Circulating long noncoding RNA ANRIL downregulation correlates with increased risk, higher disease severity and elevated pro-inflammatory cytokines in patients with acute ischemic stroke

Background To investigate the correlation of plasma lncRNA ANRIL expression with stroke risk, severity and inflammatory cytokines levels in acute ischemic stroke (AIS) patients. Methods A total of 126 AIS patients and 125 controls were consecutively recruited in this case-control study. Blood samples from all participants were collected, and plasma was separated. Plasma lncRNA ANRIL expression was quantified by quantitative real-time polymerase chain reaction (qRT-PCR). Plasma tumor necrosis factor-alpha (TNF-alpha) and interleukin (IL)-1 beta (IL-1 beta), IL-6, IL-8, IL-10, and IL-17 levels were measured by enzyme-linked immunosorbent assay (ELISA). National Institutes of Health Stroke Scale (NIHSS) scores were used to assess the stroke severity in AIS patients. Results Plasma lncRNA ANRIL expression was lower in AIS patients than in controls (P < 0.001), and the receiver operating characteristic (ROC) curve showed a good prediction value of lncRNA ANRIL for AIS risk with area under curve (AUC) of 0.759 (95% CI: 0.741-0.849). In addition, lncRNA ANRIL expression was negatively correlated with NIHSS score (r = -0.351, P < 0.001). Furthermore, while lncRNA ANRIL expression was negatively associated with hs-CRP level (r = -0.247, P = 0.005), no correlation was found between lncRNA ANRIL expression and ESR level (P = 0.619). For inflammatory cytokines, lncRNA ANRIL expression was inversely associated with TNF-alpha (r = -0.216, P = 0.015) and IL-6 levels (r = -0.326, P < 0.001), while it positively correlated with IL-10 level (r = 0.210, P = 0.018). Conclusion Circulating lncRNA ANRIL downregulation correlates with increased stroke risk, higher disease severity and elevated inflammation in AIS patients.