Lau Wai-Hoe, Leong Wing-Seng, Ismail Zhari, Gam Lay-Harn
School of Pharmaceutical Sciences, Universiti Sains Malaysia, USM, Penang, Malaysia.
Int J Biol Sci. 2008 Aug 4;4(4):215-22. doi: 10.7150/ijbs.4.215.
Kidney stone disease affects 1 - 20% of the general population. At present, the diagnosis of a stone is done using radiography method when noticeable symptoms appeared. We developed a non-invasive quantitative assay for urinary THP, namely ELISA; whereby our previous study and other reports had shown the usefulness of THP as biomarker for kidney stone disease. Since urine is biological fluid that is easily obtainable, this method could be used as a screening assay for kidney stone prior to confirmation with radiography. The ELISA gave assay linearity r(2) > 0.999 within the range of 109 ng/mL to 945 ng/mL THP. Assay precisions were < 4% (C.V.) for repeatability and < 5% (C.V.) for reproducibility. Assay accuracy range from 97.7% to 101.2% at the various THP concentrations tested. Assay specificity and sensitivity were 80% and 86%, respectively. The cut-off points at P < 0.05 were 37.0 and 41.2 mug/mL for male and female, respectively. The assay is cost effective and rapid whereby the cost for assaying each urine sample in duplicate is approximately USD0.35 and within 5 hours, 37 samples can be assayed alongside full range of standards and 3 QC samples in each plate. Furthermore, sample preparation is relatively easy where urine sample was diluted 10 times in TEA buffer. The usability of the ELISA method for diagnosis of kidney stone disease is evaluated with 117 healthy subjects and 58 stone formers.
肾结石疾病影响着1%至20%的普通人群。目前，当出现明显症状时，采用放射成像方法来诊断结石。我们开发了一种用于检测尿液中THP的非侵入性定量检测方法，即酶联免疫吸附测定法（ELISA）；我们之前的研究以及其他报告已表明THP作为肾结石疾病生物标志物的效用。由于尿液是一种易于获取的生物流体，这种方法可在通过放射成像确诊之前用作肾结石的筛查检测。ELISA法在109 ng/mL至945 ng/mL的THP范围内检测线性r(2) > 0.999。检测精密度方面，重复性的变异系数（C.V.）< 4%，再现性的变异系数（C.V.）< 5%。在测试的各种THP浓度下，检测准确度范围为97.7%至101.2%。检测特异性和灵敏度分别为80%和86%。在P < 0.05时，男性和女性的截断点分别为37.0和41.2 μg/mL。该检测方法具有成本效益且快速，每份尿液样本进行双份检测的成本约为0.35美元，并且在5小时内，每个平板可检测37个样本以及一整套标准品和3个质量控制样本。此外，样本制备相对容易，尿液样本在TEA缓冲液中稀释10倍即可。采用117名健康受试者和58名结石形成者对ELISA方法在诊断肾结石疾病方面的实用性进行了评估。
