Stability of cytokines, chemokines and soluble activation markers in unprocessed blood stored under different conditions

Abstract

Background Biomarkers such as cytokines, chemokines, and soluble activation markers can be unstable when processing of blood is delayed. The stability of various biomarkers in serum and plasma was investigated when unprocessed blood samples were stored for up to 24 h at room and refrigerator temperature. Methods Blood was collected from 16 healthy volunteers. Unprocessed serum, EDTA and heparinized blood was stored at room (20–25 °C) and refrigerator temperature (4–8 °C) for 0.5, 2, 4, 6, 8, and 24 h after collection before centrifugation and separation of serum and plasma. Samples were batch tested for various biomarkers using commercially available immunoassays. Statistically significant changes were determined using the generalized estimating equation. Results IFN-γ, sIL-2Rα, sTNF-RII and β2-microglobulin were stable in unprocessed serum, EDTA and heparinized blood samples stored at either room or refrigerator temperature for up to 24 h. IL-6, TNF-α, MIP-1β and RANTES were unstable in heparinized blood at room temperature; TNF-α, and MIP-1β were unstable in unprocessed serum at room temperature; IL-12 was unstable in unprocessed serum at refrigerator temperature; and neopterin was unstable in unprocessed EDTA blood at room temperature. IL-1ra was stable only in unprocessed serum at room temperature. Conclusion All the biomarkers studied, with the exception of IL-1ra, were stable in unprocessed EDTA blood stored at refrigerator temperature for 24 h. This indicates that blood for these biomarkers should be collected in EDTA and if delays in processing are anticipated the unseparated blood should be stored at refrigerator temperature until processing.

Biomarkers related to bullous pemphigoid activity and outcome

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Plasma immunological markers in pregnancy and cord blood: A possible link between macrophage chemo‐attractants and risk of childhood type 1 diabetes

“…Weaknesses of the study include suboptimal sample handling. In cord samples, marker concentrations could be influenced by a longer period before separation, and an increase in neopterin levels has been reported in similar conditions . However, because of our prospective design, any influence of suboptimal sample handling should not depend on outcome (T1D case status) and is therefore not likely to create any spurious association.…”

Transient Expression of Interleukin-21 in the Second Hit of Acute Pancreatitis May Potentiate Immune Paresis in Severe Acute Pancreatitis

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