Correlation of Circulating T Lymphocytes and Intracranial Hypertension in Intracerebral Hemorrhage.

Background: The close correlation between intracerebral pressure (ICP) and immunologic responses has been well described, but the role of T lymphocytes in this process remains unknown. This study targeted the relationship of circulating T lymphocytes and ICP in patients with intracerebral hemorrhage (ICH).

Methods: Between October 2015 and October 2016, consecutive patients age 18-65 years with ICH were enrolled. ICP values were recorded hourly for 5 days, and the screened patients were divided into 2 groups based on ICP: the elevated ICP group (ICP >20 mmHg) and normal ICP group (ICP ≤20 mmHg). Peripheral blood was collected on admission and T lymphocyte subpopulations were analyzed by flow cytometry. Glasgow Coma Scale score on admission and Glasgow Outcome Scale (GOS) score at 30 days after ICH were analyzed.

Results: A total of 44 patients were enrolled, including 18 patients in the elevated ICP group and 26 in the normal ICP group. Both CD3 and CD4 T lymphocyte counts were higher in the elevated ICP group (P = 0.004 and 0.000, respectively). The CD8 T lymphocyte count was not significantly different between the 2 groups (P = 0.751). There were correlation trends between the maximum ICP value and CD3 lymphocyte count (P = 0.003), CD4 T lymphocyte count (P = 0.000), and the CD4/CD8 T lymphocyte ratio (P = 0.000). The area under the curve (AUC) of CD4/CD8 T lymphocyte ratio was the largest among them (P = 0.011 and 0.033), with a significant cutoff value and good specificity and sensitivity. There was a close correlation between the CD4/CD8 T lymphocyte ratio and the 30-day GOS score (P = 0.003, AUC = 0.812).

Conclusions: The CD4/CD8 T lymphocyte ratio may be a valuable indicator for predicting postoperative ICP and the short-term prognosis after ICH.