Changes in Regulatory T-Cell Levels in Acute Cerebral Ischemia

Background Acute stroke causes intense and significant changes in the immune system as well as in the number and the ratio of various immune cells. Material and Methods Several large-scale studies have shown that ischemic stroke leaves the human body in a state of immunodepression. The regulatory T (Treg) cells may be strongly associated with a change of immune status. In this trial, we collected venous blood from a cohort of patients who were diagnosed with acute ischemic stroke within the last 24 hours (n = 139). We obtained their Treg cells/CD4⁺ T-cell ratio (Treg%) on days 1, 3, 7, and 14 using flow cytometry. Results We divided the patients into groups A and B based on the cerebral infarct volume being lesser or greater than 28.6 mL (the median infarct volume), respectively (calculated using the Pullicino formula). We also divided them per the trial of ORG 10172 in acute stroke treatment (TOAST) criteria. Compared with the controls, group A patients showed a slight increase on day 1 and an increase on days 3, 7, and 14 (p < 0.05). group B patients showed a decrease on days 1 and 3 and an increase on days 7 and 14 (p < 0.05). Group B patients showed higher infection rates than group A patients. We used repeated analysis of variance to confirm that gender, cerebral hemisphere, and infection had no influence on the frequency of Treg cells. Conclusion Our findings indicate that the Treg cells/CD4⁺ T-cell ratios undergo different changes in frequency in small- and large-volume strokes.