Evaluation of the in vitro stability of direct oral anticoagulants in blood samples under different storage conditions.
Author(s): Thuile K, Giacomuzzi K, Jani E, Marschang P, Mueller T
Publication: Scand J Clin Lab Invest, 2021, Vol. 81, Page 461-468
PubMed ID: 34278897 PubMed Review Paper? No
Purpose of Paper
This paper investigated the stability of oral anticoagulants in blood specimens stored at room temperature, in plasma stored at room temperature and 4°C, and in plasma stored at -20°C that experienced freeze-thaw cycling.
Conclusion of Paper
Although some statistically significant changes were observed, the four anticoagulants of interest remained stable, as changes remained well below the acceptable change limit (ACL), during a 24 h delay to centrifugation, afterstorage of isolated plasma at room temperature or 4°C for up to 24 h, or after 90 days of storage at -20°C with up to three freeze-thaw cycles.
Studies
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Study Purpose
This study investigated the stability of oral anticoagulants in blood specimens stored at room temperature, plasma stored at room temperature or 4°C, and plasma stored at -20°C that experienced up to 3 freeze-thaw cycles. Six tubes of sodium citrate blood were collected via venipuncture from each of 57 patients taking dabigatran (11 patients), rivaroxaban (12 patients), apixaban (20 patients), or edoxaban (14 patients) for atrial fibrillation (45 patients) or due to a history of venous thromboembolism (12 patients). All specimens were immediately taken to the laboratory. Upon arrival, three specimens from each patient were immediately centrifuged at 2800 x g for 10 min and isolated plasma was aliquoted. Plasma aliquots were stored at room temperature or 4°C for 4, 8 or 24 h before analysis. The remaining plasma aliquots were stored at -20°C and thawed, analyzed and refrozen after 30 (freeze-thawed once), 60 (freeze-thawed twice) and 90 (freeze-thawed three times) days. The remaining tubes of blood were aliquoted and stored at room temperature on an agitator for 4, 8 or 24 h before centrifugation and analysis. Levels of dabigatran, rivaroxaban, apixaban and edoxaban were quantified in plasma using specifically calibrated dTT or anti-Xa assays on an automated HemosIL coagulation analyzer. The ACL for all four anticoagulants was defined as 22% which was 2.77 x the largest coefficient of variance (CV).
Summary of Findings:
The four oral anticoagulants of interest remained stable during a delay to centrifugation of up to 24 h at room temperature, storage of isolated plasma at room temperature or 4°C for up to 24 h, or for up to 90 days at -20°C with three freeze-thaw cycles, as all changes were well below the ACL of 22% (all <12%). Nevertheless, statistically significant differences in the levels of all four anticoagulants were observed at one or more timepoint during delayed centrifugation of blood or during plasma storage at room temperature or 4°C. While frozen storage of plasma did not significantly affect levels of dabigatran, plasma specimens stored for 30 days at -20°C had significantly lower levels of apixaban, rivaroxaban, and edoxaban than fresh plasma; plasma stored for 60 days had a significantly lower level of rivaroxaban, and plasma specimens stored for 90 days had significantly lower levels of rivaroxaban (thawed once or 3 times) and edoxaban (thawed once only).
Biospecimens
Preservative Types
- None (Fresh)
- Frozen
Diagnoses:
- Other diagnoses
Platform:
Analyte Technology Platform Small molecule Clinical chemistry/auto analyzer Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Biospecimen Aliquots and Components Centrifugation Centrifugation delays investigated
Storage Storage conditions Plasma
Blood
Storage Freeze/thaw cycling 0 cycles
1 cycle
2 cycles
3 cycles
Storage Storage temperature Room temperature
4°C
-20°C
Storage Storage duration 0 h
4 h
8 h
24 h
30 days
60 days
90 days