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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.
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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
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Abstract
Microfluidics is an emerging field in diagnostics that allows for extremely precise fluid control and manipulation, enabling rapid and high-throughput sample processing in integrated micro-scale medical systems. These platforms are well-suited for both standard clinical settings and point-of-care applications. The unique features of microfluidics-based platforms make them attractive for early disease diagnosis and real-time monitoring of the disease and therapeutic efficacy. In this chapter, we will first provide a background on microfluidic fundamentals, microfluidic fabrication technologies, microfluidic reactors, and microfluidic total-analysis-systems. Next, we will move into a discussion on the clinical applications of existing and emerging microfluidic platforms for blood analysis, and for diagnosis and monitoring of cancer and infectious disease. Together, this chapter should elucidate the potential that microfluidic systems have in the development of effective diagnostic technologies through a review of existing technologies and promising directions.
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Affiliation(s)
- Alison Burklund
- Thayer School of Engineering, Dartmouth College, Hanover, NH, United States
| | - Amogha Tadimety
- Thayer School of Engineering, Dartmouth College, Hanover, NH, United States
| | - Yuan Nie
- Thayer School of Engineering, Dartmouth College, Hanover, NH, United States
| | - Nanjing Hao
- Thayer School of Engineering, Dartmouth College, Hanover, NH, United States
| | - John X J Zhang
- Thayer School of Engineering, Dartmouth College, Hanover, NH, United States; Norris Cotton Cancer Center, Dartmouth Hitchcock Medical Center, Lebanon, NH, United States.
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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.
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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.
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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.
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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
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Damhorst GL, Watkins NN, Bashir R. Micro- and nanotechnology for HIV/AIDS diagnostics in resource-limited settings. IEEE Trans Biomed Eng 2013; 60:715-26. [PMID: 23512111 DOI: 10.1109/tbme.2013.2244894] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Thirty-four million people are living with HIV worldwide, a disproportionate number of whom live in resource-limited settings. Proper clinical management of AIDS, the disease caused by HIV, requires regular monitoring of both the status of the host's immune system and levels of the virus in their blood. Therefore, more accessible technologies capable of performing a CD4+ T cell count and HIV viral load measurement in settings where HIV is most prevalent are desperately needed to enable better treatment strategies and ultimately quell the spread of the virus within populations. This review discusses micro- and nanotechnology solutions to performing these key clinical measurements in resource-limited settings.
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Affiliation(s)
- Gregory L Damhorst
- Department of Bioengineering and the Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
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Liu T, Hogan JW, Wang L, Zhang S, Kantor R. Optimal Allocation of Gold Standard Testing under Constrained Availability: Application to Assessment of HIV Treatment Failure. J Am Stat Assoc 2013; 108:1173-1188. [PMID: 24672142 DOI: 10.1080/01621459.2013.810149] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The World Health Organization (WHO) guidelines for monitoring the effectiveness of HIV treatment in resource-limited settings (RLS) are mostly based on clinical and immunological markers (e.g., CD4 cell counts). Recent research indicates that the guidelines are inadequate and can result in high error rates. Viral load (VL) is considered the "gold standard", yet its widespread use is limited by cost and infrastructure. In this paper, we propose a diagnostic algorithm that uses information from routinely-collected clinical and immunological markers to guide a selective use of VL testing for diagnosing HIV treatment failure, under the assumption that VL testing is available only at a certain portion of patient visits. Our algorithm identifies the patient sub-population, such that the use of limited VL testing on them minimizes a pre-defined risk (e.g., misdiagnosis error rate). Diagnostic properties of our proposal algorithm are assessed by simulations. For illustration, data from the Miriam Hospital Immunology Clinic (RI, USA) are analyzed.
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Affiliation(s)
- Tao Liu
- Assistant Professor, Department of Biostatistics, Center for Statistical Sciences, Brown University School of Public Health, Providence, RI 02912
| | - Joseph W Hogan
- Professor, Department of Biostatistics, Center for Statistical Sciences, Brown University School of Public Health, Providence, RI 02912
| | - Lisa Wang
- Graduate Student, Department of Biostatistics, Center for Statistical Sciences, Brown University School of Public Health, Providence, RI 02912
| | - Shangxuan Zhang
- Statistical Programmer, Memorial Sloan-Kettering Cancer Center, New York City, NY 10016
| | - Rami Kantor
- Associate Professor of Medicine, Division of Infectious Diseases, the Alpert Medical School of Brown University, Providence, RI 02912
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Tang YW, Ou CY. Past, present and future molecular diagnosis and characterization of human immunodeficiency virus infections. Emerg Microbes Infect 2012; 1:e19. [PMID: 26038427 PMCID: PMC3630918 DOI: 10.1038/emi.2012.15] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Revised: 05/08/2012] [Accepted: 05/21/2012] [Indexed: 12/31/2022]
Abstract
Substantive and significant advances have been made in the last two decades in the characterization of human immunodeficiency virus (HIV) infections using molecular techniques. These advances include the use of real-time measurements, isothermal amplification, the inclusion of internal quality assurance protocols, device miniaturization and the automation of specimen processing. The result has been a significant increase in the availability of results to a high level of accuracy and quality. Molecular assays are currently widely used for diagnostics, antiretroviral monitoring and drug resistance characterization in developed countries. Simple and cost-effective point-of-care versions are also being vigorously developed with the eventual goal of providing timely healthcare services to patients residing in remote areas and those in resource-constrained countries. In this review, we discuss the evolution of these molecular technologies, not only in the context of the virus, but also in the context of tests focused on human genomics and transcriptomics.
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Affiliation(s)
- Yi-Wei Tang
- Memorial Sloan-Kettering Cancer Center , New York, NY 10065, USA
| | - Chin-Yih Ou
- Centers for Disease Control and Prevention , Atlanta, GA 30333, USA
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Abstract
Two hundred HIV-exposed Kenyan infants were tested for HIV infection at birth and at age 6, 12, 24 and 48 weeks, by DNA polymerase chain reaction (PCR) and Cavidi reverse transcriptase (RT) assays and after age 18 months by HIV antibody test. Eleven (5.5%) infants became HIV infected. In 6 infants, positive RT preceded positive DNA PCR. The use of RT assay may facilitate earlier HIV diagnosis in infants.
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Balakrishnan P, Iqbal HS, Shanmugham S, Mohanakrishnan J, Solomon SS, Mayer KH, Solomon S. Low-cost assays for monitoring HIV infected individuals in resource-limited settings. Indian J Med Res 2011; 134:823-34. [PMID: 22310816 PMCID: PMC3284092 DOI: 10.4103/0971-5916.92628] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Indexed: 11/23/2022] Open
Abstract
Use of a combination of CD4 counts and HIV viral load testing in the management of antiretroviral therapy (ART) provides higher prognostic estimation of the risk of disease progression than does the use of either test alone. The standard methods to monitor HIV infection are flow cytometry based for CD4+ T cell count and molecular assays to quantify plasma viral load of HIV. Commercial assays have been routinely used in developed countries to monitor ART. However, these assays require expensive equipment and reagents, well trained operators, and established laboratory infrastructure. These requirements restrict their use in resource-limited settings where people are most afflicted with the HIV-1 epidemic. With the advent of low-cost and/or low-tech alternatives, the possibility of implementing CD4 count and viral load testing in the management of ART in resource-limited settings is increasing. However, an appropriate validation should have been done before putting them to use for patient testing.
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Affiliation(s)
- Pachamuthu Balakrishnan
- YRG Centre for AIDS Research & Education, Voluntary Health Services, Taramani, Chennai, India.
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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]
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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.
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Affiliation(s)
- Paul Stewart
- The University of North Carolina at Chapel Hill, Department of Biostatistics, Chapel Hill, NC 27599-7420, USA. paul
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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.
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Affiliation(s)
- Sonia Napravnik
- Department of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
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