Influence of Pre-Analytical Factors on Thymus- and Activation-Regulated Chemokine Quantitation in Plasma

Xuemei Zhao; Liliana Delgado; Russell Weiner; Omar F. Laterza

doi:10.33393/jcb.2015.2060

Authors

Xuemei Zhao Translational Molecular Biomarkers, Merck Research Laboratories, Rahway, NJ, USA
Liliana Delgado Translational Molecular Biomarkers, Merck Research Laboratories, Rahway, NJ, USA
Russell Weiner Translational Sciences, Biomarkers & Companion Diagnostics, Daiichi Sankyo, Inc., Edison, NJ, USA
Omar F. Laterza Translational Molecular Biomarkers, Merck Research Laboratories, Rahway, NJ, USA

DOI:

https://doi.org/10.33393/jcb.2015.2060

Keywords:

Pharmacodynamic biomarker, Pre-analytical factors, Platelet-free plasma, Platelet-containing plasma, Freeze-thaw, Thymus, Activation-regulated chemokine, Atopic dermatitis

Abstract

Thymus- and activation-regulated chemokine (TARC) in serum/plasma associates with the disease activity of atopic dermatitis (AD), and is a promising tool for assessing the response to the treatment of the disease. TARC also exists within platelets, with elevated levels detectable in AD patients. We examined the effects of pre-analytical factors on the quantitation of TARC in human EDTA plasma. TARC levels in platelet-free plasma were significantly lower than those in platelet-containing plasma. After freeze-thaw, TARC levels increased in platelet-containing plasma, but remained unchanged in platelet-free plasma, suggesting TARC was released from the platelets during the freeze-thaw process. In contrast, TARC levels were stable in serum independent of freeze-thaw. These findings underscore the importance of pre-analytical factors to TARC quantitation. Plasma TARC levels should be measured in platelet-free plasma for accurate quantitation. Pre-analytical factors influence the quantitation, interpretation, and implementation of circulating TARC as a biomarker for the development of AD therapeutics.