Correlation Between Systemic Immune-inflammation Index And Acute Ischemic Stroke Severity And Prognosis

Objective:To investigate the relevance between the systemic immune-inflammation index(SII)and stroke severity in patients with acute ischemic stroke(AIS)and the predictive value of SII for hemorrhagic transformation(HT)7 days after onset and neurological prognosis of patients with acute ischemic stroke 90 days after stroke onset.Method:This retrospective study enrolled the AIS patients who were admitted within 24 hours after the database of Stroke Prevention and Treatment Engineer Management Project from August 2020 to August 2021.Routine blood tests were completed within 24 hours of admission and SII values were calculated based on peripheral platelet,neutrophil and lymphocyte counts.The first NIHSS score was completed within 3 hours of admission and the 90-day clinical prognosis was evaluated using a modified Rankin scale.The differences in baseline characteristics between the mild stroke(NIHSS≤5)group and moderate-severe stroke(NIHSS≥6)group,between the HT group and non-HT group and between the good prognosis(m RS≤2)group and poor prognosis(m RS≥3)group were compared.The relationship between SII and severity of disease,occurrence of HT within 1 week,and clinical prognosis was analyzed by logistic regression.The AUC analysis was used to evaluate the prognostic value of SII,NLR,and PLR for stroke prognosis and HT.P<0.05 was defined as a statistically significant difference.Result:1.Relationship between SII and stroke severity: This study included 168 cases(63.2%)in the mild group and 98 cases(36.8%)in the moderate-severe group.In the moderate-severe group,the white blood cell count,neutrophil percentage,NLR,PLR,SII,TC,LDL-C,and INR were significantly higher than those of the mild group and HDL-C and the percentage of lymphocytes was significantly lower than that of the mild group(P<0.05).Logistic regression analysis showed that high SII(OR 1.004,95%CI 1.001～1.006,P=0.007)was correlated with stroke severity at admission.2.Relationship between SII and HT: This study included 213 cases(80.1%)in the non-HT group and 53 cases(19.9%)in the HT group.Compared with patients in the non-HT group,patients in the HT group were older and had larger infarct size,higher NIHSS score on admission,and more patients with poor prognosis.Patients in the HT group had higher white blood cell count,neutrophil percentage,platelet count,NLR,PLR,SII,INR,and lower lymphocyte percentage(P<0.05).Logistic regression analysis showed that high SII(OR 1.326,95%CI 1.126～1.438,P=0.005)was correlated with HT at admission.3.Relationship between SII and stroke prognosis: 44 cases(23.8%)had poor prognosis in mild stroke group and 56 cases(57.1%)in moderate-severe stroke group.The levels of neutrophil percentage,platelet count,NLR,PLR,and SII in the poor prognosis group were significantly higher than those in the good prognosis group,and the lymphocyte percentage was lower than that in the good prognosis group(P<0.05).Logistic regression analysis showed that high SII(OR 1.016,95%CI 1.005～1.032,P=0.016)was correlated with prognosis at admission.In a subgroup analysis of prognosis in patients with moderate to severe stroke,high SII(OR 1.010,95%CI 1.006～1.011,P=0.025)was correlated with prognosis at admission.4.The predictive value of SII for stroke: The AUC value of SII,NLR,PLR,and SII combined with NIHSS for predicting HT were 0.857(95%CI 0.808-0.907),0.832(95%CI0.775-0.890),0.848(95%CI 0.798-0.898)and 0.815(95%CI 0.745-0.884)(P<0.001).After comparison by Med Calc 19.0 software,it was found that the accuracy of SII in predicting HT was not statistically different from the accuracy of NLR,PLR,and SII combined with NIHSS scores(P>0.05).The AUC value of SII,NLR,PLR,and SII combined with NIHSS to predict poor prognosis in AIS patients were 0.880(95%CI0.836-0.924),0.806(95%CI 0.751-0.862),0.892(95%CI 0.851-0.933),and 0.902(95%CI0.860-0.944)(P<0.001),and after comparison by Med Calc 19.0 software,it was found that the difference between the accuracy of SII in predicting poor prognosis and NLR and SII combined with NIHSS scores was statistically significant(P<0.05),and the difference between PLR in predicting poor prognosis was not statistically different(P>0.05).Conclusion:1.High SII was a risk factor for stroke severity in AIS patients.2.SII was correlated with HT in AIS patients.The higher the level of SII,the greater risk of HT.The SII had predictive value for the occurrence of HT in patients with AIS,and its predictive accuracy was the same as NLR and PLR,and its predictive accuracy was not significantly improved after the SII combined with NIHSS score.3.High SII was a risk factor for poor prognosis of AIS patients after 90 days of onset.SII had predictive value for poor 90-day prognosis in patients with AIS.The predictive accuracy of SII for poor 90-day prognosis in patients with AIS was higher than NLR and the same as PLR,and the predictive accuracy of SII combined with NIHSS score for poor prognosis was better than that of SII alone.