González C, Cava F, Ayllón A, Guevara P, Navajo J A, González-Buitrago J M
Servicio de Bioquímica, Hospital Universitario, Salamanca, Spain.
Clin Chem Lab Med. 2001 Sep;39(9):836-41. doi: 10.1515/CCLM.2001.139.
Components of biological variation can be used to assess the usefulness of reference values, to evaluate the significance of changes in serial results from an individual and to define objective analytical goals. The aim of the study was to assess, in 15 healthy subjects studied at regular monthly intervals over a period of 6 consecutive months, the biological variation of interleukin-1beta (IL-1beta), interleukin-8 (IL-8), and tumor necrosis factor-alpha (TNF-alpha). Biological variation data (within-subject and between-subject coefficient of variation (CV)) were determined using a simple nested analysis of variance. Derived parameters (index of individuality, reliability coefficient and critical diferences) were calculated from within-subject and between-subject CV. The mean and standard deviation (SD), within-subject CV, between-subject CV, index of individuality and reliability coefficient were as follows: for IL-1beta, 0.67 (0.32) pg/ml, 30%, 36%, 0.85, and 0.76; for IL-8, 3.68 (1.45) pg/ml, 24%, 31%, 0.85 and 0.75; and for TNF-alpha, 3.14 (1.87) pg/ml, 43%, 29%, 1.56 and 0.50, respectively. We conclude that between-subject variation and within-subject variation are quite similar for IL-1beta and IL-8 and are relatively high for the three cytokines studied. Index of individuality is less than 1.4 for IL-1beta and IL-8, and thus reference intervals based on population studies are of limited value. On the contrary, the index of individuality for TNF-alpha is greater than 1.4 and reference values can be used for diagnosis. Quality goals for imprecision are easily achieved for the three cytokines with current methodology.
生物学变异的组成部分可用于评估参考值的实用性、评估个体连续检测结果变化的显著性以及定义客观的分析目标。本研究的目的是在连续6个月每月定期研究的15名健康受试者中，评估白细胞介素-1β（IL-1β）、白细胞介素-8（IL-8）和肿瘤坏死因子-α（TNF-α）的生物学变异。使用简单的嵌套方差分析确定生物学变异数据（受试者内和受试者间变异系数（CV））。从受试者内和受试者间CV计算得出衍生参数（个体性指数、可靠性系数和临界差异）。IL-1β、IL-8和TNF-α的均值、标准差（SD）、受试者内CV、受试者间CV、个体性指数和可靠性系数如下：IL-1β分别为0.67（0.32）pg/ml、30%、36%、0.85和0.76；IL-8分别为3.68（1.45）pg/ml、24%、31%、0.85和0.75；TNF-α分别为3.14（1.87）pg/ml、43%、29%、1.56和0.50。我们得出结论，IL-1β和IL-8的受试者间变异和受试者内变异相当相似，且在所研究的三种细胞因子中相对较高。IL-1β和IL-8的个体性指数小于1.4，因此基于群体研究的参考区间价值有限。相反，TNF-α的个体性指数大于1.4，参考值可用于诊断。使用当前方法很容易实现这三种细胞因子不精密度的质量目标。
