Analytical performance of a highly sensitive C-reactive protein-based immunoassay and the effects of laboratory variables on levels of protein in blood.

Author(s): Aziz N, Fahey JL, Detels R, Butch AW

Publication: Clin Diagn Lab Immunol, 2003, Vol. 10, Page 652-7

PubMed ID: 12853400 PubMed Review Paper? No

Purpose of Paper

Conclusion of Paper

Studies

1. Study Purpose

   The purpose of this paper was to determine the effects of blood component, patient gender, delayed centrifugation, storage temperature and freeze-thaw cycling of serum on CRP levels in healthy individuals and those tested positive for human immunodeficiency virus (HIV).

   Summary of Findings:

   CRP levels were not significantly different between EDTA-plasma, heparinated-plasma and serum or between males and females. When specimens were held at room temperature for 6 h instead of 1 h, prior to centrifugation, serum CRP levels were slightly lower, but the change was not significant. After 3 weeks of storage, serum levels of CRP in specimens stored at room temperature or 4 degrees C were not significantly different from those in specimens stored at -70 degrees C. While no statistically significant changes in CRP were noted after as many as 10 freeze-thaw cycles, some individual specimens had much lower CRP levels after 10 cycles leading the authors to conclude that specimens should not be subjected to more than 7 freeze-thaw cycles. There was a very strong correlation between CRP levels measured by the immunoassay and those measured using the automated BNII nephelometer.

   Biospecimens

   • Bodily Fluid - Plasma
   • Bodily Fluid - Serum
   • Bodily Fluid - Blood

   Preservative Types

   • Frozen

   Diagnoses:

   • AIDS/HIV-related
   • Normal

   Platform:

   Analyte	Technology Platform
   Protein	Clinical chemistry/auto analyzer
   Protein	Immunoassay

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Storage	Freeze/thaw cycling	1 cycle 3 cycles 7 cycles 10 cycles
   Storage	Time at room temperature	1 h 6 h
   Storage	Storage temperature	-70 degrees C 4 degrees C Room temperature
   Biospecimen Aliquots and Components	Blood and blood products	Plasma Serum
   Immunoassay Specific	Technology platform	BNII nephelometer
   Preaquisition	Patient gender	Female Male
   Biospecimen Acquisition	Anticoagulant	EDTA Heparin None
   Biospecimen Aliquots and Components	Centrifugation	Centrifugation delays investigated

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