Relationship Between Asthma And β₂ Adrenergic Receptor Gene Polymorphism In Children Aged 6 To 12 Years From Different Areas Of Air Pollution In Taiyuan City

Objective:To investigate the relationship between asthma andβ₂ adrenergic receptor gene expression in children aged 6 to 12 years in different polluted areas of Taiyuan City.Methods:In Taiyuan,children with different air quality in three areas were selected.A total of181 children with asthma were included in the asthma group and 150 healthy children were included in the control group.Their serum total Ig E levels were measured by ELISA.Serum DNA was extracted and PCR was used to detect gene expression of arginine（Arg）/glycine（Gly）at site 16 and glutamine（Gln）/glutamic acid（Glu）at site 27ofβ₂ adrenergic receptor.The frequency of each genotype and allele was counted.The relationship between the level of serum total Ig E in the asthma group and the control group was compared,and the relationship between the level of contaminated areas and the level of serum total Ig E in different genotypes in the asthma group was compared.Meanwhile,the frequency distribution of different genotypes and gene frequencies were compared between asthma group and control group in different polluted areas.All results were analyzed using SPSS25.0 statistical software,and P<0.05 was considered statistically significant.Results:1.Compared with the control group,the serum total Ig E level in the asthmatic group was significantly higher,and the difference was statistically significant（P<0.05）.2.At different levels of air pollution,the serum total Ig E levels ofβ2 adrenergic receptor locus 16 and 27 genotypes in asthmatic children showed no significant difference（P>0.05）.3.There were significant differences in the frequency of different genotypes and alleles ofβ2 adrenergic receptor 16 sites in the three polluted areas in the asthma group（P<0.05）,but no significant differences in the control group（P>0.05）.For asthmatic children,air pollution level was positively correlated with the frequency of each genotype（rs=0.402,P<0.05）and the frequency of each allele（rs=0.243,P<0.05）.With the aggravation of air pollution,Arg/Arg genotype OR value gradually decreased to<1.0in the high-pollution area,and Gly/Gly genotype OR value gradually increased to>1.0in the high-pollution area.4.The frequency ofβ2 adrenergic receptor 27 genotypes in the three polluted areas was statistically different in the asthma group（P<0.05）,but not in the control group（P>0.05）.For asthmatic children,air pollution was negatively correlated with the frequency of each genotype（rs=-0.221,P<0.05）,and positively correlated with the frequency of each allele（rs=0.184,P<0.05）.OR values of Gln/Gln genotype and Glu/Glu genotype were all<1.0 and>1.0 in the three polluted areas.Conclusion:The polymorphisms ofβ₂ adrenergic receptor sites 16 and 27 detected under different air quality may not be correlated with serum total Ig E levels in asthmatic patients.Different levels of air pollution might be related to the polymorphism ofβ2adrenergic receptor locus 16 gene in children with asthma.The pollution level is positively correlated with the frequency of different genotypes in children with asthma.The more serious air pollution was,the less frequency of Arg/Arg genotype was,suggesting that this genotype may be a protective factor for asthma.The more serious the air pollution was,the more frequency of Gly/Gly genotype,suggesting that this genotype may be a risk factor for asthma.Different levels of air pollution may also be associated withβ2 adrenergic receptor 27 gene polymorphism in asthmatic children,and pollution levels is negatively correlated with the frequency of different genotype.Gln/Gln genotype may be a protective factor for asthma,and Glu/Glu genotype may be a risk factor for asthma.