Ralston S H, Caine N, Richards I, O'Reilly D, Sturrock R D, Capell H A
Centre for Rheumatic Diseases, Glasgow Royal Infirmary.
Ann Rheum Dis. 1988 Sep;47(9):759-63. doi: 10.1136/ard.47.9.759.
Measurements of protein/creatinine ratio in 'spot' urine samples were compared with measurements of 24 hour quantitative proteinuria and side room 'dipstick' testing in 104 samples from 90 patients presenting consecutively to a rheumatology unit. Linear regression analysis showed a highly significant correlation between the random urinary protein/creatinine ratio and total protein excretion in 24 hour urine samples (r = 0.92, p less than 0.001, y = 6.55x + 0.04). Although an approximation of 24 hour urinary protein excretion could have been made from the regression line: 24 hour urine protein = 6.55 x protein/creatinine ratio + 0.04 (g/l), there was a wide scatter of values, particularly in patients with greater than 1 g/24 h urinary protein excretion. Nevertheless, significant proteinuria (greater than 300 mg/24 h) could have been confirmed or excluded with a sensitivity and specificity of 97% by adopting random protein/creatinine values of less than 0.04 as 'normal'. Specificity and sensitivity could have been increased to 100%, however, by excluding patients with values lying between 0.01 and 0.10 as all the false negatives (n = 3) and false positives (n = 3) lay within this range. In comparison, dipstick testing, although 100% sensitive, had a poor specificity due to the high false positive rate (40/83 (48%] in patients with 1+ to 3+ readings. Assessment of random urinary protein/creatinine ratio may obviate the need for 24 hour urine collections in the initial assessment of suspected proteinuria. A wider application of this technique seems indicated in view of the obvious advantages in terms of cost, time, and patient convenience.
对90例连续就诊于风湿病科的患者的104份“即时”尿样进行了尿蛋白/肌酐比值测定，并与24小时尿蛋白定量测定及床边“试纸条”检测结果进行了比较。线性回归分析显示，随机尿蛋白/肌酐比值与24小时尿样中的总蛋白排泄量之间存在高度显著的相关性（r = 0.92，p < 0.001，y = 6.55x + 0.04）。虽然可以根据回归线对24小时尿蛋白排泄量进行估算：24小时尿蛋白 = 6.55×蛋白/肌酐比值 + 0.04（g/l），但各值的离散度较大，尤其是在24小时尿蛋白排泄量大于1 g的患者中。然而，通过将随机蛋白/肌酐值小于0.04作为“正常”值，以97%的灵敏度和特异性可以确诊或排除显著蛋白尿（大于300 mg/24 h）。不过，通过排除值在0.01至0.10之间的患者，特异性和灵敏度可提高到100%，因为所有假阴性（n = 3）和假阳性（n = 3）均在此范围内。相比之下，试纸条检测虽然灵敏度为100%，但由于假阳性率高（1+至3+读数的患者中为40/83（48%）），特异性较差。在疑似蛋白尿的初始评估中，测定随机尿蛋白/肌酐比值可能无需收集24小时尿液。鉴于该技术在成本、时间和患者便利性方面具有明显优势，似乎有必要更广泛地应用此技术。
