呼吸道合胞病毒毛细支气管炎免疫发病机制的研究

目的　研究呼吸道合胞病毒毛细支气管炎 (简称RSV毛支 )免疫发病机制。方法　对 12例确诊为呼吸道合胞病毒毛细支气管炎急性期患儿 (毛支组 )和 10例年龄匹配的健康婴幼儿 (对照组 )外周血T细胞亚群和单核细胞 (PBMC)分泌的细胞因子IFN -γ和IL - 4进行检测。结果　毛支组CD8+T淋巴细胞和NK细胞明显低于对照组 (P <0 0 2 ,0 0 1) ,CD3+T、CD4 +T、CD4 +T/CD8+T与对照组比较无显著差异 (P >0 0 5 )。毛支组IFN -γ水平明显低于对照组 (P <0 0 1) ,IL - 4,IL - 4/IFN -γ较对照组明显增高 (P <0 0 1,0 0 1) ,且IFN -γ与IL - 4呈负相关 (r =- 0 81,P <0 0 5 ) ;毛支组中特应征 +患儿与特应征 -比较 ,前者IFN -γ明显降低 (P <0 0 1) ,IL - 4和IL - 4/IFN -γ明显增高 (P <0 0 1,0 0 5 )。结论　RSV毛支急性期存在Th1/Th2 平衡紊乱 ,表现Th2 优势应答 ,与遗传特应征与细胞因子分泌异常有一定关系 ,同时NK和CD8+T细胞在RSV毛支免疫发病机制中也起重要作用。

Study of the Immunological Pathogenesis of Respiratory Syncytial Virus Bronchiolitis in Infants

Objective To study the immunological pathogenesis of respiratory syncytial virus (RSV) bronchiolitis in infants. Methods The T cell subsets of peripheral blood and the level of IL-4 and IFN-γin culture supernatants of PHA-stimulated peripheral blood mononuclear cells from 12 cases having a clinical and radiological diagnosis of acute bronchiolitis and being confirmed RSV infection and 10 cases well infants were measured separately by enzyme linked immunosorbent assay (ELISA). Results The level of CD 8+ T and NK cells in RSV bronchiolitis patients were much less than those of control (P<0.05, 0.01) whereas the levels of CD 3+ T, CD 4+ T and CD 4+ T/CD 8+ T showed no obvious difference between patients and control (P>0.05). Compared with the controls, the level of IFN-γ was significantly lower while the level of IL-4 and IL-4/IFN-γ were obviously increased in infants with RSV bronchiolitis (P<0.01, 0.01,0.01). which were more obvious in those with atopy history than those without atopy history among RSV bronchiolitis patients (P<0.01, 0.01,0.05). The level of IFN was negatively correlated to that of IL-4 in patients (r=-0.81, P<0.05). Conclusion These results suggested that Th 1/Th 2 functional imbalance existed in RSV bronchiolitis, expressing Th 2 subset cell up-regulated, CD 8+ T, NK cells and heredity might be involved in the mechanism of RSV bronchiolitis.