A-097 Stability Study of 21 Common Plasma Biochemistries in Unspun Whole Blood

Abstract

Abstract Background Most blood collection tube manufacturers typically recommend separating serum/plasma from red blood cells within 2 h of collection prior to biochemical analysis to minimize cell contact and thus maintain stability of analytes. This can lead to rejected testing when uncentrifuged samples are transported from ambulatory sites to core laboratories over long distances, leading to delayed patient care and decreased patient satisfaction from having to be redrawn. Few studies are available to make recommendations of specimen acceptance with delayed centrifugation time. Our study aimed to assess whole blood stability of routinely ordered chemistry tests. Methods Between November 30–December 1, 2022, venous blood from 20 non-fasting healthy adults(30% male) with ages ranging from 23 to 57 years were collected into 3-mL plastic Becton Dickinson(BD) Vacutainer™plasma separated tubes(PST). For each person, 6 PST were collected. One whole blood sample was centrifuged immediately(T0) at 4000g for 3 min at room temperature(RT) and analyzed. Remaining 5 whole blood samples were stored at either RT or 4 °C and the subsequent centrifugation of the samples occurred at 2, 4, 6, 12 and 24 h after collection. The analytes studied using Abbott Alinity instrumentation were comprehensive metabolic panel(CMP), lipid panel, TSH and FT4. Absolute and percent bias at various time points for each participant were calculated using the reference sample(T0). Observed biases were compared to allowable total error based on desirable biological variation(BV) from European-Federation-of-Laboratory-Medicine(EFLM) database and Clinical-Laboratory-Improvement-Amendments(CLIA) 2024 upcoming limits. Results Analytes stable in the whole blood at both RT and 4 °C up to 24 h based on EFLM-BV and CLIA were ALP, ALT, AST, BUN, cholesterol, creatinine, HDL, total bilirubin, triglycerides, and TSH. Analytes with variable stability times are shown in the table below: Conclusion This study provides a guideline of acceptable times for whole blood samples sent for routine chemistry tests when centrifugation was not performed within 2 h from collection.