Neutrophil kinetics and function after major trauma: A systematic review

Area of Science:

• Immunology
• Trauma Medicine
• Critical Care

Background:

• Immune dysfunction post-trauma is linked to high morbidity and mortality.
• Neutrophils are central mediators of this immune dysfunction.
• Conditions like multiple organ dysfunction syndrome (MODS), sepsis, and inflammation are associated outcomes.

Purpose of the Study:

• To systematically review recent literature on neutrophil kinetics and function after major trauma in humans.
• To explore potential mechanisms behind neutrophil dysfunction in trauma patients.

Main Methods:

• Systematic literature search of Medline, Embase, and PubMed up to January 2021.
• Inclusion criteria: adults (>18 years) with Injury Severity Score > 12 admitted to ICU.
• Hand-searched reference lists for additional relevant studies.

Main Results:

• 48 studies were included, revealing persistently elevated neutrophil counts and altered cell-surface markers.
• Heterogeneous and immunosuppressive neutrophil populations were observed in circulation.
• Some neutrophil changes correlate with clinical outcomes like MODS and secondary infections.

Conclusions:

• Neutrophil phenotype understanding after trauma is advancing.
• Further research should focus on functional markers and extravasated neutrophils for improved risk stratification.
• Standardized study designs are needed to better assess neutrophil behavior post-trauma.