不同浓度地塞米松和甲泼尼龙对支气管哮喘患儿外周血单个核细胞免疫功能的影响

目的 观察不同浓度地塞米松(DEX)和甲泼尼龙(MP)对支气管哮喘患儿外周血单个核细胞(PBMC)中CD4+T淋巴细胞中2个功能性亚群(Th1/Th2)功能状态的影响.方法 选择2001年6月-2002年6月在重庆医科大学附属儿童医院就诊的15例哮喘患儿和14例健康体检儿童为研究对象.分为哮喘对照组、10-7mol·L-1DEX干预组、10-8mol·L-1DEX干预组、10-9mol·L-1DEX干预组、10-7mol·L-1MP干预组、10-8mol·L-1MP干预组、10-9mol·L-1MP干预组.清晨取其空腹静脉血5 mL,肝素抗凝,采用密度梯度离心法分离PBMC,加植物血凝素进行刺激培养,分别用10-7mol·L-1、10-8mol·L-1及10-9mol·L-1DEX或MP体外干预培养48 h.同期采集健康儿童空腹静脉血,同法分离培养.用ELISA法测定培养上清中γ干扰素(IFN-γ)、IL-4、IL-10及IL-12水平,并计算不同浓度DEX或MP对PBMC分泌细胞因子的抑制率.结果 1.哮喘对照组PBMC分泌IL-4水平显著高于健康对照组(P<0.05),IFN-γ/IL-4比值较健康对照组显著降低(P<0.05),2组间IFN-γ、IL-10及IL-12水平比较差异均无统计学意义(Pa>0.05).2.DEX和MP均可明显抑制哮喘患儿PBMC分泌IFN-γ、IL-4及IL-12,但对IL-10抑制作用差;与健康对照组比较,哮喘组DEX和MP抑制PBMC分泌IL-10的作用弱,差异有统计学意义(Pa<0.05).3.DEX和MP均以浓度依赖方式抑制哮喘患儿PBMC分泌IL-4,DEX在10-9mol·L-1时有促进IL-4分泌的效应,MP在10-9mol·L-1时可抑制IL-4的分泌,二组比较差异有统计学意义(P<0.05). 若以IFN-γ/IL-4表示Th1/Th2间的平衡,则MP可恢复Th1/Th2平衡(P<0.05).结论 DEX和MP均可抑制Th1/Th2类细胞因子分泌,但MP有助于恢复Th1/Th2平衡,提示临床选择MP治疗支气管哮喘更有利.

Effects of Different Concentrations of Dexamethasone and Methylprednisolone on Immunofunctions of Periphe-ral Blood Mononuclear Cells in Children with Asthma

Objective To observe the effects of different concentrations of dexamethasone(DEX) and methylprednisolone(MP) on the Th1/Th2 cytokines secretion in the peripheral blood mononuclear cells(PBMC) in children with asthma.Methods Fifteen children with asthma and 14 healthy children who visited in the Children′s Hospital of Chongqing Medical University from Jun.2001 to Jun.2002 were selected.Five millilitre fasting blood samples were collected,and PBMC were isolated using Ficoll-Hypaque density gradient centrifugation.The samples were divided into several groups,including healthy control group,asthma control group,10-7 mol·L-1DEX group,10-8 mol·L-1 DEX group and 10-9 mol·L-1 DEX group,10-7 mol·L-1MP group,10-8 mol·L-1 MP group and 10-9 mol·L-1 MP group.PBMC were incubated with phytohemagglutinin and DEX or MP in the concentration of 10-7mol·L-1,10-8mol·L-1and 10-9mol·L-1respectively.After 48 hours incubation,supernatant was harvested to determine levels of gamma interferon(IFN-γ),IL-4,IL-10 and IL-12 by ELISA,and the inhibition ratios of different concentrations of DEX and MP on the cytokines were calculated.Results 1.IL-4 level in children with asthma was significantly increased than that in the healthy children(P<0.05),and the ratio of IFN-γ and IL-4 statistically declined(P<0.05).There was no significant difference of IFN-γ,IL-10 and IL-12 levels beween the 2 groups.2.DEX and MP inhibited significantly the secretion of IFN-γ,IL-4,and IL-12,and had mild inhibition on IL-10,which was significantly weaker in children with asthma compared with that in the healthy children(Pa<0.05).3.DEX and MP inhibited the secretion of IL-4 in a concentration-dependent manner.In the concentration of 10-9mol·L-1,MP still inhibited the secretion IL-4,while DEX promoted IL-4 level,and there was significant difference between the 2 groups(P<0.05).If the balance of Th1/Th2 was represented by IFN-γ/IL-4,MP could restore the imbalance(P<0.05).Conclusions DEX and MP can inhibit the secretion of Th1/Th2 cytokines,but MP can restore the imbalance of Th1/Th2,which suggests that MP is better in the therapy for asthma.