胃幽门螺杆菌感染与哮喘急性发作及CD4^+CD25^+T细胞的作用机制研究

Relationship among helicobacter pylori infection,acute asthma attack and mechanism of CD4^+CD25^+ regulatory T cells

目的探讨胃幽门螺杆菌(HP)感染与哮喘急性发作的关系及免疫机制,为更好地预防和治疗哮喘提供理论依据。方法 32例哮喘发作期和20例哮喘缓解期患儿通过14C尿素呼气试验(14C-UBT)检测HP感染情况,同时采集所有患儿及同期10例健康儿童外周静脉血,通过流式细胞仪测定CD4+CD25+调节性T细胞占CD4+T细胞的百分比。结果哮喘急性发作期患儿14C-UBT阳性率明显高于缓解期患儿(P<0.05);HP阳性哮喘患儿CD4+CD25+调节性T细胞水平显著低于HP阴性哮喘患儿及对照组;无论HP感染阳性还是阴性患儿,其哮喘发作期CD4+CD25+调节性T细胞水平均低于哮喘缓解期,且哮喘发作期HP阳性组CD4+CD25+调节性T细胞水平低于HP阴性组(P<0.05)。结论 HP感染可能是诱导哮喘急性发作的原因之一,HP感染后激发和加重了机体的免疫异常,进一步抑制了CD4+CD25+调节性T细胞的表达而不能有效发挥其免疫抑制功能,是哮喘急性发作的可能机制。

Objective To investigate the relationship between acute asthma attack and helicobacter pylori（HP）infection and the immunologic mechanism.Methods Thirty-two children in acute episode and 20 children in remission stage were analyzed by 14 carbon urea breath tests（14 C-UBT）to detect Hp infection.Peripheral blood was collected from all patients and 10 healthy children.CD4＋ CD25＋ regulatory T cells in percentage of CD4＋ T Cells were calculated by flow cytometry.Results The positive rates of 14 C-UBT in acute episode was significantly higher than that in remission stage（P0.05）.The percentage of CD4＋ CD25＋ regulatory T cells in peripheral blood in HP-positive children with asthma was lower than that in HP-negative children with asthma and the controls.For either HP-positive children or HP-negative children,the level of CD4＋ CD25＋ T cells in acute episode was lower than that in remission stage.The level of CD4＋ CD25＋ T cells in HP-positive children was lower than that in HP-negative children.Conclusion HP infection might be one of the factors inducting acute asthma attack.HP infection stimulates and aggravates the immunologic abnormality of organism,which further inhibits the expression and immune suppression of CD4＋ CD25＋ T cells and affects its immunosuppressive ability.