血清前列腺特异性抗原同源异构体p2PSA的体外稳定性评估

In vitro stability evaluation of serum prostate specific antigen isoforms p2PSA

目的通过评估不同条件下血清中p2PSA的稳定性,为实验室检测分析前过程提供准确可靠的依据。方法随机挑选60名健康体检男性,将所有的新鲜血用化学发光法检测其血清中的p2PSA作为基线值,60例样本再随机分为6组,即在不同的条件下存储并按不同的时间节点进行检测,对各个样本的检测值进行偏倚的计算,以偏倚超过10%为单个样本不稳定的判断标准,以80%样本合格率来判断整个条件下p2PSA的稳定性。结果血清p2PSA水平有随着时间的延长而升高的趋势,全血常温放置时的p2PSA升高得最为显著,将血清样本分离并保存于4℃、-20℃或-70℃,血清p2PSA随时间变化的幅度减小,冻融循环2次不会影响p2PSA的稳定性。结论要保证p2PSA结果的准确性,在抽取血液后应在2 h内及时离心,3 h内完成检测,4℃保存时于6 h内完成检测;若将血清单独分离出来的情况下,4℃保存可稳定24 h,-20℃或-70℃条件下保存可稳定半年。

To evaluate the stability of serum p2PSA, blood samples from 60 healthy men were gathered and subjected to detect p2PSA simultaneously. Baseline measurements were performed on the Access analyzer, and samples were randomly divided into 6 groups and stored under various conditions prior to measurements. The stability of p2PSA was evaluated with the bias of a single sample exceeding 10% as the judging standard of instability of a single sample, and the rate of instable samples less than 80% as the judging standard of instability of the whole sample. The serum p2PSA level were increased over time, and the level increased most significantly when the blood placed at room temperature, p2PSA level changed slightly over time under the condition of the separated serum and the lower temperature, and freeze-thaw cycles have no effect on p2PSA stability. In conclusion, for proper measurement of p2PSA, blood samples should be centrifuged within 2 h of blood draw, and complete the detection within 3 h, it may be allowed 6 h if stored at 4 ℃. With the condition of serum separated, p2PSA may keep stable within 24 h at 4℃, and half a year at -20 ℃ or -70℃.