OBJECTIVETo investigate the association of polymorphisms of STAT6 gene and air pollutants of PM(10), NO(2), and SO(2), with asthma in Chinese children.

METHODS418 subjects aged 14 years and under were recruited in a case-control study. The association between STAT6 polymorphisms and childhood asthma were tested by allele frequency, genotype analysis, and MDR analysis. Exposure to outdoor air pollutants was estimated by a 5-day moving average level. Statistical analyses were performed with SAS 9.1 software.

RESULTSOnly 3 alleles of GT repeats at exon 1 of STAT6 were found in Chinese children. C258T and T710C were 2 new SNPs of STAT6 at 3'-UTR. Children who carried T allele of C258T were more common in asthma children than in control subjects (P<0.05). The MDR analysis showed that GT repeats, C258T and T710C of STAT6 polymorphisms interacted together in leading to susceptibility to childhood asthma among Chinese people. After confounding factors were controlled, such as SNP C258T, family history of asthma, frequency of influenza within a year, the 5-day average of SO(2) was tested to be a key risk factor of asthma in Chinese children (P<0.05).

CONCLUSIONChinese children differed in polymorphisms of STAT6 and in its relation with childhood asthma.

Adolescent ; Air Pollutants ; toxicity ; Asian Continental Ancestry Group ; genetics ; Asthma ; chemically induced ; epidemiology ; genetics ; Case-Control Studies ; Child ; Child, Preschool ; China ; epidemiology ; Dinucleotide Repeats ; Female ; Genetic Predisposition to Disease ; Humans ; Male ; Polymorphism, Single Nucleotide ; STAT6 Transcription Factor ; genetics ; Sulfur Dioxide ; toxicity

The risk of asthma has been increasing in parallel with use of acetaminophen, which is a potential source of oxidative stress. Toll-like receptor 4 (TLR4) plays a critical role not only in innate immunity, but also in mediating reactive oxygen species induced inflammation. Therefore, we investigated associations between acetaminophen usage and TLR4 polymorphism on asthma and bronchial hyperresponsiveness (BHR). The number of 2,428 elementary school children in Seoul and Jeongeup cities was recruited. Subjects who used acetaminophen with a family history of asthma had an increased risk of both asthma diagnosis ever and current asthma. Individuals with CT+TT genotypes at the TLR4 polymorphism, in combination with acetaminophen usage, also demonstrated an increased risk of asthma diagnosis ever (aOR, 2.08; 95% confidence interval [CI], 1.10-3.92). Family history of asthma and acetaminophen usage were risk factors for BHR. Although TLR4 was not an independent risk factor for BHR, individuals with CT+TT genotypes at the TLR4 polymorphism had an increased risk of BHR when combined with acetaminophen usage (aOR, 1.74; 95% CI, 1.03-2.94). In conclusion, acetaminophen usage may be associated with asthma and BHR in genetically susceptible subjects. This effect may be modified by polymorphism at TLR4.
Acetaminophen/*adverse effects/therapeutic use ; Adolescent ; Asthma/chemically induced/epidemiology/*genetics ; Bronchial Hyperreactivity/chemically induced/epidemiology/*genetics ; Child ; Cross-Sectional Studies ; Eosinophils/immunology ; Female ; Genetic Predisposition to Disease ; Genotype ; Humans ; Immunoglobulin E/blood/immunology ; Inflammation/immunology ; Male ; Oxidative Stress/drug effects ; Polymorphism, Single Nucleotide ; Questionnaires ; Reactive Oxygen Species/immunology ; Risk ; Risk Factors ; Toll-Like Receptor 4/*genetics