Abstract: Objective　To analyze the changes in routine immunological indicators of refractory Mycoplasma pneumoniae pneumonia（RMPP） by controlling age factors. Methods　A retrospective analysis was performed for the routine immunological indicators of 120 children with MPP admitted between January 2016 and December 2019 in Children’s Hospital of Fudan University. Compared to the reference values of peripheral blood lymphocyte subsets of healthy children in different age and sex groups in China，the 120 children were divided to normal or abnormal group，and the abnormal group was further divided as decreased group or increased group. The differences of changes in lymphocyte subsets between general Mycoplasma pneumoniae pneumonia（GMPP） and RMPP children were compared. Results　The proportion of children with abnormal lymphocyte subsets in the RMPP group is higher than that in the GMPP group. There were significant differences between the two groups in the percentage of CD3+，CD19+，and NK lymphocytes subsets（P＜ 0.05）. The majority of children in both groups showed a decrease in lymphocyte counts，absolute counts of CD3+，CD4+，CD8+，and NK lymphocytes. The authors further analyzed the children with decreased lymphocyte subsets in the two groups and found significant differences in CD3+ and NK cell counts，the percentage of CD3+，NK and CD4+ cells，and CD4+/CD8+ between the two groups（P＜0.05）. There was no significant difference in serum immunoglobulin（IgA，IgM，IgG，IgE） levels in each group（P＞ 0.05）. Conclusion　T cells and NK cells play an important role in the inflammatory response to MPP，and CD4+ cells and NK cells are related to the severity of MPP，which may be one of the pathogenic mechanisms of RMPP.

Key words: refractory Mycoplasma pneumoniae pneumonia, CD4+ Th cell, NK cell

摘要： 目的　通过控制年龄因素，探讨难治性肺炎支原体肺炎（RMPP）常规免疫指标变化。方法　回顾性分析2016年1月至2019年12月复旦大学附属儿科医院住院的120例MPP患儿的常规免疫指标。参考中国不同年龄及性别的健康儿童的外周血淋巴细胞亚群的参考值，将120例患儿分为正常或异常组，对于异常组的患儿进一步分为减少组或增多组。比较普通型肺炎支原体肺炎（GMPP）与RMPP两组患儿常规免疫指标的变化的差异性。 结果　RMPP组淋巴细胞亚群异常的患儿比例均高于GMPP组， 两组CD3+， CD19+及NK细胞百分比的差异具有统计学意义（P＜0.05）。两组多数患儿均表现为淋巴细胞计数、 CD3+、 CD4+、 CD8+及NK细胞绝对计数减少。进一步对淋巴细胞减少的亚群分析， 发现两组CD3+及NK细胞计数、 CD3+及NK细胞百分比、 CD4+百分比、 CD4+/CD8+差异具有统计学意义（P＜0.05）。各组血清免疫球蛋白（IgA、 IgM、 IgG、 IgE）水平差异无统计学意义（P＞0.05）。 结论　T细胞及NK细胞在MPP炎性反应中发挥重要作用， CD4+ 细胞及NK细胞与MPP的严重程度相关， 可能是RMPP的免疫致病机制之一。

关键词: 难治性肺炎支原体肺炎, CD4+辅助性T细胞, NK细胞