Peripheral Blood Mononuclear Cells in Sepsis: Immune Trajectories, Monocyte Dysfunction, and Translational Biomarkers

Area of Science:

• Immunology
• Critical Care Medicine
• Translational Research

Background:

• Sepsis features a dynamic immune response with coexisting hyperinflammation and immunosuppression.
• Peripheral blood mononuclear cells (PBMCs) offer insights into sepsis progression and can be monitored over time.

Purpose of the Study:

• To review recent evidence on time-dependent PBMC remodeling in sepsis.
• To explore monocyte/macrophage dysfunction and the potential of PBMC-based biomarkers.
• To identify challenges and future directions for clinical translation of PBMC monitoring.

Main Methods:

• Narrative review synthesizing data from single-cell and spatial omics.
• Analysis of mechanistic studies and PBMC biomarker research.
• Focus on time-dependent PBMC changes, immune cell dysfunction, and biomarkers.

Main Results:

• PBMC remodeling in sepsis includes monocyte state transitions, HLA-DR downregulation, lymphocyte apoptosis/exhaustion, and immunometabolic reprogramming.
• These alterations correlate with patient recovery, persistent immunoparalysis, or secondary infections.
• PBMC biomarkers show promise for immune phenotyping and risk stratification.

Conclusions:

• PBMC remodeling is a critical hallmark of sepsis, influencing patient outcomes.
• PBMC-derived biomarkers could enhance immune monitoring and risk assessment in sepsis.
• Further longitudinal, age-stratified, and biomarker-guided studies are needed for clinical translation of PBMC monitoring to guide immunomodulatory strategies.