儿童难治性肺炎支原体肺炎肺泡灌洗液病菌量与Th1/Th2细胞免疫应答的相关性研究

Study on the Correlation Between the Amount of Bacteria in the Alveolar Lavage Fluid of Children With Refractory Mycoplasma Pneumoniae Pneumonia and the Immune Response of Th1/Th2 Cells

目的探究儿童难治性肺炎支原体肺炎肺泡灌洗液病菌量与Th1/Th2细胞免疫应答的相关性。方法随机选择郑州大学附属儿童医院诊治的96例难治性肺炎支原体肺炎患儿为研究对象,根据肺泡灌洗液中肺炎支原体DNA含量进行分组,即>106/m L为高菌量组(n=35),103~106/m L为中菌量组(n=30),<103/m L为低菌量组(n=31)。检测三组患儿肺泡灌洗液的炎性因子水平,对比三组的炎性因子水平、肺部影像学与实验室检查结果、临床表现和基础情况,分析肺泡灌洗液中肺炎支原体DNA含量与炎性因子的相关性。结果在体温高于39℃、热程高于10天患儿占比以及总发热时间、使用抗生素后热程、住院时间、乳酸脱氢酶、血小板计数、中性粒细胞计数、淋巴细胞计数上,三组比较差异有统计学意义(P<0.05),白细胞计数比较差异无统计学意义(P>0.05);双侧或大量胸腔积液、肺不张或者大片肺实变发生率、白细胞介素-4(interleukin-4,IL-4)水平比较,差异有统计学意义(P<0.05),三组之间的双侧肺病变、左侧肺病变、右侧肺病变发生率以及肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)、干扰素(interferon-γ,INF-γ)、IL-8水平比较差异无统计学意义(P>0.05);肺泡灌洗液中IL-4与肺炎支原体DNA水平呈正相关(P<0.05),肺泡灌洗液中TNF-α、INF-γ、IL-8与肺炎支原体DNA水平无相关性(P>0.05)。结论儿童难治性肺炎支原体肺炎肺泡灌洗液病菌量与Th1/Th2细胞免疫应答具有相关性,肺炎支原体DNA菌量越高,肺内外损害和肺部炎症越严重,Th1/Th2免疫应答失衡。

Objective To explore the correlation between the amount of bacteria in alveolar lavage fluid and Th1/Th2 cell immune response in children with refractory Mycoplasma pneumoniae pneumonia.Methods 96 children with refractory Mycoplasma pneumoniae pneumonia diagnosed and treated in our hospital were randomly selected as the research objects.They were grouped according to the DNA content of Mycoplasma pneumoniae in alveolar lavage fluid,that was,more than 106/mL was the high bacterial volume group(n=35),103~106/mL was the medium bacterial volume group(n=30),and less than 103/mL was the low bacterial volume group(n=31).The levels of inflammatory factors in alveolar lavage fluid of the three groups were detected.The levels of inflammatory factors,lung imaging and laboratory examination results,clinical manifestations,and basic conditions of the three groups were compared,and the correlation between Mycoplasma pneumoniae DNA content in alveolar lavage fluid and inflammatory factors was analyzed.Results The proportion of children with body temperature higher than 39℃,heat course higher than 10 days,total fever time,heat course after antibiotics,hospitalization time,lactate dehydrogenase,platelet count,neutrophil count,lymphocyte count.Above,there was a significant difference in the comparison between the high bacterial count group,the medium bacterial count group,and the low bacterial count group(P<0.05).There was no significant difference in white blood cell counts among the three groups(P>0.05);there were significant differences in the incidence of bilateral or large pleural effusion,atelectasis,or large-scale lung consolidation,and interleukin-4(IL-4)levels(P<0.05).There were no significant differences in the incidence of bilateral lung lesions,left lung lesions,right lung lesions,and the levels of tumor necrosis factor-α(TNF-α),interferon-γ(INF-γ),and IL-8 among the three groups(P>0.05);IL-4 in the lavage fluid was positively correlated with the DNA level of Mycoplasma pneumoniae(P<0.05),and there was no correlation between TNF-α,INF-γ,IL-8 and the DNA level of Mycoplasma pneumoniae in the alveolar lavage fluid(P>0.05).Conclusions The amount of bacteria in the alveolar lavage fluid of refractory Mycoplasma pneumoniae pneumonia in children is correlated with Th1/Th2 cellular immune response.The higher the amount of Mycoplasma pneumoniae DNA,the more severe the internal and external lung damage and inflammation,and the imbalance of Th1/Th2 immune response.