Association of early CD4⁺ T-lymphocyte depletion with 28 day mortality in sepsis: a retrospective single-center cohort study.

Abstract

Introduction: Sepsis-induced immune dysregulation, characterized by T-cell loss, is associated with poor outcomes. This study investigated the association between early peripheral T-lymphocyte subset profiles and 28 day mortality in patients with sepsis.

Methods: In this single-center retrospective cohort study, 60 critically ill patients with sepsis and 30 healthy controls were included. Patients with sepsis were classified as 28 day survivors (n = 30) or non-survivors (n = 30). Peripheral T-lymphocyte subset percentages (CD3⁺, CD4⁺, and CD8⁺) were measured by flow cytometry within 24 h of ICU admission.

Results: Compared with healthy controls, patients with sepsis had lower CD3⁺ (55.23±9.15%vs. 68.12±8.04%) and CD4⁺ T-cell percentages (30.88±10.52%vs. 40.15±7.21%) and a lower CD4⁺/CD8⁺ ratio (all p < 0.001). Non-survivors had lower CD3⁺ and CD4⁺ T-cell percentages than survivors (both p < 0.001). In multivariable logistic regression, lower CD4⁺ T-cell percentage (OR = 0.85, 95% CI 0.77-0.94; p = 0.002) and higher APACHE II score (OR = 1.42, 95% CI 1.18-1.71; p < 0.001) were independently associated with 28-day mortality. Adding CD4⁺ T-cell percentage to APACHE II increased the area under the receiver operating characteristic curve from 0.86 to 0.91 (p = 0.03).

Conclusion: Early reduction in peripheral CD4⁺ T-cell percentage was independently associated with 28 day mortality in this selected cohort. CD4⁺ T-cell assessment may provide incremental prognostic information beyond APACHE II, but external validation in larger prospective cohorts is required.