肾移植术后患者血清半胱氨酸蛋白酶抑制物水平与肾功能的关系

目的 探讨肾移植术后患者血清半胱氨酸蛋白酶抑制物(CyC)的水平变化与移植肾功能的相关性.方法选择193例使用他克莫司(FK506)加霉酚酸酯(MMF)加泼尼松(Pred)三联免疫抑制剂肾移植患者术后的血、尿标本,测定血清CyC和血、尿肌酐.经统计学分析,与常规的血清肌酐(SCr)浓度及尿肌酐清除率(CCr)和内生肌酐清除率(CkCCr)作相关性比较,评估CyC判断移植肾肾小球滤过功能的敏感性和特异性.结果 193例肾移植患者术后第5天血清CyC、SCr和CCr、CkCCr分别为(1.91±1.28)mg/L、(174.2±129.1)μmol/L、(67.9±27.3)ml/min、(68.1±27.8)ml/min.其中CyC浓度＜1.25 mg/L者42例,1.25～2.00 mg/L者102例,＞2.0 mg/L者49例;SCr浓度＜125/μmol/L者62例,125～200μmol/L者83例,＞200/μmol/L者48例;CkCCr＞80ml/min者52例,80～60 ml/min者96例,＜60 ml/min者45例.CyC与SCr呈正相关(r=0.886,P＜0.001),与CkCCr呈负相关(r=-0.907,P＜0.001);SCr与CkCCr呈负相关(r=-0.889,P＜0.001).非参数受试者工作特征曲线分析CyC、SCr、CCr、CkCCr曲线下面积分别为0.877、0.771、0.832、0.909,其诊断敏感性和特异性分别为91.6%、69.3%,52.2%、96.1%,67.5%、77.1%和84.6%、71.3%. 结论 肾功能轻度损害时,血清CyC比SCr先一步增高,有可能成为评定肾移植患者移植肾功能的敏感性标志物.

Use of cystatin C in the evaluation of post-transplant renal allograft function

Objective To study the correlation between the post-transplant renal allograft function and the variation of serum cystatin C (CyC) concentration in renal allograft recipients. Methods One hundred and ninety-three renal allograft recipients accepted the same combination immunosuppressive regimen of tacrolimus, mycophenolate and prednisone were enrolled into the study. Patient's serum and urine samples were collected on day 5 post-transplant to detect serum cystatin C, serum and urine creatinine (SCr). Correlation analysis was used to analyze correlation between CyC concentration and SCr concentration or the calculated creatinine clearance rate (CkCCr) by using the Cockcroft-Gault equation and urine creatinine clearance rate (CCr). Specificity and sensitivity of using the CyC concentration to evaluate glomerular filtration rate (GFR) were calculated as well.Results The mean concentrations of serum CyC and SCr on day 5 post-transplant were (1.91±1.2)mg/L and (174.0±129.1)μmol/L, respectively. While the CCr and CkCCr were (67.9±27.3)ml/min and (68.1±27.8)ml/min, respectively. Forty-two patients had a CyC concentration below 1.25 mg/L, 102 patients'CyC concentrations were between 1.25 and 2.0 mg/L and 49 patients'CyC concentrations were above 2. 0 mg/L. As for SCr, 62 patients had a concentration below 125 μmol/L, 83 patients'concentrations were between 125 and 200 μmol/L and 48 patients'concentrations were above 200 μmol/L. For CkCCr, there were 52 cases with a concentration above 80 ml/min, 96 cases with a concentration between 80 and 60 ml/min and 45 cases with a concentration below 60 ml/min. Serum CyC concentration had a negative correlation with CkCCr (r=-0. 907, P＜0. 001) and had a significantly positive correlation with SCr concentration (r=0. 886, P＜0. 001). SCr had a significantly negative relationship with CkCCr (r=-0. 889 ,P＜0. 001). Serum CyC had higher correlation with CkCCr than the correlation between SCr and CkCCr. The ROC curves showed that areas under curve of CyC, SCr, CCr and CkCCr were 0. 877, 0. 771, 0. 832 and 0. 909, respectively. Specificity and sensitivity of CyC, SCr,CCr and CkCCr were 69.3%, 96.1%, 77.1%, 71.3%and 91.6%, 52.2%, 67.5%, 84.6%, respectively.Conclusions Serum CyC concentration elevates earlier than SCr concentration when there is slight renal function impairment. Serum CyC concentration might become a more sensitive marker to evaluate the post-transplant renal allograft function in renal transplant recipients.