Joo Shil Lee

Allergic Diseases in Preschoolers Are Associated With Psychological and Behavioural Problems

Purpose The aim of the present study was to investigate the relationship between three major allergic diseases, asthma, allergic rhinitis (AR), and atopic dermatitis (AD), and psychological and behavioural problems in preschoolers based on a community survey. Methods A cross-sectional survey was conducted using a modified International Study of Asthma and Allergies in Childhood questionnaire to determine the prevalence of symptoms and diagnosed allergic diseases, and a Korean version of the Child Behaviour Checklist to assess internalizing, externalizing, and sleep problems among 780 preschoolers. Five-hundred and seventy-five preschoolers with valid data were included in this study. Results The prevalence of lifetime diagnosis and treatment in the past 12 months was 8.7% and 4.4% for asthma, 24.4% and 19.2% for AR, and 35.1% and 16.6% for AD, respectively. Scores for internalizing and sleep problems were significantly higher in those diagnosed with AR. Preschoolers who had been treated for AD in the past 12 months had higher attention problem and attention-deficit/hyperactivity disorder scores. Sleep problems were more severe in moderate to severe AD compared to control and mild AD groups, categorised according to SCOring index of AD. The severity of sleep problems correlated positively with the percentage of eosinophils in peripheral blood. Conclusions Psychological and behavioural problems differed among the three major allergic diseases, weaker association for asthma and stronger association for AR and AD. The results of this study may lead to the identification of potential underlying shared mechanisms common to allergic diseases and psychological and behavioural problems.

Optimization of Allergen Standardization

Preparation of high quality allergen extracts is essential for the diagnosis and immunotherapy of allergic disorders. Standardization of allergen extracts concerns determination of the allergen unit, development of reference material and measurement of the overall IgE binding capacity of an allergen extract. Recently, quantification of individual allergens has been the main focus of allergen standardization because the allergenicity of most allergen extracts is known to be mainly dependent on the content of a small number of allergen molecules. Therefore, characterization of major allergens will facilitate the standardization of allergens. In this article, we review the current state of allergen standardization. In addition, we briefly summarize the components of allergen extracts that should be under control for the optimization of allergen standardization, since its adjuvant-like activities could play an important role in allergic reactions even though the molecule itself does not bind to the IgE antibodies from subjects.

Assessment of Total/Specific IgE Levels Against 7 Inhalant Allergens in Children Aged 3 to 6 Years in Seoul, Korea

Purpose Childhood allergies are a serious problem, as they may lead to lifetime chronic disease. Determination of total and specific IgE levels is known to be a diagnostic tool for allergic sensitization; however, IgE levels are affected by various factors, such as age, sex, ethnicity, and geographic area. Thus, we evaluated the distribution of total and specific serum IgE levels against seven inhalant allergens in preschool children and examined their association with allergic diseases in Seoul, Korea. Methods Total/specific serum IgE determination and skin prick tests for seven common allergens were performed on 509 children aged 3 to 6 years from 16 child care centers in Seoul, Korea. Demographic characteristics were surveyed from parents using a modified International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. A diagnosis of atopic dermatitis was made by physicians. Results The geometric mean of total IgE was 80.48±3.80 kU/L in preschool children. IgE levels were higher in boys (boys, 102.34±3.52 kU/L; girls, 62.37±3.93 kU/L; P<0.001) and atopic subjects (atopic, 158.00±3.35 kU/L; non-atopic, 52.75±3.44 kU/L; P<0.001). An increased prevalence of atopy was associated with a high monthly household income (P=0.004) and higher maternal education level (above university-level education; P=0.009), as well as increased total IgE levels (P=0.036). Physician-diagnosed atopic dermatitis was associated with sensitization to inhalant allergens. Conclusions Total IgE levels were very high as compared with those in previous reports from other countries. The most common sensitized allergen was Dermatophagoides farinae, and the positive response rate peaked at age 3 years and was maintained thereafter, particularly in boys. Specific IgE levels for seven inhalant allergens varied with age in preschool children. Although further investigations are needed with a broad range of ages and various allergens, the distribution of the total and specific serum IgE levels in preschool children might help to serve as a reference value to diagnose atopy.

Fraction of exhaled nitric oxide and wheezing phenotypes in preschool children.

Asthma is a chronic lower airway inflammatory disease. Nitric oxide is an inflammatory mediator produced endogenously in the airway. Previous studies have demonstrated that the fractional concentration of exhaled nitric oxide (FeNO) is increased in asthma.

Standardization of House Dust Mite Extracts in Korea

Purpose House dust mites are the most important cause of respiratory allergy in Korea. Standardization of allergen extracts is essential for improving diagnostics and immunotherapeutics. This study was undertaken to evaluate the allergenicity of standardized house dust mite allergen extracts from Korean house dust mite isolates. Methods Allergen extracts were prepared from cultured Korean house dust mites (Dermatophagoides farinae and D. pteronyssinus). Allergenic activities of Korean house dust mite extracts were compared to standardized extracts from a company in the United States whose allergen concentrations were expressed as Allergy Units (AUs). Specifically, we compared group 1 and 2 major allergens using two-site enzyme-linked immunosorbent assay (ELISA) kits and an in vivo intradermal test. Results Major allergen concentrations were 17.0 µg/mg (5.0 µg/mg of Der f 1 and 12.0 µg/mg of Der f 2) for a D. farinae extract and 24.0 µg/mg (11.6 µg/mg of Der p 1 and 12.4 µg/mg of Der p 2) for a D. pteronyssinus extract. Using chloramphenicol (CAP) inhibition assays, AUs were 12.5 AU/µg for a D. farinae extract and 12.8 AU/µg for a D. pteronyssinus extract. Allergenic activities were 3- to 4-fold stronger when assessed by intradermal skin tests for in vivo standardization. Conclusions Allergen extracts were prepared from Korean house dust mites and the allergenicities of the extracts were estimated using AU measurements. House dust mite extracts prepared in this study could be utilized as a reference material, which will be useful for the development of diagnostic and immunotherapeutic reagents in Korea.

Interactions Between Innate Immunity Genes and Early-Life Risk Factors in Allergic Rhinitis

Purpose Allergic rhinitis (AR) is a common chronic disease. Many factors could affect the development of AR. We investigated early-life factors, such as delivery mode, feeding method, and use of antibiotics during infancy, which could affect the development of AR. In addition, how interactions between these factors and innate gene polymorphisms influence the development of AR was investigated. Methods A cross-sectional study of 1,828 children aged 9-12 years was conducted. Three early-life factors and AR were assessed by a questionnaire. Skin prick tests were done. Polymorphisms of TLR4 (rs1927911) and CD14 (rs2569190) were genotyped. Results Use of antibiotics during infancy increased the risk of AR (aOR [95% CI] 1.511 [1.222-2.037]) and atopic AR (aOR [95% CI], 1.565 [1.078-2.272]). There were synergistic interactions between caesarean delivery, formula feeding, and use of antibiotics in the rate of atopic AR (aOR [95% CI], 3.038 [1.256-7.347]). Additional analyses revealed that the risk for the development of AR or atopic AR subjects with the TLR4 CC genotype were highest when all the 3 early-life factors were present (aOR [95% CI], 5.127 [1.265-20.780] for AR; 6.078 [1.499-24.649] for atopic AR). In addition, the risk for the development of AR or atopic AR in subjects with the CD14 TT genotype were highest when all the 3 early-life factors were present (aOR [95% CI], 5.960 [1.421-15.002] for AR; 6.714 [1.440-31.312] for atopic AR). Conclusions Delivery mode, feeding method, and use of antibiotics during infancy appeared to have synergistic interactions in the development of AR. Gene-environment interactions between polymorphism of innate genes and early- life risk factors might affect the development of AR.

Clinical Application of Exhaled Nitric Oxide Measurements in a Korean Population

Nitric oxide (NO) is a biologic mediator of various physiologic functions. Recent evidence suggests the clinical utility of fractional exhaled NO (FeNO) as a biomarker for assessing asthma and other respiratory diseases. FeNO methodologies have been recently standardized by international research groups and subsequently validated in several Korean population studies. Normal ranges for FeNO have been reported for various ethnic groups, and the clinical utility has been widely evaluated in asthma and various respiratory diseases. Based on current evidence including most of Korean population data, this position paper aims to introduce the methodological considerations, and provide the guidance for the proper clinical application of FeNO measurements in Korean populations.

Reference Values of Impulse Oscillometry and Its Utility in the Diagnosis of Asthma in Young Korean Children

Aims. The aims of this study were (1) to determine the reference values for impulse oscillometry (IOS) and (2) to apply them to the evaluation of asthma in the general population of young Korean children. Methods. We performed a questionnaire survey and IOS measurements in 390 children aged 3–7 years in Seoul and Gyeonggi province, Korea, from July to August 2010. IOS measurements included respiratory resistance (Rrs) and respiratory reactance (Xrs) at 5, 10, 15, 20, 25, and 35 Hz, respiratory impedance (Zrs), and resonance frequency (RF) before and 15 min after inhalation of 200 μg salbutamol. To determine the reference values for IOS, 161 children defined as healthy controls were assessed. Results. The IOS measurements were presented as means and standard deviations. The reference equations for IOS variables were determined by multiple linear regression analysis taking into account their height, weight, and age (R5 = 2.242 – 0.008 × height (cm) – 0.005 × age (months), coefficients of determination (R2) = 0.213). Height had the greatest correlation with IOS variables, similar to previous studies. Positive airway obstruction was defined as R5 greater than the 95th percentile of predicted R5 from the reference equation. There was a higher percentage of children with positive airway obstruction in children with asthma than in healthy controls (27.3% vs. 6.2%). Multivariate logistic regression analysis indicated that positive airway obstruction was a significant risk factor for the diagnosis of asthma (adjusted odds ratio (aOR), 6.245; 95% confidence interval (CI), 2.270–17.175). Conclusion. This study provided reference values for IOS in young Korean children and applied the reference values to evaluate children with asthma. We suggest the 95th percentile of predicted R5 as a cut-off value for positive airway obstruction, which may increase the risk for diagnosis of asthma.

Association between menarche and increased bronchial hyper-responsiveness during puberty in female children and adolescents.

Bronchial hyper‐responsiveness (BHR) is a key feature of asthma. The degree of BHR in children may be altered by several factors. We evaluated the prevalence of BHR according to age and gender in pediatric and adolescent population and analyzed the associated factors for gender differences.

Anxiety and depressive symptoms among patients infected with human immunodeficiency virus in South Korea

Patients infected with human immunodeficiency virus (HIV) may develop mental health problems such as anxiety and depression, which negatively impact of disease progression. We investigated factors associated with the prevalence of anxiety and depression symptoms among HIV-infected patients in Korea. A total of 840 HIV-infected patients who participated in the Korea HIV/AIDS Cohort Study from 2006 to 2012 were evaluated. Socio-demographic, epidemiologic, and clinical variables were obtained through standardized questionnaires. The State-Trait Anxiety Inventory and Beck Depression Inventory were used to assess the symptoms of anxiety and depression. Multiple logistic regression analyses were performed to identify factors associated with symptoms of anxiety and depression. The prevalence of anxiety and depressive symptoms among HIV-infected patients was 32% and 36%, respectively. Ex-smoker and persistent symptoms for more than one week within the past six months and diagnosis of HIV infection within one year were associated with increased anxiety symptoms (odds ratio [OR] 1.71, 95% confidence interval [CI] 1.09–2.69; OR 1.52, 95% CI 1.09–2.11; OR 1.49, 95% CI 1.02–2.20) and current smoking and persistent symptoms were also associated with increased depressive symptoms (OR 2.10, 95% CI 1.31–3.30; OR 1.87, 95% CI 1.25–2.79). Marital status, current smoking, current drinking, and persistent symptoms were associated with both increased anxiety and depressive symptoms (OR 1.75, 95% CI 1.07–2.88; OR 1.66, 95% CI 1.06–2.61; OR 1.88, 95% CI 1.18–2.99). The prevalence of anxiety and depressive symptoms among HIV-infected patients is higher than those estimated for the general population. This study shows the necessity to evaluate symptoms of anxiety and depression and suggest psychological support for HIV-infected patients who smoke or have persistent symptoms or have sexual partner or drink.