Predictive effect of the decline in CD4 T cell levels in blood on infection in patients with severe hemorrhagic stroke and mechanism.

Objective: The purpose of this research was to evaluate the influence of immunity on infection in patients with severe hemorrhagic stroke and explore the mechanism underlying this connection.

Methods: Clinical data obtained from 126 patients with severe hemorrhagic stroke were retrospectively analyzed, and the factors affecting infection were screened by multivariable logistic regression models. Nomograms, calibration curves, the Hosmer-Lemeshow goodness-of-fit test, and decision curve analysis were used to examine the effectiveness of the models in evaluating infection. The mechanism underlying the reduction in CD4 T-cell levels in blood was explored by analysis of lymphocyte subsets and cytokines in cerebrospinal fluid (CSF) and blood.

Results: The results showed that CD4 T-cell levels of <300/μL was an independent risk factor for early infection. The models for multivariable logistic regression involving the CD4 T-cell levels and other influencing factors had good applicability and effectiveness in evaluating early infection. CD4 T-cell levels decreased in blood but increased in CSF. Similarly, interleukin (IL)-6 and IL-8 levels in CSF had a significant increase, generating a substantial concentration gradient between the CSF and the blood.

Conclusion: Reduced blood CD4 T-cell counts among patients who had severe hemorrhagic stroke increased the risk of early infection. CSF IL-6 and IL-8 may be involved in inducing the migration of CD4 T cells into the CSF and decreasing blood CD4 T-cell levels.