Stability of prothrombin time and activated partial thromboplastin time tests under different storage conditions.

Author(s): Rao LV, Okorodudu AO, Petersen JR, Elghetany MT

Publication: Clin Chim Acta, 2000, Vol. 300, Page 13-21

PubMed ID: 10958859 PubMed Review Paper? No

Purpose of Paper

Conclusion of Paper

Studies

1. Study Purpose

   The purpose of this study was to determine the effects of storage temperature and duration on PT and aPTT in sodium citrate plasma from inmates requiring coagulation testing.

   Summary of Findings:

   For specimens with an initial PT in the normal range, there was no effect of storing plasma at room temperature for 24 h prior to analysis, but when plasma was stored frozen at -20 degrees C for more than 12 h or at 4 degrees C for 24 h, PT was significantly increased (p<0.01 and p<0.05, respectively). In contrast, when the initial PT was above the normal range, the value was not significantly changed by storage of plasma for up to 24 h at any of the 3 temperatures. When the initial aPTT was within the normal range, aPTT increased after 6 h of storage at -20 degrees C (p<0.01) and after 24 h of storage at 4 degrees C (p<0.001) or room temperature (p<0.01). In plasma with initial aPTT above normal, the value was not significantly different after 24 h of storage at 4 degrees C or room temperature, but aPTT increased after storage at -20 degrees C for more than 24 h.

   Biospecimens

   • Bodily Fluid - Plasma

   Preservative Types

   • None (Fresh)

   Diagnoses:

   • Not specified

   Platform:

   Analyte	Technology Platform
   Morphology	Hematology/ auto analyzer

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Storage	Storage duration	0 h 6 h 12 h 24 h
   Storage	Storage temperature	-20 degrees C 4 degrees C Room temperature
   Preaquisition	Biomarker level	Normal range PT Prolonged PT Normal range aPTT Prolonged aPTT

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2. Study Purpose

   The purpose of this study was to determine the effects of storage temperature and duration on PT, aPTT and PT-INR in sodium citrate whole blood from healthy volunteers.

   Summary of Findings:

   PT, aPTT and PT-INR were unaffected by storage of whole blood at room temperature or 4 degrees C for 18 h or less. Storage of whole blood for 24 h or more at either temperature led to significantly prolonged PT and aPTT. Further, PT-INR was significantly increased in whole blood stored at room temperature for 36 h or more and at 4 degrees C for 24 h or more.

   Biospecimens

   • Bodily Fluid - Blood

   Preservative Types

   • None (Fresh)

   Diagnoses:

   • Normal

   Platform:

   Analyte	Technology Platform
   Morphology	Hematology/ auto analyzer

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Storage	Storage temperature	4 degrees C Room temperature
   Storage	Storage duration	0 h 12 h 18 h 24 h 36 h 48 h

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