Neutrophil kinetics and function after major trauma: A systematic review

ARTICLE HIGHLIGHTS

Research background

Neutrophils play an important role in immune dysfunction after major traumatic injury and alterations in this cell type are associated with the development of complications including organ failure and secondary infection. The kinetics of neutrophil dysfunction in the context of trauma is not completely understood and may have important implications for therapy.

Research motivation

Developing a granular and nuanced understanding of neutrophil kinetics and changes after trauma is necessary if key associations with disease and therapeutic targets are to be identified.

Research objectives

This review aimed to provide an overview of established aspects of neutrophil immunophenotypes in trauma, with special attention to factors which may hold prognostic value.

Research methods

This study was a systematic review of the PubMed, Ovid Medline and Embase databases for all papers on neutrophil kinetics or function after major trauma (injury severity score > 12) in adults (≥ 18 years) since 1990.

Research results

Key findings include a notable increase in immature (CD16^dim/CD62L^bright) neutrophils poorly responsive to subsequent bacterial stimuli which may confer susceptibility to bacteraemia. Highly inflammatory neutrophils which express adhesion markers and chemoattractant receptors such as CD11b and CXCR2 extravasate into end organs where they may damage host tissues and cause organ dysfunction.

Research conclusions

Neutrophil dysfunction after major trauma is complex and changes over time. Several stereotyped changes have been observed in multiple studies, as discussed above. Immunophenotyping of multiple cell types combined with clinical and laboratory data may yield endotypes likely to respond to different therapies.

Research perspectives

Areas of ongoing research include integration of multiple markers of immune dysfunction, enrichment strategies for clinical trials of immunomodulatory agents and the assessment of live cells in tissues rather than the circulation.