Thrombus composition and regulatory T cell expression are associated with clinical outcomes in acute ischemic stroke patients with thrombectomy.

OBJECTIVES To analyze the relationship between thrombus composition and regulatory T cell expression with clinical outcome in acute ischemic stroke (AIS) patients with thrombectomy. METHODS We consecutively enrolled AIS patients with thrombectomy in the Department of Neurology, Shaoxing Hospital of China Medical University from June 2021 to October 2022. All thrombus specimens were subjected to hematoxylin-eosin staining and immunohistochemistry. Semi-quantitative analysis was performed to determine the content of red blood cells, fibrinogen/platelets, and regulatory T cells. Clinical data, vascular recanalization status, and neurologic outcomes at 3 months were collected. A modified Rankin Scale score of 0-2 was defined as a favorable outcome. RESULTS A total of 44 patients with complete thrombus data were included, including 15 patients with red cell type, 11 patients with mixed type, and 18 patients with fibrin/platelet type. The TOAST etiological classification among the three groups had statistical significance (P=0.001), while no significant difference was found in other general clinical data and surgical data (P>0.05). According to the TOAST etiology, 28 cases were classified into large atherosclerosis type and 16 cases were cardioembolic type. The proportion of red blood cells in thrombus was significantly higher in patients with large atherosclerosis than in those with cardiogenic embolism [58.00%(44.25%, 72.50%) and 24.00%(12.75%, 48.00%), respectively, P<0.01]. The ratio of fibrin to platelet in patients with cardiogenic embolism was significantly higher than that in patients with large atherosclerosis (73%(49.25%, 84.50%) and 40% (25.25%, 54.50%), respectively, P<0.01). Among the 44 patients, 19 had good neurological outcomes and 25 had poor outcomes. Univariate logistic regression analysis was performed on the relevant data of the patients, and it was found that age, operation time, CD4+CD25+T cell number were correlated with the functional outcomes of the patients (P<0.05). However, other clinical and surgical data were not correlated with clinical outcomes (P>0.05). Multivariate logistic regression analysis was performed, including age, operation time, CD4+CD25+T cell count and other variables, and it was found that thrombus CD4+CD25+T cell count was an independent factor affecting the functional outcome of patients (OR=1.369, 95%CI: 1.101-1.701, P=0.005). CONCLUSIONS There was no significant correlation between erythrocyte and fibrin/platelet components in thrombus and functional outcome, but increased expression of regulatory T cells was associated with good functional outcome.