D. Y. Wang

Allergic rhinitis and its impact on asthma (ARIA) 2008 update (in collaboration with the World Health Organization, GA(2)LEN and AllerGen)

J. Bousquet, N. Khaltaev, A. A. Cruz, J. Denburg, W. J. Fokkens, A. Togias, T. Zuberbier, C. E. Baena-Cagnani, G. W. Canonica, C. van Weel, I. Agache, N. A t-Khaled, C. Bachert, M. S. Blaiss, S. Bonini, L.-P. Boulet, P.-J. Bousquet, P. Camargos, K.-H. Carlsen, Y. Chen, A. Custovic, R. Dahl, P. Demoly, H. Douagui, S. R. Durham, R. Gerth van Wijk, O. Kalayci, M. A. Kaliner, Y.-Y. Kim, M. L. Kowalski, P. Kuna, L. T. T. Le, C. Lemiere, J. Li, R. F. Lockey, S. Mavale-Manuel , E. O. Meltzer, Y. Mohammad, J. Mullol, R. Naclerio, R. E. O Hehir, K. Ohta, S. Ouedraogo, S. Palkonen, N. Papadopoulos, G. Passalacqua, R. Pawankar, T. A. Popov, K. F. Rabe, J. Rosado-Pinto, G. K. Scadding, F. E. R. Simons, E. Toskala, E. Valovirta, P. van Cauwenberge, D.-Y. Wang, M. Wickman, B. P. Yawn, A. Yorgancioglu, O. M. Yusuf, H. Zar Review Group: I. Annesi-Maesano, E. D. Bateman, A. Ben Kheder, D. A. Boakye, J. Bouchard, P. Burney, W. W. Busse, M. Chan-Yeung, N. H. Chavannes, A. Chuchalin, W. K. Dolen, R. Emuzyte, L. Grouse, M. Humbert, C. Jackson, S. L. Johnston, P. K. Keith, J. P. Kemp, J.-M. Klossek, D. Larenas-Linnemann, B. Lipworth, J.-L. Malo, G. D. Marshall, C. Naspitz, K. Nekam, B. Niggemann, E. Nizankowska-Mogilnicka, Y. Okamoto, M. P. Orru, P. Potter, D. Price, S. W. Stoloff, O. Vandenplas, G. Viegi, D. Williams

Effect of cetirizine, levocetirizine, and dextrocetirizine on histamine-induced nasal response in healthy adult volunteers.

Background: Cetirizine, an effective H1‐receptor antagonist, is a racemate mixture of two enantiomers: levocetirizine (R enantiomer) and dextrocetirizine (S enantiomer).

Opposing roles of IL-17A and IL-25 in the regulation of TSLP production in human nasal epithelial cells.

To cite this article: Xu G, Zhang L, Wang DY, Xu R, Liu Z, Han DM, Wang XD, Zuo KJ, Li HB. Opposing roles of IL‐17A and IL‐25 in the regulation of TSLP production in human nasal epithelial cells. Allergy 2010; 65: 581–589.

Genome-wide association study for atopy and allergic rhinitis in a Singapore Chinese population.

Allergic rhinitis (AR) is an atopic disease which affects about 600 million people worldwide and results from a complex interplay between genetic and environmental factors. However genetic association studies on known candidate genes yielded variable results. The aim of this study is to identify the genetic variants that influence predisposition towards allergic rhinitis in an ethnic Chinese population in Singapore using a genome-wide association study (GWAS) approach. A total of 4461 ethnic Chinese volunteers were recruited in Singapore and classified according to their allergic disease status. The GWAS included a discovery stage comparing 515 atopic cases (including 456 AR cases) and 486 non-allergic non-rhinitis (NANR) controls. The top SNPs were then validated in a replication cohort consisting of a separate 2323 atopic cases (including 676 AR cases) and 511 NANR controls. Two SNPs showed consistent association in both discovery and replication phases; MRPL4 SNP rs8111930 on 19q13.2 (ORu200a=u200a0.69, Pcombinedu200a=u200a4.46×10−05) and BCAP SNP rs505010 on chromosome 10q24.1 (ORu200a=u200a0.64, Pcombinedu200a=u200a1.10×10−04). In addition, we also replicated multiple associations within known candidates regions such as HLA-DQ and NPSR1 locus in the discovery phase. Our study suggests that MRPL4 and BCAP, key components of the HIF-1α and PI3K/Akt signaling pathways respectively, are two novel candidate genes for atopy and allergic rhinitis. Further study on these molecules and their signaling pathways would help in understanding of the pathogenesis of allergic rhinitis and identification of targets for new therapeutic intervention.

Allergic airway diseases in a tropical urban environment are driven by dominant mono‐specific sensitization against house dust mites

Southeast Asian populations are increasingly affected by allergic airway diseases. Etiology and specific causes, however, are still unknown. The aim of this study is therefore to identify allergens and risk factors for the high prevalence of allergic airway disease in the tropical urban environment.

Nuclear Magnetic Resonance Structure and IgE Epitopes of Blo t 5, a Major Dust Mite Allergen

A high incidence of sensitization to Blomia tropicalis, the predominant house dust mite species in tropical regions, is strongly associated with allergic diseases in Singapore, Malaysia, and Brazil. IgE binding to the group 5 allergen, Blo t 5, is found to be the most prevalent among all B. tropicalis allergens. The NMR structure of Blo t 5 determined represents a novel helical bundle structure consisting of three antiparallel α-helices. Based on the structure and sequence alignment with other known group 5 dust mite allergens, surface-exposed charged residues have been identified for site-directed mutagenesis and IgE binding assays. Four charged residues, Glu76, Asp81, Glu86, and Glu91 at around the turn region connecting helices α2 and α3 have been identified to be involved in the IgE binding. Using overlapping peptides, we have confirmed that these charged residues are located on a major putative linear IgE epitope of Blo t 5 from residues 76–91 comprising the sequence ELKRTDLNILERFNYE. Triple and quadruple mutants have been generated and found to exhibit significantly lower IgE binding and reduced responses in skin prick tests. The mutants induced similar PBMC proliferation as the wild-type protein but with reduced Th2:Th1 cytokines ratio. Mass screening on a quadruple mutant showed a 40% reduction in IgE binding in 35 of 42 sera of atopic individuals. Findings in this study further stressed the importance of surface-charged residues on IgE binding and have implications in the cross-reactivity and use of Blo t 5 mutants as a hypoallergen for immunotherapy.

The upper and lower airway responses to nasal challenge with house-dust mite Blomia tropicalis

Background: The house dust mite Blomia tropicalis (B.u2003tropicalis) was found to be the most prevalent domestic mite in Singapore. However, its pathogenicity in allergic airway diseases remains to be investigated.

Variability of bronchial inflammation in chronic obstructive pulmonary disease: implications for study design

There is variability in the distribution of inflammatory cells in bronchial tissue in chronic obstructive pulmonary disease (COPD). Better strategies for biopsy sampling of the airway mucosa may improve the capacity to show a difference between study populations where variability in distribution exists. The current authors have examined sources of biological variability in the quantification of inflammatory cells in endobronchial biopsies using immunostained samples taken from 51 subjects with COPD, with a mean forced expiratory volume in one second of 1.71u2005L, 55% predicted. The distribution of variance contributed by different sources was similar for different inflammatory cell types. For CD8+ cells, a key inflammatory cell in COPD, the largest contribution to intra-subject variability (39%) was time (i.e. 10 weeks between biopsies of placebo-treated subjects), followed by airway generation (23%), biopsy (2.5%), zone (within section; 1.4%) and section (0.4%). Power calculations demonstrated that examining one section from one biopsy, from each of two airway generations, would require a sample size of 32 subjects per group to show a difference of one doubling or halving in CD8+ cells, compared with 47 subjects per group if only one airway generation was sampled. Therefore, biopsies from more than one airway generation should be examined in order to maximise statistical power to detect a difference between study groups.

Poor Reproducibility of Allergic Rhinitis SNP Associations

Replication of reported associations is crucial to the investigation of complex disease. More than 100 SNPs have previously been reported as associated with allergic rhinitis (AR), but few of these have been replicated successfully. To investigate the general reproducibility of reported AR-associations in candidate gene studies, one Swedish (352 AR-cases, 709 controls) and one Singapore Chinese population (948 AR-cases, 580 controls) were analyzed using 49 AR-associated SNPs. The overall pattern of P-values indicated that very few of the investigated SNPs were associated with AR. Given published odds ratios (ORs) most SNPs showed high power to detect an association, but no correlations were found between the ORs of the two study populations or with published ORs. None of the association signals were in common to the two genome-wide association studies published in AR, indicating that the associations represent false positives or have much lower effect-sizes than reported.

Expression profiles of regulatory and helper T‐cell‐associated genes in nasal polyposis

Nasal polyposis (NP) is a Th2‐skewed inflammatory disorder, but it is unclear what role regulatory T cells (T‐reg) play in disease pathology. We investigated the expression profiles of T‐reg and T‐helper‐cell‐associated genes and their response to glucocorticosteroid (GC) treatment in Chinese patients with NP.