免疫治疗对毛细支气管炎后哮喘发生的干预机制研究

Effect of Bacille Calmette Guerin inoculation with or without IFN-γ/Vit A on immunologic status of infant with bronchiolitis

目的:探讨卡介苗(Bacille Calmette Guerin,BCG)或联用干扰素γ(IFNγ-)/维生素A(VitA)对毛细支气管炎患儿免疫功能状态的影响。方法:毛细支气管炎患儿共44例,25例患儿给予单独BCG或合并IFNγ-/VitA治疗,治疗前和治疗3个月后分别进行纯结核蛋白衍生物(PPD)皮试,采用ELISA和逆转录-聚合酶链反应(RT-PCR)方法测定外周血单个核细胞(peripheral blood mononuclear cells,PBMC)体外产生IL-12、IL-18、IL-10、IL-4、IFNγ-的水平及膜表面蛋白质分子淋巴细胞活化基因3(lymphocyte ac-tivation gene-3,LAG-3)mRNA的表达,并随访平均1年时间,临床观察喘息发作的情况。19例未接受BCG接种的毛细支气管炎患儿,作为疾病对照组。结果:干预后IL-12、IL-18、及IFNγ-水平明显高于干预前,LAG-3 mRNA的表达增强,IL-4水平显著降低,差异具有显著意义,IL-10水平略下降。BCG接种后PPD平均硬结直径大于干预前及毛细支气管炎对照组恢复期。BCG单用或联用IFNγ-/(VitA)组1年内喘息发作频率低于对照组恢复期,单用或联用组间差异无显著意义。临床疗效及细胞因子的产生在合并IFNγ-/VitA治疗组未显示出优势。结论:BCG可促进毛细支气管炎患儿PPD皮试阳转、增强TH1细胞功能的作用,推测IL-10水平未显著降低可能与BCG诱导产生调节性T细胞(CD4+CD25+Tr)有关。

AIM： To discuss the effects of Bacille Calmette Guerin （BCG） inoculation with or without supplement of vitamin A/IFN-γ on tubercle bacillus protein purified derivative （PPD） skin test, wheezing episode and in vitro the cytokine levels of peripheral blood mononuclear cells （PBMC） in infants with acute bronchiolitis. METHODS： 44 acute bronchiolitis infants （ABI） were treated with BCG alone or BCG combined with Vitamin A/ IFN-γ. 19 ABI treated without BCG as control. PPD skin test, in vitro production of IL-10,IL-12,IL-18,IL-4 and IFN-γ by supematant of PBMC of bronchiolitis measured by ELISA, and expression of lymphocyte activation gene-3 （LAG-3） mRNA from PBMC of bronchiolitis measured by semi-quantitative RT-PCR were observed before and 3 months after BCG inoculation. Follow up for average 12 months was to observe the wheezing episodes. RESULTS： The diameters of PPD skin test in ABI after BCG inoculation combined with IFN-γ/VitA were larger than those of ABI before inoculation and control group. The frequencies and persistence of wheezing were lower in interfered infants with acute bronchiolitis either by BCG alone or BCG combined with IFN-γ/VitA than those of control group by 1 year. IL-12,IL-18 and IFN-γ activities in ABI treated with BCG or BCG combined with IFN-γ/ Vitamin A in vitro were higher than those of pre-treatment bronchiolitis infants; the level of IL-4 was lower; the level of IL-10 was a little bit lower, and expression of LAG- 3 mRNA was stronger. Frequency of wheezing episode in 1 year in acute bronchiolitis infants with BCG or BCG combined with IFN-γ/Vitamin A was lower than that of control group. There were no difference between ABI with BCG or BCG combined with IFN-γ/ Vitamin A. Clinical manifestation and the level of cytokines do not show superiority in BCG with IFN-γ/Vitamin A. CONCLUSION： BCG inoculation is able to enhance PPD skin test response, promote Thl reactivity, and prevent from recurrent wheezing after acute bronchiolitis. The level of IL-10 was degraded lightly after BCG intervention, presumably concerning with regular T cells（CD4 ^＋ CD25^ ＋ Tr）induced by BCG inoculation.