肺炎支原体肺炎患儿外周血CD4^+T淋巴细胞表面IL-18Rα的表达

Expression of IL-18Rα on CD4+ T cells from children with Mycoplasma pneumoniae

目的探讨肺炎支原体肺炎(MPP)患儿外周血CD4+T淋巴细胞表面IL-18Rα表达的意义。方法采用流式细胞术测定35例MPP患儿外周血T淋巴细胞亚群(CD3/CD4/CD8)和CD4+T淋巴细胞表面IL-18Rα的表达水平,并与健康对照组比较。结果MPP患儿T细胞亚群与健康对照组相比,CD3+细胞百分率降低(P<0.05),51.4%的MPP患儿CD4+/CD8+在1.0~1.9的范围之外。急性期MPP组CD4+T淋巴细胞表面IL-18Rα的表达较正常对照组明显升高,差异有统计学意义(P<0.01);恢复期与对照组比较差异有统计学意义(P<0.05)。恢复期表达水平下降,与急性期比较差异有统计学意义(P<0.05)。T细胞亚群异常组与正常组相比,CD4+T淋巴细胞IL-18Rα表达明显增高(P<0.01),T细胞亚群正常组与健康对照组比较,差异无统计学意义(P>0.05)。结论MPP患儿存在细胞免疫功能紊乱,外周血T淋巴细胞存在Th1/Th2失衡,急性期表现为Th1优势应答。

Objective To investigate the significance of IL-18Rα expression on CD4＋ T cells in peripheral blood （PB） of children with Mycoplasma pneumoniae pneumonia （MPP）. Methods T cell subtype CD3/CD4/CD8 and expression of IL-18Rα on CD4＋ T cells in PB from 35 children with MPP and 15 age- and sex-matched control subjects was determined by flow cytometry. Results Compared with that of healthy control, CD3＋ and CD4＋ positive cells in MPP children were decreased （P〈 0.01）. Both in acute-stage and convalescence MPP IL-18Rα＋/CD4 ＋ expression were higher than healthy controls （P〈0.01, P〈0.0.5）. IL-18Rα＋/ CD4＋ expression in convalescence MPP was deceased and lower than that of in acute-stage MPP （P〈0.05）. IL18Rα on CD4＋ T cells from MPP patients with abnormal T subtype were significantly higher （P〈0.01） than those in normal T subtype patients. There was no difference between MPP patients with normal T subtype and healthy control （P〉0.05）. Conclusion There exists cell-mediated immune function disorders and Th1/Th2 imbalance in children with MPP. Th1 immune response is dominant in acute-stage MPP.