关键词: 难治性肺炎支原体肺炎, CD4+辅助性T细胞, NK细胞

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