IFNγCA重复序列多态性与呼吸道合胞病毒毛细支气管炎易感性的关系

The association of IFNγ CA short tandem repeat gene polymorphism with the susceptibility of respiratory syncytial virus bronchiolitis

目的研究IFNγ基因第一内含子区CA重复序列多态性与RSV毛细支气管炎易感性的关系,探讨影响儿童发生RSV毛细支气管炎的宿主遗传因素。方法采用毛细管电泳法对168例RSV毛细支气管炎、215例非RSV肺炎住院患儿及88例健康儿童IFNγ基因第一内含子区CA重复序列进行检测,同时用ELISA方法测定50例RSV毛细支气管炎患儿、50例非RSV肺炎患儿血清IFN-γ的浓度,并采用呼吸评分法对RSV毛细支气管炎患儿进行RSV感染严重度的评估。结果①RSV毛细支气管炎组中(CA12)+/(CA12)+占8.93%,(CA12)+/(CA12)-占58.33%,(CA12)-/(CA12)-占32.74%,而非RSV肺炎组中(CA12)+/(CA12)+占19.53%,(CA12)+/(CA12)-占52.09%,(CA12)-/(CA12)-占28.37%,两组IFNγCA重复序列基因多态性差异有统计学意义(2χ=8.392,P=0.015)。②RSV毛细支气管炎患儿IFNγCA重复12次的频率为38.10%,低于非RSV肺炎组45.58%,差异有统计学意义(2χ=4.331,P=0.037)。③RSV毛细支气管炎组中血清IFNγ浓度(pg/ml)(M=6.22,P25=2.21,P75=18.34)低于非RSV肺炎组(M=10.07,P25=5.12,P75=29.67),差异有统计学意义(Z=2.096,P=0.036)。④IFNγCA重复12次的患儿血清IFNγ浓度高于CA重复非12次者,差异有统计学意义(P<0.05)。⑤IFNγCA重复12次的患儿临床呼吸评分(2.91±0.46)低于CA重复序列非12次者(3.0±0.43),差异有统计学意义(t=2.005,P=0.047)。结论IFNγ基因CA重复序列多态性与RSV毛细支气管炎易感性有关,当CA重复序列12次时其血清IFNγ水平较高,病情较轻,发展为重症RSV毛细支气管炎的可能性较低。

Objectives To explore the association of IFN3, CA short tandem repeat gene polymorphism with the susceptibility of respiratory syncytial virus （RSV） bronchiolitis. Methods One hundred and sixty-eight children hospitalized for RSV bronchiolitis （RSV group）, 215 children hospitalized for pneumonia but not RSV infection （non-RSV group）, and 88 healthy control children have been recruited. All enrolled children were under 2 years old. The IFNγ, CA short tandem repeat was defined by capillary electrophoresis in all subjects. The IFNγ, level was measured by ELISA in 50 subjects in RSV group and non-RSV group respectively. Respiratory score has been chosen to evaluate the severity of RSV infection. Results （1） The frequency of （CA12）^＋/（CA12）^＋, （CA12）^＋/（CA12）^-, and （CA12）^-/（CA12）^- were 8.93%, 58.33%, and 32.74% in RSV group respectively. These frequencies were 19.53%, 52.09%, and 28.37% in non-RSV group respectively. There is a significant difference in the frequency distribution between two groups （X^2 = 8.392, P = 0.015）. （2） The frequency of IFN3, CA repeat 12 times was 38.10% in RSV group, which was significantly less than that was 45.58% in non-RSV group （X^2 = 4.331, P = 0.037）. （3） The mean level of IFNγ （pg/ml） was 6.22 （P25 = 2.21, P75 = 18.34） in RSV group and 10.07 （P25 = 5.12, P75 = 29.67） in non-RSV group. The difference was significant （Z = 2.096, P = 0.036）. （4） The subjects whose IFNγ, CA repeat was 12 times had a high IFNγ, level than whose non-12 times. A significant difference was found （P 〈 0.05）. （5） The respiratory score was 2.91 ± 0.46 in the 12 times CA repeat subjects and 3.0 ± 0.43 in the non-12 times CA repeat subjects. The difference was significant （t = 2.005, P = 0.047）. Conclusions These findings supported that IFNγ, CA short tandem repeat is associated with the susceptibility of RSV bronchiolitis. The 12 times IFNγ, CA repeat subjects had a higher lever of IFNγ and a less severity of RSV bronchiolitis than non-12 times CA repeat subjects.