Seibert Felix S, Rosenberger Christian, Mathia Susanne, Arndt Robert, Arns Wolfgang, Andrea Huppertz, Pagonas Nikolaos, Bauer Frederic, Zidek Walter, Westhoff Timm H
1 Medical Department 1, Universitätsklinikum Marien Hospital Herne, Ruhr-University of Bochum, Germany. 2 Department of Nephrology, Charité-Campus Benjamin Franklin, Berlin, Germany. 3 Department of Nephrology, Charité-Campus Mitte, Berlin, Germany. 4 Medical Clinic I, Clinic of Cologne, Cologne, Germany.
Transplantation. 2017 Feb;101(2):387-394. doi: 10.1097/TP.0000000000001124.
Urinary calprotectin has recently been identified as a promising biomarker for the differentiation between prerenal and intrinsic acute kidney injury (AKI) in the nontransplant population. The present study investigates whether calprotectin is able to differentiate between these 2 entities in transplant recipients as well.
Urinary calprotectin was assessed by enzyme-linked immunosorbent assay in 328 subjects including 125 cases of intrinsic acute allograft failure, 27 prerenal graft failures, 118 patients with stable graft function, and 58 healthy controls. Acute graft failure was defined as AKI stages 1 to 3 (Acute Kidney Injury Network criteria), exclusion criteria were obstructive uropathy, urothelial carcinoma, and metastatic cancer. The clinical differentiation of prerenal and intrinsic graft failure was performed either by biopsy or by a clinical algorithm including response to fluid repletion, history, physical examination, and urine dipstick examination.
Reasons for intrinsic graft failure comprised rejection, acute tubular necrosis, urinary tract infection/pyelonephritis, viral nephritis, and interstitial nephritis. Calprotectin concentrations of patients with stable graft function (50.4 ng/mL) were comparable to healthy controls (54.8 ng/mL, P = 0.70) and prerenal graft failure (53.8 ng/mL, P = 0.62). Median urinary calprotectin was 36 times higher in intrinsic AKI (1955 ng/mL) than in prerenal AKI (P < 0.001). Receiver-operating characteristic curve analysis revealed a high accuracy of calprotectin (area under the curve, 0.94) in the differentiation of intrinsic versus prerenal AKI. A cutoff level of 134.5 ng/mL provided a sensitivity of 90.4% and a specificity of 74.1%. Immunohistochemical stainings for calprotectin in renal allograft biopsy specimens confirmed the serological results.
Urinary calprotectin is a promising biomarker for the differentiation of prerenal and intrinsic acute renal allograft failure.
尿钙卫蛋白最近被确定为非移植人群中区分肾前性和内在性急性肾损伤（AKI）的一种有前景的生物标志物。本研究调查了钙卫蛋白是否也能够在移植受者中区分这两种情况。
采用酶联免疫吸附测定法对328名受试者的尿钙卫蛋白进行评估，其中包括125例内在性急性移植肾失功、27例肾前性移植肾失功、118例移植肾功能稳定的患者以及58名健康对照者。急性移植肾失功定义为AKI 1至3期（急性肾损伤网络标准），排除标准为梗阻性尿路病、尿路上皮癌和转移性癌。肾前性和内在性移植肾失功的临床鉴别通过活检或包括对液体补充的反应、病史、体格检查和尿试纸检查的临床算法进行。
内在性移植肾失功的原因包括排斥反应、急性肾小管坏死、尿路感染/肾盂肾炎、病毒性肾炎和间质性肾炎。移植肾功能稳定患者的钙卫蛋白浓度（50.4 ng/mL）与健康对照者（54.8 ng/mL，P = 0.70）和肾前性移植肾失功患者（53.8 ng/mL，P = 0.62）相当。内在性AKI患者的尿钙卫蛋白中位数（1955 ng/mL）比肾前性AKI患者高36倍（P < 0.001）。受试者工作特征曲线分析显示，钙卫蛋白在区分内在性与肾前性AKI方面具有较高的准确性（曲线下面积，0.94）。截断值为134.5 ng/mL时，敏感性为90.4%，特异性为74.1%。肾移植活检标本中钙卫蛋白的免疫组化染色证实了血清学结果。
尿钙卫蛋白是区分肾前性和内在性急性移植肾失功的一种有前景的生物标志物。
