Successful use of Plasma Preparation Tubes™(PPTs) in the COBAS® AmpliPrep/COBAS® TaqMan® HIV-1 Test

• Type of Material: Article
• Authors: Colleen S Kraft, Emory University; Jose N Binongo, Emory University; Eileen Burd, Emory University; Molly Ellen Eaton, Emory University; Cindy B. McCloskey, University of Oklahoma; Helen Fernandes, University of Medicine and Dentistry of New Jersey; Charles E Hill, Emory University; Angela M Caliendo, Emory University
• Language: English
• Date: 2013-05
• Publisher: Elsevier: 12 months
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2012 Elsevier B.V. All rights reserved.
• License: Creative Commons Attribution-NonCommerical-NoDerivs 3.0 Unported
• Final Published Version (URL): http://dx.doi.org/10.1016/j.jcv.2012.12.015
• Title of Journal or Parent Work: Journal of Clinical Virology
• ISSN: 1386-6532
• Volume: 57
• Issue: 1
• Start Page: 77
• End Page: 79
• Grant/Funding Information: This work was supported in part by the Center for AIDS Research (P30 AI050409).; Financial support by a NIH/NCRR KL2 TR-000455 supported CSK.
• Keywords: COBAS Amplicor/COBAS Ampliprep; Viral load; Plasma Preparation Tubes; HIV-1
• Research Categories: Health Sciences, Pathology; Biology, Virology

Abstract

Background Since switching to the COBAS® AmpliPrep/COBAS® TaqMan® HIV-1 Test, v. 1.0 from the Amplicor HIV-1 Monitor Test, v. 1.5, an increase in detectable viral load results was noted. We were concerned that this was due to the use of Plasma Preparation Tubes (PPT) in this test. Objective To assess the impact of different pre-analytical processing conditions on HIV-1 viral load results on the COBAS® AmpliPrep/COBAS® TaqMan® HIV-1 Test. Study design Sixty-three HIV-infected patients were consented and had 3 PPTs and 1 K2EDTA drawn for HIV-1 viral load testing. Three methods of PPT processing were compared against the referent K2EDTA tube which was spun at 1100 × g for 20 min, poured off and frozen; PPT1 was refrigerated with an additional centrifugation prior to testing, PPT2 was processed similarly to EDTA, and PPT3 was centrifuged, frozen and centrifuged again prior to testing. Results PPT1 and PPT3 yielded results that were most similar to the referent EDTA processing, with a concordance correlation coefficient (CCC) of 0.80 and 0.85, compared to PPT2 with CCC of 0.37. Both PPT1 and PPT3 involved additional centrifugation prior to testing. In 26 patients with residual samples from the PPT2 processing, 9 (34.6%) were found to have the presence of proviral DNA, which likely contributed to the elevated HIV-1 RNA viral loads in these individuals. Conclusion PPTs can be used in the COBAS® AmpliPrep/COBAS® TaqMan® HIV-1 Test with an additional centrifugation in order to avoid misleading elevated HIV-1 RNA viral loads that may change patient management.