Prognostic value of T lymphocyte CD40L expression levels in patients with sepsis

This study aimed to analyze the expression characteristics of CD40L on peripheral blood T lymphocytes in patients with sepsis and explore its value in assessing disease severity and prognosis.

This prospective study collected blood samples and clinical data from adult sepsis patients admitted to the Department of Critical Care Medicine at the First Affiliated Hospital of Soochow University between March 2023 and March 2024, with the primary endpoint being 28-day mortality. Multivariate Cox regression analysis was performed to evaluate the association between T lymphocyte CD40L expression and 28-day mortality. Additionally, machine learning algorithms were applied to determine the importance of CD40L-related features, and latent class mixed model analysis was conducted to identify different expression trajectories.

A total of 112 sepsis patients were included, with a 28-day mortality rate of 20.5%. CD40L expression levels on peripheral blood CD4⁺ and CD8⁺ T lymphocytes were significantly higher in sepsis patients compared to healthy controls. Three distinct expression patterns were identified for both CD4⁺ and CD8⁺ T cells. Patients with persistently low CD40L expression levels had significantly lower survival rates (P < 0.001). Moreover, multivariate Cox analysis identified day 1 CD40L levels on CD4⁺ (HR 0.712, 95% CI 0.606-0.837, P < 0.001) and CD8⁺ T cells (HR 0.593, 95% CI 0.481-0.731, P < 0.001) as an independent predictor of 28-day mortality. ROC analysis revealed strong associations between day 1 CD40L expression and mortality, with AUCs of 0.847 and 0.875, respectively. Finally, the combination of CD40L expression with SOFA scores improved clinical decision-making compared to SOFA scoring alone.

Peripheral blood T lymphocyte CD40L was identified as an independent predictor of 28-day mortality in sepsis patients. Identifying distinct expression trajectories of CD40L in peripheral blood T lymphocytes can effectively assist in predicting short-term prognosis in patients with sepsis.