Research Of Gene Polymorphism In Child Asthma And Asthmatic Bronchitis

Objective:â‘ To explore the correlation between asthmatic bronchitis and asthma in molecule level and provides the molecular biology evidence for asthma early diagnosis through analyzing genotypes and alleles frequency ofβ₂-adrenergic receptors(β₂-AR) 16,27 loci in asthmatics bronchitis and child asthma, and the characteristic of the plasma concentration of total IgE and the peripheral blood eosinophil (EOS) count in each genotypes.â‘¡To find the risk factors of infant asthma coming from asthmatics bronchitis and provides the basic consideration for intervention of early asthma in kids.Methods: All objects were enrolled in this study coming from outpatients and inpatients in the department of pediatric of southwest hospital. Two hundred and seveteen cases (135 boys and 82 girls) with unrelated asthma (mean age 5.5yr, 1.1yr to 17yr) and fifty healthy children (32 boys and 18 girls) (mean age 4.9yr, 2yr to 13yr) were enrolled from Oct 2006 to Sep 2007. One hundred and nineteen cases (78 boys and 41 girls) with asthmatics bronchitis (mean age 1.8yr, 0.3yr to 2.9yr) were enrolled from Oct 2006 to Feb 2007. All objects were Chongqing affiliation, the Han Nationality children. Every case enrolled in this study was surveyed by retrospectively questionnaire. The questionnaires included the medical history, individual allergic history (eczema, allergic rhinitis, food drug allergy and so on), the family history (parents'history with asthma and allergic, history of second level relative with asthma and allergic and so on) and breast milk feeding. The genotypes and alleles frequency ofβ₂-adrenergic receptors (β₂-AR) 16 and 27 loci in asthmatic bronchitis group, child asthma group and control group were detected with PCR restriction fragment analysis. The frequency of genotype and loci ofβ₂-AR 16 and 27 in three groups were compared. The plasma concentration of total IgE were detected with enzyme linked immunosorbent assay (ELISA). The total IgE in three groups and the total IgE of each genotype were compared. The peripheral blood eosinophil (EOS) count was determined with eosin staining method. The asthmatic bronchitis infants were followed-up for 12 months in order to analyze the risk factors of child asthma coming from asthmatic bronchitis.Result :â‘ There was no significant difference in the frequencies of genotypes (Arg/Arg 0.37,Arg/Gly 0.51,Gly/Gly 0.12) and alleles (Gly 0.37)β₂-AR 16 loci in asthma group compared with control group (P>0.05). There was no significant difference in the frequencies of genotypes (Arg/Arg 0.35,Arg/Gly 0.48,Gly/Gly 0.17) and alleles (Gly 0.41)β₂-AR 16 loci in asthmatic bronchitis group compared with in asthma group and control group (P>0.05). The frequency of Glu/Glu genotype (0.20) and alleles (Glu 0.48)β₂-AR 27 loci in asthma group was significant lower than control group (P<0.05). There was no significant difference in asthmatic bronchitis group (Glu/Glu 0.26, Glu 0.51) compared with control group and asthmatic group (P>0.05).â‘¡The plasma concentration of total IgE and the EOS count of the asthma group with acute episode were significantly higher than the normal control group and the asthmatic bronchitis (P<0.05). The total plasma concentration of IgE and the EOS count of the asthmatic bronchitis were higher than those of control group (P<0.05).â‘¢There were no significant difference in plasma total IgE among the three genotypesβ₂-AR 16 loci (P>0.05). The IgE level of Gln/Gln was significant higher than Glu/Glu and Gln/Glu in asthma and asthmatic bronchitis group (P<0.05), and there was no difference between Glu/Glu and Gln/Glu (P>0.05).â‘£One hundred and nineteen cases with asthmatic bronchitis infants were followed-up for 12 months. 108 cases were followed-up successfully, 66 cases (61.11%) had two times gasp episode explicitly and been diagnosed child asthma, and been called asthma group, 42 cases (38.89%) had not gasp episode again and been called asthmatic bronchitis group. Seven kinds of risk factors were conducted on the single factor analysis. Individual eczema history, individual allergic history, mother allergy history, father allergy history and breast milk feeding insufficient 4 months were considered statistically significant for child asthma coming from asthmatic bronchitis (P<0.05). Logistic analysis discovered that individual eczema history (OR=2.820,95%CI:1.107～7.184, P<0.05), individual allergic history (OR=2.756,95%CI:1.097～6.925,P<0.05), mother allergy history (OR=2.860,95%CI:1.070～7.642, P<0.05), breast milk feeding insufficient 4 months (OR=2.901,95%CI:1.176～7.155, P<0.05) were risk factors of child asthma coming from asthmatic bronchitis. The plasma concentration of total IgE and the EOS count of the asthma group coming from asthmatic bronchitis were significantly higher than the asthmatic bronchitis group (P<0.05).Conclusion:①β₂-AR16 locus genetic polymorphism is not correlated with child asthma and asthmatic bronchitis. Asthmatic bronchitis is correlated with asthma inβ₂-AR 27 locus genetic polymorphism. Especially, the asthmatic bronchitis with Gln/Gln genotypeβ₂-AR27 loci and high total IgE can be considered correlated with earlier asthma closely.â‘¡The total plasma concentration of IgE and the EOS count are not only parameters of the immunity pathological change of the child asthma, but also characteristics of asthmatic bronchitis. Asthmatic bronchitis has similar pathology process as asthma.â‘¢The IgE level ofβ₂-AR27 loci Gln/Gln is significant higher than other genotypes in asthmatic bronchitis as same as child asthma. So the asthmatic bronchitis infant with Gln/Gln genotypeβ₂-AR27 loci and high total IgE can be considered correlated with child asthma closely.â‘£The risk factors of child asthma coming from asthmatic bronchitis are individual eczema history, individual allergic history, mother allergy history, breast milk feeding insufficient 4 months. The child sex, father allergy history and history of second level relative with asthma and allergic are not the risk factor of child asthma. So child asthma is the result of many factors interaction. The asthmatic bronchitis with risk factors and higher the total plasma concentration of IgE and the EOS count will be possibly developed asthma, and they should be highly noticed and be carried out prophylactic intervention measure in order to degrade the incidence of child asthma.