Inorganic Phosphorus and Potassium Are Putative Indicators of Delayed Separation of Whole Blood

Abstract

ObjectivesThe delayed separation of whole blood can influence the concentrations of circulating blood components, including metabolites and cytokines. The aim of this study was to determine whether clinical-biochemistry analytes can be used to assess the delayed separation of whole blood.MethodsWe investigated the plasma and serum concentrations of five clinical-biochemistry analytes and free hemoglobin when the centrifugation of whole blood stored at 4°C or room temperature was delayed for 4 hours, 6 hours, 24 hours, or 48 hours, and compared the values with those of matched samples that had been centrifuged within 2 hours after whole-blood collection.ResultsThe inorganic phosphorus (IP) levels in the plasma and serum samples were elevated ≥ 1.5-fold when whole-blood centrifugation was delayed at room temperature for 48 hours. Furthermore, the IP levels in the plasma samples showed excellent assessment accuracy [area under the receiver-operating-characteristic curve (AUC) > 0.9] after a 48-hour delay in whole-blood separation, and high sensitivity (100%) and specificity (95%) at an optimal cutoff point. The IP levels in the serum samples also exhibited good assessment accuracy (AUC > 0.8), and high sensitivity (81%) and specificity (100%). The potassium (K+) levels were elevated 1.4-fold in the serum samples following a 48-hour delay in whole-blood separation. The K+ levels showed excellent assessment accuracy (AUC > 0.9) following a 48-hour delay in whole-blood separation, and high sensitivity (95%) and specificity (91%) at an optimal cutoff point.ConclusionOur study showed that the IP and K+ levels in the plasma or serum samples could be considered as putative indicators to determine whether whole-blood separation had been delayed for extended periods.

Concordance in COVID-19 serology, bone mineralization, and inflammatory analytes between venous and self-collected capillary blood samples exposed to various pre-analytical conditions

“…The limited available literature provides limited evidence on the effects of processing delays on Ca and Ph levels, which is not unexpected, particularly for Ph, due to its known poor stability during delayed separation of whole blood. 26 While one study showed that rapidly processed capillary specimens had lower Ca levels than venous specimens (≤5%), 14 another study found that capillary blood collected via finger prick and stored at room temperature for 72 h had significantly higher Ca levels compared to rapidly processed venous samples, with a mean difference of 0.3 mmol/L. This clinically significant difference was attributed to the higher calcium in interstitial fluid than in capillary blood and to finger squeezing, which could have contributed to the increased component of interstitial fluid.…”

Proteomics and Lipidomics in Inflammatory Bowel Disease Research: From Mechanistic Insights to Biomarker Identification

“…For proteomic studies, the scientific community has developed and published useful guidelines [ 84 , 85 , 86 ]. Rigorous analytical quality control is crucial and can be supported by automated LC-MS/MS performance monitoring systems [ 87 , 88 ], together with specific sample quality metrics (e.g., [ 89 , 90 ]). To prevent late failures of biomarker candidates, it has been suggested that a core method validation (e.g., including estimates of accuracy, precision, and limits of quantification) should be performed when designing biomarker discovery workflows [ 91 ].…”

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“…To better assess the effects of prolonged incubation time between blood collection and plasma preparation, efforts have been made to discover potential indicators of blood processing delay. Lee et al (2015) observed that if blood separation was postponed by 48 h, the plasma content of inorganic phosphate and potassium rose prominently [6]. Similarly, the same group also suggested a panel of cytokines (L-1β, GM-CSF, sCD40L, IL-8, MIP-1α, and MIP-1β) as potential indicators of the delay in plasma and serum preparations [7].…”