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Newman H, Hardie D. HIV-1 viral load testing in resource-limited settings: Challenges and solutions for specimen integrity. Rev Med Virol 2020; 31:e2165. [PMID: 32978882 DOI: 10.1002/rmv.2165] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 08/20/2020] [Accepted: 08/22/2020] [Indexed: 11/07/2022]
Abstract
HIV-1 viral load (VL) testing is a crucial element in providing an antiretroviral treatment monitoring program. The success of these programs depends on the availability and quality of the VL testing services. There are several pre-analytic factors which can affect the quality of VL testing. Many of the challenges faced by resource-limited countries result in a compromise of specimen integrity, thus limiting widespread access to VL monitoring. The various logistic and financial challenges that exist are not insurmountable and several innovative solutions currently exist to overcome these barriers to providing widespread VL testing. This review summarizes the VL testing challenges in resource-limited settings and provides an overview of potential solutions including testing dried blood spots, dried plasma spots, plasma separation cards and the use of point of care tests.
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Affiliation(s)
- Howard Newman
- National Health Laboratory Service, South Africa.,Department of Pathology, Division of Medical Virology, Stellenbosch University, Stellenbosch, South Africa.,Faculty of Health Sciences, Nelson Mandela University, Port Elizabeth, South Africa
| | - Diana Hardie
- National Health Laboratory Service, South Africa.,Department of Pathology, Division of Virology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
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Luo R, Markby J, Sacks J, Vojnov L. Systematic review of the accuracy of plasma preparation tubes for HIV viral load testing. PLoS One 2019; 14:e0225393. [PMID: 31751392 PMCID: PMC6874077 DOI: 10.1371/journal.pone.0225393] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 11/03/2019] [Indexed: 01/28/2023] Open
Abstract
Expanding access to HIV viral load testing is essential to improving the care and treatment of people living with HIV/AIDS and ending the AIDS epidemic. Though significant investments have been made in the past five years, many high burden, low resource countries continue to have viral load access rates below 50%. Plasma preparation tubes (PPTs) can simplify storage, transport, and preparation of plasma used for viral load testing. A systematic review was conducted to evaluate the accuracy of plasma preparation tubes for HIV viral load testing. Study results regarding the accuracy of PPT viral load measurements across various storage and transportation conditions were examined. The quality of evidence was evaluated using GRADE and QUADAS-2 criteria. The review identified 16 studies using PPTs with data from 6,141 individuals from 1995 to 2014. Overall the quality of evidence was rated as moderate, with unclear applicability for studies evaluating viral load assays that are no longer commercially available. Significantly elevated viral load results (>0.3 log copies/ml difference) have been observed with PPTs; however, when manufacturer handling instructions are followed, when plasma is aliquoted into a secondary tube, or when PPTs are centrifuged prior to testing, PPT results only differed from standard EDTA plasma testing using commercially available viral load assays by a range on average of -0.03 to +0.08 log copies/ml across studies. Although spuriously elevated viral load results have been observed with PPTs, following proper sample handing techniques have been shown to provide accurate results. PPTs, therefore, provide a high quality alternative specimen type for countries seeking solutions to infrastructure and specimen transportation challenges in an effort to scale-up viral load testing and achieve 90-90-90 targets.
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Affiliation(s)
- Robert Luo
- World Health Organization, Geneva, Switzerland
- * E-mail:
| | - Jessica Markby
- Clinton Health Access Initiative, Boston, Massachusetts, United States of America
| | - Jilian Sacks
- Clinton Health Access Initiative, Boston, Massachusetts, United States of America
| | - Lara Vojnov
- World Health Organization, Geneva, Switzerland
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Hardie D, Korsman S, Ameer S, Vojnov L, Hsiao NY. Reliability of plasma HIV viral load testing beyond 24 hours: Insights gained from a study in a routine diagnostic laboratory. PLoS One 2019; 14:e0219381. [PMID: 31269089 PMCID: PMC6609026 DOI: 10.1371/journal.pone.0219381] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 06/23/2019] [Indexed: 01/20/2023] Open
Abstract
Background Viral load testing is key to monitoring response to anti-retroviral therapy (ART). However, in lower and middle income countries with large epidemics, pre-analytical challenges threaten the quality of testing. It is unknown how much delayed processing and adverse storage affects the validity of results. The aim of this study was to determine the impact of delayed testing and warmer storage conditions on HIV RNA stability in diagnostic samples. Methods 1194 samples, collected in EDTA or plasma preparation (PPT) tubes, were studied. Immediately after initial testing, primary tubes were stored for 72, 96 or 168 hours at 4°C, 20°C or 30°C. The viral load was then repeated and the 2 results were compared. Results Viral loads were very stable, with <0.5 log copies/ml median difference noted between paired tests for all storage times and temperatures. The viral load in samples stored for up to a week reliably differentiated between ART-suppressed and failing patients in 98.83% of instances. However, re-centrifugation immediately prior to repeat testing was essential to avoid falsely elevated readings, probably due to contamination of plasma with cell-associated viral nucleic acids. Approximately 20% of samples with initially undetectable viral loads were weakly positive (<100 copies/mL) on repeat. This was not exacerbated by duration or temperature of storage. Conclusion Viral RNA in diagnostic samples is stable well beyond currently recommended limits. However, when testing stored primary samples, contamination of plasma with cellular material easily occurs. Low viral loads (<100copies/mL) in samples stored in this way should be interpreted with caution.
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Affiliation(s)
- Diana Hardie
- Division of Virology, Department of Pathology, University of Cape Town, Cape Town, South Africa
- National Health Laboratory Service, Cape Town, South Africa
- * E-mail:
| | - Stephen Korsman
- Division of Virology, Department of Pathology, University of Cape Town, Cape Town, South Africa
- National Health Laboratory Service, Cape Town, South Africa
| | - Sharifa Ameer
- National Health Laboratory Service, Cape Town, South Africa
| | - Lara Vojnov
- World Health Organization, Geneva, Switzerland
| | - Nei-Yuan Hsiao
- Division of Virology, Department of Pathology, University of Cape Town, Cape Town, South Africa
- National Health Laboratory Service, Cape Town, South Africa
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Solomon Tsegaye T, Gnirß K, Rahe-Meyer N, Kiene M, Krämer-Kühl A, Behrens G, Münch J, Pöhlmann S. Platelet activation suppresses HIV-1 infection of T cells. Retrovirology 2013; 10:48. [PMID: 23634812 PMCID: PMC3660175 DOI: 10.1186/1742-4690-10-48] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Accepted: 04/22/2013] [Indexed: 11/10/2022] Open
Abstract
Background Platelets, anucleate cell fragments abundant in human blood, can capture HIV-1 and platelet counts have been associated with viral load and disease progression. However, the impact of platelets on HIV-1 infection of T cells is unclear. Results We found that platelets suppress HIV-1 spread in co-cultured T cells in a concentration-dependent manner. Platelets containing granules inhibited HIV-1 spread in T cells more efficiently than degranulated platelets, indicating that the granule content might exert antiviral activity. Indeed, supernatants from activated and thus degranulated platelets suppressed HIV-1 infection. Infection was inhibited at the stage of host cell entry and inhibition was independent of the viral strain or coreceptor tropism. In contrast, blockade of HIV-2 and SIV entry was less efficient. The chemokine CXCL4, a major component of platelet granules, blocked HIV-1 entry and neutralization of CXCL4 in platelet supernatants largely abrogated their anti-HIV-1 activity. Conclusions Release of CXCL4 by activated platelets inhibits HIV-1 infection of adjacent T cells at the stage of virus entry. The inhibitory activity of platelet-derived CXCL4 suggests a role of platelets in the defense against infection by HIV-1 and potentially other pathogens.
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Successful use of Plasma Preparation Tubes™ (PPTs) in the COBAS® AmpliPrep/COBAS® TaqMan® HIV-1 test. J Clin Virol 2013; 57:77-9. [PMID: 23332979 DOI: 10.1016/j.jcv.2012.12.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 12/14/2012] [Accepted: 12/18/2012] [Indexed: 11/24/2022]
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.
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Cobb BR, Vaks JE, Do T, Vilchez RA. Evolution in the sensitivity of quantitative HIV-1 viral load tests. J Clin Virol 2011; 52 Suppl 1:S77-82. [DOI: 10.1016/j.jcv.2011.09.015] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Evaluation of effect of specimen-handling parameters for plasma preparation tubes on viral load measurements obtained by using the Abbott RealTime HIV-1 load assay. J Clin Microbiol 2010; 48:2464-8. [PMID: 20484602 DOI: 10.1128/jcm.00083-10] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
HIV-1 viral load testing is essential to the management of HIV-1-infected patients, and proper specimen handling ensures accurate viral load (VL) results. This study was performed to (i) evaluate the effect of freezing plasma in situ in BD Vacutainer plasma preparation tubes (PPT) on the accuracy of HIV-1 viral load results using the Abbott RealTime HIV-1 assay and (ii) evaluate the effect of whole-blood storage in the PPT for 6 h at room temperature prior to centrifugation (PPT6H) rather than 2 h as specified in the PPT product insert. Of the 64 HIV-positive subjects evaluated, 29 had average viral load counts of >40 copies/ml in at least one of the tubes tested and 35 subjects had a result of either "undetected target" or "below the limit of quantification" (LOQ) for all or some of the tubes regardless of handling condition. For the 29 subjects with VLs that were >LOQ, the mean biases between plasma from Vacutainer K(2)EDTA tubes and plasma frozen in situ in PPT and between K(2)EDTA tube plasma and plasma from PPT6H (log(10) copies/ml) were 0.005 and -0.001, respectively, and r(2) was >0.92 for all correlations. We conclude that VLs determined from plasma frozen in situ in PPT are equivalent to VLs in K(2)EDTA tube plasma and can be used for accurate quantification of HIV-1 RNA in the Abbott RealTime HIV-1 assay. Furthermore specimens collected in PPT can be stored for 6 h at room temperature with no effect on viral load results as measured by the Abbott RealTime HIV-1 assay.
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Overestimation of human immunodeficiency virus type 1 load caused by the presence of cells in plasma from plasma preparation tubes. J Clin Microbiol 2009; 47:2170-4. [PMID: 19420166 DOI: 10.1128/jcm.00519-09] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The human immunodeficiency virus type 1 (HIV-1) load is an important marker of disease progression and treatment efficacy in patients with HIV-1 infection. In recent years, an increase in the number of samples with detectable HIV-1 RNA has been reported among patients with previously suppressed viral loads, affecting clinical patient care and leading to repeat measurements of viral load and drug resistance. This rise seems to have coincided with the increased use of plasma preparation tubes (PPTs) for sample collection, and we have aimed to explain why PPTs might yield elevated HIV-1 RNA levels. The impacts of different sample-processing procedures on HIV-1 RNA levels were compared retrospectively. Prospectively, the presence of different cells and cell-associated HIV-1 nucleic acids in paired plasma samples from PPTs centrifuged before (PPT1) and after (PPT2) transportation to the laboratory was compared. A retrospective analysis of 4,049 patient samples with <1,000 HIV-1 RNA copies/ml showed elevated HIV-1 RNA levels in plasma from PPT1 compared with the levels from PPT2 and standard EDTA-containing tubes. Prospective data revealed cell-associated HIV-1 nucleic acids and abundant blood cells in plasma from PPT1 but not from the corresponding PPT2. The levels of HIV-1 RNA correlated with the lymphocyte counts in plasma in PPT1. Cells could be removed by the recentrifugation of PPT1 before analysis. In conclusion, the transportation of PPTs after centrifugation may render cells in the plasma fraction containing cell-associated HIV-1 nucleic acids that contribute significantly to the HIV-1 RNA copy numbers in patients with low viral loads.
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Rebeiro PF, Kheshti A, Bebawy SS, Stinnette SE, Erdem H, Tang YW, Sterling TR, Raffanti SP, D'Aquila RT. Increased detectability of plasma HIV-1 RNA after introduction of a new assay and altered specimen-processing procedures. Clin Infect Dis 2008; 47:1354-7. [PMID: 18922071 DOI: 10.1086/592693] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
After changes to assay and specimen-processing methods, plasma human immunodeficiency virus type 1 (HIV-1) RNA was frequently detectable in patients who previously had well-suppressed HIV-1 RNA levels. This artifact is attributable to shipping frozen plasma in primary plasma preparation tubes and is not caused by the HIV-1 RNA detection assay; it can be avoided by shipping plasma in a secondary tube.
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Affiliation(s)
- Peter F Rebeiro
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-2582, USA
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García-Bujalance S, Ladrón de Guevara C, González-García J, Arribas JR, Zamora F, Gutiérrez A. Elevation of viral load by PCR and use of plasma preparation tubes for quantification of human immunodeficiency virus type 1. J Microbiol Methods 2007; 69:384-6. [PMID: 17363096 DOI: 10.1016/j.mimet.2007.01.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2006] [Revised: 01/12/2007] [Accepted: 01/30/2007] [Indexed: 10/23/2022]
Abstract
HIV-1 viral load testing from 51 patients was compared in plasma samples simultaneously processed and stored in primary Vacutainer plasma preparation tubes (PPTs) and PPT sample aliquots transferred in secondary tubes before freezing, using RT-PCR quantification with an ultrasensitive method (the Roche AMPLICOR HIV-1 MONITOR). We concluded that freezing the primary sample in the PPT collection tube can artificially elevate the HIV-1 viral load. We therefore store samples as frozen aliquots in a second tube.
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Affiliation(s)
- S García-Bujalance
- Department of Microbiology and Parasitology, La Paz University Hospital, Paseo de la Castellana 261, 28046 Madrid, Spain.
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Abstract
During the past decade and a half, quantitation of plasma-associated human immunodeficiency virus type 1 (HIV-1) RNA level, or HIV-1 load, has been validated in clinical practice and clinical trials as an important surrogate marker of HIV-1 disease progression and of the potency and durability of antiretroviral regimens. This review highlights some of the history, accomplishments, and impact of Tom Merigan's laboratory on the use of HIV-1 load as a marker, as well as on updating technologies for determining HIV-1 load, their performance, interpretation of the results, and their use in clinical practice.
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Affiliation(s)
- Mark Holodniy
- AIDS Research Center, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, USA.
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Griffith BP, Mayo DR. Increased levels of HIV RNA detected in samples with viral loads close to the detection limit collected in Plasma Preparation Tubes (PPT). J Clin Virol 2005; 35:197-200. [PMID: 16253548 DOI: 10.1016/j.jcv.2005.08.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2005] [Revised: 08/01/2005] [Accepted: 08/15/2005] [Indexed: 10/25/2022]
Abstract
BACKGROUND The accurate and reliable quantification of HIV RNA is an essential part of the management of HIV infected individuals, and elucidation of factors that may affect HIV RNA measurements, such as the use of Vacutainer Plasma Preparation Tubes (PPT), is crucial. OBJECTIVES The objective of this study was to determine if plasma samples with viral loads close to the lower limit of the dynamic range of the assay collected in PPT tubes had increased levels of HIV RNA as compared to samples collected in standard EDTA tubes. STUDY DESIGN HIV RNA levels were compared in 112 paired plasma samples collected in PPT and standard EDTA tubes. All samples had been frozen prior to testing. RESULTS Discrepancies between PPT and EDTA tubes did not occur for samples with high viral loads. However, in samples with viral loads close to the lower limit of the dynamic range, levels of HIV RNA detected were higher in a large proportion of PPT as compared to the corresponding EDTA plasma samples. Forty percent of plasma pairs had no detectable HIV RNA in the EDTA aliquot, but had low levels of HIV RNA in the corresponding PPT aliquot. CONCLUSIONS This prospective study underlines the need for cautious interpretation of small transient viral load changes in samples with values close to the detection limit.
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Affiliation(s)
- Brigitte P Griffith
- VA CT Virology Reference Laboratory, VA Connecticut Healthcare System, West Haven, CT 06516, USA.
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