Serum IL-17A and IL-6 in paediatric Mycoplasma pneumoniae pneumonia: implications for different endotypes

ABSTRACT

Paediatric Mycoplasma pneumoniae pneumonia (MPP) is a heterogeneous disease with a diverse spectrum of clinical phenotypes. No studies have demonstrated the relationship between underlying endotypes and clinical phenotypes as well as prognosis about this disease. Thus, we conducted a multicentre prospective longitudinal study on children hospitalized for MPP between June 2021 and March 2023, with the end of follow-up in August 2023. Blood samples were collected and processed at multiple time points. Multiplex cytokine assay was performed to characterize serum cytokine profiles and their dynamic changes after admission. Cluster analysis based on different clinical phenotypes was conducted. Among the included 196 patients, the levels of serum IL-17A and IL-6 showed remarkable variabilities. Four cytokine clusters based on the two cytokines and four clinical groups were identified. Significant elevation of IL-17A mainly correlated with diffuse bronchiolitis and lobar lesion by airway mucus hypersecretions, while that of IL-6 was largely associated with lobar lesion which later developed into lung necrosis. Besides, glucocorticoid therapy failed to inhibit IL-17A, and markedly elevated IL-17A and IL-6 levels may correlate with lower airway obliterans. Our study provides critical relationship between molecular signatures (endotypes) and clustered clinical phenotypes in paediatric patients with MPP.

KEYWORDS:

• Paediatric Mycoplasma pneumoniae pneumonia
• cytokine profile
• endotype
• phenotype
• lower airway obliterans

Acknowledgments

The authors would like to thank all patients and their family members who agreed to participate in this study, and all inpatient staff who assisted in the recruitment of the patients. In addition, HW is grateful to Chen Shen, PhD, and laboratorians at Beijing Children’s Hospital for providing research facilities, instruments and kind guidance. We also thank the reviewers for their suggestions to improve the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Clinical Medicine Development of Special Funding Support, Beijing Hospitals Authority [ZYLX202118] and the Respiratory Research Project of National Clinical Research Center for Respiratory Diseases [HX2X-202103].