Serum Superoxide Dismutase Activity Levels In The Early Stage Of Acute Pancreatitis And Its Relationship With Prognosis

Background:Current research suggests that oxidative stress is an important event in the pathogenesis of acute pancreatitis(AP).Oxidative stress occurs when a large amount of reactive oxygen species(ROS)exceeds the ability of the body’s antioxidant system to clear it.Oxidative stress plays an important role in pancreatic injury,local and systemic complications.Superoxide dismutase(SOD)is an important antioxidant enzyme that removes ROS in the body and can effectively participate in the body’s oxidative stress response.However,the changes of serum SOD activity and its clinical significance in the early stages of AP patients are unclear.Objective:Observe the relationship between the changes of serum SOD activity and the severity of the disease in the early stages of AP;study the correlation between serum SOD activity and organ failure,pancreatic necrosis and mortality;explore the predictive value of SOD activity on organ failure and mortality in AP patients.Methods:A retrospective study was used to extract 2549 cases from January 1,2013 to December 31,2017 in the AP database of the First Affiliated Hospital of Nanchang University.They were older than 18 years old and less than 75 years old,had onset of symptoms for 24 hours,and had complete SOD data of the 854 adult patients with AP,the clinical data of the patients included in the study were compiled.1.Patients were divided into mild acute pancreatitis(MAP),moderately severe acute pancreatitis(MSAP),and severe acute pancreatitis(SAP)according to the revised Atlanta classification.The analysis of variance was used to compare the changes and differences in serum SOD activity among the three severity AP patients at admission 24 hours,48 hours,and 72 hours.2.Chi-square test statistical method was used to compare serum SOD activity in patients with persistent respiratory failure,persistent circulatory failure,persistent renal failure,and mortality;Chi-square test statistical method was used to compare serum SOD activity between patients with SAP that occurred within 48 hours and patients with SAP that occurred after 48 hours;Chi-square test statistical method was used to compare the difference in SOD activity between patients with organ failure that occurred within 48 hours and those with organ failure that occurred after 48 hours.3.Spearman’s correlation was used to determine the correlation between SOD activity and AP severity,persistent respiratory failure,persistent circulatory failure,persistent renal failure,pancreatic necrosis and mortality.4.The area under the ROC curve was used to analyze the accuracy of predicting the occurrence of SAP,persistent respiratory failure,persistent circulatory failure,persistent renal failure,and mortality by SOD activity within 24 hours of admission.And compared SOD,CPR,and APACHEII to predict the accuracy of continuous circulatory failure and mortality.Results:According to the inclusion and exclusion criteria,854 AP patients were eventually included,of which had 300 case patients with MAP(35.1%),387 case patients with MSAP(45.3%),and 167 case patients with SAP(19.6%).1.The serum SOD activity of patients with MAP at admission 24 hours,48 hours,and 72 hours were 97.75 ± 26.75 U/ml,97.61 ± 27.12 U/ml,89.75 ± 21.14 U/ml,and that of MSAP patients were 95.61 ±27.93 U/ml,94.97 ± 25.13 U/ml,77.24 ± 18.1 U/ml,and that of SAP patients were 88.95 ± 31.14 U/ml,86.55 ± 23.71 U/ml,74.81 ± 27.38 U/ml.The results showed that there were significant differences in SOD activity between patients with MAP,MSAP,and SAP(P = 0.005).Serum SOD activity decreased with the severity of the disease,and further decreased with the onset of prolonged disease.2.Serum SOD activity with and without persistent circulatory failure [(66.2 ± 14.9)U/ml vs(94.1 ± 28.2)U/ml,P <0.001],with and without continuous renal failure [(77.8 ± 37.2)U/ml vs(94.6 ± 27.5)U/ml,P <0.001],with and without persistent respiratory failure [(90.32 ± 31.5)U/ml vs(94.6 ± 27.5)U/ml,P = 0.026],with and without pancreatic necrosis [(87.0 ± 27.5)U/ml vs(94.4 ± 27.3)U/ml,P <0.001],and death and survival [(64.3 ± 16.0)U/ml vs(94.0 ± 28.2)U/ml,P <0.001] were significantly different among patients.There was no statistically significant difference in SOD activity between SAP occurring within 48 hours and SAP patients occurring after 48 hours.There was no statistically significant difference in SOD activity between patients with organ failure occurring within 48 hours and those with organ failure occurring after 48 hours.3.Spearman correlation analysis showed that there were all significant negative correlations between serum SOD activity and AP severity(r =-0.143,P﹤0.001),pancreatic necrosis(r =-0.126,P﹤0.001),persistent respiratory failure(r =-0.095,P = 0.006),persistent renal failure(r =-0.170,P﹤0.001),persistent circulatory failure(r =-0.124,P﹤0.001),and mortality(r =-0.115,P﹤0.001).4.ROC curve analysis showed that serum SOD activity within 24 hours of admission was more accurate in predicting persistent circulatory failure and mortality.When the optimal cut-off point for serum SOD was 76.5 U/ml,the area under(AUC)of ROC curve for predicting continuous circulatory failure was 0.83(0.74,0.92).Its prediction accuracy is better than CRP [AUC = 0.81(0.70,0.93)] and APACHEII score [AUC = 0.81(0.69,0.95)].When the optimal cut-off point for serum SOD was 76.5 U/ml,the area under the ROC curve for predicting mortality was 0.84(0.73,0.95).Its accuracy in predicting mortality of AP is better than CRP [AUC = 0.71(0.50,0.94)],and weaker than APACHEII score [AUC = 0.92(0.85,0.98)].Conclusions:1.In the early stage of the onset of AP,SOD activity decreases with the severity of the disease and the prolonged onset time.2.SOD activity was negatively correlated with organ failure,pancreatic necrosis and mortality.3.SOD activity has higher accuracy in predicting continuous circulatory failure and mortality in patients with AP.