目的 评价肺炎支原体（MP）感染对哮喘患儿急性期、稳定期支气管肺泡灌洗液（BALF）中T 细胞功能的影响，探讨MP 感染与哮喘的关系。方法 71 例患儿（支气管炎、肺炎、哮喘），分为无MP 感染对照组（无MP 感染的肺炎、支气管炎）、无MP 感染的哮喘组、MP 感染的哮喘组；用流式细胞仪技术检测各组患儿急性期、稳定期BALF 中CD3⁺、CD4⁺、CD8⁺T 细胞和CD4⁺/CD8⁺ 水平。结果 哮喘患儿无论在急性期还是稳定期，BALF 中CD3⁺、CD4⁺、CD8⁺ 和CD4⁺/CD8⁺ 与对照组比较均有明显差异（P<0.05），急性期，CD3⁺、CD4⁺ 较对照组有所降低，CD8⁺ 上升，而CD4⁺/CD8⁺ 则有明显降低（P<0.05）；稳定期，CD3⁺、CD4⁺及CD4⁺/CD8⁺ 低于对照组，CD8⁺ 稍有上升（P<0.05）。MP 感染哮喘患儿与非感染哮喘患儿相比较，急性期CD3⁺、CD4⁺ 显著下降，CD8⁺ 升高（P<0.05）、CD4⁺/CD8⁺ 显著下降（P<0.05）；稳定期CD3⁺、CD4⁺、CD8⁺ 无明显差异（P>0.05），CD4⁺/CD8⁺ 明显下降（P<0.05）。结论 MP 感染的哮喘患儿在急性期和稳定期可使气道T 细胞功能明显降低，进而引起免疫紊乱，提示MP 可能与哮喘发病有关。

Objective To investigate the effect of Mycoplasma pneumoniae (MP) infection on the function of T lymphocytes in the bronchoalveolar lavage fluid (BALF) of asthmatic children in acute and stable periods and the relationship between MP infection and asthma. Methods Seventy-one hospitalized children (with bronchitis, pneumonia, and asthma) were divided into non-MP infection control group (group A, pneumonia and bronchitis without MP infection), non-MP infection asthma group (group B), and MP infection asthma group (group C). Flow cytometry was used to determine CD3⁺, CD4⁺, and CD8⁺ T cell counts and CD4⁺/CD8⁺ ratio in BALF among all children in acute and stable periods. Results Compared with group A, groups B and C showed significant differences in CD3⁺, CD4⁺, and CD8⁺ T cell counts and CD4⁺/CD8⁺ ratio (P<0.05) in acute and stable periods, had decreased CD3⁺ and CD4⁺ T cell counts, an increased CD8⁺ T cell count, and a significantly decreased CD4⁺/CD8⁺ ratio (P<0.05) in the acute period, and had decreased CD3⁺ and CD4⁺ T cell counts and CD4⁺/CD8⁺ ratio and an increased CD8⁺ T cell count (P<0.05) in the stable period. Compared with group B, group C had significantly decreased CD3⁺ and CD4⁺ T cell counts and CD4⁺/CD8⁺ ratio (P<0.05) and a significantly increased CD8⁺ T cell count (P<0.05) in the acute period and showed no significant differences in CD3⁺, CD4⁺, and CD8⁺ T cell counts (P>0.05) and a significant decrease in CD4⁺/CD8⁺ ratio (P<0.05) in the stable period. Conclusions The immunological function of T lymphocytes in the airway declines significantly among asthmatic children with MP infection in acute and stable periods, leading to immue system disorder. MP may be associated with the pathogenesis of asthma.