The Application Of Brain Injury Biomarkers In The Treatment Of Intravenous Thrombolysis Of Patients With Acute Ischemic Stroke

Brain injury biomarkers are substances that can be detected in cerebrospinal fluid or peripheral blood when brain tissue is injured.The biomarkers in peripheral blood can be collected easily and detected quickly,and have great potential in the assessment of brain tissue injury.Brain injury biomarkers have been widely studied in traumatic brain injury,and the application of them in assessing the severity of the condition has been written into expert consensus.However,there are few studies in the field of stroke.Reperfusion therapy is the treatment with the highest level of evidence and recommendation for the ultra-early treatment of ischemic stroke.Studies focusing on the characteristics of brain injury biomarkers in stroke patients receiving reperfusion therapy are limited.This study will comprehensively explore the application of brain injury biomarkers in the treatment of intravenous thrombolysis(IVT)from the following three aspects: the assessment of infarct volume,the judgment of hemorrhagic transformation(HT)and the prediction of clinical prognosis.Part one.The association between brain injury biomarkers and infarct volume in patients after intravenous thrombolysisBackground and objective: Predicting the level of brain tissue injurie in patients with acute ischemic stroke accurately can help neurologists to judge the severity of patients and select the appropriate therapeutic strategy.Theoretically,the levels of brain injury biomarkers in peripheral blood are correlated with the degree of brain injury.In this part of the study,we aim to investigate whether brain injury biomarkers can predict tissue injuries in patients with acute ischemic stroke after IVT treatment.Methods: This is a prospective,multicenter and observational cohort study enrolling patients with acute ischemic stroke after IVT who met the inclusion and exclusion criteria in the First Hospital of Jilin University between September 2016 and April 2023,and in the other 15 stroke centers in Jilin province between September 2021 and February 2022.Venous blood samples were drawn from the cubital vein of each patient 24 hours after IVT,and levels of brain injury biomarkers were measured.Diffusionweighted imaging(DWI)sequences during hospitalization were collected and final infarct volume were calculated.Brain injury biomarkers included astroglial injury and neuronal cell body injury biomarkers.Glial fibrillary acidic protein(GFAP)and S100β were used as markers to reflect the degree of astroglial injury,and ubiquitin carboxyterminal hydrolases L1(UCH-L1)and neuron-specific enolase(NSE)were used as markers of neuronal cell body.Results: We enrolled 1028 patients with acute ischemic stroke after IVT that were able to complete follow-ups,of whom 84 patients did not complete DWI examination during hospitalization.Finally,944 patients were included in the analysis.The mean age was 62.71 years and 655(70.4%)patients were male.The median(interquartile range,IQR)of GFAP,S100β,UCH-L1 and NSE levels of 944 patients was 27.465 pg/m L(11.929-94.408),0.128 ng/m L(0.055-0.270),122.719 pg/m L(50.183-222.738)and 13.858 ng/m L(9.362-20.330),respectively.Patients were divided into four groups according to quarters of biomarker levels.Linear regression showed that the highest GFAP(>94.408 pg/m L,β,37.801,95% confidence interval [CI],27.019-48.584,P<0.001),S100β(>0.270 ng/m L,β: 35.544,95%CI: 25.052-46.036,P<0.001),UCH-L1(>222.738 pg/m L,β:34.395,95%CI: 23.725-45.065,P<0.001)and NSE(>20.330 ng/m L,β: 16.734,95%CI: 6.137-27.331,P=0.002)levels were independently correlated with larger final infarct volume comparing with patients with lowest respective levels.Conclusion: Serum GFAP,S100β,UCH-L and NSE measured 24 hours after IVT were independently associated with final infarct volume,could be used to predict brain injuries.Part two.The association between brain injury biomarkers and hemorrhagic transformation in patients after intravenous thrombolysisBackground and objective: There is a certain risk of hemorrhagic transformation(HT)after IVT treatment,which is directly related to the following antiplatelet or anticoagulant treatment after IVT and influence the clinical outcomes of these patients.Studies have shown that brain injury biomarkers have the potential to differentiate hemorrhagic and ischemic stroke.There are some similarities between intracerebral hemorrhage and HT after IVT.Therefore,in this part of the study,we aimed to explore the association between brain injury biomarkers and HT after IVT and to determine whether brain injury biomarkers can be used to help to indicate the occurrence of HT in patients with acute ischemic stroke after IVT.Methods: In this section,1028 patients with acute ischemic stroke after IVT collected in 16 centers in Jilin province in the first part of the study were enrolled.Blood samples were drawn from the cubital vein of each patient 24 hours after IVT,and brain injury biomarkers were measured.Simultaneously,CT examinations were performed to screen the occurrence of HT.HT were classified as hemorrhagic infarction type 1(HI1),hemorrhagic infarction type 2(HI2),parenchymal hematoma type 1(PH1),parenchymal hematoma type 1(PH2),and remote parenchymal hematoma(r PH)according to the European Collaborative Acute Stroke Study(ECASS).The measured brain injury biomarkers were the same as those in the first part,including astroglial injury(GFAP and S100β)and neuronal cell body injury biomarkers(UCH-L1 and NSE).Further,cases from the First Hospital of Jilin University were randomly assigned to training(70%)and testing(30%)cohorts for internal validation,and the external validation cohort included patients from the other 15 hospitals.Cutoff levels of GFAP and UCH-L1 for predicting non-HT were deviated in the training cohort and were validated in testing and validation cohorts.Results: Overall,1028 patients were included in this part of the study,of whom two patients did not complete CT examinations 24 hours after IVT.Finally,1026 patients were included in the analysis,of whom 87(8.5%)patients had HT.The mean age was 62.61 years and 721(70.3%)patients were male.The median(IQR)of GFAP,S100β,UCH-L1 and NSE levels of 1026 patients was 26.289 pg/m L(11.740-88.478),0.120 ng/m L(0.051-0.269),118.800 pg/m L(50.000-222.599)and 13.858 ng/m L(9.349-20.312),respectively.Multivariable binary and ordinal logistic regression analyses showed that higher GFAP,S100β and UCH-L1 levels were independently associated with HT and ordered HI1,HI2,PH1,and PH2 after IVT comparing with patients with the lowest respective levels;however,no significant association between NSE and HT was found.Additionally,cutoff levels(12.6 and 63.1 pg/m L,respectively)excluded patients with HT with a sensitivity of 98.04%(95% CI,88.21–99.90)and negative predictive value(NPV)of 98.28%(95%CI,89.54-99.91)in the training cohorts.In the testing,and validation cohort,sensitivity was 100.00%(95%CI 79.08-100.00)and 100.00%(95% CI,77.08–100.00),respectively,and NPV was 100.00%(95% CI,75.93–100.00)and 100.00%(95% CI,82.19–100.00),respectively.Conclusion:1.Serum GFAP,S100β and UCH-L1 levels measured 24 hours after IVT were independently associated with HT.2.The combination of GFAP and UCH-L1 exhibit high sensitivity for predicting absence of HT 24 hours after IVT.Part three.The association between brain injury biomarkers and clinical outcomes in patients after intravenous thrombolysisBackground and objective: Ischemic stroke is one of the major causes of disability in our country.IVT therapy currently has the highest level of evidence and recommendation for the treatment of acute ischemic stroke.However,even after IVT therapy,there are still nearly half of patients who do not receive favorable outcomes.Therefore,it is important to find objective,quantitative and rapid markers to predict the functional prognosis of these patients.In our first and second parts of the study,we have demonstrated that the level of brain injury biomarkers at 24 hours after IVT were independently associated with tissue outcomes and the occurrence of HT in these patients.In this part of the study,we aimed to explore the association between brain injury biomarkers and clinical outcomes to determine whether brain injury biomarkers can be used to predict prognosis of patients with acute ischemic stroke after IVT.Methods: In this section,1028 patients with acute ischemic stroke after IVT collected in 16 centers in Jilin province in the first part of the study were collected.Blood samples were drawn from the cubital vein of each patient 24 hours after IVT,and brain injury biomarkers were measured.Clinical outcomes included short-term and long-term outcomes.Short-term outcomes were defined as National Institutes of Health Stroke Scale(NIHSS)scores at 24 hours after IVT and seven days after stroke,and long-term outcomes were defined as modified Rankin Scale(m RS)scores at 90 days.A m RS score of ≤1 at 90 days was defined as a favorable outcome.The measured brain injury biomarkers were the same as those in the first part,including astroglial(GFAP and S100β)and neuronal cell body injury biomarkers(UCH-L1 and NSE).Further,cases from the First Hospital of Jilin University were randomly assigned to training(70%)and testing(30%)cohorts for internal validation,and the external validation cohort included patients from the other 15 hospitals.Cutoff levels of GFAP and UCH-L1 for predicting 3-month unfavorable outcomes were deviated in the training cohort and were validated in testing and validation cohorts.Biomarkers based model was established in the training cohort and were subjected to internal and external validation.Results: All of 1028 patients were included in the analysis of this part.The mean age was 62.62 years and 722(70.2%)patients were male.The median(IQR)of GFAP,S100β,UCH-L1 and NSE levels was 26.360 pg/m L(11.759-88.261),0.120 ng/m L(0.052-0.270),119.400 pg/m L(50.000-222.738)and 13.835 ng/m L(9.324-20.292),respectively.Linear regression showed that the higher GFAP,S100β,UCH-L1 and NSE levels were independently correlated with higher 24-hour and 7-day NIHSS.Multivariable binary and ordinal logistic regression analyses showed that higher GFAP,S100β,UCH-L1 and NSE levels were independently associated with unfavorable outcomes and ordered m RS distribution 90 days after IVT comparing with patients with the lowest respective levels.Additionally,cutoff levels(116 and 292 pg/m L,respectively)predicted patients with 3-month unfavorable outcomes with specificity of 97.56%(95%CI,94.51-99.00)and positive predictive value(PPV)of 88.68%(95% CI,76.28-95.31)in the training cohorts.In the testing,and validation cohort,specificity was 97.83%(91.62-99.62)and 96.90%(95% CI,91.77-99.00)respectively,and the PPV was 90.00%(95% CI,66.87-98.25)and 75.00%(95% CI,47.41-91.67),respectively.With regard to prediction of 3-month unfavorable outcomes,the area under the receiver operating characteristic curve of the nomogram model based GFAP,UCH-L1,age,serum fasting glucose and 24-hour-NIHSS was 0.853(95%CI,0.822–0.884),0.833(95%CI,0.781–0.884),and 0.832(95%CI,0.775–0.889)in the training,internal testing,and external validation cohorts,respectively.Conclusion:1.Serum GFAP,S100β,UCH-L and NSE measured 24 hours after IVT were independently associated with prognosis.2.The combination of GFAP and UCH-L1 exhibit high accuracy for predicting 3-month unfavorable outcomes.3.The nomogram model based GFAP,UCH-L1,age,serum fasting glucose and 24-hour-NIHSS performed accurately in predicting 3-month unfavorable outcomes,providing an individualized early prediction of the 3-month unfavorable outcomes in patients treated with IVT.