Gislefoss Randi E, Grimsrud Tom K, Mørkrid Lars
Institute of Population-Based Cancer Research, Cancer Registry of Norway, Oslo, Norway.
Clin Chem Lab Med. 2009;47(5):596-603. doi: 10.1515/CCLM.2009.121.
Human serum from biobanks is frequently used in prospective epidemiological studies. Long-term storage may modify its composition. A better understanding of the stability of the serum components may improve the interpretation of future studies.
The concentrations of selected proteins; immunoglobulins, carrier proteins and enzymes in samples stored at -25 degrees C for 25 years and 2 years were compared with 1-month-old samples. For each length of storage time, 130 specimens were randomly selected from apparently healthy male blood donors aged 40-49 years. We examined the distribution of values, compared dispersion and localization of central tendency, and established reference intervals for each component.
The study demonstrated non-significant or numerically small group differences in the concentrations of albumin, aspartate amino transferase, cystatin C, immunoglobulin E, immunoglobulin G, and sex hormone binding globulin. Mean values between fresh and 25-year-old samples suggested larger differences during storage for alanine amino transferase (-73.4%), creatinine kinase (-96.1%), insulin C-peptide (-98.7%), ferritin (-18.5%) and transferrin (+8.2%).
The findings showed that long-term storage can introduce a considerable bias for vulnerable components.
生物样本库中的人血清常用于前瞻性流行病学研究。长期储存可能会改变其成分。更好地了解血清成分的稳定性可能会改善对未来研究的解读。
将储存在-25摄氏度下25年和2年的样本中选定蛋白质（免疫球蛋白、载体蛋白和酶）的浓度与储存1个月的样本进行比较。对于每个储存时间长度，从40至49岁的明显健康男性献血者中随机抽取130份标本。我们检查了数值分布，比较了离散度和集中趋势的定位，并为每个成分确定了参考区间。
研究表明，白蛋白、天冬氨酸氨基转移酶、胱抑素C、免疫球蛋白E、免疫球蛋白G和性激素结合球蛋白的浓度在组间差异不显著或数值较小。新鲜样本与储存25年样本之间的平均值表明，储存期间丙氨酸氨基转移酶（-73.4%）、肌酸激酶（-96.1%）、胰岛素C肽（-98.7%）、铁蛋白（-18.5%）和转铁蛋白（+8.2%）的差异更大。
研究结果表明，长期储存会给易受影响的成分带来相当大的偏差。
