Abstract: Objective:To study the clinical characteristics and immune mechanism of refractory Mycoplasma pneumonia pneumonia(RMPP) in children.
Methods:A total of 97 RMPP children treated in our hospital from March 2017 to March 2019 were included as the observation group, and they were divided into severe RMPP group and mild RMPP group. According to the ratio of 1∶2, 46 children with common pneumonia in the same period were included as the control group. Flow cytometry was used to determine the level of T cell subsets in bronchoalveolar lavage fluid; enzyme linked immunosorbent assay was used to determine the level of interleukin-5(IL-5), IL-6, tumor necrosis factor α (TNF-α) and sB7-H3; the differences in them were analyzed.
Results:The level of CD3 and CD4 and value of CD4/CD8 in severe RMPP group was (45.7±8.6)%，（20.4±6.5）% and 0.97±0.14, which were significantly lower than those of mild RMPP group and control group, and the differences were statistically significant(P<0.05). The CD8 level was (20.6±3.3)% in severe group, which was not statistically different from that in mild group ［(22.3±4.7)%(P>0.05). The level of IL-5，IL-6 and TNF-α in severe RMPP group was (18.7±3.2)ng/L, (27.2±1.3)ng/Land (112.7±13.5)ng/L, respectively, which was significantly higher than that in mild RMPP group and control group(P<0.05). The level of sB7-H3 expression was 132.7 ng/L, significantly higher than that of control group(P<0.05), but it was not statistically different from that of mild group(P>0.05)
Conclusion:IL-5，IL-6, TNF-α and sB7-H3 are all involved in the disease progression of RMPP, which is manifested by the disorder of CD3, CD4 and CD4/CD8 of T cell Subsets, affecting the immune function of human body and aggravating the disease.
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Key words: Refractory Mycoplasma pneumoniae pneumonia, Lymphocyte, Cytokine, Bronchoalveolar lavage fluid, Children