Systemic Inflammation Index Values Are Associated With Worsened Disease Severity And Poor Response To Autoimmune Encephalitis Treatment

Background:Autoimmune encephalitis is a rare,disabling and possibly curable neurological disease.There are different subtypes of autoimmune encephalitis,which are characterized by antibodies to intracellular antigens(intrasynaptic,cytoplasmic or nucleoprotein)or extracellular synaptic proteins and cell surface antigens.Some clinically diagnosed autoimmune encephalitis cases have no known autoantibodies been detected,so they are called "serum negative" autoimmune encephalitis.Some autoimmune encephalitis is not accompanied by other diseases,while some autoimmune encephalitis is related to potential malignant tumors,namely paraneoplastic autoimmune encephalitis.Patients with autoimmune encephalitis usually show behavioral changes,memory and cognitive impairment,seizures and dyskinesia.In the acute stage of the disease,there may be severe disability symptoms.Some patients will get better prognosis after early immunotherapy,but some patients may still have neurological symptoms.The prognosis of patients with autoimmune encephalitis varies with antibody subtypes.The prognosis of patients with cell surface antibody is better,while the prognosis of typical paraneoplastic autoimmune encephalitis cases targeting intracellular antigens is poor.However,even in the same subtype of autoimmune encephalitis,the long-term prognosis of patients is inconsistent.Understanding which factors may affect the prognosis is very important for the future treatment decision of autoimmune encephalitis.Objective:We aimed to explore the predictive value of the systemic inflammation index(SII)at admission as a peripheral biomarker of treatment response of Autoimmune encephalitis.Methods:The hospitalized patients diagnosed with autoimmune encephalitis for the first time from January 2018 to September 2020 in the First Affiliated Hospital of Zhengzhou University were selected for research.In strict accordance with the inclusion and exclusion criteria,146 patients with autoimmune encephalitis who met the requirements were finally included in this study.The modified Rankin score(m RS)was used to evaluate the disease severity of Autoimmune encephalitis after 30 days of first-line immunotherapy.According to the treatment response,the patients who met the inclusion criteria were divided into two groups,and the general information,past history,prodromal symptoms,clinical manifestations,imaging and biochemical examinations of the two groups were compared respectively.The predictive value of systemic inflammatory immune index for the treatment responsiveness of autoimmune encephalitis was calculated by the ROC curve analysis.Univariate analysis and binary Logistic regression model were used to analyze the risk factors of poor response to treatment of autoimmune encephalitis.Results:1.A retrospective analysis of 146 patients with autoimmune encephalitis was conducted.ROC analysis showed that the best cut-off value of systemic inflammation response index(SII)for predicting poor response to autoimmune encephalitis treatment was 863.3,with 83.0%sensitivity and 72.0%specificity,and the area under the curve(AUC)was 0.75.2.Multivariable binary logistic regression with backward stepwise method showed that decreased levels of consciousness,time until treatment initiation and SII were associated with poor response to immunotherapy.Moreover,the SII≤863.3 group had lower rates of decreased consciousness levels,admission to the intensive care unit,and mechanical ventilation;lower cerebrospinalfluid pressure,blood neutrophil count,and platelet count;and higher blood lymphocyte count and GCS scores.Conclusions:The SII was associated with worsened disease severity and poor response to treatment after 30 days of the initially diagnosed AE,and patients with an SII>863.3 were more likely to have poor response to immunotherapy.