G. W. K. Wong

Effects of air pollution on asthma hospitalization rates in different age groups in Hong Kong

Aims To assess the relationship between levels of ambient air pollutants and hospitalization rates for asthma in Hong Kong (HK).

Asthma and atopy are associated with chromosome 17q21 markers in Chinese children

Background:u2002 Single‐nucleotide polymorphism (SNP)‐based genome‐wide association study revealed that markers on chromosome 17q21 were linked to childhood asthma but not atopy in Caucasians, with the strongest signal being detected for the SNP rs7216389 in the ORMDL3 gene. Such association was unknown in Chinese. This study delineated the allele and genotype frequencies of 10 SNPs at chromosome 17q21, and investigated the relationship between these SNPs and asthma and plasma IgE in southern Chinese children.

Declining asthma prevalence in Hong Kong Chinese schoolchildren

Background Many studies have reported an increase in the prevalence of asthma and related atopic disorders. The lack of standardized methodologies and ‘objective’ measurements make reliable comparison and monitoring of trends of asthma very difficult.

How well do questionnaires perform compared with physical examination in detecting flexural eczema? Findings from the International Study of Asthma and Allergies in Childhood (ISAAC) Phase Two

Backgroundu2002 Questionnaires are widely used in epidemiological studies to measure eczema symptom prevalence, but there are concerns regarding their accuracy if used as a diagnostic tool.

Temporal relationship between air pollution and hospital admissions for asthmatic children in Hong Kong.

Background Many epidemiological studies have shown positive association between respiratory health and current levels of outdoor air pollution in Europe and America.

Asthma epidemiology in the Far East.

Asthma has become a major health issue worldwide [1]. The rising trends of prevalence and mortality not only occur in western countries [2-7] . but are also evident in some countries in the Far East [8-11]. Although epidemioiogical data on asthma are still relatively few in the latter region, interest has been growing amongst local researchers to investigate its prevalence, mortality and associated risk factors. With its diverse cultural, socioeconomic and racial background, as well as the rapid growing economy and urbanization., the Far East provides an ideal setting for epidemiologists to explore the role of genetic and environmental factors in the pathogenesis of asthma. In this article we will review existing data on asthma prevalence and mortality in the region. particularly focusing on their time trends and variations between populations of different geographical locations and of dillcrent ethnic origins.

Increased macrophage-derived chemokine in exhaled breath condensate and plasma from children with asthma

Background Type 2 helper T lymphocyte‐specific chemokines including macrophage‐derived chemokine (MDC), thymus and activation‐regulated chemokine (TARC) and eotaxin are important mediators for allergic airway inflammation.

Symptoms of asthma and atopic disorders in preschool children: prevalence and risk factors

Background Published epidemiological data suggested that asthma and allergies may be increasing in preschool children. Identification of the risk factors is important for planning possible early intervention to prevent asthma. This study was designed to measure the prevalence of, and risk factors for, asthma and atopic disorders in preschool children from Hong Kong.

Validation of the Chinese translated version of ISAAC core questions for atopic eczema

Background The International Study of Asthma and Allergies in Childhood (ISAAC) was designed to allow international comparison of epidemiological data on atopic conditions in childhood. In so doing, further aetiological information would be obtained that in turn would provide a framework for future studies. The global ISAAC results on the prevalence of atopic dermatitis indicated a 60‐fold variation recorded in different countries. Such a degree of difference may be partially due to the translated questionnaires that were not validated in all of the involved countries.

Asthma and atopy are associated with DEFB1 polymorphisms in Chinese children

Human β-defensin (HBD)-1 is constitutively expressed in the airway, and hBD-1 plays crucial roles in innate immunity against respiratory pathogens. Asthma was associated with DEFB1 polymorphisms in Caucasians. This study investigates whether three single nucleotide polymorphisms (SNPs) in 5′-untranslated region of DEFB1 are associated with asthma phenotypes in Chinese children. Subjects aged 5–18 years were recruited from general pediatric clinics. Plasma IgE concentrations were measured by immunoassays. DEFB1 SNPs were characterized by restriction fragment length polymorphism. In all, 305 asthmatics and 156 controls were recruited. For asthma diagnosis, atopy and plasma total IgE, higher percentages of subjects with these outcomes had the minor alleles −20A and −52G (P=0.041–0.0002). For log-transformed total IgE, the covariate was positive and significant for G-20A under recessive model (P=0.001) and for G-52A under both recessive and codominant models (P=0.008 and 0.035). The recessive model covariate was also positive and significant (P=0.020) for C-44G on peripheral blood eosinophil count. The GCA haplotype of DEFB1 was significantly associated with asthma (odds ratio (95% confidence interval): 1.64 (1.05–2.57); P=0.029). These results suggest that DEFB1 is a candidate gene for asthma and atopy in children.