Raimann J G, Kirisits W, Gebetsroither E, Carter M, Callegari J, Rosales L, Levin N W, Kotanko P
Renal Research Institute, New York City, NY 10128, USA.
Clin Nephrol. 2011 Jul;76(1):23-8. doi: 10.5414/cn106826.
A noninvasive test for determining elevated levels of blood urea nitrogen (BUN) may be useful under circumstances in which there is limited access to laboratories. Because saliva urea nitrogen (SUN) parallels BUN, we investigated the diagnostic performance of a semiquantitative SUN dipstick to test for elevated BUN levels in patients with chronic kidney disease (CKD).
Patients with CKD Stages 1 to 5D were studied. 50 µl of saliva were transferred onto the SUN test strip (Integrated Biomedical Technology, Elkhart, Indiana, IN, USA). SUN was determined after 1 minute by visual comparison of the color of the moistened test pad with 6 calibrated color blocks. Interobserver reproducibility was evaluated by independent observers, masked to urea concentrations of 6 calibrated urea solutions. Correlation between SUN and BUN was quantified by Spearman's rank correlation coefficient (RS), Kappa Statistic was employed to evaluate within-sample reproducibility of duplicates. Receiver operating characteristic (ROC) analysis was used to assess the diagnostic performance of SUN.
68 patients (31 females, 60 ± 14 years; 34 hemodialysis patients, 34 patients CKD Stages 1 - 4) were studied. Interobserver coefficient of variation was 4.9% at SUN levels > 50 mg/dl; within-sample reproducibility was 90%. SUN and BUN were correlated significantly (RS = 0.63; p < 0.01). Elevated BUN was diagnosed with high accuracy by SUN determination (area under the ROC curve: 0.90 (95% CI 0.85 - 0.95)).
Semiquantitative dipstick measurements of SUN can reliably identify CKD patients with elevated BUN levels.
在实验室检测条件有限的情况下，一种用于测定血尿素氮（BUN）水平升高的非侵入性检测方法可能会很有用。由于唾液尿素氮（SUN）与BUN水平平行，我们研究了一种半定量SUN试纸条对慢性肾脏病（CKD）患者BUN水平升高的诊断性能。
对CKD 1至5D期的患者进行研究。将50微升唾液转移到SUN试纸条（美国印第安纳州埃尔克哈特市综合生物医学技术公司）上。1分钟后，通过将湿润的测试垫颜色与6个校准色块进行视觉比较来测定SUN。由独立观察者评估观察者间的可重复性，观察者对6种校准尿素溶液的尿素浓度不知情。通过Spearman等级相关系数（RS）对SUN和BUN之间的相关性进行量化，采用Kappa统计量评估重复样本的样本内可重复性。采用受试者工作特征（ROC）分析来评估SUN的诊断性能。
研究了68例患者（31例女性，60±14岁；34例血液透析患者，34例CKD 1 - 4期患者）。SUN水平>50 mg/dl时，观察者间变异系数为4.9%；样本内可重复性为90%。SUN和BUN显著相关（RS = 0.63；p < 0.01）。通过SUN测定能高精度地诊断BUN升高（ROC曲线下面积：0.90（95%CI 0.85 - 0.95））。
SUN的半定量试纸条测量能够可靠地识别BUN水平升高的CKD患者。
