCLUSIONS: An epidemic of respiratory infections led to an increase in the incidence of KD. Patients with respiratory pathogen-negative KD could have greater recalcitrance to intravenous immunoglobulin than those with respiratory pathogen-positive KD.

Decreased levels of histidine-rich glycoprotein and increased levels of high-mobility group box 1 are risk factors for refractory Kawasaki disease.

OBJECTIVES: Histidine-rich glycoprotein (HRG) and high-mobility group box 1 (HMGB1) regulate the activation of neutrophils and vascular endothelium. The aim of this study was to quantify HRG and HMGB1 levels in patients with Kawasaki disease (KD) and evaluate their use in the clinical management of KD. METHODS: This study was prospectively performed. Patients were divided into two groups and analysed depending on whether KD symptoms improved by Day 10 of illness. HRG, HMGB1, and other laboratory variables were measured before the first treatment in all cases and, in most cases, afterwards for assessing trends. RESULTS: In this prospective study, we enrolled 60 patients with KD and 48 healthy controls. The HRG level in the KD group was significantly lower than that in the healthy control group; HMGB1 levels showed no obvious differences. In the KD group, HRG levels were negatively correlated with white blood cell and neutrophil counts. In the poor responders and responders groups, a tendency for a decrease in HRG and HMGB1 levels, respectively, was observed from pretreatment to post-treatment. CONCLUSIONS: HRG and HMGB1 are related to the pathogenesis of KD; low HRG and high HMGB1 levels cause resistance against KD treatment.

Neonatal sepsis and Kawasaki disease.

The purpose of this study is to clarify the relationship between neonatal sepsis and future development of Kawasaki disease (KD). We analyzed data from the National Hospital Organization Neonatal Intensive Care Unit (NHO-NICU) registry study in Japan. Participants in this study were children with a history of hospitalization in the NICU at the participating institutions from 2010 to 2014. A questionnaire was administered at age 3 years to obtain information about the patient's history of KD. There were 8275 infants who were eligible for this study. At 3 years of age, parents of 2161 children responded to the follow-up survey (follow-up rate, 26.1%). Multivariate logistic regression analysis adjusted for preterm birth, sex, use of antibiotics in the NICU, parity, and maternal smoking showed that children with neonatal sepsis were more likely to have a history of KD at 3 years of age (adjusted odds ratio [aOR]: 11.67, 95% confidence interval [CI]: 2.84-47.96). CONCLUSIONS: Among infants admitted to the NICU, neonatal sepsis might be associated with development of KD later in life. Further large studies are needed to elucidate the relationship between neonatal infections and KD development. WHAT IS KNOWN: • Preterm birth is known to be a risk factor for Kawasaki disease. •It is not yet known which factors related to preterm birth increase the risk of developing Kawasaki disease. WHAT IS NEW: •Neonatal sepsis is associated with an increased risk of subsequent development of Kawasaki disease. •Antibiotic use in the neonatal intensive care unit may also be an independent risk factor for subsequent development of Kawasaki disease.

Preterm birth and Kawasaki disease: a nationwide Japanese population-based study.

BACKGROUND: Previous studies showed that preterm birth increased the risk for hospital admissions in infancy and childhood due to some acute diseases. However, the risk of preterm children developing Kawasaki disease remains unknown. In the present study, we investigate whether preterm birth increased the morbidity of Kawasaki disease. METHODS: We included 36,885 (34,880 term and 2005 preterm) children born in 2010 in Japan. We examined the association between preterm birth and hospitalization due to Kawasaki disease using a large nationwide survey in Japan. RESULTS: In log-linear regression models that were adjusted for children's characteristics (sex, singleton birth, and parity), parental characteristics (maternal age, maternal smoking, paternal smoking, maternal education, and paternal income), and residential area, preterm infants were more likely to be hospitalized due to Kawasaki disease (adjusted risk ratio: 1·55, 95% confidence interval: 1.01-2.39). We then examined whether breastfeeding status modified the potential adverse effects of preterm birth on health outcome. Preterm infants with partial breastfeeding or formula feeding had a significantly higher risk of hospitalization due to Kawasaki disease compared with term infants with exclusive breastfeeding. CONCLUSIONS: Preterm infants were at a high risk for Kawasaki disease, and exclusive breastfeeding might prevent this disease among preterm infants. IMPACT: Previous studies showed that preterm birth increased the risk for hospital admissions in infancy and childhood due to some acute diseases, however, the risk of preterm children developing Kawasaki disease remains unknown. This Japanese large population-based study showed that preterm infants were at a high risk for Kawasaki disease for the first time. Furthermore, this study suggested that exclusively breastfeeding might prevent Kawasaki disease among preterm infants.

Anti-high mobility group box 1 monoclonal antibody suppressed hyper-permeability and cytokine production in human pulmonary endothelial cells infected with influenza A virus.

OBJECTIVE: High mobility group box-1 (HMGB1) has been reported to be involved in influenza A virus-induced acute respiratory distress syndrome (ARDS). We studied the efficacy of an anti-HMGB1 mAb using an in vitro model of TNF-α stimulation or influenza A virus infection in human pulmonary microvascular endothelial cells (HMVECs). METHODS: Vascular permeability of HMVECs was quantified using the Boyden chamber assay under tumor necrosis factor-α (TNF-α) stimulation or influenza A virus infection in the presence of anti-HMGB1 mAb or control mAb. The intracellular localization of HMGB1 was assessed by immunostaining. Extracellular cytokine concentrations and intracellular viral mRNA expression were quantified by the enzyme-linked immunosorbent assay and quantitative reverse transcription PCR, respectively. RESULTS: Vascular permeability was increased by TNF-α stimulation or influenza A infection; HMVECs became elongated and the intercellular gaps were extended. Anti-HMGB1 mAb suppressed both the increase in permeability and the cell morphology changes. Translocation of HMGB1 to the cytoplasm was observed in the non-infected cells. Although anti-HMGB1 mAb did not suppress viral replication, it did suppress cytokine production in HMVECs. CONCLUSION: Anti-HMGB1 mAb might be an effective therapy for severe influenza ARDS.

Infantile leukocytoclastic vasculitis caused by enterotoxin-producing methicillin-sensitive Staphylococcus aureus.

Staphylococcus aureus infections are known to cause leukocytoclastic vasculitis (LCV). Herein, we describe a case of an 18-month-old with LCV caused by enterotoxin-producing methicillin-sensitive Staphylococcus aureus (MSSA) emanating from an unrecognized pharyngeal abscess. It is critical to consider the possibility of extracutaneous sources of MSSA infection when investigating an infant with vasculitis. Prompt diagnosis and appropriate treatment are vital in preventing potentially life-threatening complications.

Effect of growth hormone therapy on thyroid function in isolated growth hormone deficient and short small for gestational age children: a two-year study, including on assessment of the usefulness of the thyrotropin-releasing hormone (TRH) stimulation test.

Background The relationship between growth hormone (GH)-replacement therapy and the thyroid axis in GH-deficient (GHD) children remains controversial. Furthermore, there have been few reports regarding non-GHD children. We aimed to determine the effect of GH therapy on thyroid function in GHD and non-GHD children and to assess whether thyrotropin-releasing hormone (TRH) stimulation test is helpful for the identification of central hypothyroidism before GH therapy. Methods We retrospectively analyzed data from patients that started GH therapy between 2005 and 2015. The free thyroxine (FT4) and thyroid-stimulating hormone (TSH) concentrations were measured before and during 24 months of GH therapy. The participants were 149 children appropriate for gestational age with GHD (IGHD: isolated GHD) (group 1), 29 small for gestational age (SGA) children with GHD (group 2), and 25 short SGA children (group 3). Results In groups 1 and 2, but not in group 3, serum FT4 concentration transiently decreased. Two IGHD participants exhibited central hypothyroidism during GH therapy, and required levothyroxine (LT4) replacement. They showed either delayed and/or prolonged responses to TRH stimulation tests before start of GH therapy. Conclusions GH therapy had little pharmacological effect on thyroid function, similar changes in serum FT4 concentrations were not observed in participants with SGA but not GHD cases who were administered GH at a pharmacological dose. However, two IGHD participants showed central hypothyroidism and needed LT4 replacement therapy during GH therapy. TRH stimulation test before GH therapy could identify such patients and provoke careful follow-up evaluation of serum FT4 and TSH concentrations.