Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
Am J Kidney Dis. 2011 May;57(5):733-43. doi: 10.1053/j.ajkd.2010.12.022. Epub 2011 Apr 1.
Proteinuria is an established marker of decreased kidney function after kidney transplant. It recently has been suggested that albuminuria might be a more reliable marker. Although albuminuria often is regarded as a marker of glomerular damage, because chronic renal allograft damage is believed to be predominantly an interstitial process, albuminuria in this case might reflect tubular damage. Accordingly, we investigated the value of albuminuria, proteinuria, and tubular damage markers (KIM-1 [kidney injury molecule 1], NAG [N-acetyl-β-d-glucosaminidase], NGAL [neutrophil gelatinase-associated lipocalin], and H-FABP [heart fatty acid binding protein]) in predicting graft outcome in kidney transplant recipients.
Prospective observational cohort study.
SETTING & PARTICIPANTS: 606 patients visiting our outpatient kidney transplant clinic in 2001-2003 were included and used in the analysis for death-censored graft failure. Median follow-up was 4.7 (25th-75th percentile, 3.8-5.2) years. 577 patients had follow-up longer than 1 year and were included in the analysis for estimated glomerular filtration rate (eGFR) decrease. Median follow-up was 3.2 (25th-75th percentile, 2.7-3.7) years.
Urine protein, albumin, and tubular damage markers in 24-hour urine samples.
Death-censored graft failure and decrease in eGFR.
There were 42 patients with graft failure; mean eGFR change was -0.46 ± 3.7 (standard deviation) mL/min/1.73 m(2)/y. The area under the receiver operating characteristic curve for death-censored graft failure showed that albuminuria (0.78; 95% CI, 0.59-0.76) was significantly higher than proteinuria (0.67; 95% CI, 0.59-0.76; P = 0.001), NGAL (0.63; 95% CI, 0.52-0.74; P = 0.02), and H-FABP (0.62; 95% CI, 0.53-0.73; P = 0.005) and not significantly different from KIM-1 (0.74; 95% CI, 0.66-0.82) and NAG (0.75; 95% CI, 0.67-0.83). Results were similar for the eGFR decrease outcome.
Single-center observational study.
Measuring albuminuria may provide superior predictions for long-term renal outcomes after kidney transplant than total proteinuria. Additional assessment of urinary excretion of tubular damage markers may have limited value.
蛋白尿是肾移植后肾功能下降的既定标志物。最近有人提出，白蛋白尿可能是更可靠的标志物。尽管白蛋白尿通常被认为是肾小球损伤的标志物，但由于慢性肾移植损伤主要是间质过程，因此这种情况下的白蛋白尿可能反映了肾小管损伤。因此，我们研究了白蛋白尿、蛋白尿和肾小管损伤标志物（肾损伤分子 1 [KIM-1]、N-乙酰-β-D-氨基葡萄糖苷酶 [NAG]、中性粒细胞明胶酶相关脂质运载蛋白 [NGAL]和心脏脂肪酸结合蛋白 [H-FABP]）在预测肾移植受者移植物结局中的价值。
前瞻性观察队列研究。
2001-2003 年期间，我们纳入了 606 名在我们门诊肾移植诊所就诊的患者，并对其进行了分析以预测死亡相关的移植物失功。中位随访时间为 4.7 年（25%至 75%，3.8 至 5.2）。577 名患者的随访时间超过 1 年，纳入估算肾小球滤过率（eGFR）下降的分析。中位随访时间为 3.2 年（25%至 75%，2.7 至 3.7）。
24 小时尿液样本中的尿蛋白、白蛋白和肾小管损伤标志物。
死亡相关的移植物失功和 eGFR 下降。
有 42 名患者发生移植物失功；平均 eGFR 变化为 -0.46 ± 3.7（标准差）mL/min/1.73 m(2)/y。死亡相关移植物失功的受试者工作特征曲线下面积显示，白蛋白尿（0.78；95%CI，0.59-0.76）显著高于蛋白尿（0.67；95%CI，0.59-0.76；P=0.001）、NGAL（0.63；95%CI，0.52-0.74；P=0.02）和 H-FABP（0.62；95%CI，0.53-0.73；P=0.005），与 KIM-1（0.74；95%CI，0.66-0.82）和 NAG（0.75；95%CI，0.67-0.83）无显著差异。对于 eGFR 下降的结果也相似。
单中心观察性研究。
与总蛋白尿相比，测量白蛋白尿可能对肾移植后长期肾脏结局提供更好的预测。肾小管损伤标志物尿排泄的额外评估可能具有有限的价值。
