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Purpose Previous estimates of the cause- and age-specific frequency of pediatric meningitis in Korea were mainly derived from single- and multi-center studies. Herein, we used data on the number of cases of bacterial and viral meningitis from the Health Insurance Review and Assessment Service database to examine time- and sex-related trends. Methods We extracted data on meningitis diagnoses registered in the Health Insurance Review and Assessment Service from 2009 to 2017, using Korean Standard Classification of Disease and Cause of Death codes. Information on 202,254 children aged 0 to 18 years was extracted. Detailed demographic and disease information was available for 84,543 children who underwent hospitalization. Results Among all hospitalized patients, 2166, 36,155, and 46,192 children were diagnosed with bacterial, viral, or other types of meningitis, respectively. There were 30 cases of fungal meningitis and another 30 cases of meningitis attributable to other pathogens. The number of cases of bacterial and viral meningitis was highest among infants (1,087 [50.2%]) and patients in their early childhood (12,949 [35.9%]), respectively. Meningitis outbreaks were most likely to occur during the summer, and boys were more susceptible to meningitis than girls. The following pathogens most commonly caused infant meningitis: group B Streptococcus, Escherichia coli, and type B Haemophilus influenzae. Conclusion This study reports the number of pediatric meningitis cases, stratified by age, disease type, and month/year. The present findings contribute to a better understanding of pediatric meningitis in Korea and provide a foundation for future research to identify the risk factors for this disease.

In a meta-analysis of three GWAS for susceptibility to Kawasaki disease (KD) conducted in Japan, Korea, and Taiwan and follow-up studies with a total of 11,265 subjects (3428 cases and 7837 controls), a significantly associated SNV in the immunoglobulin heavy variable gene (IGHV) cluster in 14q33.32 was identified (rs4774175; OR = 1.20, P = 6.0 × 10−9). Investigation of nonsynonymous SNVs of the IGHV cluster in 9335 Japanese subjects identified the C allele of rs6423677, located in IGHV3-66, as the most significant reproducible association (OR = 1.25, P = 6.8 × 10−10 in 3603 cases and 5731 controls). We observed highly skewed allelic usage of IGHV3-66, wherein the rs6423677 A allele was nearly abolished in the transcripts in peripheral blood mononuclear cells of both KD patients and healthy adults. Association of the high-expression allele with KD strongly indicates some active roles of B-cells or endogenous immunoglobulins in the disease pathogenesis. Considering that significant association of SNVs in the IGHV region with disease susceptibility was previously known only for rheumatic heart disease (RHD), a complication of acute rheumatic fever (ARF), these observations suggest that common B-cell related mechanisms may mediate the symptomology of KD and ARF as well as RHD.

Purpose Febrile seizures (FS) are the most common seizures found in pediatric patients. Recently, microRNA (miRNA) have been used as a novel biomarker for the diagnosis of various diseases. This study aims to explore the exosomal miRNA expression profile of the cerebrospinal fluid (CSF) in atypical FS patients. Methods This is a case-control study including CSF specimens of 41 pediatric patients. The CSF specimens were categorized into FS and a control group. Microarray assays were performed to evaluate the CSF exosomal miRNA expression profile. Quantitative PCR (qPCR) assays were conducted to validate the microarray assay result. Bioinformatic analysis was performed to analyze the result. Results Thirteen (62%) patients in the FS group experienced complex FS. A total of 96 miRNAs were significantly expressed in the CSF study samples and 95 amongst them, exhibited higher expression in FS than in the control group. Further validation qPCR test indicated that the top 5 highly expressed miRNA (miR-4486, miR-6850-5p, miR-642b-3p, miR-7107-5p, miR-4281) showed same results as in the microarray assay. Bioinformatic analysis identified 455 target genes in the FS group. Conclusion FS patients displayed higher CSF exosomal miRNA profiles than the control. These altered miRNA profiles appeared to be related to complex FS.

The epidemiology of demyelinating diseases in the Korean pediatric population has not been reported to date. This study aimed to identify the epidemiology of demyelinating diseases in Korean children by using big data. The subjects were children (0-17 years old) diagnosed with acute-disseminated encephalomyelitis, multiple sclerosis, neuromyelitis optica, and Guillain-Barré syndrome enrolled in the Korean Health Insurance Review and Assessment Service (HIRA) from January 2010 to December 2017.Of 1722 enrolled children, 553 (32.1%) had acute-disseminated encephalomyelitis, 170 (9.9%) had multiple sclerosis, 68 (3.9%) had neuromyelitis optica, and 931 (54.1%) had Guillain-Barré syndrome. The male-female ratios were 1.47:1 in acute-disseminated encephalomyelitis, 1.43:1 in Guillain-Barré syndrome, 1:1.66 in multiple sclerosis, and 1:1.62 in neuromyelitis optica. Demyelinating diseases were most prevalent in summer. The prevalence differed by region, with 545 (31.6%) in Seoul and 298 (17.3%) in Gyeonggi. This study is the first to identify the incidence of demyelinating diseases in South Korea.

Kawasaki disease (KD) is an acute, self-limited vasculitis, mainly affecting children younger than 5 years old, with accompanying fever and signs of mucocutaneous inflammation. Intravenous immunoglobulin (IVIG) is the standard treatment for KD; however, ~15% of patients are resistant to IVIG treatment. To identify protein coding genetic variants influencing IVIG resistance, we re-analyzed our previous genome-wide association study (GWAS) data from 296 patients with KD, including 101 IVIG non-responders and 195 IVIG responders. Five nonsynonymous SNPs (nsSNPs) in five immune-related genes, including a previously reported SAMD9L nsSNP (rs10488532; p.Val266Ile), were associated with IVIG non-response (odds ratio [OR] = 1.89–3.46, P = 0.0109–0.0035). In a replication study of the four newly-identified nsSNPs, only one in the interleukin 16 (IL16) gene (rs11556218, p.Asn1147Lys) showed a trend of association with IVIG non-response (OR = 1.54, P = 0.0078). The same IL16 nsSNP was more significantly associated with IVIG non-response in combined analysis of all data (OR = 1.64, P = 1.25 × 10−4). Furthermore, risk allele combination of the IL16 CT and SAMD9L TT nsSNP genotypes exhibited a very strong effect size (OR = 9.19, P = 3.63 × 10−4). These results implicate IL16 as involved in the mechanism of IVIG resistance in KD.

We investigated head-up tilt test (HUTT) results across age-groups in syncope/presyncope patients to establish pediatric postural orthostatic tachycardia syndrome (POTS) characteristics. We retrospectively reviewed syncope patients' medical records. Adolescents were defined as 10 to 19 years old, adults as 20 to 59 years old, and older individuals as ≥60 years old. From HUTT results, we determined POTS prevalence and differences among the age-groups. We included 147 adolescents, 269 adults, and 123 older patients. Seventy (13.0%) patients (61.4% females; median age: 20 [17-25] years) were diagnosed with POTS. The syndrome was more prevalent among adolescents (33 [22.4%]) than adults (37 [13.8%]), and was absent among older individuals. Affected adolescents had significantly lower resting diastolic blood pressure (DBP) and heart rate (HR), and converted to maximum HR more rapidly than adolescents without the syndrome during the passive phase. Adolescents with POTS demonstrated several unique characteristics compared to adults with and adolescents without this syndrome. POTS may be underrecognized among syncope and presyncope patients, among which 22.4% of adolescents were diagnosed with the syndrome. POTS should be considered when evaluating syncope patients.

Highlights • Febrile seizures were reported to be associated with seasonal viral epidemics. • The seasonal distribution of febrile seizures was high from late spring to summer. • Influenza virus and enterovirus was most frequently associated with febrile seizure., Purpose The seasonal distribution patterns of febrile seizures and of respiratory and enteric viral pathogens are similar. In this study, we analyzed trends in febrile seizures and viral infection in Korean children, using big data from the Korean Health Insurance Review and Assessment Service (HIRA). Methods We analyzed children younger than 6 years who visited the hospital and were diagnosed with febrile seizures from 2009 to 2016, using medical records in the HIRA database. A total of 666,136 medical records of children with a main or subdiagnosis of febrile seizure from 2008 to 2016 were included. Of these records, patients younger than 1 month and records before 2009 were excluded. Finally, 558,130 records were extracted. Results The medical records included 315,774 male children and 242,356 (43.4%) female children, with a mean age of 2.31 ± 1.31 years. The annual incidence of febrile seizure was 25.4 per 1000 person-years (27.9 for boys and 22.7 for girls). The ratio of male to female children was 1.30: 1, and records of 1-year-old children comprised the highest proportion (n = 210,400, 33.70%). The total monthly number of patients was highest in May (n = 64,969, 11.6%), and peaks were formed from April to July. The fewest patients were seen in October (n = 34,424, 6.17%). The most common viral pathogens were influenza in April and enterovirus during May–July. Conclusion The seasonal distribution of febrile seizures was high from late spring to summer, and influenza virus and enterovirus were most frequently associated.

Kawasaki disease (KD) is a systemic vasculitis affecting infants and children; it manifests as fever and signs of mucocutaneous inflammation. Intravenous immunoglobulin (IVIG) treatment effectively attenuates the fever and systemic inflammation. However, 10–20% patients are unresponsive to IVIG. To identify genetic variants influencing IVIG non-response in KD, a genome-wide association study (GWAS) and a replication study were performed using a total of 148 IVIG non-responders and 845 IVIG-responders in a Korean population. rs28662 in the sterile alpha motif domain-containing protein 9-like (SAMD9L) locus showed the most significant result in the joint analysis of GWAS and replication samples (odds ratio (OR) = 3.47, P = 1.39 × 10−5). The same SNP in the SAMD9L locus was tested in the Japanese population, and it revealed a more significant association in a meta-analysis with Japanese data (OR = 4.30, P = 5.30 × 10−6). These results provide new insights into the mechanism of IVIG response in KD.

Irritable bowel syndrome (IBS) is a common pediatric functional gastrointestinal disorder. It is characterized by recurrent abdominal pain and changes in bowel habits and is more prevalent in obese patients. We investigated the association between obesity and IBS in pediatric patients through fecal calprotectin testing. Patients under 18 years of age with IBS who underwent fecal calprotectin testing from January 2015 through April 2020 were retrospectively investigated. The patients were divided into groups based on body mass index (BMI): group I (BMI85th percentile) and group II (BMI ≥ 85th percentile). Group II was divided into group IIa, overweight (85th percentile ≤ BMI95th percentile), and group IIb, obese (BMI ≥ 95th percentile). Among 277 included patients, 202 (72.9%) were in group I, and 75 (27.1%) were in group II (mean calprotectin levels, 75.60 ± 103.48 vs 45.89 ± 66.57 µg/g, respectively; P = .006). There were significant differences in mean calprotectin levels between groups I and IIa (75.60 ± 103.48 vs 45.45 ± 63.38 µg/g, respectively; P = .028) and groups I and IIb (75.60 ± 103.48 vs 46.22 ± 69.59 µg/g, respectively; P = .025). There was a significant difference in mean calprotectin levels between groups I and II (85.69 ± 142.13 vs 32.04 ± 28.17 µg/g, respectively; P = .029) among patients between 6 and 12 years of age but not among adolescents aged between 12 and 18 years (P = .139). Fecal calprotectin was lower when moderate-to-severe fatty livers were observed by ultrasound compared with normal livers (68.52 ± 97.22 vs 18.53 ± 18.56 µg/g, respectively; P = .017). Fecal calprotectin levels were higher in normal-weight pediatric IBS patients than in their obese counterparts, and this difference was more prominent in younger patients. In young children, IBS symptoms are thought to be influenced more by factors other than intestinal inflammation.

Background After the global epidemic of coronavirus disease 2019 (COVID-19), lifestyle changes to curb the spread of COVID-19 (e.g., wearing a mask, hand washing, and social distancing) have also affected the outbreak of other infectious diseases. However, few studies have been conducted on whether the incidence of gastrointestinal infections has changed over the past year with COVID-19. In this study, we examined how the incidence of gastrointestinal infections has changed since COVID-19 outbreak through open data. Methods We summarized the data on the several viruses and bacteria that cause gastrointestinal infections from the open data of the Korea Disease Control and Prevention Agency for 3 years from March 2018 to February 2021 (from Spring 2018 to Winter 2020). Moreover, we confirmed three most common legal gastrointestinal infectious pathogens from March 2016. Results From March 2020, when the COVID-19 epidemic was in full swing and social distancing and personal hygiene management were heavily emphasized, the incidence of infection from each virus was drastically decreased. The reduction rates compared to the averages of the last 2 years were as follows: total viruses 31.9%, norovirus 40.2%, group A rotavirus 31.8%, enteric adenovirus 13.4%, astrovirus 7.0%, and sapovirus 12.2%. Among bacterial pathogens, the infection rates of Campylobacter and Clostridium perfringens did not decrease but rather increased in some periods when compared to the average of the last two years. The incidence of nontyphoidal Salmonella, Staphylococcus aureus, or enteropathogenic Escherichia coli somewhat decreased but not significantly compared to the previous two years. Conclusion The incidence of infection from gastrointestinal viruses, which are mainly caused by the fecal-to-oral route and require direct contact among people, was significantly reduced, whereas the incidence of bacterial pathogens, which have food-mediated transmission as the main cause of infection, did not decrease significantly., Graphical Abstract

Background Endoscopy is used for diagnosing and treating various digestive diseases in children as well as in adults. However, in pediatric patients, it is recommended that sufficient sedation should be ensured before conducting endoscopy, since insufficient sedation may cause serious complications. However, in Korea, no studies have yet described the types of sedation drugs, effects of sedation, and efficiency of endoscopy with respect to the sedation instructor. Thus, we investigated the effectiveness of sedative procedures performed by anesthesiologists. Methods We retrospectively reviewed the medical records of patients aged < 18 years who underwent endoscopy during March 2014–July 2019. Data of sedation instructors, sedation drugs and their doses, complications, and the recovery after sedation were evaluated. Results Of 257 patients, 217 underwent esophagogastroduodenoscopy (EGD) and 40 underwent colonoscopies. Before EGD, 29 patients (13.4%) underwent sedation by the pediatric endoscopist and 188 (86.6%) were sedated by the anesthesiologist. The anesthesiologist performed the sedation for all 40 patients who underwent colonoscopy. Endoscopic examinations performed by the anesthesiologist were relatively more time-consuming (401.0 ± 135.1 seconds vs. 274.9 ± 106.1 seconds, P < 0.001). We observed that in patients who underwent EGD, there was a difference in the dose of midazolam administered (P = 0.000). When comparing EGD and colonoscopy in patients undergoing sedation by the anesthesiologist, there were no significant differences in the doses of midazolam and ketamine, but the dose of propofol increased for colonoscopy (2.50 ± 0.95 mg/kg vs. 4.71 ± 1.66 mg/kg, P = 0.000). The cognitive recovery time according to drug dose was associated with propofol only in EGD with a shorter endoscopy time. The longer cognitive recovery time in colonoscopy and the discharge time of EGD and colonoscopies were not associated with propofol use. Conclusion When sedation is performed by an anesthesiologist, various drugs are used with sufficient doses and complications are reduced, but the discharge time does not change. For performing pediatric endoscopy in Korea, anesthesiologists should be considered for inducing anesthesia., Graphical Abstract

Background and objectives Patients with Kawasaki disease (KD) are clinically heterogeneous because its diagnosis is based solely on clinical observation and there are no definitive biomarkers. We dissected the clinical heterogeneity of KD patients using the KD-associated genetic variants. Methods We performed a genetic association analysis in several KD subgroups categorized by clinical characteristics using the KD-associated variants of the B lymphoid tyrosine kinase (BLK; rs6993775) and Fc gamma receptor II a (FCGR2A; rs1801274) in a large number of case (n=1,011) and control (n=4,533) samples. Results BLK and FCGR2A were very significantly associated with KD in Korean KD patients (odds ratio [OR],1.48; p=4.63×10⁻¹¹ for BLK, and OR, 1.26; p=1.42×10⁻⁴ for FCGR2A). However, in KD subgroup analysis, we found that neither BLK nor FCGR2A were associated with either incomplete Kawasaki disease (iKD) type patients or those older than 5 years of age (p>0.2), suggesting that patients with iKD or those older than 5 years of age are a unique subgroup of KD. In genetic association analysis after excluding iKD patients and those older than 5 years old, we found that BLK was associated with all KD subgroups, whereas FCGR2A was specifically associated with male KD patients younger than 1 year of age (OR, 2.22; p=2.35×10⁻⁵). Conclusions KD is a clinically and genetically heterogeneous disease. These findings will provide new insights into the clinical and genetic heterogeneity of KD.

Kawasaki disease (KD) is an acute pediatric vasculitis that affects genetically susceptible infants and children. To identify coding variants that influence susceptibility to KD, we conducted whole exome sequencing of 159 patients with KD and 902 controls, and performed a replication study in an independent 586 cases and 732 controls. We identified five rare coding variants in five genes (FCRLA, PTGER4, IL17F, CARD11, and SIGLEC10) associated with KD (odds ratio [OR], 1.18–4.41; p = 0.0027–0.031). We also performed association analysis in 26 KD patients with coronary artery aneurysms (CAAs; diameter > 5 mm) and 124 patients without CAAs (diameter < 3 mm), and identified another five rare coding variants in five genes (FGFR4, IL31RA, FNDC1, MMP8, and FOXN1), which may be associated with CAA (OR, 3.89–37.3; p = 0.0058–0.0261). These results provide insights into new candidate genes and genetic variants potentially involved in the development of KD and CAA.

Highlights • The present study analyzed the diagnosis pattern of childhood malignant diseases using public health data and viral surveillance data in Korea. • The number of newly diagnosis showed the highest monthly average in January, and the lowest in September. • Seasonal trends were apparent in acute myeloid leukemia, Non-Hodgkin’s lymphoma, acute lymphoblastic leukemia and germ cell tumors. • In winter, significantly more patients were diagnosed with acute lymphoblastic leukemia, acute myeloid leukemia, neuroblastoma, and Hodgkin’s lymphoma than in other seasons. • There was a temporal correlation with the diagnostic trends of several diseases and the prevalence of recent human parainfluenza virus., Background Several studies have reported a seasonal trend in the diagnosis of childhood cancer suggesting seasonal factors such as infection. The present study aimed to analyze the diagnosis pattern of childhood malignant diseases using public health data, and to compare this pattern with seasonal viral infection trends. Method Using the open data source of the Health Insurance Review and Assessment Service, we extracted data regarding all patients under 21 years of age and who had any cancer, aplastic anemia or myelodysplastic syndrome between September 2009 and December 2013. The positive detection rates of 11 viruses was collected from the surveillance data of Korea Centers for Disease Control and Prevention, and seasonality analysis were conducted with both data. Results In total, 9085 patients were diagnosed with malignant disease during the study period; there were about 175 new cases per month on average. Monthly stacked time series by year showed an apparent seasonal variation with the highest monthly average in January as 236, and the lowest in September as 120. In winter, significantly more patients were diagnosed with acute lymphoblastic leukemia, acute myeloid leukemia, neuroblastoma, and Hodgkin’s lymphoma than in other seasons. There was a temporal correlation with the diagnostic trends of several diseases and the prevalence of recent human parainfluenza virus. Conclusion This study tentatively suggests that the diagnosis of childhood malignancy follows a seasonal trend in Korea, and has a possible correlation with viral prevalence in several diseases. Further long-term analysis of epidemiological data is needed to explore possible causality.

Kawasaki disease (KD) is an acute, self-limited vasculitis, mainly affecting children younger than 5 years old, with accompanying fever and signs of mucocutaneous inflammation. Intravenous immunoglobulin (IVIG) is the standard treatment for KD; however, ~15% of patients are resistant to IVIG treatment. To identify protein coding genetic variants influencing IVIG resistance, we re-analyzed our previous genome-wide association study (GWAS) data from 296 patients with KD, including 101 IVIG non-responders and 195 IVIG responders. Five nonsynonymous SNPs (nsSNPs) in five immune-related genes, including a previously reported SAMD9L nsSNP (rs10488532; p.Val266Ile), were associated with IVIG non-response (odds ratio [OR] = 1.89-3.46, P = 0.0109-0.0035). In a replication study of the four newly-identified nsSNPs, only one in the interleukin 16 (IL16) gene (rs11556218, p.Asn1147Lys) showed a trend of association with IVIG non-response (OR = 1.54, P = 0.0078). The same IL16 nsSNP was more significantly associated with IVIG non-response in combined analysis of all data (OR = 1.64, P = 1.25 × 10

A 12-year-old boy who underwent gastric wedge resection was transferred to our hospital because of vomiting, growth failure, and weight loss in January, 2016. We tried to restore his general condition by maintaining additional nutritional supply through peripheral parenteral nutrition (PN). However, continuous vomiting, weight loss, and superior mesenteric artery syndrome persisted because of low treatment compliance. The findings of hyponatraemia and bicytopenia did not improve. Bone marrow biopsy was performed, and it revealed copper deficiency. PN with additional micronutrient agents, including copper, were administered. In particular, invasive diagnosis and treatment, and adequate education improved the treatment compliance of the child. His copper deficiency and bicytopenia improved, and his weight and dietary intake also increased. We confirmed that treatment compliance is important in paediatric patients with malnutrition. In chronic malnutrition, attention should also be paid to deficiency of micronutrients such as copper, which can lead to haematologic problems.

Background An increase in the numbers of patients with gastrointestinal symptoms has recently been observed. Purpose To investigate the effects of proton pump inhibitor (PPI) therapy on intestinal inflammation in children and adolescents as confirmed by clinical manifestations and objectively assessed by fecal calprotectin (FC) level measurement. Methods Consecutive children (aged 3-18 years) who presented with gastrointestinal symptoms and were treated with or without PPI for at least 1 month were enrolled. Patients were divided into PPI and non-PPI groups. The PPI group was further subdivided by treatment duration and type of PPI used. Stool samples were collected for FC evaluation at baseline and after treatment and clinical data and FC levels were compared between the groups. Results Fifty-one patients (15 boys, 36 girls) were enrolled in the study. The PPI group included 37 patients, while the non-PPI group included 14 patients. Clinical symptoms were not significantly different. FC levels and laboratory results, including C-reactive protein levels, white blood cell count, and absolute neutrophil count, were not statistically different before versus after PPI treatment. After treatment, FC levels decreased to 8.1 mg/kg (-575.4 to 340.3 mg/kg) in the PPI group and increased to 5.6 mg/kg (-460.0 to 186.9 mg/kg) in the non-PPI group compared to those before treatment (P=0.841). The number of patients with increased FC levels was not significantly different between the 2 groups (48.6% vs. 64.3%, P=0.363), similar to that observed in patients with an FC level > 50 mg/kg (24.3% and 7.1%, P=0.250). PPI therapy type and duration did not affect the FC levels (P=0.811 and P=0.502, respectively). Conclusion Although we aimed to confirm the evidence of intestinal inflammation due to PPI use in children and adolescents through clinical symptoms and FC measurement, no significant changes were observed.

Background and Objectives Kawasaki disease (KD) is an acute systemic vasculitis that affects the coronary arteries. Abnormal immune reactions are thought to contribute to disease pathogenesis. The effect of immunoglobulin (Ig) isotype (IgG, IgA, IgM, and IgE) on inflammatory data and clinical outcomes of patients with KD was examined. Methods Ig levels in 241 patients with KD were measured during the acute, subacute, convalescent, and normal phases of the disease. Results Compared with reference Ig values, IgG, IgA, and IgM levels were significantly higher in the subacute phase, while IgE levels were elevated in 73.9% (178/241) of patients with KD in all clinical phases. However, high IgE levels were not associated with clinical outcomes, including intravenous immunoglobulin unresponsiveness and coronary artery lesions (CALs). Significantly more CALs were observed in the high IgA group than in the normal IgA group (44.7% vs. 20.8%, respectively; p

Purpose The study aimed to assess the association between Apgar scores at 1 and 5min after birth and seizures in infants less than 1 year old. Methods We conducted a retrospective, observational, hospital-based study by utilising medical records from the Chung-Ang University Hospital admissions from January 2006 to May 2015 in order to identify infants less than 1 year old who had a history of seizures. Using electronic medical records, infants who were diagnosed with infantile seizures at the Chung-Ang University Hospital from January 2006 to May 2015 were included in the seizure group ( n =93), and a control group consisting of 296 age-matched cases without a history of seizures was selected from a group of infants born at Chung-Ang University Hospital during the same study period. Results We found that Apgar scores were significant risk factors for infantile seizures. Apgar scores differed depending on gestational age and birth weight. We found strong associations between Apgar scores and infantile seizures in the full-term and the normal-birth weight groups (bodyweight ≥2.5kg), regardless of delivery mode. The Apgar scores were inversely correlated with the EEG class, and only the 1-min Apgar scores were correlated with MRI findings. Conclusion Low Apgar scores are significant perinatal risk factors for infantile seizures, especially in full-term and normal-birth weight infants, and have a strong negative linear relationship with EEG and brain MRI results in the seizure group.

Objective The side effects of methylphenidate (MPH) on growth remain a controversial concern. This study aimed to investigate the effect of MPH on clinical symptoms, growth, and physical fitness in Korean children. Methods Fifty male children with attention deficit hyperactivity disorder (ADHD) treated with methylphenidate (MPH-ADHD), 69 MPH-naive male children with ADHD (Naive-ADHD), and 60 age-matched and sex-matched healthy control subjects were recruited. Intelligence quotient (IQ), clinical symptoms of ADHD, body index (height, weight, and body mass index [BMI]), and physical fitness (muscular strength, endurance, flexibility, agility, speed, and balance) were assessed. Results Total IQ and performance IQ scores were significantly different among the three groups, as were mean Korean Attention Deficit Hyperactivity Disorder (K-ARS)-total, K-ARS-inattention, and K-ARS-hyperactivity scores. There was no significant difference in height, weight, or BMI among the three groups. There were significant differences in skill-related fitness scores for balance (healthy controls > MPH-ADHD > Naive-ADHD) and agility shuttle test time (healthy controls

Hemophagocytic lymphohistiocytosis (HLH) is a rare disease resulting in clinical and biochemical manifestations of extreme inflammation. Myelodysplastic syndrome (MDS) represents a heterogenous group of clonal hematopoietic disorders. The development of MDS is common in children with trisomy of chromosome 8. Here, we report a fatal case of 8-year-old girl who was admitted to the emergency department with status epilepticus, and later diagnosed with HLH associated with MDS and trisomy of chromosome 8. We believe this is the first reported case of HLH associated with MDS and trisomy 8 in a pediatric patient.

Kawasaki disease (KD) is a self-limited systemic vasculitis of an unknown pathogenesis mainly affecting children

Purpose: The aim of this study was to investigate the potential effects of mild hypoxia in the mature and immature brain. Methods: We prepared organotypic slice cultures of the hippocampus and used hippocampal tissue cultures at 7 and 14 days in vitro (DIV) to represent the immature and mature brain, respectively. Tissue cultures were exposed to 10% oxygen for 60 minutes. Twenty-four hours after this hypoxic insult, propidium iodide fluorescence images were obtained, and the damaged areas in the cornu ammonis 1 (CA1), CA3, and dentate gyrus (DG) were measured using image analysis. Results: In the 7-DIV group compared to control tissue, hypoxia-exposed tissue showed decreased damage in two regions (CA1: 5.59%±2.99% vs. 4.80%±1.37%, P =0.900; DG: 33.88%±12.53% vs. 15.98%±2.37%, P =0.166), but this decrease was not statistically significant. In the 14-DIV group, hypoxia-exposed tissue showed decreased damage compared to control tissues; this decrease was not significant in the CA3 (24.51%±6.05% vs. 18.31%±3.28%, P =0.373) or DG (15.72%±3.47% vs. 9.91%±2.11%, P =0.134), but was significant in the CA1 (50.91%±5.90% vs. 32.30%±3.34%, P = 0.004). Conclusion: Although only CA1 tissues cultured for 14 DIV showed significantly less damage after exposure to hypoxia, the other tissues examined in this study showed a tendency towards less damage after hypoxic exposure. Therefore, mild hypoxia might play a protective role in the brain.

Kawasaki disease (KD) is a systemic vasculitis affecting infants and children; it manifests as fever and signs of mucocutaneous inflammation. Intravenous immunoglobulin (IVIG) treatment effectively attenuates the fever and systemic inflammation. However, 10-20% patients are unresponsive to IVIG. To identify genetic variants influencing IVIG non-response in KD, a genome-wide association study (GWAS) and a replication study were performed using a total of 148 IVIG non-responders and 845 IVIG-responders in a Korean population. rs28662 in the sterile alpha motif domain-containing protein 9-like (SAMD9L) locus showed the most significant result in the joint analysis of GWAS and replication samples (odds ratio (OR) = 3.47, P = 1.39 × 10

Kawasaki disease (KD), a systemic vasculitis of infants and children, manifests as fever and mucocutaneous inflammation. Although its etiology is largely unknown, the epidemiological data suggest that genetic factors are important in KD susceptibility. To identify genetic variants influencing KD susceptibility, we performed a genome-wide association study (GWAS) and replication study using a total of 915 children with KD and 4553 controls in the Korean population. Six single-nucleotide polymorphisms (SNPs) in three loci were associated significantly with KD susceptibility (P

Background Hepatitis B virus (HBV) infection is the most common cause of liver disease in endemic areas such as South Korea. After HBV vaccination, hepatitis B surface antibody (HBsAb) titers gradually decrease. Trends in HBsAb titers have not been evaluated among children in South Korea over the past decade. Methods We screened 6155 patients (aged 7 months to 17 years) who underwent HBV antigen/antibody testing at Chung-Ang University Hospital from May 2012 to April 2015. Titer criteria were defined as follows: positive, titer ≥100 IU/L; weakly positive, titer 10–99 IU/L; and negative, titer

Rationale: Tracheal atresia (TA) involves complete or partial tracheal absence below the larynx. It involves failure of complete separation of the laryngotracheal diverticulum from the foregut at the 4th gestational week. In TA, the trachea and main bronchi generally proceed in the normal caudal directions. Patient concerns: At the gestational age of 34 weeks and 6 days, a male baby weighing 2290 g was born via cesarean section. A brisk bag was used, and mask ventilation was performed, but was not effective. Intubation was attempted; however, the endotracheal tube did not advance below the vocal cord. Diagnosis: Tracheal atresia. Interventions: An emergent open neck exploration could not reveal the trachea. On computed tomography, the tracheoesophageal fistula (TEF) started from the lower esophagus just above the gastroesophageal junction. The trachea arose upward to form the main bronchus. Outcomes: His parents signed the “Do not resuscitate” form due to poor outcome. On the 23rd day of birth, the baby expired. Lessons: Our case involved TA with tracheoesophageal fistula forming between the trachea and main bronchi in a cephalic direction as detected on computed tomography. Further, the trachea arose from the gastroesophageal junction; thus, it does not belong to any Floyd classification. Herein, we report a TA case with a cephalically developed lung bud.

Purpose As the importance of breastfeeding has been reinforced, human milk is often stored for practical reasons. Therefore, we evaluated optimal storage and processing methods for human milk from a nutritional standpoint. Methods Human milk samples were collected between June 2017 and February 2018. Also, data about maternal information were collected. Human milk was analyzed for macronutrients and caloric content. The samples were subdivided into groups for nutrient analysis. The control group (fresh milk) was not stored or processed. The other groups (9 groups) consisted of samples analyzed based on different storage temperatures (room temperature, refrigerated, frozen), defrosting methods (bottle warmer, room temperature thawing, microwave oven), and storage period (1 week, 1 month, 2 months) and compared with the control group. Results There was no statistically significant difference in the nutrient content of human milk among the collected samples. A significant change in the content of macronutrients in milk samples was observed under storage condition at different temperatures for 1 week with subsequent thawing with bottle warmer compared to fresh milk. Under storage at -20°C for 1 week with subsequent thawing with different defrosting methods, a significant change in the content of macronutrients in milk samples was observed compared to fresh milk. After storage at -20°C for different periods and thawing with a bottle warmer, a significant change in macronutrient content in milk samples was observed compared to fresh milk regardless of the storage period. Conclusion Unlike previous guidelines, changes in macronutrient content in milk samples were observed regardless of the method of storing and thawing. Apparently, it is proposed that mothers should feed fresh human milk to their babies without storing.

MicroRNAs (miRNAs) are small, non-coding RNAs that regulate the expression of protein-coding genes. Recently, miRNA levels have been used as a novel non-invasive biomarker for the diagnosis of various diseases. We aimed to identify serum miRNAs elevated in patients with Kawasaki disease (KD) and to explore the potential biological function of identified candidate miRNAs. Serum specimens were collected from children with KD (n = 12) and healthy controls (n = 6). miRNA microarray assays were performed using the PANArray™ miRNA expression profiling kit (PANAGENE Co., Daejeon, Korea). We used TargetScan and the database for annotation, visualization, and integrated discovery program to obtain a list of enriched biological pathways targeted by miRNAs elevated in KD patients. As a result, miR-200c and miR-371-5p were significantly upregulated in the KD group compared with the control group (p = 0.032 in both). By using TargetScan, we obtained a list of 421 and 542 genes predicted to be targeted by miR-200c and miR-371, respectively, and these genes were significantly (p < 0.05) clustered in 17 and 3 pathways, respectively. Many of them are major pathways involved in inflammatory responses. The present data support the hypothesis that the inflammatory response is a crucial mechanism for pathogenesis of KD, and miRNAs might be the main regulators of this inflammatory response.

Congenital chloride diarrhea (CLD) is a rare inherited autosomal recessive disorder. Mutations of the solute carrier family 26 member 3 gene cause profuse, chloride ion rich diarrhea, which results in hypochloremia, hyponatremia and metabolic alkalosis with dehydration. If a fetal ultrasound shows bowel dilatation suggestive of bowel obstruction, or if a neonate shows persistent diarrhea and metabolic alkalosis, CLD should be considered in the differential diagnosis. The severity of CLD varies, but early detection and early therapy can prevent complications including growth failure. We report a case of dizygotic twins affected by CLD who had been born to non-consanguineous parents. Both of them showed growth failure, but one of the twins experienced worse clinical course. He showed developmental delay, along with dehydration and severe electrolyte imbalance. He was diagnosed with CLD first at 6-month age, and then the other one was also diagnosed with CLD.

We report a case of Henoch-Schonlein purpura (HSP) presenting without typical skin lesion; atypical symptoms initially appeared following influenza infection. A 4-year-old girl with influenza presented with epigastric pain and vomiting. On physical examination, there was epigastric tenderness, but no other signs, such as skin rash. On the second day, she vomited blood 10 times. Ultrasonography indicated focal bowel wall thickening in the right upper quadrant. Esophagogastroduodenoscopy showed oedematous and purpuric mucosa in the gastric pylorus and duodenum. Steroid therapy was initiated, and symptoms improved, but microscopic haematuria persisted. Even in the absence of typical purpura, if any gastrointestinal symptoms are observed and HSP is suspected, aggressive diagnostic tools must be considered, including ultrasonography or endoscopy. With only a few reported cases of HSP associated with influenza infection, this is the first reported case with gastrointestinal involvement and renal impairment, but without typical skin lesions.

Adequate organ growth is an important aspect of growth evaluation in children. Renal size is an important indicator of adequate renal growth; computed tomography (CT) can closely estimate actual kidney size. However, insufficient data are available on normal renal size as measured by CT. This study aimed to evaluate the relationships of anthropometric indices with renal length and volume measured by CT in Korean pediatric patients. Renal length and volume were measured using CT images in 272 pediatric patients (age < 18 years) without renal disease. Data for anthropometric indices—including height, weight, and body surface area (BSA)—were obtained using medical records. Using the equation for an ellipsoid, renal volume was calculated in cubic centimeters. Height showed greatest correlation with renal length on stepwise multiple linear regression analysis; BSA showed the strongest significant correlation with renal volume. The mean renal size for each age group and height group was determined; it showed a tendency to increase with age and height. This is the first Korean study to report the relationship between body indices and renal size measured by CT. These results can serve as normative standards for assessing adequate renal growth., Graphical Abstract

This study was undertaken to determine the genotype variability of human metapneumovirus (hMPV) and its circulation pattern over a 3.5-year period, and to evaluate its clinical characteristics in Korean children. We investigated 4599 pediatric patients who were referred for a routine respiratory virus test by RT-PCR. hMPV genotype analyses were performed using a nested PCR-restriction fragment length polymorphism assay. Clinical and laboratory data obtained from medical records were reviewed retrospectively. Of the 4599 samples tested, 325 (7.1%) were positive for hMPV, and the co-infection rate among these 325 was 16%. Nested PCR-restriction fragment length polymorphism analysis clearly identified four of the five hMPV genotypes (A2a, A2b, B1, and B2) in 97.8%. The predominant genotype of hMPV changed over the 3.5-year study period from genotype A2a to B2 and then back to A2a. The most common genotype was A2a (214/325, 65.8%). Evidence of recurrent infection was obtained in one child only. Lymphocytosis was more frequent in children with a co-infection, but sputum production was less frequent than in children with a single infection. In genotype A2a hMPV-infected children, sneezing and neutrophilia were more frequent than in genotype B1 or B2 hMPV-infected children. This study broadens knowledge regarding the prevalence, the seasonal incidence, the occurrences of co-infection and re-infection, and the genotype diversity of hMPV in Korea.