Effects of sample handling on the stability of interleukin 6, tumour necrosis factor-α and leptin
Effects of sample handling on the stability of interleukin 6, tumour necrosis factor-α and leptin
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DOI：
10.1006/cyto.2000.0764
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发表时间：
2000-11-01
期刊：
影响因子：
3.8
通讯作者：
Mohamed-Ali, V
中科院分区：
文献类型：
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作者：
Flower, L;Ahuja, RH;Mohamed-Ali, V
IL-6、TNF-α和Leptin的检测水平可能会受到保存方法、抗凝剂或反复冻融的影响。来自22名健康受试者的血液样本：(I)在分离前或分离后放置1、2、4或6小时，然后在-70℃下冷冻；(Ii)取有肝素锂、柠檬酸钠、EDTA或不含抗凝剂的试管，分离并冷冻；(Iii)分离，在化验前反复冻融血浆最多6个循环。用放射免疫法测定瘦素水平，用高灵敏度ELISA法测定IL-6和肿瘤坏死因子-α水平。(1)分离标本IL-6和肿瘤坏死因子-α水平无明显变化，但放置4h后IL-6平均下降14.3%(3.7%)，肿瘤坏死因子-α升高9.6%(2.3%)(P分别为0.003和0.002)。瘦素水平保持不变。(Ii)血清和EDTA血浆样本对所有三种细胞因子的检测结果具有可比性，但其他抗凝剂样本的水平差异很大。(3)IL-6和Leptin水平在冻融6个周期内无明显变化，但在冻融3个周期后，IL-6和Leptin水平升高17.0%(3.7%)，这些分子的浓度因保存条件的不同而发生显著变化，因此在流行病学和临床研究中需要对其进行标准化，研究之间的水平比较可能不可靠。(C)2000年学术出版社。
Detected levels of IL-6, TNF-alpha and leptin may be affected by methods of storage, anticoagulant or repeated freezing-thawing. Blood samples from 22 healthy subjects were: (i) allowed to stand for 1, 2, 4 or 6 h prior to, or after separation, before freezing at -70 degreesC; (ii) taken into tubes with lithium heparin, sodium citrate, EDTA or no anticoagulant, separated and frozen; and (iii) separated, and plasma repeatedly freeze-thawed for up to six cycles prior to assay. Leptin was assayed by RIA, and IL-6 and TNF-alpha by high-sensitivity ELISA, (i) IL-6 and TNF-alpha levels were not altered significantly in separated samples but IL-6 declined by mean (SEM) 14.3% (3.7%) and TNF-alpha increased by 9.6% (2.3%) in samples left unseparated for 4 h (P=0.003 and 0.002, respectively). Leptin remained unchanged. (ii) Serum and EDTA-plasma samples gave comparable results for all three cytokines, but levels in the other anticoagulant samples were highly variable. (iii) IL-6 and leptin levels were not altered by up to 6 cycles of freeze-thawing, but TNF-alpha increased by 17.0% (3.7%) after 3 cycles, Concentrations of these molecules are significantly altered by storage conditions, therefore they need to be standardized for epidemiological and clinical studies, and between-study comparisons of levels may not be reliable. (C) 2000 Academic Press.