Heightened Local Th17 Cell Inflammation Is Associated with Severe Community-Acquired Pneumonia in Children under the Age of 1 Year

Mediators Inflamm. 2021 Sep 22:2021:9955168. doi: 10.1155/2021/9955168. eCollection 2021.

Abstract

Severe community-acquired pneumonia (sCAP) early in life is a leading cause of morbidity, mortality, and irreversible sequelae. Herein, we report the clinical, etiological, and immunological characteristics of 62 children age < 1 year. We measured 27 cytokines in plasma and bronchoalveolar lavage (BAL) from 62 children age < 1 year who were diagnosed with CAP, and then, we analyzed correlations among disease severity, clinical parameters, and etiology. Of the entire cohort, three cytokines associated with interleukin-17- (IL-17-) producing helper T cells (Th17 cells), IL-1β, IL-6, and IL-17, were significantly elevated in sCAP patients with high fold changes (FCs); in BAL, these cytokines were intercorrelated and associated with blood neutrophil counts, Hb levels, and mixed bacterial-viral infections. BAL IL-1β (area under the curve (AUC) 0.820), BAL IL-17 (AUC 0.779), and plasma IL-6 (AUC 0.778) had remarkable predictive power for sCAP. Our findings revealed that increased local Th17 cell immunity played a critical role in the development of sCAP in children age < 1 year. Th17 cell-related cytokines could serve as local and systemic inflammatory indicators of sCAP in this age group.

MeSH terms

  • Bronchoalveolar Lavage Fluid / immunology
  • Community-Acquired Infections / etiology*
  • Community-Acquired Infections / immunology
  • Cytokines / analysis
  • Female
  • Hemoglobins / analysis
  • Humans
  • Infant
  • Inflammation / immunology*
  • Male
  • Pneumonia / etiology*
  • Pneumonia / immunology
  • Th17 Cells / immunology*

Substances

  • Cytokines
  • Hemoglobins