Cytokine concentrations in bronchoalveolar lavage fluid (BALF) from children with severe community-acquired pneumonia (SCAP) from Shanghai

Background: It has been well known that overreaction of host immune systems plays a critical role in severe community-acquired pneumonia (SCAP). However, few of previous studies focused on the association between cytokine concentrations in bronchoalveolar lavage fluid (BALF) and SCAP. Object: We examined cytokine concentrations in BALF from children with SCAP and explored predictive value of cytokine concentrations for SCAP. Method: It was a retrospective study. A total of 100 children with SCAP who underwent parallel bronchoalveolar lavage between July 2017 and June 2019 were enrolled. 100 patients with mild community-acquired pneumonia (MCAP) who were admitted to the hospital were matched based on age and sex during the same time period . Basic clinical information were collected. Flow cytometry was used to determine the cytokine concentrations in BALF. Receiver operating characteristic curve was used to analyze their predictive value for SCAP. Result: A total of 106 males and 94 females were included in this study. The results showed that the CRP, PCT, ESR, LDH, and D-dimer were significantly increased in the SCAP group. The SCAP patients also had longer fever duration, hospitalization stays, and higher hospitalization costs. The IL-5，IL-17A，IL-18，and TnF-α in BALF of SCAP group were significantly higher than those in MCAP group. ROC curve analysis demonstrated AUC of those cytokines were all among 0.5~0.7. Conclusion: The IL-5，IL-17A，IL-18，and TnF-α in BALF of children with SCAP group were highe. However, the efficacy of those cytokines in the clinical diagnosis of SCAP is not excellent to be used as a predictor.