Limor Cohen1, Alissa Keegan2, Stacy E F Melanson2, David R Walt3. 1. Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, United States; Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, MA 02115, United States; Department of Chemical Biology, Harvard University, Boston, MA 02115, United States. 2. Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, United States. 3. Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, United States; Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, MA 02115, United States. Electronic address: dwalt@bwh.harvard.edu.
Abstract
OBJECTIVES: In this study, we evaluated the impact of clinical sample handling and processing on IL-6, IL-10, IFNγ, and IL-2 measurements in plasma. DESIGN AND METHODS: We collected whole blood samples and analyzed various pre-analytical parameters. We assessed the following: 1) cytokine stability in whole blood that was stored over a ten-hour period at room temperature and 4 °C; 2) cytokine stability in plasma over 6 h; 3) vigorous sample handling including repeated dropping and transport through a pneumatic transport system; and 4) freeze-thaw stability of cytokines in plasma. To ensure ability to measure IL-6, IL-10, IFNγ, and IL-2 levels in plasma, we used Simoa, an ultra-sensitive immunoassay platform. RESULTS: We show that whole blood storage at room temperature results in decreased cytokine levels and that whole blood storage at 4 °C results in greater cytokine stability. We also show that cytokines are stable when whole blood samples are subjected to vigorous sample handling. Lastly, we show that cytokines are stable in plasma over three freeze-thaw cycles. CONCLUSIONS: Clinical sample handling and processing can affect measurements of IL-6, IL-10, IFNγ, and IL-2 in plasma. We believe this study will be a useful reference for future studies in which these cytokines are used as potential biomarkers.
OBJECTIVES: In this study, we evaluated the impact of clinical sample handling and processing on IL-6, IL-10, IFNγ, and IL-2 measurements in plasma. DESIGN AND METHODS: We collected whole blood samples and analyzed various pre-analytical parameters. We assessed the following: 1) cytokine stability in whole blood that was stored over a ten-hour period at room temperature and 4 °C; 2) cytokine stability in plasma over 6 h; 3) vigorous sample handling including repeated dropping and transport through a pneumatic transport system; and 4) freeze-thaw stability of cytokines in plasma. To ensure ability to measure IL-6, IL-10, IFNγ, and IL-2 levels in plasma, we used Simoa, an ultra-sensitive immunoassay platform. RESULTS: We show that whole blood storage at room temperature results in decreased cytokine levels and that whole blood storage at 4 °C results in greater cytokine stability. We also show that cytokines are stable when whole blood samples are subjected to vigorous sample handling. Lastly, we show that cytokines are stable in plasma over three freeze-thaw cycles. CONCLUSIONS: Clinical sample handling and processing can affect measurements of IL-6, IL-10, IFNγ, and IL-2 in plasma. We believe this study will be a useful reference for future studies in which these cytokines are used as potential biomarkers.
Authors: Alissa Keegan; Biagio Ricciuti; Padric Garden; Limor Cohen; Reiko Nishihara; Anika Adeni; Cloud Paweletz; Julianna Supplee; Pasi A Jänne; Mariano Severgnini; Mark M Awad; David R Walt Journal: J Immunother Cancer Date: 2020-10 Impact factor: 13.751