S100A8/A9 and sRAGE kinetic after polytrauma; an explorative observational study

Area of Science:

• Immunology
• Trauma Medicine
• Biomarker Discovery

Background:

• Trauma-induced innate immune activation leads to systemic inflammation, organ failure, and infection risk.
• S100A8/S100A9 complex (an alarmin) and soluble RAGE (sRAGE) are potential biomarkers for post-trauma complications.

Purpose of the Study:

• To characterize the time-dependent kinetics of S100A8/S100A9 and sRAGE after severe trauma.
• To evaluate their potential as early biomarkers for organ damage, infection, and mortality.

Main Methods:

• Blood samples collected from 38 severe trauma patients at ICU admission (Day 0), Day 1, Day 3, and Day 5.
• S100A8/A9 and sRAGE levels measured using ELISA.
• Biomarker levels analyzed in relation to clinical outcomes like infection, shock, renal failure, and mortality.

Main Results:

• S100A8/A9 complex levels increased significantly over time (p=0.001), but showed a smaller increment in patients who developed infection (p=0.011).
• sRAGE levels decreased over time (p<0.0001) and were higher in patients with persistent shock (p=0.02-0.045).
• Admission sRAGE levels were higher in non-survivors (p=0.015) and patients developing renal failure (p=0.011).

Conclusions:

• A smaller increase in S100A8/A9 over time is associated with infectious complications post-trauma.
• Declining sRAGE levels correlate with shock and ischemic injury markers.
• Admission sRAGE levels predict mortality and renal failure development, highlighting their utility in trauma management.