干扰素γCA重复序列基因多态性与宫内乙型肝炎病毒感染易感性的关系

IFN-γ CA short tandem repeat gene polymorphism is associated with susceptibility to intrauterine HBV infection

目的 了解宫内乙型肝炎病毒(HBV)感染儿童干扰素-γ(IFN -γ)CA重复序列基因多态性与宫内HBV感染易感性的关系,探讨宫内HBV感染的遗传易感因素。方法 母亲为HBV携带者,新生儿出生后按程序使用乙型肝炎疫苗或乙型肝炎疫苗联合乙型肝炎免疫球蛋白进行免疫。出生时外周静脉血HBsAg和(或)HBV- DNA阳性并持续阳性6个月以上者为宫内HBV感染者(Ⅰ组)。出生时及以后随访中未曾出现过HBsAg或HBV- DNA阳性,1岁时抗HBs达保护滴度以上者为正常免疫儿童(Ⅱ组)。选取Ⅰ组42例,Ⅱ组68例,用毛细管电泳法对IFN -γCA重复序列基因多态性进行测定。结果 在42 例宫内HBV感染组儿童中IFN- γCA重复序列基因多态性(CA12 )+/(CA12)+减少,42 例中仅有5 例,占11.90%, (CA12 )+/(CA12 )- 占26. 19%, (CA12 )-/(CA12 )- 占61.91%;正常免疫儿童IFN γ( CA12 )+/( CA12 )+ 占26. 47%, ( CA12 )+/( CA12 )- 占33. 82%,(CA12)-/(CA12)-占39.71%。宫内HBV感染组与正常免疫组比较趋势(P=0.0176),宫内HBV感染儿童(CA12)+/(CA12)+较正常免疫儿童减少。宫内HBV感染儿童IFN γCA重复12次的频率为25%,比正常免疫儿童IFN- γCA重复12次的频率43.38%明显降低,χ2 =7.548,P=0.0060,差异有统计学意义。结论 提示IFN -γ重复序列基因多态性可能?

Objective To explore the susceptibility of children to develop intrauterine hepatitis B virus (HBV) infection through studying the association between IFN-γ CA short tandem repeat gene polymorphism and intrauterine HBV infection. Methods The subjects were selected from outpatients who were in our hepatitis B(HB) vaccine following-up clinics. These subjects whose mothers were HBV carriers were inoculated with HB vaccine or HB vaccine and hepatitis B immunoglobulin(HBIg) on procedure. Intrauterine HBV infection children were defined that peripheral blood were HBsAg and/or HBV DNA positive at birth and lasting for six months (group Ⅰ). Immunocompetent children were defined that serum HBV marker were negative for HBV marker after birth and HBsAb titers were above protective level(group Ⅱ). The subjects were composed of two groups. The group Ⅰ consisted of 42 children with intrauterine HBV infection. The group Ⅱ was composed of 68 normal children. IFN-γ CA short tandem repeat gene polymorphism was tested in both groups by capillary electrophoresis. Results IFN-γ CA short tandem repeat gene polymorphism was tested successfully. (CA_(12))^+/(CA_(12))^+ of IFN-γ CA short tandem repeat polymorphism was 11.90% in the intrauterine HBV infection group, and 26.47% in the immunocompetent children group. A significant difference was found in the frequency distribution between two groups(χ~2=5.64,P=0.0176).Frequency of IFN-γ CA repeat 12 times was 25% in the intrauterine HBV infection group, and 43.38% in the normal immune children group. In the intrauterine HBV infection group the frequency of IFN-γ CA repeat 12 times was more less than normal immune group. A significant difference was found in the frequency distribution between two groups(χ~2=7.548,P=0.0060). Conclusions IFN-γ CA short tandem repeat gene polymorphism was associated with intrauterine HBV infection. IFN-γ CA short tandem repeat gene polymorphism might play an important role in determining the susceptibility to develop intrauterine HBV infection.