Long-term stability of coagulation variables: Protein S as a biomarker for preanalytical storage-related variations in human plasma.

Author(s): Betsou F, Roussel B, Guillaume N, Lefrère JJ

Publication: Thromb Haemost, 2009, Vol. 101, Page 1172-5

PubMed ID: 19492164 PubMed Review Paper? No

Purpose of Paper

Conclusion of Paper

Studies

1. Study Purpose

   The aim of this study was to identify a marker in plasma that can serve as a hallmark of frozen storage-induced alterations in protein levels. Ten coagulation factors were examined on the day of collection and after 9 years of frozen storage at -80 degrees C after a single freeze-thaw cycle.

   Summary of Findings:

   Plasma storage at -80 degrees C for 9 years resulted in significant reductions (by 68%) in factor VIII activity although values remained within the clinically normal range. Protein S activity decreased by 71% compared to day 0, and was 9% below the lower threshold for a clinically normal diagnosis, implying it holds potential as candidate biomarker for quality control. Prolonged frozen storage also resulted in significant changes in PT, antithrombin, fibrinogen, factor II (reduced), and APTT, protein C (increased).

   Biospecimens

   • Bodily Fluid - Plasma

   Preservative Types

   • Frozen

   Diagnoses:

   • Not specified

   Platform:

   Analyte	Technology Platform
   Protein	Hematology/ auto analyzer
   Glycoprotein	Hematology/ auto analyzer

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Storage	Storage duration	0 d 9 y
   Hematology/ auto analyzer Specific	Targeted peptide/protein	Fibrinogen D-dimers Factor II Factor VII Factor VIII Antithrombin Protein C Protein S Prothrombin time Partial thromboplastin time

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2. Study Purpose

   The aim of this study was to determine if the number of freeze-thaw cycles or the temperature and duration of post-thaw storage influences protein S or factor VIII levels or activities.

   Summary of Findings:

   While protein S and factor VIII levels and activity were not significantly altered by freeze-thaw cycling or post-thaw storage, levels were slightly elevated and reduced, respectively, after 10 freeze-thaw cycles or post-thaw storage at room temperature (for 24 or 48 h) compared to case-matched controls processed and analyzed the day of collection.

   Biospecimens

   • Bodily Fluid - Plasma

   Preservative Types

   • Frozen

   Diagnoses:

   • Not specified

   Platform:

   Analyte	Technology Platform
   Glycoprotein	Hematology/ auto analyzer

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Storage	Freeze/thaw cycling	0 cycles 1 cycle 10 cycles
   Storage	Post-thaw duration	24 h at 20 degrees C 48 h at 20 degrees C 12 h at 37 degrees C 24 h at 37 degrees C
   Hematology/ auto analyzer Specific	Targeted peptide/protein	Factor VIII Protein S

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