Research Of The Correlation Between ?1-antitrypsin And Acute Kidney Injury After Cardiopulmonary Bypass

Background:Cardiopulmonary bypass(CPB)is an indispensable technique in open heart surgery,which obviously decreases the mortality of people who undergo cardio surgery.Despite of the improvement in the CPB techniques,this Non-physiological alternative remains a lot of postoperative complications.Different degree of renal function injury is one of the common complications after CPB.The pathogenesis of acute kidney injury(AKI)after cardiac surgery is not completely understood.It is very unlikely that a single etiologic factor will cause perioperative AKI.It is the consequence of multiple,interactive of preoperative,intraoperative,and postoperative pathways.[1]Acute kidney injury is not irreversible in most cases,detection and treatment timely can prevent its deterioration into renal failure.Traditional method of detection such as serum creatinine and blood urea nitrogen are either not applicable for the early identification nor earlier diagnosis of kidney injury.The traditional diagnostic criteria are lack of sensitivity and specificity.Predicting and reducing AKIare of great value to clinical decision-making and future research.al-antitrypsin(al-AT),an acute-phase glycoprotein and important inhibitor of neutrophil proteases;has been reported to inhibit neutrophil adhesion,chemotaxis,and superoxide production.It has rare reported about the relationship between this biomarker and AKI following CPB.We hypothesized that ?1-AT effectively prevented kidney injury and participated as an early predicting biomarker.Objective:The purpose of this study was to figure out variety of the plasma level of al-AT in patients who undergo AKI following CPB and whether this biomarker serve as a competent predictor.Methods and materials:This study was performed in Nanfang Hospital affiliated to Southern Medical University,China.This prospective study recruited 50 patients undergoing cardiac surgery with CPB from June 2016 to June 2017.The research program was approved by the Ethics Committee of Southern Hospital of Southern Medical University.We have defined AKI following CPB according to KDIGO Clinical Practice Guideline(2012).Patients was divided into AKI(n=19)and Non-AKI(n=31)groups.A total of 5 time points were set up,baseline level,1 h,12 h,24 h and 48 hours after operation,plasma samples was taken at each time point and stored at 80?.al-AT were determined by immunoturbidimetry.SPSS 22.0 software package was used for statistical calculations.The patients were categorized into two groups according to the development of AKI.The measurement data involved in the study were tested for normality first.To compare continuous variables,we used a two-sample t-test,or Mann-Whitney rank sum test.Pearson chi-square test and Fisher's exact test was used to compare the difference on categorical variables.To measure the sensitivity and specificity for ?1-AT at 1 h cutoff values after CPB,a conventional receiver operating characteristic(ROC)curve was generated.We calculated the area under the curve to ascertain the quality of ?1-AT as a biomarker.Univariate and multivariate logistic regression analyses were undertaken to assess the risk factors of AKI.For all analyses,p values less than 0.05 were considered significant.Results:This study was based on data from 50 patients who underwent cardio surgery with CPB in our hospital from June 2016 to June 2017.31 patients developed AKI and classified into the AK1 group.There was no significant difference between two groups except age and BMI.For all patients,levels of serum creatinine were increased after surgery compared with baseline.At 1 hour after operation,? 1-AT in AKI group was significantly lower than that in Non-AKI group(0.50 ±0.50 vs 1.23± 1.00 p=0.007).The concentration of ?1-AT in AKI group gradually increased to the baseline level.In Non-AKI group,?1-AT level increased slightly at 1 hour and slowly decreased to preoperative level.The area under the curve of concentration of?1-AT at 1h after operation was 0.754(95%CI,0.604-0.903),the diagnostic value was significant(p<0.05).The sensitivity and specificity of ?1-antitrypsin level at 1h after operation was the highest when ? 1-antitrypsin concentration was 0.674g/L.After analyzed by binary multivariate logistic regression,CPB time over 146.5 minutes was the independent risk factor of AKI after operation.(OR=6.912,95%CI 1.147-41.660)and ?1-AT over 0.674g/L at 1 h after CPB(OR=0.011,95%CI 0.019-0.601)were protective factors after operation.Conclusion:The research showed that the concentration of ? 1-AT in plasma increased significantly after cardiopulmonary bypass(CPB).The level of ? 1-AT in serum over 0.674g/Lwas significantly correlated with the guard of acute kidney injury at 1 hour postoperatively,and the concentration of ?1-AT in plasma could be used as an early biomarker of AKI in CPB.