1
|
Ramalingam VV, Fletcher GJ, Kasirajan A, Demosthenes JP, Rupali P, Varghese GM, Pulimood SA, Rebekah G, Kannangai R. Can In-house HIV-2 Viral Load Assay be a Reliable Alternative to Commercial Assays for Clinical and Therapeutic Monitoring? Curr HIV Res 2022; 20:274-286. [PMID: 35692165 DOI: 10.2174/1570162x20666220609155237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 03/11/2022] [Accepted: 04/01/2022] [Indexed: 01/27/2023]
Abstract
BACKGROUND Currently, there is a global contemplation to end the AIDS epidemic by 2030. HIV-2 poses unique challenges to this end. The burden of HIV-2 is higher in resource-limited countries, and it is intrinsically resistant to NNRTI drugs. In addition, there is no FDA-approved plasma viral load assay to monitor disease progression and therapeutic efficacy. To overcome these challenges, we have developed and evaluated an in-house quantitative HIV-2 viral load assay. METHODS Blood samples were collected from 28 HIV-2 treatment-naïve monoinfected individuals and tested using an in-house qPCR HIV-2 viral load assay. The extracted RNA was amplified using Quantifast pathogen + IC kit. RESULTS The in-house qPCR has a limit of detection of 695 copies/ml. The intra- and inter-assay variation (% CV) of the assay was 0.61 and 0.95, respectively. The in-house assay quantified HIV-2 NIBSC accurately (1000 IU) with a mean of 1952 copies/mL. Among the 28 samples tested by in-house qPCR assay, 11 (39.2%) samples were quantified, whereas 17 (60.7%) samples were not detected. In comparison with Altona RealStar HIV-2 RT PCR and Exavir Load RT assay, the results were 96.4% and 69.6% concordant, respectively. No significant (p = 0.99 and p = 0.13) difference in quantifying viral load between the three assays. Based on clinical and immunological (CD4) staging, the performance characteristics were comparable. CONCLUSION To the best of our knowledge, this is the first in-house qPCR developed in India. The performance characteristics of the in-house assay are comparable to the commercial assays, and they can be used assertively to monitor HIV-2 patients.
Collapse
Affiliation(s)
| | | | - Anand Kasirajan
- Department of Clinical Virology, Christian Medical College, Vellore, Tamil Nadu, 632004, India
| | - John Paul Demosthenes
- Department of Clinical Virology, Christian Medical College, Vellore, Tamil Nadu, 632004, India
| | - Priscilla Rupali
- Department of Infectious Diseases, Christian Medical College, Vellore, Tamil Nadu, 632004, India
| | - George Mannil Varghese
- Department of Infectious Diseases, Christian Medical College, Vellore, Tamil Nadu, 632004, India
| | | | - Grace Rebekah
- Department of Biostatistics, Christian Medical College, Vellore, Tamil Nadu, 632004, India
| | - Rajesh Kannangai
- Department of Clinical Virology, Christian Medical College, Vellore, Tamil Nadu, 632004, India
| |
Collapse
|
2
|
Macchi B, Frezza C, Marino-Merlo F, Minutolo A, Stefanizzi V, Balestrieri E, Cerva C, Sarmati L, Andreoni M, Grelli S, Mastino A. Appraisal of a Simple and Effective RT-qPCR Assay for Evaluating the Reverse Transcriptase Activity in Blood Samples from HIV-1 Patients. Pathogens 2020; 9:pathogens9121047. [PMID: 33322208 PMCID: PMC7763350 DOI: 10.3390/pathogens9121047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 12/10/2020] [Accepted: 12/11/2020] [Indexed: 12/14/2022] Open
Abstract
Testing HIV-1 RNA in plasma by PCR is universally accepted as the ultimate standard to confirm diagnosis of HIV-1 infection and to monitor viral load in patients under treatment. However, in some cases, this assay could either underestimate or overestimate the replication capacity of a circulating or latent virus. In the present study, we performed the assessment of evaluating the HIV-1 reverse transcriptase (RT) activity by means of a new assay for the functional screening of the status of HIV-1 patients. To this purpose, we utilized, for the first time on blood samples, an adapted version of a real-time RT quantitative PCR assay, utilized to evaluate the HIV-1-RT inhibitory activity of compounds. The study analyzed blood samples from 28 HIV-1-infected patients, exhibiting a wide range of viremia and immunological values. Results demonstrated that plasma HIV-1 RT levels, expressed as cycle threshold values obtained with the assay under appraisal, were inversely and highly significantly correlated with the plasma HIV-1-RNA levels of the patients. Thus, an HIV-1 RT quantitative PCR assay was created which we describe in this study, and it may be considered as a promising basis for an additional tool capable of furnishing information on the functional virological status of HIV-1-infected patients.
Collapse
Affiliation(s)
- Beatrice Macchi
- Department of Chemical Science and Technology, University of Rome “Tor Vergata”, 00133 Rome, Italy;
| | - Caterina Frezza
- Department of Systems Medicine, University of Rome “Tor Vergata”, 00133 Rome, Italy; (C.F.); (C.C.); (L.S.); (M.A.)
| | - Francesca Marino-Merlo
- Department of Chemical, Biological, Pharmaceutical, and Environmental Sciences, University of Messina, 98166 Messina, Italy;
| | - Antonella Minutolo
- Department of Experimental Medicine, University of Rome “Tor Vergata”, 00133 Rome, Italy; (A.M.); (V.S.); (E.B.); (S.G.)
| | - Valeria Stefanizzi
- Department of Experimental Medicine, University of Rome “Tor Vergata”, 00133 Rome, Italy; (A.M.); (V.S.); (E.B.); (S.G.)
| | - Emanuela Balestrieri
- Department of Experimental Medicine, University of Rome “Tor Vergata”, 00133 Rome, Italy; (A.M.); (V.S.); (E.B.); (S.G.)
| | - Carlotta Cerva
- Department of Systems Medicine, University of Rome “Tor Vergata”, 00133 Rome, Italy; (C.F.); (C.C.); (L.S.); (M.A.)
- Tor Vergata University Hospital, 00133 Rome, Italy
| | - Loredana Sarmati
- Department of Systems Medicine, University of Rome “Tor Vergata”, 00133 Rome, Italy; (C.F.); (C.C.); (L.S.); (M.A.)
- Tor Vergata University Hospital, 00133 Rome, Italy
| | - Massimo Andreoni
- Department of Systems Medicine, University of Rome “Tor Vergata”, 00133 Rome, Italy; (C.F.); (C.C.); (L.S.); (M.A.)
- Tor Vergata University Hospital, 00133 Rome, Italy
| | - Sandro Grelli
- Department of Experimental Medicine, University of Rome “Tor Vergata”, 00133 Rome, Italy; (A.M.); (V.S.); (E.B.); (S.G.)
- Tor Vergata University Hospital, 00133 Rome, Italy
| | - Antonio Mastino
- The Institute of Translational Pharmacology, CNR, 00133 Rome, Italy
- Correspondence: ; Tel.: +39-3388658161
| |
Collapse
|
3
|
Mlambo T, Tshabalala M, Bandason T, Mhandire K, Mudenge B, Zijenah LS. Correlation of High Interleukin 17A and Interleukin 6 Levels with High Virus Load Among Subtype C HIV-infected, Antiretroviral Therapy-naive Zimbabwean Patients: A Cross-sectional Study. Open AIDS J 2019. [DOI: 10.2174/1874613601913010059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Introduction:
In response to the human immunodeficiency virus (HIV) infection, activated immune cells produce several cytokines that alter the immune response and HIV disease progression. We quantified Th1/Th2/Th17 cytokines in an antiretroviral therapy naïve (ART) cohort to investigate their correlation with traditional markers of HIV disease progression; CD4+ T-lymphocytes and virus load (VL).
Methods:
We enrolled 247 HIV-infected ART-naïve participants into the study. CD4+ T- and CD8+ T-lymphocytes were enumerated using flow cytometry. VL was quantified using the Cavidi ExaVirTM Load assay. IL-2, IL-4, IL-6, IL-10, IL-17A, TNF-α, and IFN-γ levels were quantified using the BD Cytometric Bead Array Human Th1/Th2/Th17 cytokine assay. The Kendall’s rank correlation coefficient was used to determine the correlation between log10 transformed data for cytokine levels and CD4+ T- and CD8+ T-lymphocytes, CD4/CD8 ratio, and VL.
Results:
The median CD4+ T- and CD8+ T-lymphocyte counts were 458 cells/µL (IQR:405-556) and 776 cells/µL (IQR:581-1064), respectively. The median CD4/CD8 ratio was 0.6 (IQR: 0.45-0.86). The median VL was log103.3.copies/mL (IQR:2.74-3.93). Low CD4+ T-lymphocyte counts (p=0.010) and CD4/CD8 ratio (p=0.044) were significantly correlated with high VL. There was no significant correlation of cytokine levels with CD4+ T-, CD8+ T-lymphocyte counts and CD4/CD8 ratio. However, high levels of IL-17A (p=0.012) and IL-6 (p=0.034) were significantly correlated with high VL.
Conclusion:
Our study contributes to the little knowledge available on the role of cytokine profiles in the immune response to subtype C HIV infection.
Collapse
|
4
|
Schneiderman N, McIntosh RC, Antoni MH. Psychosocial risk and management of physical diseases. J Behav Med 2019; 42:16-33. [PMID: 30632000 PMCID: PMC6941845 DOI: 10.1007/s10865-018-00007-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 12/18/2018] [Indexed: 12/24/2022]
Abstract
During the 40 years since the Yale conference on Behavioral Medicine and the founding of the Journal of Behavioral Medicine considerable progress has been made in understanding the role of psychosocial risk and management of physical diseases. We here describe the development of these fundamental concepts from early research on stress through studies of the Type A behavior pattern to more contemporary approaches to the relationship between psychosocial risks and benefits in relation to disease processes. This includes the relationship of psychosocial risk to cancers, cardiovascular diseases (CVD), cardiometabolic disorders, Human Immunodeficiency Virus (HIV)/Acquired Human Immune Deficiency Syndrome. During the past 40 years the effects of prolonged distress responses in the pathogenesis of some cancers and CVD have been well-established and modifiable behavioral, cognitive and social factors have been shown to produce favorable outcome components in the management of such diseases as breast cancer, coronary heart disease and HIV.
Collapse
Affiliation(s)
- Neil Schneiderman
- Health Division, Department of Psychology, University of Miami, 5665 Ponce de Leon Boulevard, Coral Gables, FL, 33124, USA.
| | - Roger C McIntosh
- Health Division, Department of Psychology, University of Miami, 5665 Ponce de Leon Boulevard, Coral Gables, FL, 33124, USA
| | - Michael H Antoni
- Health Division, Department of Psychology, University of Miami, 5665 Ponce de Leon Boulevard, Coral Gables, FL, 33124, USA
| |
Collapse
|
5
|
DeStefano JJ, Alves Ferreira-Bravo I. A highly sensitive aptamer-based HIV reverse transcriptase detection assay. J Virol Methods 2018; 257:22-28. [PMID: 29630943 DOI: 10.1016/j.jviromet.2018.04.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 03/16/2018] [Accepted: 04/05/2018] [Indexed: 12/12/2022]
Abstract
Although many new assays for HIV have been developed, several labs still use simple and reliable radioactivity-based reverse transcriptase (RT) nucleotide incorporation assays for detection and quantification. We describe here a new assay for detection and quantitation of HIV RT activity that is based on a high affinity DNA aptamer to RT. The aptamer is sequestered on 96-well plates where it can bind to RT and other constituents can be removed by extensive washing. Since the aptamer mimics a primer-template, upon radiolabeled nucleotide addition, bound RT molecules can extend the aptamer and the radioactive signal can be detected by standard methods. In addition to being procedurally simple, the assay demonstrated high sensitivity (detection limits for RT and virions were ≤6400 molecules (∼4 × 10-8 units) and ∼100-300 virions, respectively) and was essentially linear over a range of at least 104. Both wild type and drug-resistant forms of HIV-1 RT were detectable as was HIV-2 RT, although there were some modest differences in sensitivity.
Collapse
Affiliation(s)
- Jeffrey J DeStefano
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, United States; The Maryland Pathogen Research Institute, University of Maryland, College Park, MD, United States.
| | - Irani Alves Ferreira-Bravo
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, United States; The Maryland Pathogen Research Institute, University of Maryland, College Park, MD, United States
| |
Collapse
|
6
|
Assessment of the Cavidi ExaVir Load Assay for Monitoring Plasma Viral Load in HIV-2-Infected Patients. J Clin Microbiol 2017; 55:2367-2379. [PMID: 28515216 DOI: 10.1128/jcm.00235-17] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 05/10/2017] [Indexed: 11/20/2022] Open
Abstract
HIV plasma viral load is an established marker of disease progression and of response to antiretroviral therapy, but currently there is no commercial assay validated for the quantification of viral load in HIV-2-infected individuals. We sought to make the first clinical evaluation of Cavidi ExaVir Load (version 3) in HIV-2-infected patients. Samples were collected from a total of 102 individuals living in Cape Verde, and the HIV-2 viral load was quantified by both ExaVir Load and a reference in-house real-time quantitative PCR (qPCR) used in Portugal in 91 samples. The associations between viral load and clinical prognostic variables (CD4+ T cell counts and antiretroviral therapy status) were similar for measurements obtained using ExaVir Load and qPCR. There was no difference between the two methods in the capacity to discriminate between nonquantifiable and quantifiable HIV-2 in the plasma. In samples with an HIV-2 viral load quantifiable by both methods (n = 27), the measurements were highly correlated (Pearson r = 0.908), but the ExaVir Load values were systematically higher relative to those determined by qPCR (median difference, 0.942 log10 copies/ml). A regression model was derived that enables the conversion of ExaVir Load results to those that would have been obtained by the reference qPCR. In conclusion, ExaVir Load version 3 is a reliable commercial assay to measure viral load in HIV-2-infected patients and therefore a valuable alternative to the in-house assays in current use.
Collapse
|
7
|
Gupta S, Palchaudhuri R, Neogi U, Srinivasa H, Ashorn P, De Costa A, Källander C, Shet A. Can HIV reverse transcriptase activity assay be a low-cost alternative for viral load monitoring in resource-limited settings? BMJ Open 2016; 6:e008795. [PMID: 26817634 PMCID: PMC4735141 DOI: 10.1136/bmjopen-2015-008795] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
OBJECTIVE To evaluate the performance and cost of an HIV reverse transcriptase-enzyme activity (HIV-RT) assay in comparison to an HIV-1 RNA assay for routine viral load monitoring in resource limited settings. DESIGN A cohort-based longitudinal study. SETTING Two antiretroviral therapy (ART) centres in Karnataka state, South India, providing treatment under the Indian AIDS control programme. PARTICIPANTS A cohort of 327 HIV-1-infected Indian adult patients initiating first-line ART. OUTCOME MEASURES Performance and cost of an HIV-RT assay (ExaVir Load V3) in comparison to a gold standard HIV-1 RNA assay (Abbott m2000rt) in a cohort of 327 Indian patients before (WK00) and 4 weeks (WK04) after initiation of first-line therapy. RESULTS Plasma viral load was determined by an HIV-1 RNA assay and an HIV-RT assay in 629 samples (302 paired samples and 25 single time point samples at WK00) obtained from 327 patients. Overall, a strong correlation of r=0.96 was observed, with good correlation at WK00 (r=0.84) and at WK04 (r=0.77). Bland-Altman analysis of all samples showed a good level of agreement with a mean difference (bias) of 0.22 log10copies/mL. The performance of ExaVir Load V3 was not negatively affected by a nevirapine/efavirenz based antiretroviral regimen. The per test cost of measuring plasma viral load by the Abbott m2000rt and ExaVir Load V3 assays in a basic lab setting was $36.4 and $16.8, respectively. CONCLUSIONS The strong correlation between the HIV-RT and HIV-1 RNA assays suggests that the HIV-RT assay can be an affordable alternative option for monitoring patients on antiretroviral therapy in resource-limited settings. TRIAL REGISTRATION NUMBER ISRCTN79261738.
Collapse
Affiliation(s)
- Soham Gupta
- Division of Clinical Virology, Department of Microbiology, St. John's Medical College, Bangalore, India
| | - Riya Palchaudhuri
- Division of Clinical Virology, Department of Microbiology, St. John's Medical College, Bangalore, India
| | - Ujjwal Neogi
- Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Hiresave Srinivasa
- Division of Clinical Virology, Department of Microbiology, St. John's Medical College, Bangalore, India
| | - Per Ashorn
- Department for International Health, University of Tampere School of Medicine, Tampere, Finland
| | - Ayesha De Costa
- Department of Public Health Sciences, Karolinska Institute, Stockholm, Sweden
| | | | - Anita Shet
- Department of Pediatrics, St John's Medical College Hospital, Bangalore, India
| |
Collapse
|
8
|
Ondoa P, Shamu T, Bronze M, Wellington M, Boender TS, Manting C, Steegen K, Luethy R, Rinke de Wit T. Performance and logistical challenges of alternative HIV-1 virological monitoring options in a clinical setting of Harare, Zimbabwe. BIOMED RESEARCH INTERNATIONAL 2014; 2014:102598. [PMID: 25025031 PMCID: PMC4082876 DOI: 10.1155/2014/102598] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 04/25/2014] [Accepted: 05/18/2014] [Indexed: 11/29/2022]
Abstract
We evaluated a low-cost virological failure assay (VFA) on plasma and dried blood spot (DBS) specimens from HIV-1 infected patients attending an HIV clinic in Harare. The results were compared to the performance of the ultrasensitive heat-denatured p24 assay (p24). The COBAS AmpliPrep/COBAS TaqMan HIV-1 test, version 2.0, served as the gold standard. Using a cutoff of 5,000 copies/mL, the plasma VFA had a sensitivity of 94.5% and specificity of 92.7% and was largely superior to the VFA on DBS (sensitivity = 61.9%; specificity = 99.0%) or to the p24 (sensitivity = 54.3%; specificity = 82.3%) when tested on 302 HIV treated and untreated patients. However, among the 202 long-term ART-exposed patients, the sensitivity of the VFA decreased to 72.7% and to 35.7% using a threshold of 5,000 and 1,000 RNA copies/mL, respectively. We show that the VFA (either on plasma or on DBS) and the p24 are not reliable to monitor long-term treated, HIV-1 infected patients. Moreover, achieving acceptable assay sensitivity using DBS proved technically difficult in a less-experienced laboratory. Importantly, the high level of virological suppression (93%) indicated that quality care focused on treatment adherence limits virological failure even when PCR-based viral load monitoring is not available.
Collapse
Affiliation(s)
- Pascale Ondoa
- Amsterdam Institute for Global Health and Development (AIGHD), Department of Global Health, Academic Medical Center, P.O. Box 22700, 1100 DE Amsterdam, The Netherlands
| | - Tinei Shamu
- Newlands Clinic, 56 Enterprise Road, Newlands, Harare, Zimbabwe
| | - Michelle Bronze
- Department of Molecular Medicine and Haematology, University of the Witwatersrand 7 York Road, Parktown, Johannesburg 2193, South Africa
| | | | - Tamara Sonia Boender
- Amsterdam Institute for Global Health and Development (AIGHD), Department of Global Health, Academic Medical Center, P.O. Box 22700, 1100 DE Amsterdam, The Netherlands
| | - Corry Manting
- Amsterdam Institute for Global Health and Development (AIGHD), Department of Global Health, Academic Medical Center, P.O. Box 22700, 1100 DE Amsterdam, The Netherlands
| | - Kim Steegen
- Department of Molecular Medicine and Haematology, University of the Witwatersrand 7 York Road, Parktown, Johannesburg 2193, South Africa
| | - Rudi Luethy
- Newlands Clinic, 56 Enterprise Road, Newlands, Harare, Zimbabwe
| | - Tobias Rinke de Wit
- Amsterdam Institute for Global Health and Development (AIGHD), Department of Global Health, Academic Medical Center, P.O. Box 22700, 1100 DE Amsterdam, The Netherlands
| |
Collapse
|
9
|
Huang D, Zhuang Y, Zhai S, Song Y, Liu Q, Zhao S, Wang S, Li X, Kang W, Greengrass V, Plate M, Crowe SM, Sun Y. HIV reverse transcriptase activity assay: a feasible surrogate for HIV viral load measurement in China. Diagn Microbiol Infect Dis 2010; 68:208-13. [DOI: 10.1016/j.diagmicrobio.2010.06.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2010] [Revised: 06/04/2010] [Accepted: 06/10/2010] [Indexed: 11/24/2022]
|
10
|
Padiglione A, Aleksic E, French M, Arnott A, Wilson KM, Tippett E, Kaye M, Gray L, Ellett A, Crane M, Leslie DE, Lewin SR, Breschkin A, Birch C, Gorry PR, McPhee DA, Crowe SM. Extremely prolonged HIV seroconversion associated with an MHC haplotype carrying disease susceptibility genes for antibody deficiency disorders. Clin Immunol 2010; 137:199-208. [DOI: 10.1016/j.clim.2010.07.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Revised: 06/30/2010] [Accepted: 07/16/2010] [Indexed: 02/01/2023]
|
11
|
Stewart P, Cachafeiro A, Napravnik S, Eron JJ, Frank I, van der Horst C, Bosch RJ, Bettendorf D, Bohlin P, Fiscus SA. Performance characteristics of the Cavidi ExaVir viral load assay and the ultra-sensitive P24 assay relative to the Roche Monitor HIV-1 RNA assay. J Clin Virol 2010; 49:198-204. [PMID: 20832356 DOI: 10.1016/j.jcv.2010.07.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2010] [Revised: 07/21/2010] [Accepted: 07/30/2010] [Indexed: 10/19/2022]
Abstract
BACKGROUND The Cavidi viral load assay and the ultra-sensitive p24 antigen assay (Up24 Ag) have been suggested as more feasible alternatives to PCR-based HIV viral load assays for use in monitoring patients infected with HIV-1 in resource-limited settings. OBJECTIVES To describe the performance of the Cavidi ExaVir Load™ assay (version 2.0) and two versions of the Up24 antigen assay and to characterize their agreement with the Roche Monitor HIV-1 RNA assay (version 1.5). STUDY DESIGN Observational study using a convenience sample of 342 plasma specimens from 108 patients enrolled in two ACTG clinical trials to evaluate the performance characteristics of the Up24 Ag assay using two different lysis buffers and the Cavidi ExaVir Load™ assay. RESULTS In analysis of agreement with the Roche assay, the Cavidi assay demonstrated superiority to the Up24 Ag assays in accuracy and precision, as well as sensitivity, specificity, and positive and negative predictive values for HIV-1 RNA ≥ 400, ≥ 1000 and ≥ 5000 copies/mL. Logistic performance curves indicated that the Cavidi assay was superior to the Up24 assays for viral loads greater than 650 copies/mL. CONCLUSIONS The results suggest that the Cavidi ExaVir Load assay could be used for monitoring HIV-1 viral load in resource-limited settings.
Collapse
Affiliation(s)
- Paul Stewart
- The University of North Carolina at Chapel Hill, Department of Biostatistics, Chapel Hill, NC 27599-7420, USA. paul
| | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Research needs and challenges in the development of HIV diagnostic and treatment monitoring tests for use in resource-limited settings. Curr Opin HIV AIDS 2009; 3:495-503. [PMID: 19373011 DOI: 10.1097/coh.0b013e328303e5f9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
PURPOSE OF REVIEW The aim of this article is to review research priorities for current and new technologies to diagnose HIV and to monitor treatment response, including technologies to enumerate CD4 cell counts and quantify plasma viral load, in resource-limited settings. RECENT FINDINGS Numerous challenges remain before HIV diagnostic and treatment monitoring technologies can be broadly implemented, especially in rural areas. New technologies that are less costly and complex to use are in development and may be better suited than current technologies for use in resource-limited settings. Investment into research activities is needed for development, evaluation and validation of new technologies. The lack of clarity in the process for evaluation and validation for these technologies affects country and program-level decisions on the appropriateness of technologies for individual settings. Implementation research is needed to assess how best to use CD4 and viral load to guide initiation and management of antiretroviral treatment, as well as how best to scale up diagnosis of HIV serostatus in infants. Studies also need to be conducted to determine if the same CD4 cutoffs can be used in resource-limited settings for initiating antiretroviral therapy and prophylaxis against opportunistic infections due to potential regional differences and the impact of other common co-morbidities on CD4 cell counts. SUMMARY Increased availability of antiretroviral therapy in resource-limited settings increases the need for reliable, less costly and simpler to use HIV diagnostic and treatment monitoring technologies. Global leadership is needed to coordinate the research and development necessary to ensure that HIV diagnostic and treatment monitoring technologies are properly evaluated in the setting where they will be used.
Collapse
|
13
|
Effect of reverse transcriptase inhibitors and mutations on the low-cost Cavidi reverse transcriptase viral load assay. J Acquir Immune Defic Syndr 2009; 52:527-9. [PMID: 19901621 DOI: 10.1097/qai.0b013e3181b9e726] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
14
|
Assessment of the low-cost Cavidi ExaVir Load assay for monitoring HIV viral load in pediatric and adult patients. J Acquir Immune Defic Syndr 2009; 52:387-90. [PMID: 19617845 DOI: 10.1097/qai.0b013e3181b05f62] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Viral load (VL) is a critical marker for monitoring HIV disease progression and response to antiretroviral therapy. In resource-constrained settings, there is a need for a simple and inexpensive assay to monitor infected adults and children. METHODS We compared versions 2 and 3 of the ExaVir Load assay, Cavidi AB (HIV RT) with the Roche, COBAS Amplicor HIV-1 Monitor assay (HIV RNA) for quantifying HIV VL. RESULTS The HIV RT version 2 assay showed good sensitivity with detection in 94% of samples with HIV RNA >1000 copies per milliliter. Adult samples were tested using HIV RT version 2 (n = 35) and version 3 (n = 23) assays with plasma volumes of 1 mL (recommended), 0.5 mL and 0.25 mL in comparison with HIV RNA. The HIV RT and HIV RNA assay results were comparable when tested using different volumes. Comparison of results from pediatric samples (n = 27), tested using 1 mL and a smaller volume by HIV RT version 2 were not significantly different. CONCLUSIONS The HIV RT assay was comparable to the HIV RNA assay with sensitivity approaching that of HIV RNA. Smaller volumes than the recommended 1 mL can be used, improving utility of this assay for pediatric monitoring.
Collapse
|
15
|
Napravnik S, Cachafeiro A, Stewart P, Eron JJ, Fiscus SA. HIV-1 viral load and phenotypic antiretroviral drug resistance assays based on reverse transcriptase activity in comparison to amplification based HIV-1 RNA and genotypic assays. J Clin Virol 2009; 47:18-22. [PMID: 19896416 DOI: 10.1016/j.jcv.2009.10.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2009] [Revised: 09/25/2009] [Accepted: 10/04/2009] [Indexed: 11/15/2022]
Abstract
BACKGROUND Amplification based HIV-1 viral load and genotypic resistance assays are expensive, technologically complex and may be difficult to implement in resource limited settings. Inexpensive, simpler assays are urgently needed. OBJECTIVES To determine the suitability of the ExaVir Load and ExaVir Drug assays for use in patient monitoring. STUDY DESIGN Specimens from 108 adults were used to compare ExaVir Load HIV-1 RT to Amplicor HIV-1 Monitor HIV-1 RNA, and ExaVir Drug phenotype to HIV GenoSure genotype. RESULTS HIV-1 RT and HIV-1 RNA levels were comparable (Pearson correlation coefficient 0.83). Most (94%) had detectable results in both assays. The mean difference (HIV-1 RT minus HIV-1 RNA) was -0.21 log(10)cps/mLequiv. Relationship between HIV-1 RT and HIV-1 RNA was not affected by RT mutations, CD4 cell count, or efavirenz (EFV) or nevirapine (NVP) use. Phenotypes were generally consistent with genotype findings for EFV, but not for NVP. Most patients (93.9%) with phenotypic EFV resistance had at least one EFV mutation, while 78.0% of patients with phenotypic NVP resistance had at least one NVP mutation. Eleven of 49 samples tested for EFV susceptibility were found resistant (n=2) or with reduced susceptibility (n=9) despite the absence of genotypic resistance. Eleven of 45 samples tested for NVP susceptibility were found resistant (n=9) or with reduced susceptibility (n=2) with no evidence of genotypic mutations. CONCLUSIONS The ExaVir Load assay performed well and may be an alternative to amplification based techniques for HIV-1 RNA quantification. The ExaVir Drug assay for phenotypic resistance testing requires further evaluation, especially for NVP.
Collapse
Affiliation(s)
- Sonia Napravnik
- Department of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | | | | | | | | |
Collapse
|
16
|
Measure of viral load by using the Abbott Real-Time HIV-1 assay on dried blood and plasma spot specimens collected in 2 rural dispensaries in Cameroon. J Acquir Immune Defic Syndr 2009; 52:9-16. [PMID: 19620878 DOI: 10.1097/qai.0b013e3181aeccbc] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND This study aimed to evaluate the use of dried blood spots (DBSs) and dried plasma spots (DPSs) locally collected in 2 rural dispensaries in Cameroon for the quantification of HIV-1 RNA. METHODS Forty-one subjects were sampled and spots of whole blood and plasma were deposited onto Whatman 903 cards and dried at ambient temperature under local conditions. Two sets of DBS and DPS cards were done per patient. The rest of the liquid plasma (LP) was frozen until use. LPs were tested at the "Chantal Biya" International Reference Centre (Yaoundé, Cameroon) by the Abbott Real-Time HIV-1 assay (Abbott Molecular Diagnostics, Wiesbaden, Germany). One series of DBS and DPS was transported and tested between 2 and 6 weeks later at the Virology Laboratory of Saint-Etienne (France). The second series was routed by mail and tested after up to 3 months of storage at ambient temperature. RESULTS From the first series, the correlation rate between viral loads obtained from LP and DBS, and from LP and DPS, was 0.98 and 0.99, respectively; specificity of DBS and DPS results was 100%. The results obtained from the second series indicate a great stability of DBS after long-term storage. CONCLUSION This study demonstrates that DBSs collected under local conditions in resource-limited settings are suitable for the differed quantification of HIV-1 RNA.
Collapse
|
17
|
Sivapalasingam S, Wangechi B, Marshed F, Laverty M, Essajee S, Holzman RS, Valentine F. Monitoring virologic responses to antiretroviral therapy in HIV-infected adults in Kenya: evaluation of a low-cost viral load assay. PLoS One 2009; 4:e6828. [PMID: 19714253 PMCID: PMC2730572 DOI: 10.1371/journal.pone.0006828] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2009] [Accepted: 07/06/2009] [Indexed: 11/25/2022] Open
Abstract
Background A key advantage of monitoring HIV viral load (VL) in persons receiving antiretroviral therapy (ART) is the ability to detect virologic failure before clinical deterioration or resistance occurs. Detection of virologic failure will help clarify the need for enhanced adherence counseling or a change to second- line therapy. Low-cost, locally performable alternates to expensive VL assays are needed where resources are limited. Methodology/Principal Findings We monitored the response to 48-week ART in 100 treatment-naïve Kenyan adults using a low-cost VL measurement, the Cavidi reverse transcriptase (RT) assay and gold-standard assays, Roche RNA PCR and Bayer Versant HIV-1 RNA (bDNA) assays. In Altman-Bland plots, the mean difference in viral loads between the three assays was small (<0.5 log10 copies/mL). However, the limits of agreement between the methods exceeded the biologically relevant change of 0.5 log copies/ml. Therefore, the RT assay cannot be used interchangeably with the other assays to monitor individual patients. The RT assay was 100% sensitive in detecting viral loads of ≥400 copies/ml compared to gold-standard assays. After 24 weeks of treatment, viral load measured by the RT assay was undetectable in 95% of 65 patients with undetectable RNA PCR VL (<400 copies/ml), 90% of 67 patients with undetectable bDNA VL, and 96% of 57 patients with undetectable VL in both RNA PCR and bDNA assays. The negative predictive value of the RT assay was 100% compared to either assay; the positive predictive value was 86% compared to RNA PCR and 70% compared to bDNA. Conclusion The RT assay compared well with gold standard assays. Our study highlights the importance of not interchanging viral load assays when monitoring an individual patient. Furthermore, the RT assay may be limited by low positive predictive values when used in populations with low prevalence of virologic failure.
Collapse
Affiliation(s)
- Sumathi Sivapalasingam
- Division of Infectious Diseases, Department of Medicine, New York University School of Medicine, New York, New York, United States of America.
| | | | | | | | | | | | | |
Collapse
|
18
|
Evaluation of the Cavidi ExaVir Load assay (version 3) for plasma human immunodeficiency virus type 1 load monitoring. J Clin Microbiol 2009; 47:3011-3. [PMID: 19605583 DOI: 10.1128/jcm.00805-09] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
We evaluated the new low-cost ExaVir Load (version 3) reverse transcriptase viral load assay against the Roche Cobas Amplicor assay. Results for samples tested using the reverse transcriptase assay correlated well with those obtained with the Roche assay (r = 0.85; n = 202). The version 3 reverse transcriptase assay shows improved sensitivity compared to the previous version.
Collapse
|
19
|
Yari A, Passo FS, Yari V, Sanni O, Yari M, Dovenou MZ, Traore R, Hounyet JP. SMARThivVLmos: a complexity-free and cost effective dynamic model technology for monitoring HIV viral load in resource-poor settings. Bioinformation 2008; 2:246-8. [PMID: 18317574 PMCID: PMC2258432 DOI: 10.6026/97320630002246] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2007] [Revised: 01/14/2008] [Accepted: 01/19/2008] [Indexed: 11/23/2022] Open
Abstract
We design a "simple" and "low cost" model technology for monitoring HIV viral load in resource-poor settings: SMARThivVLmos. Cost and complexity are the major challenges to the developing world, in monitoring HIV patients viral load. We have previously demonstrated in our SMARThivPack model that cost and complexity of laboratory monitoring of HIV patients, may be reduced not only at a first technology development level, but also at a second technology implementation, and at a third global coordination levels. In our SMARThivPack model, the P24 HIV viral load monitoring system passed both the "cost" and the "complexity" tests. However, compared to other alternative viral monitoring systems such as the Cavidi EXAVIR, the sensitivity of the P24 system is too low. Here we describe a dynamic model technology that overcomes the sensitivity barrier of the P24 system while maintaining simplicity and low cost.
Collapse
|
20
|
Steegen K, Luchters S, De Cabooter N, Reynaerts J, Mandaliya K, Plum J, Jaoko W, Verhofstede C, Temmerman M. Evaluation of two commercially available alternatives for HIV-1 viral load testing in resource-limited settings. J Virol Methods 2007; 146:178-87. [PMID: 17686534 DOI: 10.1016/j.jviromet.2007.06.019] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2007] [Revised: 06/22/2007] [Accepted: 06/27/2007] [Indexed: 11/15/2022]
Abstract
There is an urgent need for low-cost assays for HIV-1 quantitation to ensure adequate follow-up of HIV-infected patients on antiretroviral therapy (ART) in resource-limited countries. Two low-cost viral load assays are evaluated, a reverse transcriptase activity assay (ExavirLoad v2, Cavidi) and a real-time reverse transcriptase PCR assay (Generic HIV viral load, Biocentric). Both tests were compared with the ultrasensitive HIV Amplicor Monitor assay. Samples were collected in Mombasa, Kenya, from 20 HIV-1 seronegative and 150 HIV-1 seropositive individuals of whom 50 received antiretroviral treatment (ART). The ExavirLoad and the Generic HIV viral load assay were performed in a local laboratory in Mombasa, the Amplicor Monitor assay (version 1.5, Roche Diagnostics) was performed in Ghent, Belgium. ExavirLoad and Generic HIV viral load reached a sensitivity of 98.3% and 100% and a specificity of 80.0% and 90.0%, respectively. Linear regression analyses revealed good correlations between the Amplicor Monitor and the Generic HIV viral load (r=0.935, p<0.001) with high accuracy (100.1%), good precision (5.5%) and a low percent similarity coefficient of variation (5.4%). Bland-Altman analysis found 95% of the samples within clinically acceptable limits of agreement (-1.19 to 0.87logcopies/ml). Although, the ExavirLoad also showed a good linear correlation with the Amplicor Monitor (r=0.901, p<0.001), a problem with false positive results was more significant. The cost per test remains relatively high (US$ 30 for ExavirLoad and US$ 20 for the Generic HIV viral load). Hence, false positive results and the need for an expensive PCR instrument for the Generic HIV viral load assays still limit the implementation of these tests in less equipped, less experienced laboratories.
Collapse
Affiliation(s)
- Kim Steegen
- International Centre for Reproductive Health, University Hospital, Ghent, Belgium.
| | | | | | | | | | | | | | | | | |
Collapse
|
21
|
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.
Collapse
Affiliation(s)
- Mark Holodniy
- AIDS Research Center, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, USA.
| |
Collapse
|
22
|
Fiscus SA, Cheng B, Crowe SM, Demeter L, Jennings C, Miller V, Respess R, Stevens W. HIV-1 viral load assays for resource-limited settings. PLoS Med 2006; 3:e417. [PMID: 17032062 PMCID: PMC1592347 DOI: 10.1371/journal.pmed.0030417] [Citation(s) in RCA: 122] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The authors discuss studies on the low-cost viral load assays that are currently available and their potential for use in resource-limited settings.
Collapse
Affiliation(s)
- Susan A Fiscus
- University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America.
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Corrigan GE, Hansson EO, Mörner A, Berry N, Källander CFR, Thorstensson R. Reverse transcriptase viral load correlates with RNA in SIV/SHIV-infected macaques. AIDS Res Hum Retroviruses 2006; 22:917-23. [PMID: 16989619 DOI: 10.1089/aid.2006.22.917] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Monitoring of viral load in macaques has usually been carried out using in-house PCR-based methods. A novel viral load (VL) kit (ExaVir Load) based on the measurement of lentivirus reverse transcriptase (RT) activity provides a potential alternative to methods that measure plasma viral RNA. RT is a fundamental and conserved activity of all retroviruses and the method should theoretically detect RT from all lentiviruses. To test this we compared VL measured by a commercially available RT kit with an in-house QC RT-PCR in macaques infected with SIV and SHIV. Both RT and RNA levels were measured over time in both sets of macaques. Results indicated that the relationship between both tests was strong for SIV and SHIV (r = 0.95 and r = 0.92, p < 0.0001, respectively). The VL trends also followed each other, indicating that both techniques measured the same process of viral replication. Furthermore, the RT load obtained using standardized control plasma samples supplied by NIBSC gave values close to the designated VL. However, when comparing RT load with QC RT-PCR a consistently three to five time higher level was obtained with the RT assay, highlighting potential differences in assay calibration. Even so, the data suggest that the RT assay is both sensitive and robust for use in the SIV/SHIV macaque model, particularly where molecular-based assays for SIV VL determinations are not easily available. The assay is also a commercially available kit and hence has the potential to reduce the variability seen between laboratories using in-house PCR.
Collapse
Affiliation(s)
- Gary E Corrigan
- Swedish Institute for Infectious Disease Control, Solna, Sweden., Microbiology Tumorbiology Center, Karolinska Institute, Stockholm, Sweden
| | | | | | | | | | | |
Collapse
|
24
|
Seyoum E, Wolday D, Girma M, Malmsten A, Meselle T, Gronowitz JS, Britton S. Reverse transcriptase activity for quantitation of HIV-1 subtype C in plasma: relation to RNA copy number and CD4 T-cell count. J Med Virol 2006; 78:161-8. [PMID: 16372295 DOI: 10.1002/jmv.20523] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The present study monitored the changes in human immunodeficiency virus (HIV) viral load using a reverse transcriptase (RT) assay and an HIV-1 RNA based assay, and relates these data to the dynamics of CD4 cell counts. The samples examined originate from a prospective study of HIV-1 subtype C infected, untreated Ethiopians followed twice yearly over a period of up to 5 years. The ExaVir Load test, version 1, was used for isolation and quantitation of HIV-1 RT in plasma. The RT activities recovered were compared to the HIV-1 RNA copy numbers, which had been determined previously by the NucliSens HIV-1 QT Test. There was a significant correlation between the data obtained in the two tests (r = 0.65, P < 0.0001). During follow-up, the median RT and RNA levels increased more or less in parallel up to approximately four times the values at admittance. CD4 cell counts, which had also been determined previously, decreased slowly but continuously from approximately 310 to 190 CD4 cells/ml. In the majority of individual patients, there was an inverse correlation between CD4 T-cell counts and RT activity, and with the RNA copy number, and the data obtained by either test could be used to predict CD4 T-cell counts. The ExaVir Load test thus provides data equivalent to the estimation of the number of HIV-1 RNA copies for the prediction of CD4 T-cell counts. It is based on a simple technique, can be run in any routine diagnostic laboratory, and is a competitive alternative for use in resource limited settings.
Collapse
Affiliation(s)
- Elizabeth Seyoum
- Ethio-Netherlands AIDS Research Project (ENARP), Ethiopian Health and Nutrition Research Institute (EHNRI), Addis Ababa, Ethiopia
| | | | | | | | | | | | | |
Collapse
|
25
|
Jennings C, Fiscus SA, Crowe SM, Danilovic AD, Morack RJ, Scianna S, Cachafeiro A, Brambilla DJ, Schupbach J, Stevens W, Respess R, Varnier OE, Corrigan GE, Gronowitz JS, Ussery MA, Bremer JW. Comparison of two human immunodeficiency virus (HIV) RNA surrogate assays to the standard HIV RNA assay. J Clin Microbiol 2006; 43:5950-6. [PMID: 16333081 PMCID: PMC1317157 DOI: 10.1128/jcm.43.12.5950-5956.2005] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human immunodeficiency virus (HIV) RNA testing is the gold standard for monitoring antiretroviral therapy in HIV-infected patients. However, equipment and reagent costs preclude widespread use of the assay in resource-limited settings. The Perkin-Elmer Ultrasensitive p24 assay and the Cavidi Exavir Load assay both offer potentially simpler, less costly technologies for monitoring viral load. These assays were compared to the Roche Amplicor HIV-1 Monitor Test, v1.5, using panels of clinical samples (subtype B) from HIV-positive subjects and HIV-spiked samples (subtypes A, C, D, CRF_01AE, CRF_02AG, and F). The Ultrasensitive p24 assay detected 100% of the spiked samples with virus loads of >250,000 copies/ml and 61% of the clinical samples with virus loads of 219 to 288,850 copies/ml. Detection rates were improved substantially if an external lysis buffer was added to the procedure. The Cavidi assay detected 54 to 100% of spiked samples with virus loads >10,000 copies/ml and 68% of the clinical samples. These detection rates were also greatly improved with a newly implemented version of this kit. Coefficients of variation demonstrate good reproducibility for each of these kits. The results from the Cavidi v1.0, Cavidi v2.0, and Perkin-Elmer, and the Perkin-Elmer Plus external buffers all correlated well with the results from the Roche Monitor Test (r = 0.83 to 0.96, r = 0.84 to 0.99, r = 0.58 to 0.67, and r = 0.59 to 0.95, respectively). Thus, the use of these two assays for monitoring patients, together with less-frequent confirmation testing, offers a feasible alternative to frequent HIV RNA testing in resource-limited settings.
Collapse
Affiliation(s)
- Cheryl Jennings
- Rush Medical College, Department of Immunology/Microbiology, 1653 W. Congress Parkway, Chicago, IL 60612, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Colebunders R, Moses KR, Laurence J, Shihab HM, Semitala F, Lutwama F, Bakeera-Kitaka S, Lynen L, Spacek L, Reynolds SJ, Quinn TC, Viner B, Mayanja-Kizza H. A new model to monitor the virological efficacy of antiretroviral treatment in resource-poor countries. THE LANCET. INFECTIOUS DISEASES 2006; 6:53-9. [PMID: 16377535 DOI: 10.1016/s1473-3099(05)70327-3] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Monitoring the efficacy of antiretroviral treatment in developing countries is difficult because these countries have few laboratory facilities to test viral load and drug resistance. Those that exist are faced with a shortage of trained staff, unreliable electricity supply, and costly reagents. Not only that, but most HIV patients in resource-poor countries do not have access to such testing. We propose a new model for monitoring antiretroviral treatment in resource-limited settings that uses patients' clinical and treatment history, adherence to treatment, and laboratory indices such as haemoglobin level and total lymphocyte count to identify virological treatment failure, and offers patients future treatment options. We believe that this model can make an accurate diagnosis of treatment failure in most patients. However, operational research is needed to assess whether this strategy works in practice.
Collapse
Affiliation(s)
- Robert Colebunders
- Infectious Disease Institute, Faculty of Medicine, Makerere University, Kampala, Uganda.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|