Canine endogenous adrenocorticotrophic hormone preanalytical stability after sample shipping in dry ice or recyclable ice bars

ABSTRACT: Endogenous adrenocorticotrophic hormone (eACTH) measurement is useful in hypercortisolism and hypoadrenocorticism investigation; however, since the hormone is highly unstable, blood samples require proper processing and storage, as well as shipping is often a step limiting since few laboratories offer this assay in Brazil. The aim of this note was to compare overnight dog´s eACTH preanalytical stability when frozen samples were shipped in dry ice (DI), or with recyclable ice bars (RIB). A total of 56 paired samples for eACTH measurement were analyzed. Blood samples were properly handled, plasma aliquots transferred into plastic microtubes, and stored at -80ºC. The fifty-six paired samples were overnight shipped in two thermic isolated boxes with DI or involved by RIB. Despite there was a high correlation between results from both shipping methods (r Spearman = 0.958, P<0.001), the Wilcoxon matched-pairs rank test showed that the shipping method may influence results (P<0.001). However, this difference does not affect results interpretation. By this way, when DI shipping was not possible, RIB shipping may represent a risk to eACTH preanalytical stability.

摘要：内源性促肾上腺皮质激素（endogenous adrenocorticotrophic hormone，eACTH）检测在高皮质醇血症（hypercortisolism）与肾上腺皮质功能减退症（hypoadrenocorticism）的排查中具有重要应用价值；但该激素稳定性极差，血液样本需经规范处理与保存，且由于巴西鲜有实验室可开展该项检测，运输环节常成为制约研究的瓶颈。本研究旨在对比隔夜运输条件下，采用干冰（dry ice，DI）与可重复使用冰袋（recyclable ice bars，RIB）包装的冰冻犬血浆eACTH样本的分析前稳定性。本研究共纳入56份配对样本用于eACTH检测，血液样本经规范处理后，将血浆分装至塑料微量离心管中，置于-80℃冰箱保存。将56份配对样本分别装入两个隔热保温箱，一组以干冰运输，另一组以可重复使用冰袋包裹后隔夜递送。尽管两种运输方式的检测结果呈高度相关（斯皮尔曼相关系数r=0.958，P<0.001），但威尔科克森配对秩和检验结果显示，运输方式对检测结果存在显著影响（P<0.001）。但该差异并不会对检测结果的解读造成影响。综上，当无法采用干冰运输时，使用可重复使用冰袋运输可能会对eACTH的分析前稳定性带来风险。