Stability of coagulation assays performed in plasma from citrated whole blood transported at ambient temperature.

Author(s): Zürcher M, Sulzer I, Barizzi G, Lämmle B, Alberio L

Publication: Thromb Haemost, 2008, Vol. 99, Page 416-26

PubMed ID: 18278194 PubMed Review Paper? No

Purpose of Paper

Conclusion of Paper

Studies

1. Study Purpose

   The purpose of this study was to evaluate the effect of specimen freezing on coagulation parameters in citrated blood from a single patient.

   Summary of Findings:

   Freezing of blood specimens resulted in an 8% increase in aPTT and a 22% decrease in the coagulant activity of factor V. All other parameters were not affected by specimen freezing.

   Biospecimens

   • Bodily Fluid - Blood

   Preservative Types

   • Frozen
   • None (Fresh)

   Diagnoses:

   • Not specified

   Platform:

   Analyte	Technology Platform
   Morphology	Hematology/ auto analyzer
   Glycoprotein	Hematology/ auto analyzer
   Protein	Hematology/ auto analyzer
   Peptide	Hematology/ auto analyzer
   Protein	ELISA

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Biospecimen Preservation	Type of fixation/preservation	Frozen None (fresh)
   Biospecimen Acquisition	Anticoagulant	Sodium citrate

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2. Study Purpose

   The purpose of this study was to determine the effects of transport of citrated blood specimens at ambient temperatures and subsequent freezing of plasma on coagulation parameters in specimens from patients not receiving anticoagulants and those on vitamin k antagonists. The coagulant activity of factor V and aPTT were corrected for freeze thaw effects as necessary.

   Summary of Findings:

   No significant differences were found between transport during the summer versus the winter or in fresh versus frozen specimens. Lactate dehydrogenase and hemolysis both increased during transport, but all specimens remained within the normal range. PT declined significantly in specimens transported for 24-28 h (6%) or 48-52 h (16%) which the authors attribute to declines in the coagulant activity of factor V after transport for 24-28h (12.4%) and 48-52h (27%) and factor VII after transport for 48-52h (12.8%). Interestingly the decline in PT was only present in specimens with low-normal PT values and not in specimens from patients receiving vitamin k antagonists. Similar to PT, aPTT increased significantly in specimens transported for 24-28h (5.6%) or 48-52 h (10.2%) which the authors attribute to significant declines in the coagulant activity of factors VIII and V after transport for 24-28 h (12.4% and 26.9%, respectively) or 48-52 h (27% and 32.5%, respectively). D-dimer values increased by 9.4% after transport for 48-52 h which would have led to 2% false positive and 9% false negative rates for excluding venous thromboembolism. Resistance to APC declined in specimens that were not heterozygous for the factor V Leiden mutation and were transported for 48-52 h, but the decline did not result in specimens entering the pathological range. In contrast, antithrombin (AT) did not change significantly with transport, but a slight increase did occur resulting in a specimen with low AT becoming normal. No change with storage was observed on the activity of factors II, X, IX, or XI or on the levels of fibrinogen, protein C, free protein S and the thrombin-AT complex. The authors conclude that with the exception of factor V and VII activity, transport of blood specimens for up to 24-28 h does not result in clinically significant changes in the coagulation parameters analyzed.

   Biospecimens

   • Bodily Fluid - Blood
   • Bodily Fluid - Plasma

   Preservative Types

   • Frozen
   • None (Fresh)

   Diagnoses:

   • Not specified

   Platform:

   Analyte	Technology Platform
   Morphology	Hematology/ auto analyzer
   Protein	Hematology/ auto analyzer
   Peptide	Hematology/ auto analyzer
   Glycoprotein	Hematology/ auto analyzer
   Protein	ELISA

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Biospecimen Acquisition	Anticoagulant	Sodium citrate
   Biospecimen Preservation	Type of fixation/preservation	Frozen None (fresh)
   Preaquisition	Other drugs	Vitamin K antagonists
   Preaquisition	Patient genotype	Factor V Leiden mutation
   Storage	Specimen transport duration/condition	<1 h 4-6 h 8-12 h 24-28 h 48-52 h Ambient winter (-12 degrees C to 25 degrees C) Ambient summer (11-29 degrees C)
   Storage	Within hospital transportation method	Pneumatic tube system Hand-delivered
   Biospecimen Aliquots and Components	Centrifugation	Centrifugation delays investigated

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