RESUMO
Objective To assess the capability of serum and urine neutrophil gelatinase-associated lipocalin (NGAL) in predicting acute kidney injury (AKI) in septic patients.Methods From July 1, 2014 through December 31, 2014, a prospective observational study of septic patients without AKI was carried out in Renmin Hospital, Tianjin Hospital, and Nankai Hospital, Tianjin.The patients with AKI which was developed after admission to intensive care unit (ICU) were assigned to AKI group and the patients without AKI were assigned to non-AKI group.Clinical data and serum and urine sample were collected at the admission, and at 12, 24, 36, 48, 60, 72 ,84 and 96 hours after admission for detecting creatinine and NGAL.The measurement data accorded with normal distribution were used for t test or variance analysis of repeated measures;comparison of measurement data in non-normal distribution was carried out using the Mann-Whitney U test or Fridman test;comparison of count data was performed using Fisher exact probability method.ROC curve of serum or urine NGAL was plotted and the diagnostic values of serum or urine NGAL in predicting AKI were assessed by calculation of the area under the receiver operating characteristic curve (AuROC).Results Fifty septic patients were included.Thirty-five patients were in AKI group and fifteen in non-AKI group.The median age of AKI group was 73 and the median age of non-AKI group was 60 (IQR, 47-82).The urine NGAL (uNGAL) concentration in AKI group was higher than that in non-AKI group at the every interval and serum NGAL (sNGAL) was higher in AKI group than that in non-AKI group at only first twointervals.The uNGAL showed the capability of prediction for AKI progression at the 48 hour (AuROC=0.83,95% CI:0.70-0.97), 36 hours (AuROC=0.75,95%CI:0.59-0.91), 24 hours (AuROC=0.83,95%CI:0.70-0.95), 12 hours (AuROC=0.73,95%CI:0.60-0.88) prior to AKI occurred.The sNGAL showed capability of prediction at the 48 hours (AuROC=0.69,95%CI:0.51-0.88), 36 hours (AuROC=0.69,95%CI:0.52-0.87) prior to AKI occurred.Conclusions The sNGAL and uNGAL both were useful biomarker that predicted development of AKI in early stage.But the performance of sNGAL was slightly inferior to that of uNGAL for predicting development of AKI.
RESUMO
Objective ①Observing urinary neutrophil gelatinase-associated lipocalin (uNGAL)'s concentration variation under the intervention of sepsis; ②Evaluatingu NGAL' s diagnostic value for early acute kidney injury (AKI).Method Fifty-six SD (Sprague Dawley) rats were randomly (random number) divided into four groups,including 16 rats in model group (CLG),16 rats in Xuebijing group (XBG),16 rats in Huangqi and Chaihu injection jointly applied group (HCG),and 8 rats in sham operation group (SOG).The septic models in CLG group,HCG group and XBG group were established by cecal ligation and puncture (CLP).Then,the rats in HCG group was treated with intraperitoneal injectionby Huangqi and Chaihu injections; the XBG group was treated with intravenous injection by Xuebijing injection; the SOG group was treated with open surgery without CLP.After the CLP,serial urine and serum samples were obtained at baseline (just prior to operation),6 h,12 h,18 h,24 h,36 h,48 h,and 72 h,and were measured by sCr,uCr,uNa,and uNGAL.The line graph of uNGAL' s concentration variation was plotted,based on the time.Diagnostic characteristics of urinary NGAL in predicting AKI were assessed by calculating the area under the receiver operating characteristic curve (AUC).Results After the CLP,the uNGAL of sepsis model rats increased quickly within 6 hours.The time points of each group model reaching their peak were 6 hours after CLP in CLG groupand 24 hours after CLP in HCG group and XBG group.These groups' uNGAL all decreased quickly after the peak.The cuNGAL of sepsis model rats was increased quickly within 6 hours after CLP,reached its peak at 24 hours after CLP.In CLG group,the line graphs of uNGAL or cuNGAL were almost overlapped.There is little difference in the concentration of uNGAL or cuNGAL at each time point (uNGAL:6h,t=0.691; 12h,t=1.627; 18 h,t=0.511,cuNGAL:6h,t =0.371 ; 12 h,t =0.474; 18 h,t =-1.187.Statistical significance of all above value was P ＞0.05).InXBG group,the line graph of uNGAL and cuNGAL were not overlapped,but difference between uNGAL and cuNGAL concentration at each time point was not significant (uNGAL:6 h,t =1.222 ; 12 h,t =1.178 ; 18h,t=1.272; 24h,t=0.918; 36h,t =0.442.cuNGAL:6 h,t =1.482; 12 h,t =1.314; 18 h,t=1.280; 24 h,t =0.280; 36 h,t =0.467.Statistical significance of all above value was P ＞ 0.05).In HCG group,uNGAL of AKI rats were higher than non-AKI rats at each time points since 6 hours later (6 h,t =2.351,P＜0.05; 12h,t=3.086,P＜0.01; 18h,t=2.535,P＜0.05;24h,t=2.150,P＜0.05;36h,t =2.485,P ＜ 0.05),The average cuNGAL of AKI rats and non-AKI rats have statistical significance at 6h,18 h,and 24 h (6 h,t=3.013.P＜0.01; 18 h,t =4.804,P＜0.01; 24 h,t=2.682,P＜0.05).At 6 h,Uout can increase cuNGAL' s ability of predicting AKI' s occurrence in 24 hours (AUC increased from 0.839 to 0.900,P ＜ 0.05).Conclusions The intervention to the sepsis rats have influence on the secretion volume and secretion sequence of NGAL in rat urine.uNGAL and cuNGAL are good predictor of AKI occurrence in sepsis rats.