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.