关键词: 纤维支气管镜肺泡灌洗, 重症肺炎支原体肺炎, 肺功能, 血气分析, Toll受体2, 髓样分化蛋白88, 细胞核因子-κB

Abstract:

Objective To investigate the efficacy and mechanism of fiberoptic bronchoscopic alveolar lavage （BAL） in combination with azithromycin and methylprednisolone in the treatment of severe Mycoplasma pneumoniae pneumonia （SMPP） through the Toll-like receptor 2 （TLR2）/myeloid differentiation factor 88 （MyD88）/nuclear factor-κB （NF-κB） signaling pathway. Methods Eighty-four cases of children with SMPP caused by Mycoplasma pneumoniae （MP） infection， who were admitted to the Pediatrics Department of Wuhan First Hospital from January 2022 to January 2024， were selected as the observation group （n = 84）. All of them received BAL combined with conventional symptomatic treatment， azithromycin， and methylprednisolone treatment. Another 84 cases of children with SMPP caused by MP infection during the same period were selected as the control group. The observation group received BAL combined with conventional symptomatic treatment， azithromycin， and methylprednisolone， whereas the control group received only conventional symptomatic treatment， azithromycin， and methylprednisolone. Both groups were treated for 7 days. Therapeutic efficacy， recovery parameters， lung function， blood gas analysis， and TLR2/MyD88/NF-κB signaling pathway markers were compared between the two groups before and after treatment. Adverse reactions were also monitored during the treatment period. Results After a 7-day treatment period， the total effective rate in the observation group was significantly higher than that in the control group ［97.62% （82/84） vs. 84.52% （71/84）， P < 0.05］. The durations of cough， pulmonary rales， fever resolution， and hospitalization in the observation group were significantly shorter than those in the control group （all P < 0.05）. After treatment， the levels of arterial partial pressure of carbon dioxide （PaCO?）， along with the expression of TLR2 mRNA， MyD88 mRNA， and NF-κB mRNA in peripheral blood mononuclear cells （PBMC）， decreased in both groups compared with the baseline values. Notably， the observation group exhibited significantly lower levels （all P < 0.05）. In contrast， the time to peak tidal expiratory flow as a proportion of expiratory time （TPTEF/TE）， maximum mid-expiratory flow （MMEF）， volume to peak expiratory flow as a proportion of exhaled volume （VPTEF/VE）， oxygenation index （OI）， arterial oxygen saturation （SaO?）， and arterial partial pressure of oxygen （PaO?） increased in both groups after treatment. The observation group showed significantly higher values （all P < 0.05）. The overall incidence of adverse reactions was 5.95% （5/84） in the control group and 8.33% （7/84） in the observation group， and there was no statistically significant difference between the two groups （P = 0.549）. Conclusion BAL， when combined with azithromycin and methylprednisolone， effectively enhances lung function and blood gas parameters， downregulates the TLR2/MyD88/NF-κB signaling pathway， and facilitates clinical recovery in children with MP-induced SMPP， exhibiting favorable efficacy and safety profiles.

Key words: bronchoscopic alveolar lavage, severe mycoplasma pneumoniae pneumonia, lung function, blood gas analysis, toll receptor 2, myeloid differentiation protein 88, nuclear factor-κB