Interleukin 17A as a good predictor of the severity of Mycoplasma pneumoniae pneumonia in children

Mingyue Yang,Mengyao Li,Genhong Cheng,Ruihua Lu,Yining Zhang,Fangxing Zhao,Xiaosong Wang,Man Gao,Fanzheng Meng,Kuo Wang,Lijuan Huang

doi:10.1038/s41598-017-13292-5

Abstract

Early distinction between severe Mycoplasma pneumoniae pneumonia (MPP) and mild MPP is still difficult. The aim of this study was to analyze cytokines in bronchoalveolar lavage fluid (BALF) and explore predicting factors of severe MPP in children. Retrospective analysis was performed on 150 children with MPP or bronchial foreign body (FB) admitted in our hospital. The mRNA levels of IL17A were found significantly lower in severe MPP group comparing with mild MPP group or FB group. However, no significant difference was found in the levels of IL4, IL10 or interferon beta1 (IFNβ1) between the two groups. Receiver operator characteristic (ROC) curve analysis showed that IL17A can be used to distinguish severe MPP from mild MPP. These results were confirmed in a validation cohort including 40 MPP children from another hospital. IL17A levels were correlated with some clinical characters, such as refractoriness and pleural effusion. Lower IL17A levels were more likely to be found in refractory MPP children or in MPP children with pleural effusion. Moreover, the protein levels of IL17A in BALF were also found greatly decreased in children with severe MPP. Thus, decreased IL17A levels in BALF may be a valuable biomarker to identify severe MPP in children.

Highlights

Mycoplasma pneumoniae pneumonia (MPP) counts for 20 to 40% of community-acquired pneumonia in children and shows an even higher incidence during epidemics[1,2,3]
This is a retrospective study, the MPP children were divided into mild MPP group and severe MPP group based on the clinical information collected and analyzed after September 2016, detailed criteria can be found in Methods
MPP is usually found in children and young adults to be a self-limited process, but sometimes severe MPP happens with serious complications

Summary

Introduction

Mycoplasma pneumoniae pneumonia (MPP) counts for 20 to 40% of community-acquired pneumonia in children and shows an even higher incidence during epidemics[1,2,3]. Up to data, little study has been performed to identify cytokines in BALF as biomarkers of severe MPP. It is increasingly accepted that diverse innate myeloid immune cells are able to produce IL17 These cells are strategically positioned in the barrier tissues, such as lungs, intestines, skin and peripheral lymph nodes to rapidly react to pathogens. These cells allow an immediate response, and activate and amplify the adaptive immunity responses. We performed a retrospective study to investigate the expression of IL17A, IL4, IL10 and IFNβ1 in BALF by comparing their levels in mild MPP and severe MPP children

Objectives

Methods

Results

Conclusion