Study On Early Diagnosis Of Contrast-induced Acute Kidney Injury

Objective: To study the clinical significance of early diagnosis for Contrast-induced acute kidney injury(CI-AKI)via joint evaluation of four biomarkers including the neutrophils gelatinases associated apolipoprotein(NGAL),liver type fatty acid binding protein(L-FABP),Cystatin C(Cys C),and Fibrinogen(FIB).Research methods: 240 patients with acute coronary syndromes such as acute ST elevation,non-ST elevation myocardial infarction and unstable angina were selected to undergo coronary angiography from November 2016 to August 2017 in the department of cardiovascular internal medicine of affiliated hospital of Hebei University.All patients were performed biomarker tests,including blood NGAL,urine NGAL,urine L-FABP,urine FIB,blood Cys C at 2h to 4h,24 h and 48 h before and after surgery,and 48 h Serum creatinine(SCr)after surgery,respectively.According to the guidelines for improving global renal disease prognosis in 2012 as the standard of the diagnosis of CI-AKI,those patients were divided into CI-AKI group and non-CI-AKI group(normal group).Logistic regression analysis was conducted for the risk factors of CI-AKI,and the possible risk factors of CI-AKI were identified as well;The receiver-operating characteristic curve(ROC)and area under curve(AUC)were drawn,various biomarkers and joint evaluation of those markers for diagnosis of CI-AKI clinical significance were analyzed,and the optimal cut-off value was determined.Different methodologies were performed for the six biomarkers as follows: forwarding method was utilized for Urine NGAL analysis,latex enhanced immune turbidimetry was used for serum NGAL,enzyme-linked immunosorbent assay was used for urine L-FABP and urine FIB,sarcosine oxidase method was utilized for serum Cr,immunoturbidimetry method was used for Cys C.Results: 1.There were 10 cases among 240 patients occurred CI-AKI after surgery which gave rise to 4.1% incidence.Logistic regression analyses showed that the factors such as hypertension,diabetes mellitus,contrast agent dosage and cardiac function were the risk factors regarding to the occurrences of CI-AKI in patients after PCI therapy.2.There was no significant difference between the CI-AKI group and normal group in terms of the preoperative serum and urine NGALs(P> 0 0.05).3.As far as the patients with CI-AKI concerned,the levels of the six biomarkers after operation were obviously higher than those before operation,and the difference was significant(P<0.05).Compared with the non-CI-AKI group,both serum and urine NGALs in the CI-AKI group were reached the peak at 2-4h after surgery and still increased at 24h(P<0.05),but the increasing trend of urine NGAL at 2-4h after operation was more manifest than that of blood NGAL.The urine L-FABP in the CI-AKI group increased at 4h after surgery,but the difference was not significant(P> 0 0.05).Urine FIB in the CI-AKI group began to increase more than the normal group at 24 h after operation,the difference between the two groups was significant(P<0.05).The plasma Cys C level in the CI-AKI group was higher at 24 h after surgery and remained above the normal level for 48 hours,it indicated that the difference was significant(P<0.05).4.Based on the analyses of biomarkers ROC,the specificity and sensitivity of urine NGAL to diagnose CI-AKI exceeded those of other biomarkers.While the diagnostic sensitivity and specificity of analyzing the joint evaluation of the six biomarkers for CI-AKI were much better than those of a single one.5.Urine NGAL used 23.6ng/ml as the best cut-off value to predict and diagnose CI-AKI,and its sensitivity and specificity were 89.5% and 84.5% respectively.In addition,46.8mg/L,88.5% and 78.2% were the best cut-off value,sensitivity and specificity of blood NGAL,respectively.The correspondent values for urine L-FABP were 935ug/(g.Cr),84.5% and 76.4%.The best cut-off value of urine FIB was 13.14ng/ml,the sensitivity and specificity were 68.3% and 71.4%,respectively.For blood Cys C,the best cut-off value was 1.51mg/L,the sensitivity was 73.7%,and specificity was 62.4%.Conclusion: 1.Some factors such as high blood pressure and diabetes mellitus,dosage of contrast agent and insufficiency of cardiac function may be the risk factors associated with CI-AKI.2.The manifest increases of these new experimental markers at different time in the patients who have undergone PCI operation provide a novelty diagnostic method for the early diagnosis of CI-AKI.3.The specificity and sensitivity of the joint evaluation of multiple biomarkers are much higher than that of a single one to diagnose CI-AKI 4.The determination of the best cut-off values based on ROCs of the patients can benefit early and accurate diagnosis of CI-AKI.