Age-dependent differences in pulmonary host responses in ARDS: a prospective observational cohort study

Area of Science:

• Pulmonary Medicine
• Critical Care
• Immunology

Background:

• Preclinical studies suggest age-related differences in host defense and pulmonary renin-angiotensin system (RAS) influence acute respiratory distress syndrome (ARDS) epidemiology.
• This study investigates age-dependent variations in host defense and RAS biomarkers in ARDS patients.

Purpose of the Study:

• To compare biomarkers of host defense and RAS in bronchoalveolar lavage (BAL) fluid across different age groups with ARDS.
• To determine if age influences inflammatory, endothelial, and epithelial damage markers in ARDS lungs.

Main Methods:

• Prospective observational study of 82 mechanically ventilated ARDS patients across four age groups: neonates, children, adults, and older adults.
• Bronchoalveolar lavage (BAL) fluid was collected within 72 hours of intubation.
• Assessed angiotensin converting enzyme (ACE) and ACE2 activity, alongside inflammation, endothelial activation, and epithelial damage biomarkers.

Main Results:

• Levels of myeloperoxidase, IL-6, IL-10, and p-selectin increased with age.
• Intercellular adhesion molecule-1 was elevated in neonates.
• No significant age-related differences were observed in ACE and ACE2 activity.

Conclusions:

• Age-dependent differences exist in lung biomarker levels in ARDS patients, particularly for neutrophil response markers.
• Contrary to preclinical findings, pulmonary RAS activity is not associated with age in this ARDS cohort.