High expression of CD3+T-lymphocytes in cerebrospinal fluid increases the risk of critical cerebral hemorrhage with systemic inflammatory response syndrome (SIRS) after surgery.

Objective: To assess the frequency of lymphocyte subsets and other laboratory indicators in paired cerebrospinal fluid (CSF) and peripheral blood (PB) samples from critically ill patients with intracerebral hemorrhage (ICH) who developed systemic inflammatory response syndrome (SIRS) following surgery.

Introduction: Neuroinflammation and systemic inflammatory responses significantly contribute to secondary brain injury following ICH. Post-surgery SIRS is known to worsen clinical outcomes in ICH patients; however, the immune response in the CSF and PB has not been fully characterized. Understanding immunological changes in ICH patients with SIRS could lead to improved clinical management and prognostic outcomes.

Methods: This study involved a retrospective analysis of data from patients with ICH who underwent surgery in the Neurological Intensive Care Unit (NICU) of Baoding No. 1 Hospital, Hebei Province, China, between January and July 2022. Patients were divided into SIRS and non-SIRS groups based on the clinical criteria. Demographic, clinical, and laboratory data, including lymphocyte subsets in CSF and PB, were collected and analyzed. This study compared lymphocyte subsets and other inflammatory markers between the SIRS and non-SIRS groups.

Results: Patients with SIRS demonstrated higher systolic blood pressure (SBP) at admission, worse 90-day prognoses, elevated inflammatory markers, increased levels of complement proteins C3 and C4, and lower levels of immunoglobulin G (IgG) compared to patients without SIRS. Between 3-6 days post-surgery, SIRS patients showed higher percentages of CD3+T cells, CD4+T cells, and CD4+/CD8+ ratios in the CSF than non-SIRS patients. CD3+T cell percentages in the CSF were consistently higher than those in the PB and were independent of PB levels. In contrast, CD3-CD16+CD56+ natural killer (NK) cell percentages were lower in patients with SIRS. No significant differences in PB lymphocyte subsets were found between the two groups. A high CSF CD3+T cell percentage (≥85.68 %) was identified as the strongest predictor of critical ICH with SIRS after surgery, with an appropriate use criterion (AUC) of 0.7742, sensitivity of 77.42 %, specificity of 76.19 %, and 95 % CI of 0.6655-0.8829 (P < 0.0001).

Conclusion: Elevated levels of CD3+T lymphocytes in CSF are strongly associated with an increased risk of severe cerebral hemorrhage and SIRS following surgery. These findings suggest that monitoring CSF immune markers, particularly CD3+T lymphocytes, could serve as valuable predictors for the development of SIRS in critically ill ICH patients and inform post-surgical treatment strategies.