Department of Nephrology and Hypertension, Rabin Medical Center, Petah Tikva, Israel.
Clin J Am Soc Nephrol. 2011 Apr;6(4):892-7. doi: 10.2215/CJN.05280610. Epub 2011 Jan 6.
Microalbuminuria predicts graft loss and death in the renal transplant population. Measurement of the urinary albumin-to-creatinine ratio (UACR) is recommended for its detection. There is uncertainty regarding the optimal UACR cutoff values. Few studies have examined the accuracy of UACR in the general population and none have been conducted in renal transplant recipients. The aim of this study is to determine the performance of UACR in the renal transplant population.
DESIGN, SETTING, PARTICIPANTS & MEASUREMENTS: Renal transplant recipients with a daily urinary albumin excretion rate of up to 300 mg accurately carried out a 24-hour urine collection and provided a morning urine sample for the measurement of albuminuria and UACR. The performance measures of UACR for the detection of microalbuminuria (30 to 300 mg/d) were calculated using different cutoffs.
Median albuminuria was 23 mg/d, and median UACR was 17 mg/g. The area under the receiver-operating characteristic curve was 0.94 in men and 0.98 in women. The optimal cutoff was 21 mg/g in men and 24 mg/g in women. In men, the 30-, 17-, and 21-mg/g cutoffs provided a sensitivity of 0.79, 0.89, and 0.87. In women, the 30-, 25-, and 24-mg/g cutoffs provided a sensitivity of 0.90, 0.97, and 1.0.
These data show that in the renal transplant population, lower gender-specific cutoffs should be used for the detection of microalbuminuria than the recommended 30-mg/g cutoff. These data support the need for a reappraisal of the 30-mg/g cutoff for the detection of microalbuminuria.
微量白蛋白尿可预测肾移植人群中的移植物丢失和死亡。建议检测尿白蛋白与肌酐比值（UACR）以发现微量白蛋白尿。目前，对于最佳 UACR 截断值存在不确定性。少数研究已经检查了 UACR 在普通人群中的准确性，但是在肾移植受者中尚未进行过此类研究。本研究旨在确定 UACR 在肾移植人群中的性能。
设计、地点、参与者和测量方法：每天尿白蛋白排泄率高达 300mg 的肾移植受者准确地进行了 24 小时尿液收集，并提供了晨尿样本以测量白蛋白尿和 UACR。使用不同的截断值计算 UACR 检测微量白蛋白尿（30 至 300mg/d）的性能指标。
中位白蛋白尿为 23mg/d，中位 UACR 为 17mg/g。男性和女性的受试者工作特征曲线下面积分别为 0.94 和 0.98。男性的最佳截断值为 21mg/g，女性为 24mg/g。在男性中，30、17 和 21mg/g 截断值的敏感性分别为 0.79、0.89 和 0.87。在女性中，30、25 和 24mg/g 截断值的敏感性分别为 0.90、0.97 和 1.0。
这些数据表明，在肾移植人群中，与推荐的 30mg/g 截断值相比，应使用更低的性别特异性截断值来检测微量白蛋白尿。这些数据支持重新评估 30mg/g 作为检测微量白蛋白尿的截断值的必要性。
