目的：探讨PPD反应与发作期哮喘患儿ECP,IgE及细胞因子表达的关系。方法：实验分健康对照组和哮喘发作组,均进行结核菌素纯蛋白衍化物(PPD)试验。观察PPD反应与哮喘临床症状、肺通气功能测定。血清ECP、IgE等的关系以及PPD试验后哮喘患儿外周血IFN-γ,IL-4,IL-12P40 mRNA的表达。结果：哮喘患儿PPD阴性者(24/32例)明显多于阳性者(8/32例),且PPD反应阴性患儿哮喘中/重度发作(16/24例)较PPD阳性患儿(2/8例)多,P<0.05。PPD阴性的哮喘患儿血嗜酸性细胞阳离子蛋白(ECP)及IgE较PPD阳性的哮喘患儿明显增高(P<0.05)。哮喘患儿PPD试验后IL-12 P40 mRNA,IFN-γ mRNA无明显变化,而IL-4 mRNA升高较对照组明显(P<0.05),致IFN-γ/IL-4 mRNA比值下降。结论：PPD反应阴性的哮喘患儿可能存在着细胞免疫功能低下。PPD正向免疫刺激作用在哮喘患儿中受到抑制。[中国当代儿科杂志,2003,5(1):20—22]

OBJECTIVE:To study the relationship between PPD reaction and serum ECP and IgE levels, and cytokines expression in children with acute bronchial asthma. METHODS: The PPD test was performed, serum levels of ECP and IgE were determined and the expressions of IFN-γ, IL-4 and IL-12 P40 mRNA in the peripheral blood were determined following PPD stimulation in 32 asthmatic children. Eight healthy children served as the controls. RESULTS: The number of PPD negative responders (n= 24) were significantly greater than that of PPD positive ones (n= 8). Of the 24 children with negative PPD, 16 (66.7%) had moderate or severe asthma attacks and only 2 cases (25.0%) in the 8 children with positive PPD (66.7% vs 25.0%, P < 0.05). The levels of ECP and IgE were higher in the PPD negative patients than those in the PPD positive patients ( P < 0.05). After PPD stimulation in the asthmatic patients there was no significant change of IL-12 mRNA and IFN-γ mRNA expressions, while IL-4 mRNA expression increased compared with the healthy children ( P < 0.05). CONCLUSIONS: There might be cellular immunity deficiency in PPD negtive patients. The immunoenhancement effect following PPD stimulation is suppressed in asthmatic patients.