目的 探讨呼吸道感染儿童免疫功能指标的变化。方法 将2012年1月至2012年9月在大连儿童医院住院的呼吸道疾病患儿按临床诊断结果分为支气管炎组、咽炎组、肺炎组。另选取40名正常儿童作为对照组。运用流式细胞术分别检测全血T淋巴细胞分化抗原三项CD3、CD4、CD8及CD4/CD8的比值；同时利用散射比浊终点法检测血清中免疫球蛋白（IgG、IgM、IgA）、补体（C3、C4）。结果 ① 支气管炎组、咽炎组、肺炎组检验结果显示,CD3、CD4、CD8、CD4/CD8低于对照组。② 以上3组的血清免疫球蛋白与C3水平均低于对照组，差异有统计学意义，C4水平与对照组检测结果基本一致，差异无统计学意义。③不同年龄组结果显示：0～3、4～6年龄段的患儿细胞免疫功能和体液免疫功能均低于对照组，C4与对照组检测结果基本一致，差异无统计学意义。7～12岁患儿体液免疫和细胞免疫功能与对照组比较无显著性差异。④呼吸道感染患儿性别无统计学差异。结论 呼吸道疾病患儿免疫功能低下并紊乱；6岁以下患儿年龄越低，免疫功能越低，易引起呼吸道疾病；患儿主要集中在6岁以下；患病儿童与性别无关。

Objective To investigate the index changes of the immune function of children respiratory tract infection. Methods The respiratory diseases children who hospitalized in Dalian Children's Hospital were divided into bronchitis group, pharyngitis group and pneumonia group. 40 normal children were choosed as control group. The three whole blood T lymphocyte differentiation antigen CD3, CD4, CD8 and ratio of CD4/CD8 were detected by using flow cytometry, and immunoglobulin (IgG, IgM, IgA), complement (C3, C4) in serum were detected by using nephelometry endpoint. Results The CD3, CD4, CD4/CD8 in bronchitis group, pharyngitis group and pneumonia group were lower than that of control group, while CD8 was higher than controls. The serum immunoglobulin and C3 level in three groups were lower than that of control group (p<0.05), but the C4 levels were basically the same compared with the control group without statistically significant. The cellular immune function and humoral immune function in children with ages 0-3 and 4-6 were lower than the control group, but without significant difference in 7-12 year old Children. There was no significant difference on respiratory tract infections with gender of children. Conclusion Respiratory diseases in children are immune dysfunction and disorder. The lower children ages are with the lower immune function and easier to cause respiratory diseases. Respiratory diseases in children are mainly under 6 years old and unrelated to gender.