Evaluation Of KIM-1 On Obstructive Nephropathy In Perioperative Period

Objective:To probe the value of KIM-1(Kidney injury molecule-1) for evaluating the renal function of different levels of obstructive renal nephropathy in perioperative period, through detecting the expression of KIM-1 in obstructive nephropathy patients’ urine.Methods:We collected 38 cases with unilateral obstructive nephropathy which were under operations in hospital from 2013.11 to 2014.10. We examined GFR(glomerular filtration) as standards to evaluate the renal function by 99 m Tc-DTPA Radionuclide renal dynamic imaging before the operation. Depending on the GFR of kidney on the dysfunctional side before the operation, we divided the cases into 4 groups[1]: normal group(Group A):GFR>40ml/min,low-injury group(Group B):20<GFR≤40ml/min,mid-injury group(Group C):10<GFR≤20ml/min, and high-injury group(Group D):GFR≤10 ml/min. And according to the urine test, we observed 11 healthy individuals as normal group(Group E). We took fasting patients’ blood and urine from Group A to D on the 1st、2nd、3th、7th day after and before the operations, during 6 to 8 A.M. and took some routine examinations such as Scr、BUN and so on. Using Enzyme-linked immunoassay(ELISA), we examined the expression levels of urine KIM-1 from all cases before and after the operation and exam the GFR values on the 7th day by 99 m Tc-DTPA Radionuclide renal dynamic imaging. We compared the expression of KIM-1、Scr、BUN from all groups between before and after the operation, and analysed the correlations between GFR and KIM-1、GFR and Scr、GFR and BUN from the urine before and on the 7th day after the operation, and protracted receiver operating characteristic curve(ROC curve), calculated asset under consruction(AUC), evaluated KIM-1 for examining the renal functional change in perioperative period, and calculated its specificity and sensitivity. To compare the effects of different operation methods on the expression of KIM-1 in urine after operation.Result:1 Comparison of KIM-1s,Scr,BUN from all groups before the operation(table.1): urine KIM-1 from Group A to D are significantly higher than Group E(P < 0.05). Differences between Group C and D are not statistically significant(P>0.05).Differences between Group C and A,B,E and between Gooup D and A,B,E are statistically significant(P>0.05).Scr,BUN from Group A to D are not different from Group E statistically(P>0.05)(Table.2).2 Comparison between before and after the operation of urine KIM-1 and GFR on the dysfunctional side(Fig.5;Table.1): urine KIM-1 from Group A and B during peri operation period are higher than before the operation,but insignifically(P>0.05); Values from Group C are not significally changed. GFR on the 7th day from the Group C are higher than before the operation, but insignifically(P>0.05)(Table.3);GFR from Group A and C between before and after the operation are not changed significantly.3 Pearson correlation analysis between GFR and urine KIM-1, between GFR and Scr, and between GFR and BUN: the correlation coefficient values between urine KIM-1 and GFR, Scr and GFR, and BUN and GFR before the operation are(r=-0.441,P<0.01;r=-0.115,P>0.05;r=0.019,P>0.05),urine KIM-1 is negatively correlated to GFR(Fig.3) and Scr,BUN to GFR uncorrelated.The correlation coefficient between urine KIM-1 and GFR, between Scr and BUN,and between BUN and GFR on the 7th day after the operation are(r=-0.394,P<0.05;r=-0.073,P>0.05; r=-0.035,P>0.05), urine KIM-1 is negatively correlated to GFR(Fig.4) and Scr,BUN to GFR uncorrelated.4 Sensitivity and specificity of urine KIM-1, Scr and BUN for diagnosing unilateral obstructive nephropathy and renal injury:The ROC curve analysis before the operation(Fig.1): the AUC values of urine KIM-1, Scr and BUN for diagnosing renal injury are(0.804,P=0.002),(0.441,P=0.540),(0.567,P=0.492), 95% confidenceintervals are(0.664-0.944),(0.253-0.628)、(0.371-0.762),sensitivity and specificity values are(82.6%、66.7%)、(56.5%、53.3%)、(66.9%、66.7%).The ROC curve analysis between KIM-1, Scr and BUN on the 7th day after the operation and GFR on the dysfunctional side(Fig.2): AUC values are(0.806,P=0.003)、(0.400,P=0.329)、(0.450,P=0.625);95% confidenceintervals are(0.637-0.975),(0.205-0.595),(0.242-0.658),sensitivity and specificity values are(88.9%、72.3%)、(11.1%、93.3%)、(61.1%、53.3%).5 The affections of PCNL and other operations are not significantly different.(No damage to the renal parenchyma).Conclusion:1 The expressions of urine KIM-1 of unilateral obstructive nephropathy with various degrees injury are different significantly,which is helpful for diagnosing kidney injury early in clinic.2 KIM-1 in obstructive nephropathy patients’ urine is negatively correlative to GFR on the dysfunctional side. Scr and BUN are not correlated to GFR on the disfunctional side.3 KIM-1 is expected to become a sensitive index for the monitoring of renal function after unilateral obstructive nephropathy.4 No differences of affections exists between different kinds of operations to the expressions of urine KIM-1 after the operation.