The serum interleukin 17 (IL-17) level and the prognosis of brain aneurysm- a case control study

Abstract Background Rupture of an Intracranial aneurysm (IA) may cause disability and death. Inflammation is a known mechanism in the pathogenesis of IAs, and several proinflammatory agents such as interleukins, tumor necrosis factors, complement, and so on are defined in the pathogenesis of IAs. This study investigated the link between IL-17, a pro-inflammatory cytokine, and IAs. Methods In this case–control study, 88 patients with intracranial aneurysms (IA) were divided into two groups: 44 with ruptured aneurysms and 44 with unruptured aneurysms. A blood sample was taken to measure the level of IL-17 within 48 h of the symptom onset and before surgery. To measure the IL-17 level, blood was also taken from the control group. Data were expressed as mean ± SD and analyzed using Student’s t-test, Mann–Whitney test, and Pearson correlation, with p < 0.05 considered significant. Results IL-17 levels increase with aneurysm size, and this increase is particularly visible in 5 to 6 mm aneurysms or greater. Mean IL-17 level is 44.81 ± 21.28 pg/ml in those with intra-aneurysm thrombosis and was different significantly from 32.58 ± 10.58 pg/ml in those without it ( p = 0.02). The mean IL-17 serum level was 54.80 ± 33.60 pg/ml in patients with aneurysm calcification and 33.80 ± 12.19 pg/ml in those without. Conclusions We observed a significant difference in the IL-17 serum levels among patients with thrombotic and calcified aneurysms, as well as aneurysm size as it increased. However, our study did not provide conclusive evidence that IL-17 directly causes rupture in IAs. It is possible that IL-17 plays a role in the enlargement of IAs, but further studies are required to fully understand its involvement in this process.