Investigation of T lymphocyte subsets in children with Mycoplasma pneumoniae pneumonia

This study aims to characterize the majority of immune cell subsets in peripheral blood mononuclear cells in children with Mycoplasma pneumoniae pneumonia (MPP) by a 21-color flow cytometry panel. Patients who met the predetermined eligibility criteria for pneumonia diagnosis were recruited for the research study. Multi-color flow cytometry was conducted on the peripheral blood mononuclear cells of each patient group, which were then subjected to dimensionality reduction and cluster analysis. In our study, the proportion of activated CD4 + T cell and naïve CD8 + T in children with MPP was higher than that of children with non-MPP, and the proportion of CD8 + T cell and central memory CD8 + T cell in MPP children was lower. Central memory CD4 + T cell and activated CD4 + T cell in the severe MPP were higher than those in the mild MPP. The highest proportions of CD8 + T cell, CD8 + Tn cell, activated CD8 + T cell, and total activated T cell were observed in the pulmonary consolidation-mucous group when compared to the pulmonary consolidation-necrosis and bronchiolitis groups. In the pulmonary consolidation-necrosis group, the proportions of central memory CD4 + T cell and T helper 17 cell were higher than those in pulmonary consolidation-mucous and bronchiolitis groups. In the bronchiolitis group, the percentages of CD4 + T cell, naïve CD4 + T cell, and T helper 2 cell were higher than those in pulmonary consolidation-mucous and the pulmonary consolidation-necrosis groups. The T lymphocyte subsets were different among various groups, offering new insights into the immune system of pediatric patients with Mycoplasma pneumoniae pneumonia.