Abitbol C, Zilleruelo G, Freundlich M, Strauss J
Department of Pediatrics, University of Miami School of Medicine, Florida 33101.
J Pediatr. 1990 Feb;116(2):243-7. doi: 10.1016/s0022-3476(05)82881-1.
We examined the relative feasibility of using random urinary dipstick testing and urinary protein/creatinine ratios in the quantitation of proteinuria. Sixty-four children with relapsing nephrotic syndrome, ranging in age from 1 1/2 to 16 years, contributed 145 timed urine collections and 150 random specimens, which were analyzed by urinary protein dipstick, quantitation of protein and creatinine, or both. Total protein excretion was expressed as grams per surface area per day and the urinary protein/creatinine ratio as milligrams of protein per milligram of creatinine. Degrees of proteinuria were designated as physiologic (less than 0.1 gm/m2/day), intermediate (greater than 0.1 and less than 1.0 gm/m2/day), or nephrotic (greater than 1.0 gm/m2/day). The log regression analysis of the 24-hour urinary protein/creatinine ratio (y) and total protein excretion (x) was highly significant (r = 0.97; p less than 0.001). The upper and lower confidence limits of the urinary protein/creatinine ratio (1.0 and 0.1, respectively) closely approximated the designations for nephrotic and physiologic proteinuria, respectively. These values were therefore used to classify degrees of proteinuria by the urine protein/creatinine ratio. The validity of these tests was assessed by sensitivity, specificity, and predictive value, and compared with that of random testing by urinary dipstick. The urinary protein/creatinine ratio offered good reliability as a test for classifying degrees of proteinuria and accurately predicting nephrotic and physiologic proteinuria. The random dipstick testing was reliable only when results were distinctly positive and when sensitivity and specificity were low. The error in the total protein excretion value that was imposed by collection errors with high and low variations in the creatinine value (57% of samples) was largely corrected by normalization of the data by log transformation. When controlled for creatinine excretion, linear regression analysis allowed calculation of total protein excretion (TP) from the urinary protein/creatinine ratio (U P/Cr) by the following equation: TP (gm/m2/day) = 0.63 (U P/Cr) at all levels of proteinuria. The random urinary protein/creatinine ratio appeared to offer the most sensitive test for classification of proteinuria in children with nephrosis, with the advantages of ease and expediency not afforded by the 24-hour urine quantitation.
我们研究了使用随机尿试纸条检测和尿蛋白/肌酐比值来定量蛋白尿的相对可行性。64例年龄在1.5岁至16岁之间的复发性肾病综合征患儿提供了145次定时尿标本和150次随机尿标本，这些标本通过尿蛋白试纸条、蛋白和肌酐定量或两者进行分析。总蛋白排泄量以克每平方米体表面积每天表示，尿蛋白/肌酐比值以每毫克肌酐中蛋白的毫克数表示。蛋白尿程度分为生理性（小于0.1克/平方米/天）、中度（大于0.1且小于1.0克/平方米/天）或肾病性（大于1.0克/平方米/天）。24小时尿蛋白/肌酐比值（y）与总蛋白排泄量（x）的对数回归分析具有高度显著性（r = 0.97；p小于0.001）。尿蛋白/肌酐比值的上下置信限（分别为1.0和0.1）分别与肾病性和生理性蛋白尿的定义非常接近。因此，这些值被用于通过尿蛋白/肌酐比值对蛋白尿程度进行分类。通过敏感性、特异性和预测值评估这些检测的有效性，并与随机尿试纸条检测的有效性进行比较。尿蛋白/肌酐比值作为一种分类蛋白尿程度并准确预测肾病性和生理性蛋白尿的检测方法具有良好的可靠性。随机试纸条检测仅在结果明显为阳性且敏感性和特异性较低时才可靠。肌酐值高低变化的采集误差所导致的总蛋白排泄值误差（57%的样本）在很大程度上通过对数转换对数据进行标准化得以校正。当对肌酐排泄进行控制时，线性回归分析可通过以下公式从尿蛋白/肌酐比值（U P/Cr）计算总蛋白排泄量（TP）：在所有蛋白尿水平下，TP（克/平方米/天）= 0.63（U P/Cr）。随机尿蛋白/肌酐比值似乎是对肾病患儿蛋白尿分类最敏感的检测方法，具有24小时尿定量所不具备的简便和快捷的优点。
