无免疫功能低下的肺隐球菌病患者Th1/Th2类细胞因子的变化

Changes of Th1/Th2 cytokines in immunocompetent patients with pulmonary cryptococcosis

目的 分析无免疫功能低下的肺隐球菌病（PC）患者Th1/Th2类细胞因子的变化及其机制.方法 应用酶联免疫吸附测定（ELISA）法测定20例无免疫功能低下的PC患者（PC组）血清中IL-12、γ-干扰素（IFN-γ）和IL-4的浓度,并与20名健康体检者（对照组）进行对比.分离PC组和对照组外周血单个核细胞（PBMC）,重组人IL-12 （rhIL-12）刺激48 h后收集上清液,应用ELISA法测定各组培养上清液中IFN-γ和IL-4的浓度.结果 （1）无免疫功能低下的PC患者血清IFN-γ的浓度为（14.5±2.7） ng/L,显著低于对照组的（81.8±9.8） ng/L,差异有统计学意义（t=6.590,P＜0.01）,PC组和对照组血清IL-12浓度分别为（2.5±0.5）和（2.5±0.6） ng/L,血清IL-4浓度分别为（6.9±1.3）和（7.3±1.5） ng/L,差异均无统计学意义（t值分别为0.0035和0.2136,均P＞0.05）.（2）PC组与对照组PBMC上清液中IFN-γ浓度分别为（55.7 ±13.6）和（51.1±17.5） ng/L,IL-4分别为（5.1±0.7）和（5.0±0.6）ng/L,差异均无统计学意义（t值分别为0.2979和0.0325,均P＞0.05）.（3）经rhIL-12刺激后,PC组和对照组PBMC上清液中IFN-γ的浓度均有明显增高,为（4.3±0.5）和（7.9±1.1）倍,PC组增高幅度明显低于对照组,差异有统计学意义（t=3.01,P＜0.01）；而IL-4的浓度两组分别增加了（0.9±0.4）和（1.3±0.4）倍,差异无统计学意义（t=0.7240,P＞0.05）.结论 无免疫功能低下的PC患者血清Th1类因子（IFN-γ）下降,Th2类因子（IL-4）无明显变化；Th1细胞对IL-12的反应性和敏感性下降可能是血清Th1类因子（IFN-γ）下降的原因之一.

Objective To study the changes of Th1/Th2 cytokines in immunocompetent patients with pulmonary cryptococcosis （PC）.Methods Twenty immunocompetent patients with PC were identified by histopathological examination and enrolled along with the age-and gender-matched healthy controls.The serum concentrations of interferon-γ （IFN-γ）,interleukin-4 （IL-4） and interleukin-12 （IL-12） were measured by enzyme linked immunosorbent assay （ELISA）.Peripheral blood mononuclear cells （PBMC） in both groups were isolated and incubated with or without recombinant human IL-12 （rhIL-12） for 48 hours,and the concentrations of IFN-γ and IL-4 in the supernatant were measured by ELISA.Results （1） Serum IFN-γ levels were significantly decreased in the patients compared with the control group[（14.5 ±2.7） vs （81.8 ±9.8） ng/L （t =6.590,P 〈0.01）],while no significant difference was observed in serum IL-12 and IL-4 levels[（2.5 ±0.5） vs （2.52 ±0.6） ng/L and （6.9 ± 1.3） vs （7.3 ± 1.5） ng/L,（t =0.0035 and 0.2136,P〉0.05）].（2） The concentrations of IFN-γand IL-4 in the supernatant of PBMC without rhIL-12 stimulation showed no differences between the 2 groups [（55.7 ± 13.6） vs （51.1 ± 17.5） ng/L and （5.1 ± 0.7） vs （5.0 ± 0.6） ng/L（t =0.2979 and 0.0325,P 〉 0.05）].（3） Treatment with rhIL-12 stimulated the release of IFN-γ,but the increase in the patients [（4.3 ± 0.5） folds] was less compared with that in the controls [（7.9 ± 1.1） folds] （t =3.01,P 〈0.01）,while IL-4 concentration in the supematant of PBMC was not increased in both groups [（0.9 ± 0.4） vs （1.3 ± 0.4） folds （t =0.7240,P 〉 0.05）].Conclusions Serum Th1 cytokine （IFN-γ） levels may be dampened in immunocompetent patients with PC,without significant change in serum levels of Th2 cytokines （IL-4）.Deficiency in the response to IL-12 stimulation of Th1 cells may be one of the underlying mechanisms for the decline in serum IFN-γ levels.