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Updated: May 7, 2026
A Data-Driven Approach to Quantifying Immune States in Sepsis
Published on: February 7, 2025
Age-related differences and common pathways of lymphocyte subsets in sepsis: a comparative review of elderly and
Xianwen Wang1,2, Qihang Huang1,2, Zhihong Zuo1,2
1Department of Critical Care Medicine, Hunan Provincial Clinical Research Center for Critical Care Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China.
Insights
Sepsis impacts children and older adults differently due to distinct immune system states. Understanding these age-specific lymphocyte changes is key for better sepsis treatment and outcomes.
Area of Science:
- Immunology
- Critical Care Medicine
- Gerontology
Background:
- Sepsis disproportionately affects the very young and elderly, who have unique immune vulnerabilities.
- Immunosenescence in older adults and immune immaturity in children create distinct pathways to sepsis-induced immune failure.
- Lymphocyte alterations are critical downstream consequences of the acute inflammatory response in sepsis.
Purpose of the Study:
- To comparatively review age-specific and shared alterations in lymphocyte subsets during sepsis.
- To synthesize clinical and experimental evidence on immune responses in pediatric and geriatric sepsis.
- To identify common and distinct immune failure mechanisms across age groups.
Main Methods:
- Comparative narrative review of clinical and experimental studies.
- Analysis of alterations in lymphocyte subsets (T cells, B cells, NK cells, Tregs).
- Synthesis of evidence on immune cell kinetics, mechanisms, and recovery potential.
Main Results:
- Sepsis causes lymphopenia, T cell dysfunction (activation, apoptosis, exhaustion), B cell depletion, impaired antibody production, and NK cell defects.
- Regulatory T cells (Tregs) play dynamic roles in sepsis-induced immune responses.
- Lymphocyte injury is a downstream effect of acute inflammation, impacting recovery and late mortality.
- Convergent immune phenotypes are linked to secondary infections and mortality, but kinetics and recovery differ by age.
Conclusions:
- Age-specific immune trajectories in sepsis require tailored monitoring and therapeutic strategies.
- An age-stratified approach to immune monitoring and biomarker-driven trials is needed.
- Avoiding one-size-fits-all immunomodulation can improve risk stratification and outcomes across the lifespan.
Abstract:
Sepsis disproportionately affects older adults and children, two immunologically vulnerable extremes of age. Yet sepsis is superimposed on distinct baselines-immunosenescence in the elderly and immune immaturity in neonates and young children-leading to different pathways toward immune failure. This comparative narrative review synthesizes clinical and experimental evidence on age-specific and shared alterations in lymphocyte subsets in sepsis, including lymphopenia; CD4+ and CD8+ T cell activation, apoptosis, and exhaustion; B cell depletion and impaired antibody production; NK cell cytotoxic defects; and dynamic regulatory circuits such as Tregs. Recognizing that early organ injury is initiated and amplified primarily by innate immune programs, we frame lymphocyte injury largely as a downstream cost of the acute host-response milieu that can become rate-limiting for immune recovery, secondary infections, and late mortality. We highlight convergent phenotypes linked to secondary infections and late mortality, while emphasizing differences in kinetics, mechanisms, and recovery potential. We propose an age-stratified approach to serial immune monitoring and biomarker-enriched trial design to guide immunoadjuvant therapies and avoid one-size-fits-all immunomodulation. Clarifying these trajectories may improve risk stratification and outcomes across the lifespan.
