Clinical Manifestations and Genotype of Primary Ciliary Dyskinesia Diagnosed in Korea: Multicenter Study.

Purpose: Primary ciliary dyskinesia (PCD) is a genetically heterogeneous disorder that leads to secondary ciliary dysfunction. PCD is a rare disease, and data on it are limited in Korea. This study systematically evaluated the clinical symptoms, diagnostic characteristics, and treatment modalities of pediatric PCD in Korea.

Clinical characteristics of pediatric patients infected with SARS-CoV-2 versus common human coronaviruses: a national multicenter study.

Background: Human coronaviruses (HCoV) cause mild upper respiratory infections; however, in 2019, a novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged, causing an acute respiratory disease pandemic. Coronaviruses exhibit marked epidemiological and clinical differences.

Purpose: This study compared the clinical, laboratory, and radiographic findings of children infected with SARS-CoV-2 versus HCoV.

Assessment of variables associated with prolonged admission duration in children with Mycoplasma pneumoniae pneumonia.

Introduction: Macrolide-resistant Mycoplasma pneumoniae (MRMP) has become prevalent in children. This study investigated the clinical and laboratory variables of MRMP and macrolide-sensitive M. pneumoniae (MSMP) and identified factors associated with prolonged hospital admission in children.

Diagnosis and management of asthma in infants and preschoolers.

Asthma is one of the most common chronic disease affecting children, and it often starts in infancy and preschool years. In previous birth cohorts, frequent wheezing in early life was associated with the development of asthma in later childhood and reduced lung function persisting into adulthood. Preschool wheezing is considered an umbrella term for distinctive diseases with different clinical features (phenotypes), each of which may be related to different underlying pathophysiologic mechanisms (endotypes).

Analysis of national surveillance of respiratory pathogens for community-acquired pneumonia in children and adolescents.

Background: Respiratory infections among children, particularly community-acquired pneumonia (CAP), is a major disease with a high frequency among outpatient and inpatient visits. The causes of CAP vary depending on individual susceptibility, the epidemiological characteristics of the community, and the season. We performed this study to establish a nationwide surveillance network system and identify the causative agents for CAP and antibiotic resistance in Korean children with CAP.

Clinical Characteristics of Macrolide-Refractory Pneumonia in Korean Children: A Multicenter Retrospective Study.

is a major causative pathogen of community-acquired pneumonia in children, and the treatment of choice is macrolides. There is an increasing trend in reports of refractory clinical responses despite macrolide treatment due to the emergence of macrolide-resistant . Early discrimination of macrolide-refractory pneumonia (MrMP) from macrolide-sensitive pneumonia (MSMP) is vital; however, testing for macrolide susceptibility at the time of admission is not feasible.

Viral load and rebound in children with coronavirus disease 2019 during the first outbreak in Daegu city.

Background: Viral load and shedding duration are highly associated with the transmission of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. However, limited studies have reported on viral load or shedding in children and adolescents infected with sudden acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Purpose: This study aimed to investigate the natural course of viral load in asymptomatic or mild pediatric cases.

Pulmonary function of healthy Korean children from three independent birth cohorts: Validation of the Global Lung Function Initiative 2012 equation.

Background And Objective: Global Lung Function Initiative (GLI) 2012 equations were developed to resolve the age-related disparity in interpreting spirometry results. Local validation of the equation is needed, especially in Northeast Asian children. This study evaluated the GLI equation in Korean children.

Sex-based differences in factors associated with bronchial hyperresponsiveness in adolescents with childhood asthma.

Background: Bronchial hyperresponsiveness (BHR), an important physiological feature of asthma, is a prognostic marker of childhood asthma.

Purpose: We aimed to investigate the factors associated with BHR in adolescents with childhood asthma.

Methods: Two hundred and fifteen adolescents (≥13 years of age; 149 males, 66 females) who were diagnosed with asthma during childhood were enrolled, underwent methacholine challenge tests, and were divided into the BHR group (<25 mg/mL of provocation concentration causing a 20% fall in forced expiratory volume in 1 second [FEV1] [PC20], n=113) or non-BHR group (≥25 mg/mL of PC20, n=102).

Vegetable dietary pattern may protect mild and persistent allergic rhinitis phenotype depending on genetic risk in school children.

Background: The effect of diet on allergic rhinitis (AR), its severity in children, and whether it modifies AR depending on genetic susceptibility are unknown. We investigated the association between dietary patterns and AR in school children and the influence of diet on AR according to a genetic risk score (GRS).

Methods: Totally, 435 7-year-old school children were recruited from the Panel Study on Korean Children.

Annual and seasonal patterns in etiologies of pediatric community-acquired pneumonia due to respiratory viruses and Mycoplasma pneumoniae requiring hospitalization in South Korea.

Background: Community-acquired pneumonia (CAP) is one of the leading worldwide causes of childhood morbidity and mortality. Its disease burden varies by age and etiology and is time dependent. We aimed to investigate the annual and seasonal patterns in etiologies of pediatric CAP requiring hospitalization.

Risk Factors and Comorbidities Associated With the Allergic Rhinitis Phenotype in Children According to the ARIA Classification.

Purpose: Data are lacking on the association between the allergic rhinitis (AR) phenotype and sensitization to specific allergens or bronchial hyperresponsiveness (BHR) in children. We here investigated risk factors and comorbidities, including sensitization to specific allergens and BHR, for the AR phenotype by AR and its Impact on Asthma (ARIA) classification in a general population-based birth cohort study.

Methods: We enrolled 606 children aged 7 years from the Panel Study of Korean Children.

Association between sensitization and allergic diseases in 7-years-old Korean children.

Background: Sensitization is associated with the exacerbation, severity, and prognosis of allergic diseases in children.

Objective: We characterized the association between sensitization patterns and allergic diseases.

Methods: A cohort of 548 children was enrolled from Panel Study of Korean Children (PSKC) study.

Profiles and characteristics of bronchial responsiveness in general 7-year-old children.

Background: Although bronchial responsiveness (BR) is usually categorized as normal or hyperresponsive to aid the diagnosis of asthma, it exists on a continuous spectrum, not in a dichotomous manner. We aimed to evaluate the distribution profile of BR in a general population of 7-year-olds.

Methods: In 2015, 7-year-old Korean children from a nationwide birth cohort study visited regional study hospitals for skin prick test, standard spirometry, and bronchial provocation to establish reference values for the general population.

Multicenter Adherence Study of Asthma Medication for Children in Korea.

Purpose: Adherence is a major component of successful medical treatment. However, non-adherence remains a barrier to effective delivery of healthcare worldwide.

Methods: Twenty healthcare facilities (secondary or tertiary hospitals) belonging to the Korean Academy of Pediatric Allergy and Respiratory Diseases (KAPARD) participated.

Prevalence, Risk Factors and Cutoff Values for Bronchial Hyperresponsiveness to Provocholine in 7-Year-Old Children.

Background: A US Food and Drug Administration (FDA)-approved drug methacholine chloride (Provocholine®) was recently introduced to Korea where it is now widely used in clinical practice. We aimed to evaluate the prevalence, risk factors and cutoff value of bronchial hyperresponsiveness (BHR) to Provocholine in 7-year-old children.

Methods: Six hundred and thirty-three children from the Panel Study on Korean Children who visited 16 regional hospitals were evaluated.

Neuroprotective effects of erythropoietin against hypoxic injury via modulation of the mitogen-activated protein kinase pathway and apoptosis.

Purpose: Hypoxic-ischemic encephalopathy is a significant cause of neonatal morbidity and mortality. Erythropoietin (EPO) is emerging as a therapeutic candidate for neuroprotection. Therefore, this study was designed to determine the neuroprotective role of recombinant human EPO (rHuEPO) and the possible mechanisms by which mitogen-activated protein kinase (MAPK) signaling pathway including extracellular signal-regulated kinase (ERK1/2), JNK, and p38 MAPK is modulated in cultured cortical neuronal cells and astrocytes.

Serum YKL-40 levels may help distinguish exacerbation of post-infectious bronchiolitis obliterans from acute bronchiolitis in young children.

Unlabelled: Children with post-infectious bronchiolitis obliterans (PIBO) are frequently hospitalized with acute exacerbation, but clinical differentiation of PIBO exacerbation from acute bronchiolitis is often challenging, which may result in treatment delay and chronic lung function impairment. We aimed to examine whether serum YKL-40 and growth factors could be markers for PIBO exacerbation. Thirty-seven children admitted with acute exacerbation of PIBO were enrolled and studied retrospectively.

Increased epidermal growth factor in nasopharyngeal aspirates from infants with recurrent wheeze.

Airway remodeling is known to be a consequence of repeated injury and thought to be involved in early stage of asthma. We aimed to investigate the mediators associated with airway remodeling in recurrent early wheezers. Thirty-three infants, aged 2 years or less, admitted with exacerbation of wheezing were enrolled.

Asthma in childhood: a complex, heterogeneous disease.

Asthma in childhood is a heterogeneous disease with different phenotypes and variable clinical manifestations, which depend on the age, gender, genetic background, and environmental influences of the patients. Several longitudinal studies have been conducted to classify the phenotypes of childhood asthma, on the basis of the symptoms, triggers of wheezing illness, or pathophysiological features of the disease. These studies have provided us with important information about the different wheezing phenotypes in young children and about potential mechanisms and risk factors for the development of chronic asthma.

Decreased interleukin-18 response in asthmatic children with severe Mycoplasma pneumoniae pneumonia.

Purpose: Mycoplasma pneumoniae (M. pneumoniae) is a common causative agent of pneumonia in children. The aim of this study is to determine whether there is any difference in selected cytokine or chemokines response in asthmatic children compared to non-asthmatic children during acute M.

The neuroprotective effect of recombinant human erythropoietin via an antiapoptotic mechanism on hypoxic-ischemic brain injury in neonatal rats.

Purpose: The neuroprotective effects of erythropoietin (EPO) have been recently shown in many animal models of brain injury, including hypoxic-ischemic (HI) encephalopathy, trauma, and excitotoxicity; however, limited data are available for such effects during the neonatal periods. Therefore, we investigated whether recombinant human EPO (rHuEPO) can protect against perinatal HI brain injury via an antiapoptotic mechanism.

Methods: The left carotid artery was ligated in 7-day-old Sprague-Dawley (SD) rat pups (in vivo model).

Age-related difference in immune responses to respiratory syncytial virus infection in young children.

There have been longitudinal studies of the developmental change of the immune system during the first year of life. The aim of this study was to investigate if there is any age-related difference in cytokine responses to respiratory syncytial virus (RSV) infection between the patients under 6 months of age and the patients over 12 months of age compared with age-matched controls. Forty-five children < or =24 months of age who were admitted with acute RSV bronchiolitis were enrolled.