Thomas Mark V, Branscum Adam, Miller Craig S, Ebersole Jeffrey, Al-Sabbagh Mohanad, Schuster Julie L
Division of Periodontology, Department of Oral Health Practice, University of Kentucky College of Dentistry, Lexington, KY, USA.
J Periodontol. 2009 Jul;80(7):1146-53. doi: 10.1902/jop.2009.080654.
Saliva contains a large number of biomolecules, some of which have putative diagnostic usefulness. A potential problem with the use of biomolecules in diagnosis is day-to-day fluctuation due to within-subject variability. This study evaluated the intraindividual variability of six salivary analytes in healthy adults and determined their normal range.
Unstimulated whole saliva (5 ml) was collected every 2 to 3 days on six occasions from 30 subjects in good oral and systemic health. Four of the samples were collected in the clinic, and two were collected by the subject at home. The concentration ranges of interleukin (IL)-1beta, IL-6, matrix metalloproteinase-8, prostaglandin E(2), tumor necrosis factor-alpha, interferon-alpha, and albumin were examined. Descriptive statistics were computed, and a one-way random-effects model was used to quantify within- and between-subject components of variability. Intraclass correlation coefficients (ICCs) were calculated for each subject/analyte combination.
Within-subject coefficients of variation for these analytes ranged from 67.6% to 172.1% for the in-clinic samples and from 111.9% to 201.0% for the at-home samples. The ICC for the various analytes ranged from 41% to 61% for the in-clinic samples. The at-home samples exhibited significantly more variability than did those obtained in the clinic under supervision.
There was marked within-subject variation in the salivary concentrations of these analytes. With increased interest in salivary diagnostics, the within-subject variability, normal range, and threshold levels for abnormal levels of individual salivary analytes need to be determined if these diagnostics tests are to have clinical usefulness.
唾液中含有大量生物分子，其中一些具有潜在的诊断价值。在诊断中使用生物分子的一个潜在问题是由于个体内部变异性导致的每日波动。本研究评估了健康成年人六种唾液分析物的个体内变异性，并确定了它们的正常范围。
从30名口腔和全身健康状况良好的受试者中，每隔2至3天收集一次非刺激性全唾液（5毫升），共收集六次。其中四个样本在诊所收集，两个样本由受试者在家中收集。检测白细胞介素（IL）-1β、IL-6、基质金属蛋白酶-8、前列腺素E2、肿瘤坏死因子-α、干扰素-α和白蛋白的浓度范围。计算描述性统计量，并使用单向随机效应模型量化变异性的个体内和个体间成分。计算每个受试者/分析物组合的组内相关系数（ICC）。
这些分析物在诊所样本中的个体内变异系数范围为67.6%至172.1%，在家中样本中的范围为111.9%至201.0%。诊所样本中各种分析物的ICC范围为41%至61%。在家中收集的样本比在诊所监督下收集的样本表现出明显更大的变异性。
这些分析物的唾液浓度存在明显的个体内变异。随着对唾液诊断的兴趣增加，如果这些诊断测试要有临床实用性，就需要确定个体唾液分析物的个体内变异性、正常范围和异常水平的阈值。
