Systemic immune-inflammation index is associated with clinical outcome of acute ischemic stroke patients after intravenous thrombolysis treatment

INTRODUCTION: The systemic immune-inflammation index (SII) has been proven to predict the outcome in cancerous and non-cancerous diseases. We aimed to investigate the relationship between SII and other inflammatory markers and the prognosis in patients receiving intravenous thrombolysis (IVT). METHODS: Acute ischemic stroke patients treated with IVT were collected retrospectively. SII, neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) were constructed based on admission blood testing. Favorable outcome was defined as modified Rankin Scale of less than or equal to 2 at 90 days. In addition to outcome, cerebral edema was analyzed. The severity of brain edema was graded into three levels according to Thrombolysis in Stroke-Monitoring Study. Malignant cerebral edema (MCE) was defined as brain edema with midline shift. RESULTS: 278 patients were included. 140 (50.4%) achieved favorable outcome, 35 (12.6%) developed MCE. In patients with favorable outcomes, the levels of SII, NLR and PLR were lower compared to those with unfavorable outcomes [422.33 (258.69-624.68) vs 1269.83 (750.82-2497.22), p < 0.001; 2.73 (1.68-4.40) vs 4.76 (2.59-7.72), p < 0.001; 92.98 (62.35-126.24) vs 115.64 (85.51-179.04), p < 0.001]. The area under the Receiver Operating Characteristic curve was 0.698 for SII (95% CI = 0.637-0.760, p < 0.001), 0.694 for NLR (95% CI = 0.632-0.756, p < 0.001), 0.643 for PLR (95% CI = 0.579-0.707, p < 0.001). The optimal cut-off values were 652.73 for SII (sensitivity 0.572, specificity 0.786), 3.57 for NLR (sensitivity 0.659, specificity 0.693), 127.01 for PLR (sensitivity 0.457, specificity 0.757). CONCLUSIONS: An early increase in SII levels was related to 3 months of unfavorable outcomes in AIS patients after IVT. However, it is not associated with malignant edema.