糖皮质激素受体表达与特发性血小板减少性紫癜激素抵抗关系

目的:通过研究原发性糖皮质激素抵抗型特发性血小板减少性紫癜（ITP）患儿糖皮质激素受体（GR）亚型GRα和GRβ表达水平，以揭示ITP糖皮质激素抵抗的可能机制。方法:应用实时荧光定量-PCR法检测18 例糖皮质激素敏感型、12例糖皮质激素抵抗型ITP患儿及10例正常儿童外周血单个核细胞GRα和GRβ mRNA 的表达水平，同时采用酶免疫分析法测定血清总皮质醇水平。结果:①对照组、糖皮质激素敏感组和抵抗组3组之间GRα mRNA的表达水平差异无显著性；对照组和糖皮质激素敏感组的GRβ mRNA水平差异无显著性，但糖皮质激素抵抗组的GRβ mRNA水平显著高于对照组和糖皮质激素敏感组，差异有显著性（P<0.01）。②总皮质醇水平在对照组与糖皮质激素敏感组之间差异无显著性，但糖皮质激素抵抗组总皮质醇水平明显高于糖皮质激素敏感组，差异有显著性（P<0.01）。结论: ITP患儿糖皮质激素抵抗可能与GRβ mRNA的表达增高有关。［中国当代儿科杂志，2009，11（9）：714-716］

Relationship between glucocorticoid receptors and glucocorticoid resistance in children with idiopathic thrombocytopenia purpura

Objective To identify the relationship between the expression of α and β-isoforms of glucocorticoid receptors(GR) in peripheral blood mononuclear cells(PBMC) and glucocorticoid resistance in children with idiopathic thrombocytopenia purpura(ITP).Methods Real-time PCR was used to detect the expression of GRα and GRβ mRNA in PBMC from 30 children with ITP(glucocorticoid-sensitive,n=18;glucocorticoid-resistant,n=12) and 10 healthy children(control group).Enzyme immunoassay was used to measure plasma levels of total glucocoticoits.Results There were no significant differences in PBMC GRα mRNA levels among the glucocorticoid-sensitive,the glucocorticoid-resistant and the control groups.Compared with the glucocorticoid-sensitive and the control groups,the expression of GRβ mRNA in the glucocorticoid-resistant group was significantly up-regulated(P<0.01).Plasma total glucocoticoits level in the glucocorticoid-resistant group was found to be much higher than that in the glucocorticoid-sensitive and the control groups(P<0.01).Conclusions The up-regulated expression of GRβ mRNA may associated with glucocorticoid resistance in children with ITP.