Makoto Kameda

Thymic Stromal Lymphopoietin Gene Promoter Polymorphisms Are Associated with Susceptibility to Bronchial Asthma

Thymic stromal lymphopoietin (TSLP) triggers dendritic cell--mediated T helper (Th) 2 inflammatory responses. A single-nucleotide polymorphism (SNP), rs3806933, in the promoter region of the TSLP gene creates a binding site for the transcription factor activating protein (AP)-1. The variant enhances AP-1 binding to the regulatory element, and increases the promoter--reporter activity of TSLP in response to polyinosinic-polycytidylic acid (poly[I:C]) stimulation in normal human bronchial epithelium (NHBE). We investigated whether polymorphisms including the SNP rs3806933 could affect the susceptibility to and clinical phenotypes of bronchial asthma. We selected three representative (i.e., Tag) SNPs and conducted association studies of the TSLP gene, using two independent populations (639 patients with childhood atopic asthma and 838 control subjects, and 641 patients with adult asthma and 376 control subjects, respectively). We further examined the effects of corticosteroids and a long-acting β(2)-agonist (salmeterol) on the expression levels of the TSLP gene in response to poly(I:C) in NHBE. We found that the promoter polymorphisms rs3806933 and rs2289276 were significantly associated with disease susceptibility in both childhood atopic and adult asthma. The functional SNP rs3806933 was associated with asthma (meta-analysis, P = 0.000056; odds ratio, 1.29; 95% confidence interval, 1.14-1.47). A genotype of rs2289278 was correlated with pulmonary function. Moreover, the induction of TSLP mRNA and protein expression induced by poly(I:C) in NHBE was synergistically impaired by a corticosteroid and salmeterol. TSLP variants are significantly associated with bronchial asthma and pulmonary function. Thus, TSLP may serve as a therapeutic target molecule for combination therapy.

Functional Analysis of the Thymic Stromal Lymphopoietin Variants in Human Bronchial Epithelial Cells

Thymic stromal lymphopoietin (TSLP) is an IL-7-like cytokine that triggers dendritic cell-mediated T helper (Th)2 inflammatory responses, and is implicated in the pathogenesis of allergic diseases in humans. Two TSLP splice variants have been reported. To find functional genetic variants that might contribute to disease, we conducted analyses of single nucleotide polymorphisms (SNPs) of the TSLP gene in human bronchial epithelial cells. We surveyed SNPs on the TSLP gene by sequencing genomic DNA from 36 subjects, and characterized the linkage disequilibrium of the gene. We examined whether the SNPs have functional effects on mRNA expression or protein production using real-time PCR, reporter gene analysis, and enzyme-linked immunosorbent assay. We identified a total of 23 polymorphisms in the TSLP gene. The long form of TSLP, which is associated with allergic inflammation, was highly induced by poly(I:C) (double-stranded RNA) stimulation in normal human bronchial epithelial cells (NHBE) (P = 0.0060). The SNP rs3806933 (-847C > T) in the promoter region of long-form TSLP was found to create a binding site for the transcription factor activating protein (AP)-1, and in vitro functional analyses demonstrated that the SNP enhanced AP-1 binding to the regulatory element. The functional variant increased promoter-reporter activity of long-form TSLP in response to poly(I:C) stimulation in NHBE. Functional genetic polymorphism of the TSLP gene appears to contribute to Th2-polarized immunity through higher TSLP production by bronchial epithelial cells in response to viral respiratory infections.

The GSTP1 Gene Is a Susceptibility Gene for Childhood Asthma and the GSTM1 Gene Is a Modifier of the GSTP1 Gene

Background: Bronchial asthma is a chronic airway disorder characterized by bronchial inflammation. Oxidative stress is a key component of inflammation. Glutathione S-transferase P1 (GSTP1), the abundant isoform of glutathione S-transferases (GSTs) in lung epithelium, plays a key role in cellular protection against oxidative stress. Several studies have shown that the GSTP1 geneis involved in the pathogenesis of asthma and a gene-gene interaction may occur within the GST gene superfamily. Methods: We screened single-nucleotide polymorphisms (SNPs) at the GSTP1 locus and performed an association study in the Japanese population using two independent case-control groups (group 1: 391 pediatric patients with asthma, 462 adult patients with asthma, and 639 controls, and group 2: 115 pediatric patients with asthma and 184 controls). The effect of GSTM1 null/present genotype on the association between GSTP1 Ile105Val and asthma was also investigated. Results: We identified 20 SNPs at this locus and found this region consisted of one linkage disequilibrium block represented by four SNPs (tag SNPs). The association between the Ile105Val polymorphism in the GSTP1 gene and childhood asthma was significant in both groups (p = 0.047 in group 1, and p = 0.021 in group 2). This association was only significant in patients with GSTM1-positive genotype in both groups (group 1: GSTM1 present p = 0.013 and GSTM1 null p = 0.925, and group 2: GSTM1 present p = 0.015 and GSTM1 null p = 0.362). Conclusions: These findings suggest that the GSTP1 gene is a childhood asthma susceptible gene, and the GSTM1 gene is a modifier gene of GSTP1 for the risk of childhood asthma in the Japanese population.

Japanese pediatric guidelines for the treatment and management of bronchial asthma 2008

The fourth version of the Japanese Pediatric Guidelines for the Treatment and Management of Bronchial Asthma 2008 (JPGL 2008) was published by the Japanese Society of Pediatric Allergy and Clinical Immunology in December 2008. In JPGL 2008, the recommendations were revised on the basis of the JPGL 2005. The JPGL 2008 is different to the Global Initiative for Asthma guideline in that it contains the following items: a classification system of asthma severity; recommendations for long‐term management organized by age; a special mention of infantile asthma; and an emphasis on prevention and early intervention. Here we show a summary of the JPGL 2008 revising our previous report concerning JPGL 2005.

An association study of asthma and related phenotypes with polymorphisms in negative regulator molecules of the TLR signaling pathway

AbstractAlthough associations between endotoxin exposure or respiratory infection and asthma have been recognized, the genetic effects in these conditions are unclear. Toll-like receptors (TLRs) play an essential role in innate host defense and in the control of adaptive immune responses. IL-1R-associated kinase-M (IRAK-M) and single immunoglobulin IL-1R-related molecule (SIGIRR) negatively regulate TLR-signaling pathways. To investigate whether polymorphisms in these genes were associated with asthma or asthma-related phenotypes, we screened these genes for polymorphisms by direct sequencing of 24 asthmatics and identified 19 variants in IRAK-M and 12 variants in SIGIRR. We next conducted linkage disequilibrium mapping of the genes, and examined the association of polymorphisms and haplotypes using 391 child patients with asthma, 462 adult patients with asthma, and 639 controls. None of the alleles or haplotypes of IRAK-M and SIGIRR were associated with asthma susceptibility or asthma-related phenotype. Our results indicate that polymorphisms in IRAK-M and SIGIRR are not likely to be associated with the development of asthma in the Japanese population.

Association study of the C3 gene with adult and childhood asthma

AbstractBronchial asthma (BA) is a multifactorial disorder, the development of which is affected by both environmental and genetic factors. The complement system plays an important role in immunological response against invading microorganisms. It has been shown that complement-C3-deficient mice have reduced inflammation of asthmatic airways. Previously, we reported the association of four single nuclear proteins (SNPs) in the exons of the C3 gene with childhood and adult BA. The C3 gene, however, is a large gene, and functional SNPs associated with susceptibility to BA have not yet been identified. We analyzed 26 SNPs in the C3 gene and its promoter region to narrow down the regions showing association with childhood and adult BA. Childhood and adult atopic BA patients and healthy child and adult controls were recruited from urban cities in Japan and genotyped. In SNP analysis, an SNP (SNP24, rs11569562) located in intron 31 of the C3 gene was associated with adult BA [corrected P (Pcor) = 0.030]. In linkage disequilibrium (LD) block 4 spanning exons 24-41, the frequency of the CCC haplotype in adult BA was significantly higher than that in adult controls (Pcor = 0.038). Neither the SNP nor the haplotype showing association with adult BA demonstrated a significant association with serum total immunoglobulin E (IgE) level in BA patients and controls. Our results suggest that LD block 4 confers susceptibility to adult BA with mechanisms relevant to the effector phase of allergic inflammation.

CD4 T-lymphocyte activation is associated with peak expiratory flow variability in childhood asthma

BACKGROUND Asthma has been recognized as a chronic inflammatory disorder of the airway. We have investigated the relationships among the activation markers on lymphocytes, eosinophils, their serum products in the peripheral blood, and the variability of airway obstruction in childhood asthma. METHODS Twenty-two patients with atopic asthma (mean age, 12 years) were treated regularly and asked to measure their peak expiratory flow (PEF) twice daily for 7 days, Peripheral venous blood was obtained on day 8. RESULTS The absolute counts of CD4 T lymphocytes expressing the activation marker CD25 in the peripheral blood on day 8 correlated significantly with the values of the coefficient of variation (CV) of both morning PEF (p < 0.01) and night PEF (p < 0.05) obtained over 7 days, but those of CD8+/CD25+ T lymphocytes, those of CD23+ B lymphocytes, and the serum concentrations of soluble CD25 did not. The absolute counts of peripheral blood eosinophils also demonstrated a significant correlation with the CV values of both morning PEF (p < 0.01) and night PEF (p <0.05). CONCLUSION CD4 T-lymphocyte activation and increased counts of eosinophils in peripheral blood correlate with CV of PEF in patients with asthma, suggesting that CV of PEF is a good marker for assessing not only the variability of airway obstruction but also the degree of airway inflammation.

Japanese pediatric guideline for the treatment and management of bronchial asthma 2012: Pediatric guideline for asthma

A new version of the Japanese pediatric guideline for the treatment and management of bronchial asthma was published in Japanese at the end of 2011. The guideline sets the pragmatic goal for clinicians treating childhood asthma as maintaining a “well‐controlled level” for an extended period in which the child patient can lead a trouble‐free daily life, not forgetting the ultimate goal of obtaining remission and/or cure. Important factors in the attainment of the pragmatic goal are: (i) appropriate use of anti‐inflammatory drugs; (ii) elimination of environmental risk factors; and (iii) educational and enlightening activities for the patient and caregivers regarding adequate asthma management in daily life. The well‐controlled level refers to a symptom‐free state in which no transient coughs, wheezing, dyspnea or other symptoms associated with bronchial asthma are present, even for a short period of time. As was the case in the previous versions of the guideline, asthmatic children younger than 2 years of age are defined as infantile asthma patients. Special attention is paid to these patients in the new guideline: they often have rapid exacerbation and easily present chronic asthmatic conditions after the disease is established.

Video-assisted thoracoscopic bullectomy for spontaneous pneumothorax in a Swyer-James syndrome patient

We treated a 15-year-old patient with spontaneous pneumothorax associated with Swyer-James syndrome using video-assisted thoracoscopic surgery (VATS). Thoracic computed tomography showed hyperlucent areas in the bilateral lungs. Due to major air leakage continuing for a week, we conducted VATS bullectomy. Because the opposite lung suffered hypoplasia, intermittent bilateral pulmonary ventilation was required to sustain an adequate PaO2 in arterial blood gas analysis during surgery. Because of recurrent pneumothorax, we performed reoperation 10 months later, finding a few newly generated bullae. To the best of our knowledge, this is the first report of VATS used to treat a Swyer-James syndrome patient with pneumothorax.

The use of complementary and alternative medicine by pediatric food-allergic patients in Japan.

Background: In developed countries, increasing food allergy prevalence and concern regarding food allergies have been reported. Although the use of complementary and alternative medicine (CAM) for the treatment of allergic diseases has increased in some Western countries, the actual proportion and patterns of CAM use for pediatric food allergies in Japan are still unknown. Methods: Fourteen allergy centers in Japan participated in the study using a questionnaire survey regarding the use of CAM by pediatric patients. A diagnosis of food allergy was made at each hospital by pediatric allergists. Results: Surveys were completed by parents/guardians, and data were collected for a total of 962 pediatric food-allergic patients. Overall, 8.4% of the participants used CAM to treat a food allergy. The major CAM therapies used were herbal teas (22.2%), including several Japanese herbal teas, Chinese herbal medicine (18.5%) and lactic acid bacteria (16%). Among the participants using CAM to treat food allergy, 13.6% thought that the CAM being used was very effective, while 11.1% of participants thought that CAM caused some type of side effect. Conclusions: Our study is the first large-scale national survey regarding the use of CAM in pediatric patients with food allergies in Japan. Unlike in the USA, which has a higher rate of CAM use (17%), approximately 8.4% of food-allergic patients used CAM in Japan. Interestingly, the major types of CAM used in Japan differed from those used in the USA. Cultural differences and food customs may affect the use of CAM.