Objectives: To evaluate the effect of a freeze-thaw cycle on β-trace protein (βTP) and β2-microglobulin (β2M). Design and methods: We compared βTP and β2M concentrations before and after a single freeze-thaw cycle in long-term stored samples from 172 participants of the Third National Health and Nutrition Examination Survey (NHANES III). Results: Measurements of βTP and β2M before and after freeze-thaw were highly correlated with Spearman's coefficients of 0.90 and 0.99, respectively. Serum concentrations of βTP were slightly lower after freeze-thaw (- 0.05. mg/L, P= 0.006). Measurements of β2M did not differ before and after freeze-thaw (P= 0.35). Conclusions: βTP and β2M measurements were robust to a single freeze-thaw cycle, although β2M appeared more stable than βTP. These results have implications for future studies of these biomarkers.
Bibliographical noteFunding Information:
ES, JHE, and GPR have no relevant financial relationships to disclose. JC has consulted for Amgen and Merck and has an investigator-initiated grant from Amgen. LAS has an investigator grant from Pharmalink and Gilead Inc. This project was partially funded by Siemens and by the National Institute of Diabetes and Digestive and Kidney Diseases grant U01 DK067651 . SPJ is supported in part by the NIH/NHLBI Cardiovascular Epidemiology Training Grant T32HL007024 . LAS is supported in part by the NIH/NIDDK grant K23DK081017 . Siemens had no role in the study design, data collection, analysis, interpretation of data, or report writing.
Copyright 2012 Elsevier B.V., All rights reserved.
- Kidney filtration marker
- National Health and Nutrition Examination Survey
- β-trace protein (βTP)