The Characteristics And Predictive Value Of Systemic And Local Inflammation In Severe Mycoplasma Pneumoniae Pneumonia In Children

Background and ObjectiveMycoplasma pneumoniae pneumonia(MPP)is a common respiratory disease affecting preschool and school-age children,accounting for 20-40%of communityacquired pneumonia(CAP)in children.In recent years,the prevalence of severe mycoplasma pneumoniae pneumonia(SMPP)has been increasing progressively year after year and can lead to serious complications when treatment is untimely or ineffective.The purpose of this study was to analysis the characteristics of systemic and bronchoalveolar lavage fluid(BALF)inflammatory in children with SMPP,to explore its predictive value for the etiology and complications of SMPP,to provide clinical evidence for early identification of SMPP complications,and to provide individualized and precise treatment.MethodsA total of 127 children with severe pneumonia who were selected from the Department of Pediatrics of Shandong University Qilu Hospital from Oct.2021 to Jan.2022.The children were divided into two groups according to MP infection:SMPP group(n=103)and bacterial group(n=24).According to the etiological examination,the SMPP group was subdivided into single MP group(n=51),MP+bacteria group(n=34),MP+virus group(n=18).According to the bronchoscopy,the SMPP group was subdivided into Plastic bronchitis(PB)group(n=22)and non-PB group(n=81).According to imaging examination,the SMPP group was subdivided into pleural effusion group(n=32)and non-pleural effusion group(n=71).According to the course of disease(the period from onset to discharge),the SMPP group was subdivided into course≤9d group(n=61)and course>9d group(n=42).Results1.Comparison of single MP,MP+bacteria,MP+virus and bacteria groups:(1)Compared with MP+bacteria,MP+virus and bacteria groups,the age of onset in single MP group was significantly increased,the difference was statistically significant(P<0.05);Compared with the bacteria group,the proportion of lobar pneumonia in MP+bacteria and MP+virus groups were significantly increased,the differences were statistically significant(P<0.05);(2)Compared with bacteria group,NLR,IL-1β in single MP,MP+bacteria and MP+ virus groups were increased significantly,while the levels of BALF macrophages cells was decreased significantly,IL-6,TNF-α in MP+bacteria and MP+virus groups were increased significantly,LDH,IFN-y in MP+bacteria group was increased significantly,D-Di in MP+virus group was increased significantly,the differences were statistically significant(P<0.05);Compared with the bacteria group,the level of BALF neutrophil in the single MP,MP+bacteria and MP+virus groups were increased significantly,the difference was statistically significant(P<0.05),but pairwise comparison between groups showed no significant difference(P>0.05);(3)There was no statistical significance differences in gender,symptoms and signs,atelectasis,pleural effusion,plastic bronchitis,NEU,CRP,ESR,IgE,CD3+T,CD4+T,CD8+T,CD4+/CD8+T,and BALF IL-2,IL-4,IL-10,IL12p70,IL-17 among the 4 groups(P>0.05).2.Comparison of PB and non-PB groups:(1)Compared with the non-PB group,the PB group had a high proportion of pleural effusion,the levels of NEU,NLR,CRP,PCT,D-Di,LDH and BALF IL-1 β,IL-6,TNF-α were increased significantly,while the level of LYM was decreased significantly,the differences were statistically significant(P<0.05).(2)There was no statistical significance differences in age,gender,the level of ESR and BALF IL-2,IL-4,IL-10,IL-12p70,IL-17,macrophages,epithelial,neutrophil cells between PB and non-PB groups(P>0.05).The proportion of pulmonary atelectasis and the level of BALF IFN-γ were higher in the PB group compared to the non-PB group,but the differences were not statistically significant(P>0.05).(3)The area under ROC curve for NLR,D-Di and IL-1β predicted PB were 0.741,0.767 and 0.732,respectively.3.Comparison of pleural effusion and non-pleural effusion groups:(1)Compared with the non-pleural effusion group,the pleural effusion group had a high proportion of PB,the levels of NEU,NLR,CRP,PCT,D-Di,LDH were increased significantly,the differences were statistically significant(P<0.05).(2)There was no statistical significance differences in age,gender,the levels of LYM,ESR and BALF IL-1β,IL2,IL-4,IL-6,IL-10,IL-12p70,IL-17,macrophages,epithelial,neutrophil cells between pleural effusion and non-pleural effusion groups(P>0.05).The levels of BALF TNF-α,IFN-y were higher in the pleural effusion group compared to the non-pleural effusion group,but the differences were not statistically significant(P>0.05).(3)The area under ROC curve for NEU,PCT,D-Di and LDH predicted pleural effusion were 0.718,0.757,0.837 and 0.765,respectively.4.Comparison of the course≤9d and course>9d groups:(1)Compared with the course≤9d group,the levels of LYM,IL-12p70,IL-17 in the course>9d group were increased significantly,while the levels of IL-1β,IL-6 were decreased significantly,the differences were statistically significant(P<0.05).(2)There was no statistical significance differences in age,gender,the levels of NEU,NLR,CRP,ESR,PCT,DDi,LDH,IL-2,IL-4,IL-10,TNF-α IFN-γ and BALF macrophages,epithelial,neutrophil cells between course≤9d and course>9d groups(P>0.05).(3)The area under ROC curve for IL-1β,IL-6,IL-12p70 and IL-17 predicted SMPP course>9d were 0.657,0.657,0.682 and 0.642,respectively,When the four indicators are combined,the area under ROC curve is 0.750.Conclusions1.In hospitalized patients,the systemic and local inflammatory responses of SMPP children were stronger than those of common severe pneumonia..2.In children with SMPP,the systemic and local inflammntory responses were more intense in children with PB than those without PB.NLR and D-Di have important value in predicting PB.3.In children with SMPP,the systemic inflammatory response was more intense in children with pleural effusion than the non-pleural effusion children.NEU,PCT,DDi and LDH have important value in predicting pleural effusion.4.The combination of IL-1β,IL-6,IL-12p70 and IL-17 in BALF have important value in predicting the course of SMPP.