Flow cytometry developments and perspectives in clinical studies: examples in ICU patients

Area of Science:

• Critical care medicine
• Immunology
• Diagnostic technologies

Background:

• Sepsis is a significant global health threat with high mortality.
• Flow cytometry (FCM) is an underutilized tool in intensive care unit (ICU) patient management.
• Immune dysfunctions are central to sepsis and secondary infections in critically ill patients.

Purpose of the Study:

• To review FCM-detectable biomarkers for sepsis diagnosis and outcome prediction in ICU patients.
• To explore the utility of FCM in guiding immunotherapy for immune dysfunctions.
• To highlight the potential of FCM in routine patient monitoring and stratification.

Main Methods:

• Review of FCM biomarkers including neutrophil CD64, monocyte HLA-DR, and regulatory T cells (CD4+CD25+CD127low).
• Focus on lyse-no-wash methods for rapid (1-hour) results.
• Analysis of biomarker application in diagnosis, prognosis, and immunotherapy guidance.

Main Results:

• Neutrophil CD64 is a sensitive marker for systemic infection and sepsis.
• Diminished monocyte HLA-DR predicts mortality and secondary infections.
• Increased regulatory T cells indicate lymphocyte dysfunction.

Conclusions:

• Standardized FCM biomarker panels can define ICU patient immune status.
• FCM biomarkers serve as stratification tools for clinical trials.
• Future research should focus on large trials for individualized immunotherapy guided by FCM.