Elevation of viral load by PCR and use of plasma preparation tubes for quantification of human immunodeficiency virus type 1.
Author(s): García-Bujalance S, Ladrón de Guevara C, González-García J, Arribas JR, Zamora F, Gutiérrez A
Publication: J Microbiol Methods, 2007, Vol. 69, Page 384-6
PubMed ID: 17363096 PubMed Review Paper? No
Purpose of Paper
Conclusion of Paper
Studies
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Study Purpose
The purpose of this study was to determine the effects of freezing plasma at -70 degrees C in the primary PPT rather than transferring plasma to a new PPT on the quantification of HIV load by the Amplicor monitor assay. Plasma was stored frozen for an unspecified number of days and thawed at room temperature prior to assay.
Summary of Findings:
The viral load was higher in all 21 specimens with an initial viral load of <1000 copies/mL when plasma was frozen in the primary PPT than when plasma was frozen after transferring it to a new PPT (p<0.001). Further, 11 of the 21 specimens with an intial viral load of less than 1000 copies/mL had an unquantifiable load (<50 copies/mL) when plasma was transferred to a new tube prior to freezing, but none of the specimens frozen in the original tubes had an unquantifiable viral load. Transferring plasma to a new tube prior to freezing had no significant effects on viral load when the initial viral load was >1000 copies/mL. Regardless, the authors recommend transferring specimens to a new tube prior to freezing to avoid artificial elevation of viral load.
Biospecimens
Preservative Types
- Frozen
- None (Fresh)
Diagnoses:
- AIDS/HIV-related
Platform:
Analyte Technology Platform RNA Real-time qRT-PCR Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Storage Type of storage container Primary PPT
New PPT
Preaquisition Biomarker level <1000 copies/mL
1000-40000 copies/mL
>40000 copies/mL
Biospecimen Preservation Type of fixation/preservation Frozen
None (fresh)