Division of Nephrology, Department of Medicine, University of Ottawa, Ottawa.
Division of Nephrology, Department of Medicine, University of Ottawa, Ottawa; Kidney Research Centre, Ottawa Hospital Research Institute, Ottawa; Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa.
Am J Kidney Dis. 2014 Dec;64(6):962-8. doi: 10.1053/j.ajkd.2014.07.027. Epub 2014 Oct 8.
Proteinuria has been associated with transplant loss and mortality in kidney transplant recipients. Both spot samples (albumin-creatinine ratio [ACR] and protein-creatinine ratio [PCR]) and 24-hour collections (albumin excretion rate [AER] and protein excretion rate [PER]) have been used to quantify protein excretion, but which measurement is a better predictor of outcomes in kidney transplantation remains uncertain.
Observational cohort study.
SETTING & PARTICIPANTS: Tertiary care center, 207 kidney transplant recipients who were enrolled in a prospective study to measure glomerular filtration rate. Consecutive patients who met inclusion criteria were approached.
ACR and PCR in spot urine samples, AER and PER in 24-hour urine collections.
Primary outcome included transplant loss, doubling of serum creatinine level, or death.
Urine and serum creatinine were measured using a modified Jaffé reaction that had not been standardized by isotope-dilution mass spectrometry. Urine albumin was measured by immunoturbidimetry. Urine protein was measured by pyrogallol red molybdate complex formation using a timed end point method.
Mean follow-up was 6.4 years and 22% developed the primary end point. Multivariable-adjusted areas under the receiver operating characteristic curves were similar for the different protein measurements: ACR (0.85; 95% CI, 0.79-0.89), PCR (0.84; 95% CI, 0.79-0.89), PER (0.86; 95% CI, 0.80-0.90), and AER (0.83; 95% CI, 0.78-0.88). C Index values also were similar for the different proteinuria measurements: 0.87 (95% CI, 0.79-0.95), 0.86 (95% CI, 0.79-0.94), 0.88 (95% CI, 0.82-0.94), and 0.86 (95% CI, 0.77-0.95) for log(ACR), log(PCR), log(PER), and log(AER), respectively.
Single-center study. Measurement of proteinuria was at variable times posttransplantation.
Spot and 24-hour measurements of albumin and protein excretion are similar predictors of doubling of serum creatinine level, transplant loss, and death. Thus, spot urine samples are a suitable alternative to 24-hour urine collection for measuring protein excretion in this population.
蛋白尿与肾移植受者的移植物丢失和死亡有关。点样本（白蛋白-肌酐比值 [ACR] 和蛋白-肌酐比值 [PCR]）和 24 小时采集（白蛋白排泄率 [AER] 和蛋白排泄率 [PER]）都被用于定量蛋白尿，但哪种测量方法更能预测肾移植的结果仍不确定。
观察性队列研究。
三级护理中心，207 名接受前瞻性肾小球滤过率测量的肾移植受者。符合纳入标准的连续患者被纳入研究。
点尿样本中的 ACR 和 PCR，24 小时尿液采集的 AER 和 PER。
主要结局包括移植物丢失、血清肌酐水平翻倍或死亡。
使用未通过同位素稀释质谱法标准化的改良 Jaffé 反应测量尿液和血清肌酐。通过免疫比浊法测量尿白蛋白。通过焦酚红钼络合物形成的定时终点法测量尿蛋白。
中位随访时间为 6.4 年，22%的患者发生了主要终点事件。多变量调整后的接受者操作特征曲线下面积对于不同的蛋白质测量值相似：ACR（0.85；95%CI，0.79-0.89）、PCR（0.84；95%CI，0.79-0.89）、PER（0.86；95%CI，0.80-0.90）和 AER（0.83；95%CI，0.78-0.88）。不同蛋白尿测量值的 C 指数值也相似：0.87（95%CI，0.79-0.95）、0.86（95%CI，0.79-0.94）、0.88（95%CI，0.82-0.94）和 0.86（95%CI，0.77-0.95），分别为 log(ACR)、log(PCR)、log(PER)和 log(AER)。
单中心研究。蛋白尿的测量是在移植后不同时间进行的。
白蛋白和蛋白质排泄的点样本和 24 小时测量结果是血清肌酐水平翻倍、移植物丢失和死亡的相似预测指标。因此，对于该人群，点尿样本是测量蛋白质排泄的一种合适的 24 小时尿液收集替代方法。
