Abstract:

Objective　To analyze the clinical characteristics in children with refractory Mycoplasma pneumoniae pneumonia (RMPP) and its correlation with Toll like receptor 4 (TLR4) inflammasome. Methods　A total of 97 children with Mycoplasma pneumoniae pneumonia admitted to Ankang Hospital of Traditional Chinese Medicine from August 2021 to August 2023 were selected as the research subjects. There were 46 boys and 51 girls, aged 2 to 14 years. At admission, the incidence of RMPP was statistically analyzed and the children were divided into a RMPP group and a general Mycoplasma pneumoniae pneumonia (GMPP) group. The relative expression level (mRNA) of TLR4 mononuclear cells in all children on the next day after admission was measured, the clinical data and TLR4 mRNA of the two groups were compared, and the correlation between TLR4 mRNA and RMPP was analyzed. Independent sample t test, χ² test, logistic regression analysis, and restricted cubic spline (RCS) were used. Results　According to statistics, out of 97 children with Mycoplasma pneumoniae pneumonia, 33 had RMPP, accounting for 34.02% (33/97). The proportions of fever duration >7 days, pleural effusion, and lobar atelectasis in the RMPP group were higher than those in the GMPP group, and the length of hospital stay was longer than that in the GMPP group (all P<0.05). The percentage of neutrophils, levels of C-reactive protein (CRP), interleukin-18 (IL-18), IL-1β, IL-6, and immunoglobulin A (IgA), Mycoplasma pneumoniae-DNA, and TLR4 mRNA [(0.92±0.08) vs. (0.88±0.04)] in the RMPP group were higher than those in the GMPP group (all P<0.05). Logistic regression model was constructed, and the results showed that the percentage of neutrophils, CRP, IL-18, IL-1β, IL-6, IgA, Mycoplasma pneumoniae-DNA, and TLR4 mRNA on admission were all related to the occurrence of RMPP (all P<0.05). By RCS analysis, there was a non-linear dose-response relationship between TLR4 mRNA and RMPP. When TLR4 mRNA >0.955, the risk of RMPP increased with the increase of indicator expression level. Conclusions　The duration of fever and hospitalization in RMPP children are long, often accompanied by worsening pulmonary signs and imaging manifestations, as well as severe inflammatory reactions and immune damage. TLR4 inflammasomes and their related inflammatory factors are also associated with RMPP. The high expression of TLR4 inflammasomes induces a high inflammatory response, which is an independent risk factor for RMPP, and the correlation between the two is a non-linear dose-response relationship.

Key words:

Refractory Mycoplasma pneumoniae pneumonia, Toll like receptor 4, Clinical features, Dose response analysis

摘要：

目的　分析难治性肺炎支原体肺炎（RMPP）患儿的临床特征及与Toll样受体4（TLR4）炎症小体关联性强度。方法　选取2021年8月至2023年8月期间安康市中医医院收治的97例肺炎支原体肺炎患儿作为研究对象，其中男46例，女51例，年龄2～14岁。入院时即统计RMPP发生情况并将患儿分为RMPP组与普通肺炎支原体肺炎（GMPP）组，测定所有患儿入院后次日TLR4单个核细胞中相对表达量（mRNA），比较两组临床资料及TLR4 mRNA，重点分析TLR4 mRNA与RMPP关联性强度。采用独立样本t检验、χ²检验、logistic回归分析、限制性立方样条函数（RCS）。结果　经统计，97例肺炎支原体肺炎患儿中有33例为RMPP，占34.02%（33/97）。RMPP组发热持续时间>7 d、胸腔积液、大叶性肺不张患儿占比高于GMPP组，住院天数长于GMPP组（均P<0.05）；RMPP组中性粒细胞百分比、C反应蛋白（CRP）、白细胞介素-18（IL-18）、IL-1β、IL-6、免疫球蛋白A（IgA）水平、肺炎支原体-DNA、TLR4 mRNA［（0.92±0.08）比（0.88±0.04）］均高于GMPP组（均P<0.05）。构建logistic回归模型，结果显示，入院时中性粒细胞百分比、CRP、IL-18、IL-1β、IL-6、IgA、肺炎支原体-DNA水平、TLR4 mRNA均与RMPP的发生有关（均P<0.05）。经RCS分析，TLR4 mRNA与RMPP呈非线性剂量反应关系，当TLR4 mRNA >0.955时，RMPP风险随指标表达水平升高而增加。结论　RMPP患儿发热持续时间、住院时间长，多伴有肺部体征及影像学表现加重，且存在严重的炎症反应与免疫损伤；TLR4炎症小体及其相关的炎症因子也与RMPP有关，TLR4炎症小体高表达诱导的高炎症反应是RMPP的独立危险因素，且二者呈非线性剂量反应关系。

关键词:

难治性肺炎支原体肺炎, Toll样受体4, 临床特征, 剂量反应分析