| Objective Liver surgery such as liver transplantation, partial hepatectomy often experience the liver ischemia-reperfusion(I/R) injury. Liver I/R not only effects itself but the other general organs (such as kidney, lungs, heart) will be also resulted in damages. This study will explore that:the kidney injury molecule-1(KIM-1) was expressed at kidney in the model of acute kidney injury (AKI) after rat liver I/R; investigate the changes of urine KIM-1in liver transplant recipients to dagnosis of AKI after operative; Combining clinical experiment result with basic ones to study on relative risk factors about kidney injury after liver transplantation.Method The topic divided into two parts. The first part, basic experiments:26male Sprague-Dawley(SD) rats whose weights between220-240g were selected. Experimental group included24rats and control group included2rats. According to the time of hepatic vascular occlusion, rats in experimental group were divided into three groups:A group(blocked by10mins), B group(blocked by20mins), C group(blocked by30mins); and then according to the time of hepatic reperfusion, rats were continued classified into four subgroups:A1group(reperfusion2h), A2group(reperfusion6h), A3group(reperfusion12h), A4group (reperfusion24h), meanwhile, the dividing process of B group and C group were the same as A group. The model of AKI after rat liver I/R were built, then on the basis of different time of liver reperfusion, they were killed gently and their kidney tissue would be made into paraffin blocks by10%formalin fixation, dehydration, transparent and dip wax. The paraffin blocks were cutted into4μm slice, stained by HE or anti-KIM-1antibody immunohistochemical. Then the numbers of tubular which had been positive stained were counted under microscope. The second part, clinicl expreiment:50orthotropic liver transplantation cases performed in our hospital from Aug2010to Oct2011were used as the research objects.5ml urine of patients were collected respectively at the time of preoperative and Oh,2h,6h,12h,24h liver reperfusion, whichever5ml anticoagulation vien blood were collected respectively at the time of preoperative and12h,24h,48h,72h,96h liver reperfusion. Then the chemiluminescence technique was applied to detect serum creatinine(SCr), urine creatinine(UCr), and the enzyme-linked immunosorbent assay (ELISA) was applied to detect urine KIM-1. According to the acute kidney injury network(AKIN) criteria confirmed AKI, patients were divided into two groups:AKI group and non-AKI group. The changes of urine KIM-1and SCr were observed at special time point. T-test and Repeated measure analysis of variance were applied to contrast two groups of patients with peroperative and intraoperative situation in order to analysis of significantly difference factors. To evaluate the diagnostic value of urine KIM-1detecting in AKI, through receiver operating characteristic curve(ROC) and area under the curve(AUC).Result The first part:The survival of rate postoperative (24hours later) in the model of AKI after liver I/R was100%between experiment group and control group. The model was stable and could be used to study. In contorl group, we found that the glomerular evenly distributed at the renal cortex, the tubular structures were visible by HE stained; we also found no positive specificity of KIM-1in renal tissue by anti-KIM-1immunohistochemical stained. In experimental group, we observed that renal interstitial had blood stasis, juxtaglomerular apparatus had inflammatory cell infiltration and injury, peritubular inflammatory had cell infiltration, tubular epithelial edema, glomerular atrophy by HE stained; anti-KIM-1immunohistochemical staining, we also observed that KIM-1positive stained in tubular epithelial after liver I/R. If we count the number of KIM-1positive stained tubular around the10glomerrular units under the100xmicroscope, then divided the amount by10, we could found that with the prolongation of liver ischemia or reperfusion, the number of KIM-1positive stained tubular would increase, it means C4group which the counts reach to10.1/single glomerrular units had the most number of KIM-1positive stained tubular. The second part:27in50cases had AKI after operation, the incidence rate was54%. Patient’s age, gender, preoperative SCr level, blood transfusion, blood loss, urine output, operation time were not statistically different between two groups. However the score of preoperative modification of diet in renal disease(MELD), the anhepatic phase time and the urine-free time significantly increased or extend in AKI group compared with non-AKI group, above which showed statistical difference, P<0.05. Correlation Coefficient between MELD score and urine-free time:0.39, P<0.01. Correlation Coefficient between anhepatic phase time and urine-free time:0.71, P <0.01. SCr in AKI group was significantly higher than non-AKI group when post operation24hours later, showed a statistically difference, but afterwards reduced to preoperative level. KIM-1in AKI group rose to the peak when liver reperfusion2hours, compared with non-AKI group had statistically difference, moreover this difference did not vanish until the liver reperfusion12hours later. According to the AKIN criteria, ROC AUC results showed that the specificity up to88.9%and the sensitivity up to82.6%when taking the KIM-1in urinary cutoff14.2ng g-1Ucr to diagnosis of AKI when liver reperfusion2hours later.Conclusion1. KIM-1could special reflect renal tubular injury in the model of AKI after rat liver ischemia-reperfusion.2. KIM-1in urinary could be used as effective index for early diagnosis of AKI after liver trasplantation.3. The intraoperative changes of urine KIM-1may be helpful to early prediction of AKI,when recipients in preoperative was normal renal function.4. Shorten the time of anhepatic phase in orthotopic liver transplantation without veno-venous bypass, may reduce the renal injury postoperative. |
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