Østergaard Mette, Sandfeld-Paulsen Birgitte
Department of Clinical Biochemistry, Regional Hospital Central Jutland, Viborg, Denmark.
Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
Scand J Clin Lab Invest. 2023 May;83(3):160-165. doi: 10.1080/00365513.2023.2188606. Epub 2023 Mar 29.
Allergen-specific serum immunoglobulin E (sIgE) levels are a cornerstone in allergy diagnostics. While immunoglobulins are known to be relatively stable molecules, the influence of preanalytical factors on the stability of sIgE is not thoroughly investigated. We studied the effect of several preanalytical factors: (1) delayed centrifugation of serum samples in tubes with separating gel for 10, 24 and 48 h, (2) prolonged storage at 5 °C for 3, 7, 10 and 14 days, (3) storage tube type (primary tube with separating gel or secondary tube), (4) repeated freeze-thawing cycles, and (5) prolonged storage at -20 °C for 4 and 8 weeks. We found that sIgE is stable at room temperature for 48 h before centrifugation and for 10 days at 5 °C after centrifugation. There was no effect of the separating gel after storing serum for 1 week in the freezer. However, storage for 4-8 weeks, and introducing more than one freeze-thaw cycle resulted in a larger variation of sIgE levels. In conclusion, we found that sIgEs are stable under various preanalytical conditions, which allows for flexible handling of samples for a comprehensive portfolio of sIgE analyses.
变应原特异性血清免疫球蛋白E（sIgE）水平是过敏诊断的基石。虽然已知免疫球蛋白是相对稳定的分子，但分析前因素对sIgE稳定性的影响尚未得到充分研究。我们研究了几种分析前因素的影响：（1）血清样本在含有分离胶的试管中延迟离心10、24和48小时；（2）在5℃下延长储存3、7、10和14天；（3）储存管类型（带分离胶的原管或次管）；（4）反复冻融循环；（5）在-20℃下延长储存4和8周。我们发现，在离心前，sIgE在室温下48小时内稳定，离心后在5℃下10天内稳定。血清在冰箱中储存1周后，分离胶没有影响。然而，储存4-8周以及进行不止一次冻融循环会导致sIgE水平有更大的变化。总之，我们发现sIgE在各种分析前条件下都是稳定的，这使得在进行一系列全面的sIgE分析时能够灵活处理样本。
