Role of immune inflammation in the formation of intracranial aneurysm

Abstract

Objective To investigate the role of immune inflammatory reaction in the formation of intracranial aneurysm. Methods The intracranial aneurysms in 40 patients of craniotomy (intracranial aneurysm group) and the vascular specimens in 20 craniotomy patients with traumatic brain injury (control group) were collected. Fluorescence quantitative polymerase chain reaction was used to detect the expression of interleukin (IL)-17 receptor in the arterial wall. Flow cytometry was used to detect the Th-17 cells in peripheral blood. Enzyme-linked immunosorbent assay was used to measure the levels of IL-17, IL-6 in the arterial wall and tumor necrosis factor-α (TNF-α) in peripheral blood. Results There were no significant differences in the age (62.6±8.7 years vs. 61.4±7.9 years; t=0.342; P=0.681), proportions of male (60.0%vs. 65.0%; χ2=0.246, P=0.434), hypertension (12.5% vs. 10.0%; χ2=0.315, P=0.492), diabetes (75.0% vs. 10.0%; χ2=0.284, P=0.482), and smoking (35.5% vs. 30.0%; χ2=0.224, P=0.413) between the intracranial aneurysms group and the control group. The expression of IL-17 receptor in the arterial wall (0.106±0.032 vs. 0.264±0.071; t=5.115, P=0.001) and the proportion of Th17 cells in peripheral blood (2.75%±0.53% vs. 7.18%±1.54%; t=8.436, P<0.001) and IL-17 level (7.32±1.82 μg/L vs. 22.64±4.51 μg/L; t=8.357, P<0.001) in the control group were significantly lower than those in the intracranial aneurysm group. The levels of IL-6 (1.15±0.24 μg/L vs. 19.64±4.16 μg/L; t=9.527, P<0.001) and TNF-α (1.43±0.31 μg/L vs. 26.17±4.32 μg/L; t=9.816, P<0.001) in the arterial wall in the control group were significantly lower than those in the intracranial aneurysm group. Conclusions The expression of IL-17 receptor in the arterial wall, the proportion of the Th17 cells and IL-17 level in peripheral blood were increased in patients with intracranial aneurysms. Immune inflammation may be involved in the formation of intracranial aneurysm. Key words: Intracranial Aneurysm; Inflammation; Interleukin-17; Receptors, Interleukin-17; Th17 Cells