Critical Care (Jan 2021)

Alveolar compartmentalization of inflammatory and immune cell biomarkers in pneumonia-related ARDS

  • Inès Bendib,
  • Asma Beldi-Ferchiou,
  • Frédéric Schlemmer,
  • Mathieu Surenaud,
  • Bernard Maitre,
  • Anne Plonquet,
  • Guillaume Carteaux,
  • Keyvan Razazi,
  • Veronique Godot,
  • Sophie Hüe,
  • Armand Mekontso Dessap,
  • Nicolas de Prost

DOI
https://doi.org/10.1186/s13054-020-03427-y
Journal volume & issue
Vol. 25, no. 1
pp. 1 – 13

Abstract

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Abstract Background Biomarkers of disease severity might help individualizing the management of patients with the acute respiratory distress syndrome (ARDS). Whether the alveolar compartmentalization of biomarkers has a clinical significance in patients with pneumonia-related ARDS is unknown. This study aimed at assessing the interrelation of ARDS/sepsis biomarkers in the alveolar and blood compartments and explored their association with clinical outcomes. Methods Immunocompetent patients with pneumonia-related ARDS admitted between 2014 and 2018 were included in a prospective monocentric study. Bronchoalveolar lavage (BAL) fluid and blood samples were obtained within 48 h of admission. Twenty-two biomarkers were quantified in BAL fluid and serum. HLA-DR+ monocytes and CD8+ PD-1+ lymphocytes were quantified using flow cytometry. The primary clinical endpoint of the study was hospital mortality. Patients undergoing a bronchoscopy as part of routine care were included as controls. Results Seventy ARDS patients were included. Hospital mortality was 21.4%. The BAL fluid-to-serum ratio of IL-8 was 20 times higher in ARDS patients than in controls (p < 0.0001). ARDS patients with shock had lower BAL fluid-to-serum ratio of IL-1Ra (p = 0.026), IL-6 (p = 0.002), IP-10/CXCL10 (p = 0.024) and IL-10 (p = 0.023) than others. The BAL fluid-to-serum ratio of IL-1Ra was more elevated in hospital survivors than decedents (p = 0.006), even after adjusting for SOFA and driving pressure (p = 0.036). There was no significant association between alveolar or alveolar/blood monocytic HLA-DR or CD8+ lymphocytes PD-1 expression and hospital mortality. Conclusions IL-8 was the most compartmentalized cytokine and lower BAL fluid-to-serum concentration ratios of IL-1Ra were associated with hospital mortality in patients with pneumonia-associated ARDS.

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