Exosome from IFN-γ-Primed Induced Pluripotent Stem Cell-Derived Mesenchymal Stem Cells Improved Skin Inflammation and Barrier Function.

The pathogenesis of atopic dermatitis (AD) is multifactorial, including immune dysregulation and epidermal barrier defects, and a novel therapeutic modality that can simultaneously target multiple pathways is needed. We investigated the therapeutic effects of exosomes (IFN-γ-iExo) secreted from IFN-γ-primed induced pluripotent stem cell-derived mesenchymal stem cells (iMSC) in mice with Aspergillus fumigatus-induced AD. IFN-γ-iExo was epicutaneously administered to mice with AD-like skin lesions. The effects of IFN-γ-iExo treatment were investigated through clinical scores, transepidermal water loss (TEWL) measurements, and histopathology. To elucidate the therapeutic mechanism, we used an in vitro model of human keratinocyte HaCaT cells stimulated with IL-4 and IL-13 and performed extensive bioinformatics analysis of skin mRNA from mice. The expression of indoleamine 2,3-dioxygenase was higher in IFN-γ primed iMSCs than in iMSCs. In human keratinocyte HaCaT cells, treatment with IFN-γ-iExo led to decreases in the mRNA expression of thymic stromal lymphopoietin, IL-25, and IL-33 and increases in keratin 1, keratin 10, desmoglein 1, and ceramide synthase 3. IFN-γ-iExo treatment significantly improved clinical and histological outcomes in AD mice, including clinical scores, TEWL, inflammatory cell infiltration, and epidermal thickness. Bioinformatics analysis of skin mRNA from AD mice showed that IFN-γ-iExo treatment is predominantly involved in skin barrier function and T cell immune response. Treatment with IFN-γ-iExo improved the clinical and histological outcomes of AD mice, which were likely mediated by restoring proper skin barrier function and suppressing T cell-mediated immune response.

A 17-Year-Old Girl Diagnosed With STING-Associated Vasculopathy With Onset in Infancy (SAVI) After Lung Transplantation.

CASE PRESENTATION: A 17-year-old girl received lung transplantation after chronic respiratory failure. She developed a fever (> 38 °C) once or twice weekly starting 2 months after surgery, and multiple papulopustules on the skin waxed and waned for 4 months. She then developed blood-tinged sputum. She had been treated with triple immunosuppressants, including prednisolone, tacrolimus, and mycophenolate mofetil after lung transplantation, and her symptoms appeared during prednisolone dose reduction.

Multicenter Surveillance of Cystic Fibrosis in Korean Children.

PURPOSE: Cystic fibrosis (CF), caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, is rare among non-Caucasians. We aimed to identify the clinical features and CFTR mutations in Korean children. METHODS: We included 18 pediatric patients with CF diagnosed using sweat chloride test or genetic analysis for 30 years. HEK293 cells were transfected with wild-type CFTR, ΔF508-CFTR, and L441P-CFTR mutant plasmids for 24 hours and treated with CFTR correctors (VX809 and VX661). RESULTS: The median age at diagnosis was 9.2 years. Eleven patients had growth retardation, and 6 had a respiratory failure at diagnosis. Genetic analysis was used for all patients, while sweat testing was for 8 patients. At diagnosis, the median z scores of forced expiratory volume in one second (FEV1), FEV1/forced vital capacity, and forced expiratory flow at 25%-75% of forced vital capacity were -3.61 (-5.78, 1.78), -3.38 (-4.40, -0.60), and -4.45 (-5.78, 0.54), respectively. Two patients were treated with dornase alfa and only one with CFTR modulator. Patients were followed up for 3.7 years as a median. Four patients died at 10.6 years, with 4.2 years of post-diagnosis survival. The most common mutation was exon 16-17b deletion (19.4%). Among 11 single nucleotide variants, c.1322T>C (p.Leu441Pro, L441P) was detected in 4 patients. In the functional assay, L441P-CFTR correction was well restored by CFTR correctors compared with ΔF508. CONCLUSIONS: CF is extremely rare in Korean children and is caused by different mutations from those commonly observed in Caucasians. Early diagnosis and treatment availability may improve outcomes. CFTR modulators may be effective for Asian patients with rare CFTR mutations, c.1322T>C (p.Leu441Pro).

The association of lung function changes with outcomes in children with bronchiolitis obliterans syndrome after hematopoietic stem cell transplantation.

BACKGROUND: Bronchiolitis obliterans syndrome (BOS) is a life-threatening respiratory complication of allogeneic hematopoietic stem cell transplantation (HSCT). Although pulmonary function testing is crucial for monitoring BOS, little information exists on the association of these test results with outcomes in children with BOS. OBJECTIVES: The purpose of this study was to determine the correlation between changes in lung function after BOS diagnosis and long-term outcomes. METHODS: A total of 428 children underwent allogeneic HSCT from January 2006 to December 2017 at Asan Medical Center. Twenty-three (5.4%) were diagnosed with BOS after allogeneic HSCT, and their clinical data were reviewed. Twenty-one subjects underwent regular pulmonary function testing for 24 months after BOS diagnosis. RESULTS: Among the 21 children with BOS, 8 died, 5 underwent lung transplantation (TPL), and 15 required oxygen (O2 ) therapy. The FEV1 % predicted (pred), FVC% pred, and FEF25%-75% pred were 37.8 ± 12.7% (mean ± SD), 62.2 ± 16.2%, and 16.4 ± 9.6%, respectively, at the time of BOS diagnosis. Changes in the FEV1 % pred were greater in the death and lung TPL groups (-24.8 ± 22.3%) than in the survival without lung TPL group (5.7 ± 21.8%) and greater in the O2 therapy (-19.4 ± 23.4%) group than in the group without O2 therapy (14.2 ± 20.0%) during the first 3 months after BOS diagnosis. CONCLUSION: The change in FEV1 during the first 3 months after BOS diagnosis correlated with outcomes including survival, lung TPL, and O2 therapy. These results suggest that more active intervention in the first 3 months after BOS diagnosis may be needed to improve prognosis.

Intensive pulmonary rehabilitation in a pediatric lung transplantation patient: A case report.

BACKGROUND: The pediatric lung transplant is a very important treatment for patients with end-stage lung diseae, and pulmonary rehabilitation (PR) is also an important factor in determining the prognosis. However, there is no much literature available on pulmonary rehabilitation in pediatric patients' post lung transplant. Through this case report, we would like to present our intensive PR program for pediatric patients' post-lung transplant. PATIENT CONCERNS: The 10-year-old boy's breathing before receiving a lung transplant continued to deteriorate and he eventually became dependent on a wheelchair. DIAGNOSIS: He was diagnosed with infantile acute lymphoblastic leukemia at 6 months of age. At the age of one year, he underwent allogeneic bone marrow transplantation, but was diagnosed with post-transplantation bronchiolitis obliterans (PTBO) two months later. He had a lung transplant at the age of 10. INTERVENTIONS: He was hospitalized and received an initial assessment. This assessment included functional, cognitive, and psychological evaluations. He additionally completed PR exercises twice daily for two weeks. After discharge, he continued to participate in an outpatient-based PR program for three months. During the outpatient phase, PR exercises were performed once weekly, in addition to home-based cognitive training. OUTCOMES: Our intensive post-lung PR program improved our patient's exercise capacity, lung function, and quality of life. As a comprehensive rehabilitation service, our program also included a cognitive training component. CONCLUSION: We describe an intensive PR program tailored to pediatric patients' post-lung transplant. The program was feasible and resulted in improvements in functional exercise capacity, lung function, and quality of life. Future research into our method is necessary for continued improvement of this novel program.

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. METHODS: We conducted a retrospective study in 30,994 children (aged 0-18 years) with CAP between 2010 and 2015 at 23 nationwide hospitals in South Korea. Mycoplasma pneumoniae (MP) pneumonia was clinically classified as macrolide-sensitive MP, macrolide-less effective MP (MLEP), and macrolide-refractory MP (MRMP) based on fever duration after initiation of macrolide treatment, regardless of the results of in vitro macrolide sensitivity tests. RESULTS: MP and respiratory syncytial virus (RSV) were the two most commonly identified pathogens of CAP. With the two epidemics of MP pneumonia (2011 and 2015), the rates of clinical MLEP and MRMP pneumonia showed increasing trends of 36.4% of the total MP pneumonia. In children < 2 years of age, RSV (34.0%) was the most common cause of CAP, followed by MP (9.4%); however, MP was the most common cause of CAP in children aged 2-18 years of age (45.3%). Systemic corticosteroid was most commonly administered for MP pneumonia. The rate of hospitalization in intensive care units was the highest for RSV pneumonia, and ventilator care was most commonly needed in cases of adenovirus pneumonia. CONCLUSIONS: The present study provides fundamental data to establish public health policies to decrease the disease burden due to CAP and improve pediatric health.

Associated Factors for Asthma Severity in Korean Children: A Korean Childhood Asthma Study.

PURPOSE: Childhood asthma has a considerable social impact and economic burden, especially in severe asthma. This study aimed to identify the proportion of childhood asthma severity and to evaluate associated factors for greater asthma severity. METHODS: This study was performed on 667 children aged 5-15 years with asthma from the nationwide 19 hospitals in the Korean childhood Asthma Study (KAS). Asthma was classified as mild intermittent, mild persistent, and moderate/severe persistent groups according to the National Asthma Education and Prevention Program recommendations. Multinomial logistic regression models were used to identify the associated factors for greater asthma severity. RESULTS: Mild persistent asthma was most prevalent (39.0%), followed by mild intermittent (37.6%), moderate persistent (22.8%), and severe persistent asthma (0.6%). Onset later than 6 years of age (adjusted odds ratio [aOR], 1.69 for mild persistent asthma; aOR, 1.92 for moderate/severe persistent asthma) tended to increase asthma severity. Exposure to environmental tobacco smoke (aOR, 1.53 for mild persistent asthma; aOR, 1.85 for moderate/severe persistent asthma), and current dog ownership with sensitization to dog dander (aOR, 5.86 for mild persistent asthma; aOR, 6.90 for moderate/severe persistent asthma) showed increasing trends with greater asthma severity. Lower maternal education levels (aOR, 2.32) and no usage of an air purifier in exposure to high levels of outdoor air pollution (aOR, 1.76) were associated with moderate/severe persistent asthma. CONCLUSIONS: Modification of identified environmental factors associated with greater asthma severity might help better control childhood asthma, thereby reducing the disease burden due to childhood asthma.

Umbilical cord-derived mesenchymal stem cell extracts ameliorate atopic dermatitis in mice by reducing the T cell responses.

Mesenchymal stem cells derived from Wharton's jelly of the umbilical cord (UC-MSCs) have immunomodulatory properties. The aim of this study was to explore whether extracts of MSCs (MSC-Ex) could augment the low therapeutic efficacy of the whole cells in an Aspergillus fumigatus (Af)-induced atopic dermatitis (AD) model. LPS- or TNF-α/IFN-γ-stimulated keratinocytes (HaCaT cells) were treated with MSC-Ex, and the Af-induced AD model was established in BALB/c mice. In HaCaT cells, MSC-Ex treatment significantly reduced the inflammatory cytokine (IL-6, IL-1ß, IL-4, IL-5 and TNF-α), iNOS and NF-κB levels, and upregulated the anti-inflammatory cytokines (IL-10 and TGF-ß1). In the AD mice, the MSC-Ex group showed greatly reduced dermatitis, and lower clinical symptom scores and IgE levels. The histological dermatitis scores were also markedly lower in the MSC-Ex-treated animals compared with the MSC-treated group. Decreased levels of IFN-γ (Th1) and IL-17 (Th17), IL-4 and IL-13 (Th2) were detected in T cells and the skin tissue from the MSC-Ex treated AD mice. The therapeutic capacity of MSC-Ex was preserved after lyophilization and reconstitution. MSC-Ex treatment reproducibly suppresses dermatitis and inhibits the induction of inflammatory cytokines in the skin of AD mice. MSC-Ex is therefore a potential new treatment agent for AD.

Priming with Toll-like receptor 3 agonist or interferon-gamma enhances the therapeutic effects of human mesenchymal stem cells in a murine model of atopic dermatitis.

BACKGROUND: Atopic dermatitis (AD) is a chronic and relapsing inflammatory skin disease. Great efforts have been recently made to treat AD using mesenchymal stem cells (MSCs), which have immunomodulatory functions. However, the immunomodulatory effects of MSCs need to be enhanced for clinical application in the treatment of AD. OBJECTIVES: To evaluate and characterise the therapeutic effects of human Wharton's jelly-derived MSCs (WJ-MSCs) primed with the Toll-like receptor 3 agonist poly I:C or interferon-γ (IFN-γ) in a murine model of AD. METHODS: Mice were treated with Aspergillus fumigatus extract to induce AD and then subcutaneously injected with non-primed, poly I:C-primed or IFN-γ-primed WJ-MSCs. Clinical symptom scores, transepidermal water loss (TEWL), histological characteristics and cytokine levels were determined. Transcriptome profiling and pathway analyses of primed WJ-MSCs were conducted. RESULTS: The clinical symptom score and TEWL in skin lesions were reduced in mice administered non-primed and primed WJ-MSCs. Epidermal thickness and inflammatory cell infiltration in skin lesions were reduced more in mice administered primed WJ-MSCs than in mice administered non-primed WJ-MSCs. Secretion of interleukin-17 was significantly reduced in skin draining lymph nodes of mice administered primed WJ-MSCs. Genomics and bioinformatics analyses demonstrated the enrichment of certain pathways specifically in WJ-MSCs primed with poly I:C or IFN-γ. CONCLUSIONS: Priming with poly I:C- or IFN-γ improved the therapeutic effects of WJ-MSCs in a murine model of AD. This study suggests that priming with poly I:C or IFN-γ enhances the immunomodulatory functions of WJ-MSCs and can be used as a novel therapeutic approach for AD.

The First Successful Lung Transplantation in a Korean Child with Cystic Fibrosis.

Cystic fibrosis (CF) is an autosomal recessive inherited multisystem disorder caused by mutations of the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) protein. Respiratory failure remains the most frequent cause of morbidity and mortality. Lung transplantation is the only option to treat end-stage lung disease. Very few cases of CF occur in Koreans. We report the case of a 12-year-old girl with respiratory failure due to CF who underwent lung transplantation. She had been diagnosed with CF 8 years previously after being treated for recurrent Pseudomonas aeruginosa pneumonia and malnutrition based on sweat chloride concentrations and the CFTR protein gene mutation test. Progression to end-stage lung disease and respiratory failure led to registration with the Korean Network for Organ Sharing. She underwent successful double lung transplantation in 2014. Although she has diabetes mellitus and chronic kidney disease, she has a better quality of life and a prolonged life expectancy.

The Different Clinical Aspects of Pediatric Primary Airway Tumors in the Larynx, Trachea, and Bronchi.

Primary airway tumors are rare in children and no literature reviewed their characteristics each location. We evaluate the clinical characteristics and outcomes of Korean children with primary airway tumors, from the larynx to bronchi. A retrospective chart review of children with primary tumors of the larynx, trachea, and bronchi at Asan Medical Center from January 2000 to July 2016 was conducted. Nineteen children were diagnosed with primary airway tumors of the larynx (47.4%), trachea (10.5%), and bronchi (42.1%). Median follow-up duration was 2.8 years and there were recurrences in 21.1%. Laryngeal tumors were associated with a younger median age at onset (2 months) and diagnosis (4 months), and most were relatively small (median size = 5.3 mm) and symptomatic. Tracheal and bronchial tumors were found in older children (age at onset and diagnosis > 11 years) and large (> 15.0 mm). Most (75%) patients with bronchial tumors were asymptomatic and all the patients with tracheal tumors were symptomatic. This study suggests that we should consider different the locations in primary airway tumor based on the age at onset and diagnosis, initial symptoms or signs, and size of tumor.

Association of symptom control with changes in lung function, bronchial hyperresponsiveness, and exhaled nitric oxide after inhaled corticosteroid treatment in children with asthma.

BACKGROUND: A key therapeutic approach to asthma, which is characterized by chronic airway inflammation, is inhaled corticosteroid (ICS). This study evaluated the association of symptom control with changes in lung function, bronchial hyperresponsiveness (BHR), and exhaled nitric oxide (eNO) after ICS treatment in asthmatic children. METHODS: A total of 33 children aged between 5 and 12 years with mild to moderate persistent asthma were treated with 160 µg ciclesonide per day for 3 months. At days 0 and 90, the following parameters were assessed: asthma symptom scores; lung function, including forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and forced expiratory flow at 25-75% of forced vital capacity (FEF25-75%); BHR to methacholine and adenosine 5-monophosphate (AMP); and eNO. RESULTS: Asthma symptom scores, lung function parameters, BHR to methacholine and AMP, and eNO levels at day 90 were significantly improved versus day 0 (all p < 0.001). Symptom scores at day 90 were not correlated with changes in lung function and BHR to methacholine during the follow-up period, whereas those at day 90 were more closely correlated with changes in BHR to AMP (r = 0.511, p = 0.003) than with eNO (r = -0.373, p = 0.035). Additionally, changes in PC20 AMP were correlated with changes in PC20 methacholine (r = 0.451, p = 0.011) and eNO (r = -0.474, p = 0.006). CONCLUSIONS: Changes in the BHR to AMP, and to a lesser extent eNO, correlate with asthma symptom control after ICS treatment. BHR to AMP may better reflect the relationship between improved airway inflammation due to ICS treatment and asthma symptoms.

Prenatal Particulate Matter/Tobacco Smoke Increases Infants' Respiratory Infections: COCOA Study.

PURPOSE: To investigate whether prenatal exposure to indoor fine particulate matter (PM2.5) and environmental tobacco smoke (ETS) affects susceptibility to respiratory tract infections (RTIs) in infancy, to compare their effects between prenatal and postnatal exposure, and to determine whether genetic factors modify these environmental effects. METHODS: The study population consisted of 307 birth cohort infants. A diagnosis of RTIs was based on parental report of a physician's diagnosis. Indoor PM2.5 and ETS levels were measured during pregnancy and infancy. TaqMan was used for genotyping of nuclear factor erythroid 2-related factor (Nrf2) (rs6726395), glutathione-S-transferase-pi (GSTP) 1 (rs1695), and glutathione-S-transferase-mu (GSTM) 1. Microarrays were used for genome-wide methylation analysis. RESULTS: Prenatal exposure to indoor PM2.5 increased the susceptibility of lower RTIs (LRTIs) in infancy (adjusted odds ratio [aOR]=2.11). In terms of combined exposure to both indoor PM2.5 and ETS, prenatal exposure to both pollutants increased susceptibility to LRTIs (aOR=6.56); however, this association was not found for postnatal exposure. The Nrf2 GG (aOR=23.69), GSTM1 null (aOR=8.18), and GSTP1 AG or GG (aOR=7.37) genotypes increased the combined LRTIs-promoting effects of prenatal exposure to the 2 indoor pollutants. Such effects of prenatal indoor PM2.5 and ETS exposure were not found for upper RTIs. CONCLUSIONS: Prenatal exposure to both indoor PM2.5 and ETS may increase susceptibility to LRTIs. This effect can be modified by polymorphisms in reactive oxygen species-related genes.

The Association of Lung Function, Bronchial Hyperresponsiveness, and Exhaled Nitric Oxide Differs Between Atopic and Non-atopic Asthma in Children.

PURPOSE: Although many previous studies have attempted to identify differences between atopic asthma (AA) and non-atopic asthma (NAA), they have mainly focused on the difference of each variable of lung function and airway inflammation. The aim of this study was to evaluate relationships between lung function, bronchial hyperresponsiveness (BHR), and the exhaled nitric oxide (eNO) levels in children with AA and NAA. METHODS: One hundred and thirty six asthmatic children aged 5-15 years and 40 normal controls were recruited. Asthma cases were classified as AA (n=100) or NAA (n=36) from skin prick test results. Lung function, BHR to methacholine and adenosine-5'-monophosphate (AMP), eNO, blood eosinophils, and serum total IgE were measured. RESULTS: The AA and NAA cases shared common features including a reduced small airway function and increased BHR to methacholine. However, children with AA showed higher BHR to AMP and eNO levels than those with NAA. When the relationships among these variables in the AA and NAA cases were evaluated, the AA group showed significant relationships between lung function, BHR to AMP or methacholine and eNO levels. However, the children in the NAA group showed an association between small airway function and BHR to methacholine only. CONCLUSIONS: These findings suggest that the pathogenesis of NAA may differ from that of AA during childhood in terms of the relationship between lung function, airway inflammation and BHR.

Postinfectious bronchiolitis obliterans in children: lessons from bronchiolitis obliterans after lung transplantation and hematopoietic stem cell transplantation.

Postinfectious bronchiolitis obliterans (PIBO) is an irreversible obstructive lung disease characterized by subepithelial inflammation and fibrotic narrowing of the bronchioles after lower respiratory tract infection during childhood, especially early childhood. Although diagnosis of PIBO should be confirmed by histopathology, it is generally based on history and clinical findings. Irreversible airway obstruction is demonstrated by decreased forced expiratory volume in 1 second with an absent bronchodilator response, and by mosaic perfusion, air trapping, and/or bronchiectasis on computed tomography images. However, lung function tests using spirometry are not feasible in young children, and most cases of PIBO develop during early childhood. Further studies focused on obtaining serial measurements of lung function in infants and toddlers with a risk of bronchiolitis obliterans (BO) after lower respiratory tract infection are therefore needed. Although an optimal treatment for PIBO has not been established, corticosteroids have been used to target the inflammatory component. Other treatment modalities for BO after lung transplantation or hematopoietic stem cell transplantation have been studied in clinical trials, and the results can be extrapolated for the treatment of PIBO. Lung transplantation remains the final option for children with PIBO who have progressed to end-stage lung disease.

Association between cord blood 25-hydroxyvitamin D concentrations and respiratory tract infections in the first 6 months of age in a Korean population: a birth cohort study (COCOA).

PURPOSE: Previous studies suggest that the concentration of 25-hydroxyvitamin D [25(OH)D] in cord blood may show an inverse association with respiratory tract infections (RTI) during childhood. The aim of the present study was to examine the influence of 25(OH)D concentrations in cord blood on infant RTI in a Korean birth cohort. METHODS: The levels of 25(OH)D in cord blood obtained from 525 Korean newborns in the prospective COhort for Childhood Origin of Asthma and allergic diseases were examined. The primary outcome variable of interest was the prevalence of RTI at 6-month follow-up, as diagnosed by pediatricians and pediatric allergy and pulmonology specialists. RTI included acute nasopharyngitis, rhinosinusitis, otitis media, croup, tracheobronchitis, bronchiolitis, and pneumonia. RESULTS: The median concentration of 25(OH)D in cord blood was 32.0 nmol/L (interquartile range, 21.4 to 53.2). One hundred and eighty neonates (34.3%) showed 25(OH)D concentrations less than 25.0 nmol/L, 292 (55.6%) showed 25(OH)D concentrations of 25.0-74.9 nmol/L, and 53 (10.1%) showed concentrations of ≥75.0 nmol/L. Adjusting for the season of birth, multivitamin intake during pregnancy, and exposure to passive smoking during pregnancy, 25(OH)D concentrations showed an inverse association with the risk of acquiring acute nasopharyngitis by 6 months of age (P for trend=0.0004). CONCLUSION: The results show that 89.9% of healthy newborns in Korea are born with vitamin D insufficiency or deficiency (55.6% and 34.3%, respectively). Cord blood vitamin D insufficiency or deficiency in healthy neonates is associated with an increased risk of acute nasopharyngitis by 6 months of age. More time spent outdoors and more intensified vitamin D supplementation for pregnant women may be needed to prevent the onset of acute nasopharyngitis in infants.

Toxic inhalational injury-associated interstitial lung disease in children.

Interstitial lung disease in children (chILD) is a group of disorders characterized by lung inflammation and interstitial fibrosis. In the past recent years, we noted an outbreak of child in Korea, which is possibly associated with inhalation toxicity. Here, we report a series of cases involving toxic inhalational injury-associated chILD with bronchiolitis obliterans pattern in Korean children. This study included 16 pediatric patients confirmed by lung biopsy and chest computed tomography, between February 2006 and May 2011 at Asan Medical Center Children's Hospital. The most common presenting symptoms were cough and dyspnea. The median age at presentation was 26 months (range: 12-47 months), with high mortality (44%). Histopathological analysis showed bronchiolar destruction and centrilobular distribution of alveolar destruction by inflammatory and fibroproliferative process with subpleural sparing. Chest computed tomography showed ground-glass opacities and consolidation in the early phase and diffuse centrilobular nodular opacity in the late phase. Air leak with severe respiratory difficulty was associated with poor prognosis. Although respiratory chemicals such as humidifier disinfectants were strongly considered as a cause of this disease, further studies are needed to understand the etiology and pathophysiology of the disease to improve the prognosis and allow early diagnosis and treatment.

Association of antioxidants with allergic rhinitis in children from seoul.

PURPOSE: The prevalence of allergic diseases has risen over the last few decades. Many factors, including environmental factors such as those related to diet, have been considered. Among dietary factors, intake of antioxidant-related nutrients has been associated with the risk of allergic disease. We investigated the association of antioxidant nutritional status with allergic rhinitis (AR) in Korean schoolchildren aged 6-12 years. METHODS: Subjects were 4,554 children in Seoul, Korea. The risk of allergic disease was measured using the Korean version of the International Study of Asthma and Allergies in Childhood, and dietary intake was measured by a semi-quantitative food frequency questionnaire. Intake of vitamins A (including retinol and ß-carotene), C, and E was used in the analysis. RESULTS: Vitamin C intake was negatively associated with an increased risk of current symptoms (adjusted odds ratio, 0.886; 95% confidence interval, 0.806-0.973). There was no association between AR and intake of vitamin A, retinol, ß-carotene, or vitamin E. Total serum IgE level and sensitization to allergen did not differ according to nutrient intake. CONCLUSIONS: The group of children with increased vitamin C consumption had fewer AR symptoms, despite the lack of a difference in total serum IgE level or allergen sensitization. These findings suggest that nutrient intake, especially that of vitamin C, influences AR symptoms.

Epicutaneous exposure to staphylococcal superantigen enterotoxin B enhances allergic lung inflammation via an IL-17A dependent mechanism.

Atopic dermatitis (AD) is the initial step of the atopic march: the progression from AD to allergic rhinitis and asthma. There is a close association between skin barrier abnormalities and the development of AD and the atopic march. One of cardinal features of AD is that the lesional skin of the majority of AD patients is chronically colonized with Staphylococcus aureus with half isolates producing superantigen enterotoxin B (SEB). Although diverse roles of SEB in the pathogenesis and severity of AD have been recognized, whether SEB contributes to the dermal inflammation that drives lung inflammation and airway hyperresponsiveness (AHR) has not been examined. Here we show a novel role of S. aureus superantigen SEB in augmenting allergen ovalbumin (Ova) induced atopic march through an IL-17A dependent mechanism. When mice epicutaneously (EC) sensitized with allergen Ova, addition of topical SEB led to not only augmented systemic Th2 responses but also a markedly exaggerated systemic Th17/IL-17 immune environment. The ability of SEB in enhancing Th17/IL-17 was mediated through stimulating lymphocytes in spleen and draining lymph nodes to promote IL-6 production. Epicutaneous sensitization of mice with a combination of Ova and SEB significantly enhanced Ova-induced AHR and granulocytic lung inflammation than Ova allergen alone. When IL-17A was deleted genetically, the effects of SEB on augmenting lung inflammation and AHR were markedly diminished. These findings suggest that chronic heavy colonization of enterotoxin producing S. aureus in the skin of patients with atopic dermatitis may have an important role in the development of atopic march via an IL-17A dependent mechanism.

Gene-gene interactions between candidate gene polymorphisms are associated with total IgE levels in Korean children with asthma.

OBJECTIVE: To investigate associations between total serum immunoglobulin E (IgE) levels and single nucleotide polymorphisms (SNPs) from eight candidate genes (IL-4 rs2243250, IL-4Rα rs1805010, IL-13 rs20541, IL-13Rα1 rs2495636, CD14 rs2569190, tumor necrosis factor-alpha (TNF-α) rs1800629, cytotoxic T lymphocyte-associated antigen (CTLA4) rs231775, FCER1B rs1441585) in children with asthma and to evaluate gene-gene interactions. METHODS: A total of 669 Korean children with asthma (n = 544 atopic n = 125 non-atopic) were included. Asthma phenotypes, total serum IgE levels, and methacholine challenge test results were evaluated. SNPs were genotyped using the polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP) method. Multi-factor dimensionality reduction (MDR) was used to analyze gene-gene interactions. RESULTS: The combination of the IL-13, IL-13Rα1, and CTLA4 polymorphisms was selected through MDR analysis of the data pertaining to children with atopic and non-atopic asthma (accuracy = 0.5459, cross validation consistency (CVC) = 10/10). The IL-4Rα, IL-13, IL-13Rα1, CD14, and CTLA4 polymorphisms were selected as the best model of increased total serum IgE levels in non-atopic and atopic asthma (asthma: accuracy = 0.4726, CVC = 10/10; atopic asthma: accuracy = 0.4573, CVC = 10/10). Both the IL-4Rα and the IL-13 polymorphisms were correlated with the IgE level. ANOVA analysis revealed that the combinations of the CTLA4 and IL-13, IL-13 and IL-13Rα1, IL-4Rα and IL-13, and CD14 and IL-13 polymorphisms were all significantly associated with increased total serum IgE levels. CONCLUSIONS: The best model of increased IgE level included the IL-4Rα, IL-13, IL-13Rα1, CD14, and CTLA4 polymorphisms. Of the various interactions between these polymorphisms, the combinations of the CTLA4 and IL-13 polymorphisms and the IL-13 and IL-13Rα1 polymorphisms showed synergistic effects in terms of increased total serum IgE levels in the present cohort.