乌鲁木齐支气管哮喘患儿α_1-抗糜蛋白酶杂合缺失的研究

Study on Heterozygous Deficiency in α_1-Antichymotrypsin of Children with Asthma in Urumqi

目的探讨α1-抗糜蛋白酶(α1-ACT)杂合缺失是否为乌鲁木齐儿童哮喘发病的遗传因素。方法随机选择本院儿科门诊和住院的无血缘关系哮喘儿童50例作为哮喘组,选择同期本院门诊健康体检的无血缘关系儿童50例作为健康对照组。采集2组儿童全血样本100份,哮喘组在哮喘缓解期采血,健康对照组在门诊体检时采血;采集2组19个汉族家庭父母的38份全血样本,用于家系调查。每份全血样本取1mL,柠檬酸钠-柠檬酸液抗凝,1500r·min-1离心5min,取上层血浆分装于小离心管中,应用火箭免疫电泳技术测定各组儿童血浆α1-ACT水平。家系调查确定α1-ACT杂合缺失患者。结果哮喘组患儿血浆α1-ACT水平[(0.273±0.056)g·L-1]与健康对照组[(0.271±0.053)g·L-1]比较,差异无统计学意义(t=0.023,P>0.05)。经家系调查后,哮喘组8例、健康对照组1例确定为α1-ACT杂合缺失,二组α1-ACT杂合缺失频率分别为16%、2%,哮喘组较健康对照组明显增高(χ2=2.325,P<0.05)。与非α1-ACT杂合缺失哮喘患儿比较,α1-ACT杂合缺失患儿哮喘初发年龄早(t=2.540,P<0.05),住院次数多(t=-8.380,P<0.001),放射性变应原吸附试验阳性率显著增高(χ2=15.152,P<0.01)。结论α1-ACT杂合缺失与乌鲁木齐儿童哮喘发病及其严重性存在一定联系。

Objective To explore whether the heterozygous deficiency in α1-antichymotrpsin （α1-ACT） is a factor in the pathogenesis of childhood asthma in Urumqi.Methods Fifty asthmatic children without consanguinity were randomly selected from pediatric outpatient and inpatient departments in Urumqi General Hospital as asthmatic group,while 50 cases of healthy children without consanguinity were randomly selected from pediatric outpatient department as healthy control group.One hundred whole blood samples were collected from the children in 2 groups.Whole blood samples in the asthmatic group were collected in remission,while those in the healthy control group were collected during the medical examination in outpatient department.Thirty-eight whole blood samples were collected from 19 Han families in 2 groups.Every sample included 1 mL whole blood and anticoagulat with citrated citric acid sodium.Each anticoagulated blood was centrifugated with 1 500 r·min-1 for 5 min,and then blood plasma in upper layer was sub-pachaged in small centrifuge tubes and eventually content was determined.The level of α1-ACT was examined with rocket immunoelectrophoresis.Heterozygous deficiency in α1-ACT was determined on the basis of family history.The clinical materials of asthmatic children with or without heterozygous α1-ACT deficiency were analyzed statistically.Results There was no significant difference in the level of serum α1-ACT in asthmatic group [（0.273±0.056） g·L^-1] and that in the healthy control group[（0.271±0.053） g·L^-1]（t=0.023,P〉0.05）.The heterozygous deficiency in α1-ACT including 8 cases in the asthmatic group and 1 case in healthy control group were found after family survey.The rate of heterozygous deficiency in α1-ACT was far higher in the asthmatic group than that in healthy control group（χ^2=2.325,P0.05）.Compared with children without heterozygous deficiency in α1-ACT,the children with heterozygous deficiency in α1-ACT experienced the first onset of asthma in a much younger age（t=2.540,P〈0.05）and hospitalized more frequently（t=-8.380,P〈0.001）,and they had a higher positive rate by radioallergosorbent test （χ^2=15.152,P〈0.01）.Conclusion There is a possible association of heterozygous deficiency in α1-ACT with childhood asthma and the severity of childhood asthma in Urumqi.