Next Article in Journal
Molecular Epidemiology of HIV-1 in Ghana: Subtype Distribution, Drug Resistance and Coreceptor Usage
Next Article in Special Issue
Whole-Genome Analysis of Influenza A(H3N2) and B/Victoria Viruses Detected in Myanmar during the COVID-19 Pandemic in 2021
Previous Article in Journal
Secular Trends of Clinical Characteristics and Survival of Hepatocellular Carcinoma in Taiwan from 2011 to 2019
Previous Article in Special Issue
Influenza A Outbreaks in Two Professional Ice Hockey Teams during COVID-19 Epidemic
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Viruses
Volume 15
Issue 1
10.3390/v15010129
viruses-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles thumb_up
...
Endorse textsms
...
Comment
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Development and Validation of a Rapid Screening Test for HTLV-I IgG Antibodies

by
Bobby Brooke Herrera
1,2,3,*,
Rafaela Mayoral
4 and
Carlos Brites
4
1
Division of Allergy, Immunology, Infectious Diseases, Department of Medicine, Child Health Institute of New Jersey, Rutgers Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ 08901, USA
2
Rutgers Global Health Institute, Rutgers University, New Brunswick, NJ 08901, USA
3
Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA
4
Universidade Federal da Bahia, Salvador 40170-110, Brazil
*
Author to whom correspondence should be addressed.
Viruses 2023, 15(1), 129; https://doi.org/10.3390/v15010129
Submission received: 17 November 2022 / Revised: 26 December 2022 / Accepted: 29 December 2022 / Published: 31 December 2022
(This article belongs to the Special Issue Diagnostic Virology during the COVID-19 Pandemic - Business as Usual)
Browse Figures
Review Reports Versions Notes

Abstract

:
Initial diagnosis of human T cell lymphotropic virus (HTLV) infections is mainly based by detecting antibodies in plasma or serum using laboratory-based methods. The aim of this study was to develop and evaluate a rapid screening test for HTLV-I antibodies. Our rapid screening test uses HTLV-I p24 antigen conjugated to gold nanoparticles and an anti-human IgG antibody immobilized to a nitrocellulose strip to detect human HTLV-I p24-specific IgG antibodies via immunochromatography. Performance of the rapid screening test for HTLV-I was conducted on a total of 118 serum specimens collected in Salvador, Bahia, the epicenter for HTLV-1 infection in Brazil. Using a Western blot test as the comparator, 55 serum specimens were HTLV-I positive, 5 were HTLV-I and HTLV-II positive, and 58 were negative. The sensitivity of the rapid screening test for HTLV-1 was 96.7% and the specificity was 100%. The rapid screening test did not show cross-reaction with serum specimens from individuals with potentially interfering infections including those caused by HTLV-II, HIV-I, HIV-II, hepatitis A virus, hepatitis B virus, hepatitis C virus, herpes simplex virus, Epstein–Barr virus, SARS-CoV-2, Chlamydia trachomatis, Neisseria gonorrhoeae, Treponema pallidum, Toxoplasma gondii, and Plasmodium falciparum. The rapid screening test also did not show cross-reaction with potentially interfering substances. Strategies for HTLV diagnosis in non- and high-endemic areas can be improved with low-cost, rapid screening tests.

1. Introduction

Human T cell lymphotropic virus (HTLV) was the first retrovirus to be discovered in humans [1]. While four HTLV viruses (types I to IV) have been identified, only HTLV-I and HTLV-II have been demonstrably linked to human disease [1,2,3,4]. HTLV-I is the causative agent of Adult T cell leukemia (ATL) and HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP), and other diseases [5]. HTLV-II generally causes no signs or symptoms; however, some individuals infected by HTLV-II can later develop neurological conditions and/or chronic lung infections [6,7]. HTLV-I and HTLV-II are spread globally, with high HTLV-I endemicity in Japan, Oceania, the Middle East, the Caribbean, and parts of South America (e.g., Brazil) and Africa [8,9,10,11].
HTLV is transmitted primarily via mother-to-child routes, sexual contact, and through contaminated needles shared among drug users [12,13,14]. HTLV infections can also occur through transfusion of infected blood specimens or organ transplantation [15,16]. To mitigate these risks, most developed and several developing countries have implemented protocols to screen blood products for HTLV-I/II [17,18]. However, in many countries where HTLV is considered non-endemic, limited screening occurs.
A number of laboratory-based kits that use synthetic peptides and/or viral lysates are commercially available for initial diagnosis of HTLV infections. These kits use various detection techniques including Western blot (WB), enzyme-linked immunosorbent assay (ELISA), or electrochemiluminescent immunoassay (ECLIA) and CLIA to capture HTLV-I/II antibodies in serum or plasma [19]. However, these kits often have decreased accuracy, especially in low prevalence populations, or fail to differentiate between HTLV-I and HTLV-II because the two virus types share high sequence homology [20,21]. In 2014, the FDA approved the MP Diagnostics HTLV Blot 2.4 test, which uses a combination of recombinant HTLV-I/II proteins and HTLV-I viral lysate. Using the MP Diagnostic HTLV Blot 2.4 test, several studies found many WB-indeterminate results in specific population groups including low-risk blood donors [22,23,24]. To reduce the number of inconclusive WB results, other confirmatory tests have been developed including serological (e.g., INNO-LIA HTLV) or molecular assays (e.g., quantitative polymerase chain reaction, qPCR) with higher accuracy [25,26,27].
There is a need for low-cost, non-laboratory-based methods to detect HTLV infections. The aim of this study was to develop and evaluate a rapid screening test for HTLV-I antibodies. The evaluation included cross-reaction analysis using serum specimens from individuals with potentially interfering infections and other potentially interfering substances. Performance of the rapid screening test for HTLV-I was conducted using well-characterized serum specimens collected from individuals in Salvador, Bahia, the epicenter for HTLV-I infection in Brazil [28].

2. Methods

2.1. Clinical Samples

A total of 118 serum specimens were collected from individuals in Salvador, Bahia, Brazil and initially characterized by a single person using the MP Diagnostics HTLV Blot 2.4 test (MP Biomedicals Asia Pacific Pte Ltd., 2 Pioneer Pl, Singapore, 627885), according to the manufacturer’s instructions. 55 individuals were confirmed HTLV-I positive, 5 were confirmed HTLV-I and HTLV-II positive, and 58 were confirmed negative. Of the 60 HTLV positive individuals, 36 were asymptomatic and 24 were symptomatic. The symptomatic individuals had mild to moderate neurological disease, and none were wheelchair-restricted.
The primary studies under which the serum samples were collected received ethical clearance from the Maternidade Climério de Oliveira (Universidade Federal da Bahia–UFBA) Institutional Review Board (IRB) (approval number: 4.029.414, 15 May 2020). Formal written consent was obtained from all participants, all excess samples were cryopreserved at −80 °C. Prior to analyses, samples were de-identified, thawed, blinded, then immediately processed and results called by a second person. This study received an exemption determination from the UFBA IRB.

2.2. Antigen Conjugation to Nanoparticles

HTLV-I p24 antigen (Abcam, Waltham, MA, USA) was conjugated to gold nanoparticles (Abcam, Waltham, MA, USA) according to the manufacturer’s instructions. Briefly, the antigen was diluted to 0.2 mg/mL in supplied dilution buffer. Next, 12 μL of diluted antigen was mixed with 42 μL reaction buffer. 45 μL of the mix was then used to suspend the lyophilized gold nanoparticles. The antigen-nanoparticle mix was incubated for 15 min at room temperature, followed by the addition of 5 μL of supplied quencher solution to stop the coupling reaction. After adding the quencher solution, 100 μL of 1% Tween-20 (MilliporeSigma, Burlington, MA, USA) in PBS (MilliporeSigma, Burlington, MA, USA) and 50 μL of 50% sucrose (MilliporeSigma, Burlington, MA, USA) in water were added to the gold conjugate prior to use in immunochromatography.

2.3. Antibody Application to Nitrocellulose Membranes

Nitrocellulose membrane was cut into strips using a laser cutter (Universal Laser Systems, model VLS2.30; 30 watt) at 30% power and 90% speed. Strips were attached to a wick (MilliporeSigma, Burlington, MA, USA) with adhesive paper (DCN Diagnostics, Carlsbad, CA, USA). For the control area, 0.33 μL of anti-HTLV-I p24 antibody (ThermoFisher, Waltham, MA, USA) at 2 mg/mL was spotted on the control area. The test area on the nitrocellulose was generated by pipetting 0.33 μL of anti-human IgG at 6 mg/mL. Strips were air dried and stored in a desiccator at room temperature before use.

2.4. Immunochromatography

Each immunochromatography strip was run in a separate microcentrifuge tube. The rapid test solution contained 40 μL of serum specimen, 10 μL of fetal calf serum, 5 μL of quencher solution, and 20 μL of conjugate gold nanoparticle mix. The strips were allowed to react with the mixture for 20 min and then dried and results were image captured using a mobile phone device.

2.5. Cross-Reaction Analysis

Serum samples from HTLV-I, HTLV-II, HIV-I, HIV-II, hepatitis A virus, hepatitis B virus, hepatitis C virus, herpes simplex virus, Epstein–Barr virus, SARS-CoV-2, Chlamydia trachomatis, Neisseria gonorrhoeae, Treponema pallidum, Toxoplasma gondii, and Plasmodium falciparum infections were purchased (LabCorp, Burlington, NC, USA). 40 μL of each serum specimen was processed according to the immunochromatography section in this manuscript.

2.6. Interfering Substances Analysis

10 serum specimens were spiked with either sodium heparin (MilliporeSigma, Burlington, MA, USA), sodium citrate (MilliporeSigma, Burlington, MA, USA), EDTA (MilliporeSigma, Burlington, MA, USA), or ACD solution A (MilliporeSigma, Burlington, MA, USA), and 40 μL of each serum specimen was then processed according to the immunochromatography section in this manuscript.

2.7. Reproducibility Analysis

The 10 serum specimens from HTLV-I infections were processed in replicates of 5 according to the immunochromatography section in this manuscript.

2.8. Image Analysis

The rapid screening test results were machine-read by ImageJ (NIH) to quantify the HTLV-I p24 IgG signals. The average pixel intensity was quantified at the control, background, and test areas. The background-adjusted IgG signal was then normalized to the background-subtracted control area and expressed as % of control. Plots of signals were generated using Prism (version 9.0.0).

2.9. Performance Analysis

The sensitivity, specificity, and positive and negative predictive values were calculated using the MedCalc Software (MedCalc Software Ltd., Ostend, Belgium) and are expressed as percentages. In short, sensitivity (or the true positive rate), is the probability that the rapid screening test for HTLV will be positive when the disease is present. While the specificity (or the true negative rate) is the probability that the rapid screening test will be negative when the disease is not present. Using results from both the MP Diagnostics HTLV Blot 2.4 test as the comparator and the rapid screening test for HTLV, we then calculated the sensitivity as the true positives/(true positives + false negatives) and the specificity as true negatives/(false positives + true negatives). Confidence intervals for sensitivity and specificity are “exact” Clopper-Pearson confidence intervals. Confidence intervals for the predictive values are the standard logit confidence intervals.

3. Results

To evaluate the rapid screening test for HTLV-I, we compared the sensitivity and specificity using serum specimens collected from individuals with or without HTLV-I and/or HTLV-II in Salvador, Bahia, Brazil. A total of 118 serum specimens were included in the analysis. Using the MP Diagnostics HTLV Blot 2.4 test as the comparator test, 55 serum specimens were confirmed HTLV-I positive, 5 were confirmed HTLV-I and HTLV-II positive, and 58 were confirmed negative (Table 1). Among the HTLV-I positive individuals, 53 of 55 had antibodies against HTLV p19, p24, p26, p28, p32, p36, p53, GD21, and rpg46-I; whereas one individual only had antibodies against p19, p24, GD21, and rpg46-I and the other individual only had antibodies against p19, GD21, and rpg46-I. All 5 HTLV-I and HTLV-II positive individuals had antibodies against p19, p24, p26, p28, p32, p36, p53, GD21, rpg46-I, and rpg46-II. All 58 negative individuals were non-reactive by the MP Diagnostics HTLV Blot 2.4 test.
The rapid screening test had a sensitivity of 96.7% (58/60) and a specificity of 100.0% (58/58) (Table 2, Figure 1 and Figure 2), with positive and negative predictive values of 100.0% and 98.2%, respectively. The test did not detect IgG antibodies against HTLV-I p24 in the two individuals that tested positive by the MP Diagnostics HTLV Blot 2.4 test for HTLV antibodies against p19, GD21, and rpg46-I or p19, p24, GD21, and rpg46-I (patients 51 and 57) (Figure 1A and Figure 2A). The rapid screening test did not detect IgG antibodies against HTLV-p24 in any of the HTLV-I negative individuals confirmed by the MP Diagnostics HTLV Blot 2.4 test (Figure 1B and Figure 2B). Altogether, these results confirm the potential use of a rapid screening test for HTLV-I.
To determine whether the rapid screening test for HTLV-I cross-reacted with antibodies against potentially interfering pathogens, we tested individual serum specimens from infections caused by HTLV-I, HTLV-II, HIV-I, HIV-II, hepatitis A virus, hepatitis B virus, hepatitis C virus, herpes simplex virus, Epstein–Barr virus, SARS-CoV-2, Chlamydia trachomatis, Neisseria gonorrhoeae, Treponema pallidum, Toxoplasma gondii, and Plasmodium falciparum. The rapid screening test reacted to 10 individual serum specimens from HTLV-I infections, but the test did not react with any other serum specimens from other infections (Table 3, Figure 3). Next, we tested 40 serum specimens spiked with either sodium heparin, sodium citrate, EDTA, or ACD solution A. The rapid screening test for HTLV-I antibodies, did not react with any of the potentially interfering substances (Table 3, Figure 3). The 10 serum specimens from HTLV-I infections were then tested for reproducibility, whereby each specimen was run in replicates of 5. The overall reproducibility of the rapid screening test for HTLV-I was 100% (50/50) (Table 4).

4. Discussion

HTLV-I seroprevalence data has largely been based on known endemic regions, with a scarcity of reliable estimates from highly populated countries. The most recent global estimates for the total number of people living with HTLV-I ranges from 5 to 10 million; however, infection counts are likely undercounted [8]. The distribution of HTLV-I infection continues to be focal, with known areas of high prevalence in Japan, Oceania, the Middle East, the Caribbean, and parts of South America and Africa [29]. To complicate the issue further, laboratory-based methods to screen and diagnose HTLV-I infection have been diverse and change over time, limiting the ability to systematically collect infection and associated disease estimates, especially in resource-limited regions [29].
Under current testing strategies, to screen and diagnose HTLV-I infection requires an algorithm involving two to three different laboratory-based assays [19]. Most of the assays used to screen HTLV-I infection detect antibodies in serum or plasma [20,21]. Molecular-based tests have been developed, although are not commercially available, and are used primarily to confirm the presence of HTLV-I nucleic acid sequences [26,27]. Even in high-income settings, there is a lack of accessible testing technologies for HTLV-I. The World Health Organization and the Pan American Health Organization have identified as a priority the need to develop low-cost, non-laboratory-based tests for HTLV-I screening [29,30].
For this study, we developed a rapid screening test for HTLV-I antibodies. The test uses HTLV-I p24 antigen conjugated to gold nanoparticles and an anti-human IgG antibody immobilized to a nitrocellulose strip to detect human HTLV-I p24-specific IgG antibodies via immunochromatography (Figure 4). The current cost to produce the test is $5 USD, although with scaled manufacturing the price should decrease significantly. In general, a manufacturing cost of public health screening tests should ideally be near $1 USD.
To analytically validate the rapid screening test, we conducted cross-reaction studies with potentially interfering infections. The test did not show cross-reaction with potentially interfering infections including those caused by HTLV-II, HIV-I, HIV-II, hepatitis A virus, hepatitis B virus, hepatitis C virus, herpes simplex virus, Epstein–Barr virus, SARS-CoV-2, Chlamydia trachomatis, Neisseria gonorrhoeae, Treponema pallidum, Toxoplasma gondii, and Plasmodium falciparum. We then conducted additional cross-reaction studies with potentially interfering substances including sodium heparin, sodium citrate, EDTA, or ACD solution A. Similarly, the test did not show any cross-reaction with serum spiked with the substances. To determine reproducibility, we ran 10 independent serum specimens from HTLV-I infections in replicates of 5. The rapid screening test reacted 100% of the time.
Next, we performed a clinical evaluation of the rapid screening test in serum specimens collected from individuals in Salvador, Bahia, Brazil. Using the FDA-approved MP Diagnostics HTLV Blot 2.4 test as the comparator test, 55 serum specimens were confirmed HTLV-I positive, 5 were confirmed HTLV-I and HTLV-II positive, and 58 were confirmed negative. When the serum specimens were processed via the rapid screening test, the sensitivity and specificity of the assay was 96.7% and 100%, respectively. The rapid test did not react in serum specimens in two HTLV-I positive individuals; one of the individuals was not HTLV p24 positive by the MP Diagnostics HTLB Blot 2.4 test, however, the other individual did have p24 antibodies. Our analytical and clinical results demonstrate high sensitivity and specificity, potentially enabling lower-cost, more efficient HTLV-I screening.
There were several limitations to this study. Future work should broaden the evaluation to additional settings, sample types, and disease states. While we used serum as the primary sample type, a point-of-care test for HTLV should be optimized for use with fingerstick whole blood, which will further simplify the screening process. Our analysis included 36 asymptomatic and 24 symptomatic HTLV-infected individuals. Regardless of disease state, the rapid screening test performed with high sensitivity and specificity. However, testing should be expanded on HTLV-infected individuals with HAM/TSP. There were two HTLV-I positive samples that were negative by the rapid screening test. These samples demonstrated seroconversion by the comparator assay, where one sample had HTLV-I p24 antibodies, but the other did not. Performance testing on prospectively collected samples in larger cohorts will further corroborate preliminary findings; additionally, evaluations should include testing using seroconverter specimens. Finally, development of a rapid screening test for HTLV-II antibodies should be considered. While the rapid screening test did not cross-react with serum specimens from HTLV-II infections in our analytical studies, more robust testing is warranted.
Without a vaccine and with limited available treatment options for HTLV-related diseases, it is critical to be able to easily identify those who are infected in both endemic and non-endemic regions. While current screening and diagnostic methods for HTLV infection have been shown to be relatively effective, there are no tests that can be performed outside of a laboratory, challenging widescale surveillance and seroprevalence estimates. Screening of HTLV infection, therefore, requires inexpensive, rapid, and accurate non-laboratory-based technology that can be scaled and performed globally. Immunochromatographic, serological-based tests fit these needs.

Author Contributions

Conceptualization: B.B.H. and C.B. Methodology: B.B.H., R.M. and C.B. Validation: B.B.H., R.M. and C.B. Formal Analysis: B.B.H., R.M. and C.B. Investigation: B.B.H., R.M. and C.B. Data Curation: B.B.H., R.M. and C.B. Writing—Original Draft Preparation: B.B.H. Writing—Review and Editing: B.B.H., R.M. and C.B. Visualization: B.B.H., R.M. and C.B. Supervision: B.B.H. and C.B. Funding Acquisition: B.B.H. and C.B. All authors have read and agreed to the published version of the manuscript.

Funding

The work presented in this study was funded by the Brazilian Council for Scientific Research (CNPq), grant # 311095/2020-8. The funder was not involved in the study design, collection, analysis, interpretation of data, the writing of this article or the decision to submit it for publication.

Institutional Review Board Statement

The study was conducted in accordance with the Maternidade Climério de Oliveira (Universidade Federal da Bahia–UFBA) Institutional Review Board (IRB) (approval number: 4.029.414, 15 May 2020) for studies involving humans.

Informed Consent Statement

Informed consent was obtained from all subjects involved in the study.

Data Availability Statement

All data produced in the present study are available upon reasonable request to the corresponding author.

Conflicts of Interest

BBH is a co-founder of Mir Biosciences, Inc., a company that develops T cell-based diagnostics/vaccines for infections, cancer, autoimmunity.

References

  1. Poiesz, B.J.; Ruscetti, F.W.; Gazdar, A.F.; Bunn, P.A.; Minna, J.D.; Gallo, R.C. Detection and isolation of type C retrovirus particles from fresh and cultured lymphocytes of a patient with cutaneous T-cell lymphoma. Proc. Natl. Acad. Sci. USA 1980, 77, 7415–7419. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  2. Kalyanaraman, V.S.; Sarngadharan, M.G.; Robert-Guroff, M.; Miyoshi, I.; Golde, D.; Gallo, R.C. A new subtype of human T-cell leukemia virus (HTLV-II) associated with a T-cell variant of hairy cell leukemia. Science 1982, 218, 571–573. [Google Scholar] [CrossRef] [PubMed]
  3. Calattini, S.; Chevalier, S.A.; Duprez, R.; Bassot, S.; Froment, A.; Mahieux, R.; Gessain, A. Discovery of a new human T-cell lymphotropic virus (HTLV-3) in Central Africa. Retrovirology 2005, 2, 30. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  4. Wolfe, N.D.; Heneine, W.; Carr, J.K.; Garcia, A.D.; Shanmugam, V.; Tamoufe, U.; Torimiro, J.N.; Prosser, A.T.; Lebreton, M.; Mpoudi-Ngole, E.; et al. Emergence of unique primate T-lymphotropic viruses among central African bushmeat hunters. Proc. Natl. Acad. Sci. USA 2005, 102, 7994–7999. [Google Scholar] [CrossRef] [Green Version]
  5. Verdonck, K.; Gonzalez, E.; Van Dooren, S.; Vandamme, A.M.; Vanham, G.; Gotuzzo, E. Human T-lymphotropic virus 1: Recent knowledge about an ancient infection. Lancet Infect. Dis. 2007, 7, 266–281. [Google Scholar] [CrossRef]
  6. Araujo, A.; Hall, W.W. Human T-lymphotropic virus type II and neurological disease. Ann. Neurol. 2004, 56, 10–19. [Google Scholar] [CrossRef]
  7. Murphy, E.L.; Ownby, H.E.; Smith, J.W.; Garratty, G.; Hutching, S.T.; Wu, Y.; Ameti, D.I. Pulmonary function testing in HTLV-I and HTLV-II infected humans: A cohort study. BMC Pulm. Med. 2003, 3, 1. [Google Scholar] [CrossRef] [Green Version]
  8. Gessain, A.; Cassar, O. Epidemiological Aspects and World Distribution of HTLV-1 Infection. Front. Microbiol. 2012, 3, 388. [Google Scholar] [CrossRef] [Green Version]
  9. de The, G.; Bomford, R. An HTLV-I vaccine: Why, how, for whom? AIDS Res. Hum. Retrovir. 1993, 9, 381–386. [Google Scholar] [CrossRef]
  10. Proietti, F.A.; Carneiro-Proietti, A.B.; Catalan-Soares, B.C.; Murphy, E.L. Global epidemiology of HTLV-I infection and associated diseases. Oncogene 2005, 24, 6058–6068. [Google Scholar] [CrossRef]
  11. Watanabe, T. Current status of HTLV-1 infection. Int. J. Hematol. 2011, 94, 430–434. [Google Scholar] [CrossRef] [PubMed]
  12. Sugiyama, H.; Doi, H.; Yamaguchi, K.; Tsuji, Y.; Miyamoto, T.; Hino, S. Significance of postnatal mother-to-child transmission of human T-lymphotropic virus type-I on the development of adult T-cell leukemia/lymphoma. J. Med. Virol. 1986, 20, 253–260. [Google Scholar] [CrossRef] [PubMed]
  13. Paiva, A.; Casseb, J. Sexual transmission of human T-cell lymphotropic virus type 1. Rev. Soc. Bras. Med. Trop. 2014, 47, 265–274. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  14. Khabbaz, R.F.; Onorato, I.M.; Cannon, R.O.; Hartley, T.M.; Roberts, B.; Hosein, B.; Kaplan, J.E. Seroprevalence of HTLV-1 and HTLV-2 among intravenous drug users and persons in clinics for sexually transmitted diseases. N. Engl. J. Med. 1992, 326, 375–380. [Google Scholar] [CrossRef] [PubMed]
  15. Okochi, K.; Sato, H. Transmission of ATLV (HTLV-I) through Blood Transfusion. In Retroviruses in human lymphoma/leukemia; Japan Scientific Society Press: Tokyo, Japan, 1984; Volume 15, pp. 129–135. [Google Scholar]
  16. Gout, O.; Baulac, M.; Gessain, A.; Semah, F.; Saal, F.; Peries, J.; Cabrol, C.; Foucault-Fretz, C.; Laplane, D.; Sigaux, F.; et al. Rapid development of myelopathy after HTLV-I infection acquired by transfusion during cardiac transplantation. N. Engl. J. Med. 1990, 322, 383–388. [Google Scholar] [CrossRef]
  17. Williams, A.E.; Fang, C.T.; Slamon, D.J.; Poiesz, B.J.; Sandler, S.G.; Darr, W.F., 2nd; Shulman, G.; McGowan, E.I.; Douglas, D.K.; Bowman, R.J.; et al. Seroprevalence and epidemiological correlates of HTLV-I infection in U.S. blood donors. Science 1988, 240, 643–646. [Google Scholar] [CrossRef] [PubMed]
  18. Inaba, S.; Sato, H.; Okochi, K.; Fukada, K.; Takakura, F.; Tokunaga, K.; Kiyokawa, H.; Maeda, Y. Prevention of transmission of human T-lymphotropic virus type 1 (HTLV-1) through transfusion, by donor screening with antibody to the virus. One-year experience. Transfusion 1989, 29, 7–11. [Google Scholar] [CrossRef] [PubMed]
  19. Ji, H.; Chang, L.; Yan, Y.; Jiang, X.; Sun, H.; Guo, F.; Wang, L. A Strategy for Screening and Confirmation of HTLV-1/2 Infections in Low-Endemic Areas. Front. Microbiol. 2020, 11, 1151. [Google Scholar] [CrossRef]
  20. Andersson, S.; Thorstensson, R.; Ramirez, K.G.; Krook, A.; von Sydow, M.; Dias, F.; Biberfeld, G. Comparative evaluation of 14 immunoassays for detection of antibodies to the human T-lymphotropic virus types I and II using panels of sera from Sweden and West Africa. Transfusion 1999, 39, 845–851. [Google Scholar] [CrossRef]
  21. da Silva Brito, V.; Santos, F.L.N.; Goncalves, N.L.S.; Araujo, T.H.A.; Nascimento, D.S.V.; Pereira, F.M.; Boa-Sorte, N.C.A.; Grassi, M.F.R.; Caterino-de-Araujo, A.; Galvao-Castro, B. Performance of Commercially Available Serological Screening Tests for Human T-Cell Lymphotropic Virus Infection in Brazil. J. Clin. Microbiol. 2018, 56, e00961-18. [Google Scholar] [CrossRef]
  22. Mahieux, R.; Horal, P.; Mauclere, P.; Mercereau-Puijalon, O.; Guillotte, M.; Meertens, L.; Murphy, E.; Gessain, A. Human T-cell lymphotropic virus type 1 gag indeterminate western blot patterns in Central Africa: Relationship to Plasmodium falciparum infection. J. Clin. Microbiol. 2000, 38, 4049–4057. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  23. Ando, Y.; Ekuni, Y.; Matsumoto, Y.; Nakano, S.; Saito, K.; Kakimoto, K.; Tanigawa, T.; Kawa, M.; Toyama, T. Long-term serological outcome of infants who received frozen-thawed milk from human T-lymphotropic virus type-I positive mothers. J. Obstet. Gynaecol. Res. 2004, 30, 436–438. [Google Scholar] [CrossRef] [PubMed]
  24. Yao, K.; Hisada, M.; Maloney, E.; Yamano, Y.; Hanchard, B.; Wilks, R.; Rios, M.; Jacobson, S. Human T lymphotropic virus types I and II western blot seroindeterminate status and its association with exposure to prototype HTLV-I. J. Infect. Dis. 2006, 193, 427–437. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  25. Zrein, M.; Louwagie, J.; Boeykens, H.; Govers, L.; Hendrickx, G.; Bosman, F.; Sablon, E.; Demarquilly, C.; Boniface, M.; Saman, E. Assessment of a new immunoassay for serological confirmation and discrimination of human T-cell lymphotropic virus infections. Clin. Diagn. Lab. Immunol. 1998, 5, 45–49. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  26. Montanheiro, P.; Olah, I.; Fukumori, L.M.; Smid, J.; Oliveira, A.C.; Kanzaki, L.I.; Fonseca, L.A.; Duarte, A.J.; Casseb, J. Low DNA HTLV-2 proviral load among women in Sao Paulo City. Virus Res. 2008, 135, 22–25. [Google Scholar] [CrossRef] [PubMed]
  27. Campos, K.R.; Gonçalves, M.G.; Caterino-de-Araujo, A. Failures in detecting HTLV-1 and HTLV-2 in patients infected with HIV-1. AIDS Res. Hum. Retrovir. 2017, 33, 382–385. [Google Scholar] [CrossRef]
  28. Nunes, D.; Boa-Sorte, N.; Grassi, M.F.R.; Taylor, G.P.; Teixeira, M.G.; Barreto, M.L.; Dourado, I.; Galvao-Castro, B. HTLV-1 is predominantly sexually transmitted in Salvador, the city with the highest HTLV-1 prevalence in Brazil. PloS ONE 2017, 12, e0171303. [Google Scholar] [CrossRef]
  29. World Health Organization. Human T-lymphotropic Virus Type 1: Technical Report; WHO: Geneva, Switzerland, 2021. [Google Scholar]
  30. Pan American Health Organization. International Health Policy Forum for the Elimination of HTLV: Meeting Report; PAHO: Washington, DC, USA, 2021. [Google Scholar]
Viruses 15 00129 g001 550
Figure 1. Screening rapid test performance on HTLV-I positive, HTLV-I and HTLV-II positive, or negative serum specimens collected in Salvador, Bahia, Brazil. Serum specimens collected from (A) HTLV-I or HTLV-I and HTLV-II infected individuals (n = 60) or (B) HTLV negative individuals (n = 58) were processed by the rapid screening test, then image captured.
Figure 1. Screening rapid test performance on HTLV-I positive, HTLV-I and HTLV-II positive, or negative serum specimens collected in Salvador, Bahia, Brazil. Serum specimens collected from (A) HTLV-I or HTLV-I and HTLV-II infected individuals (n = 60) or (B) HTLV negative individuals (n = 58) were processed by the rapid screening test, then image captured.
Viruses 15 00129 g001
Viruses 15 00129 g002 550
Figure 2. Image analysis of the rapid screening test for HTLV-I. The HTLV p24-specific IgG signal from the rapid screening test was determined and plotted as a % of control for individuals who tested (A) positive or (B) negative by the comparator test. The y-axis corresponds to the background subtracted IgG signal normalized to the control for each test. Dashed line, cutoff.
Figure 2. Image analysis of the rapid screening test for HTLV-I. The HTLV p24-specific IgG signal from the rapid screening test was determined and plotted as a % of control for individuals who tested (A) positive or (B) negative by the comparator test. The y-axis corresponds to the background subtracted IgG signal normalized to the control for each test. Dashed line, cutoff.
Viruses 15 00129 g002
Viruses 15 00129 g003 550
Figure 3. Representative image of the rapid screening test in cross-reaction studies with potentially interfering infections and substances. Serum specimens collected from infected individuals or spiked with substances were processed by the rapid screening test for HTLV-I then image captured. HAV, hepatitis A virus; HBV, hepatitis B virus; HCV, hepatitis C virus; HSC, herpes simplex virus; EBV, Epstein–Barr virus.
Figure 3. Representative image of the rapid screening test in cross-reaction studies with potentially interfering infections and substances. Serum specimens collected from infected individuals or spiked with substances were processed by the rapid screening test for HTLV-I then image captured. HAV, hepatitis A virus; HBV, hepatitis B virus; HCV, hepatitis C virus; HSC, herpes simplex virus; EBV, Epstein–Barr virus.
Viruses 15 00129 g003
Viruses 15 00129 g004 550
Figure 4. Schematic of the rapid screening test for HTLV-I. The test uses HTLV-I p24 antigen conjugated to gold nanoparticles and an anti-human IgG antibody immobilized to a nitrocellulose strip at the “Test” area to detect human HTLV-I p24-specific IgG antibodies via immunochromatography. An HTLV-I p24-specific antibody is also immobilized to the nitrocellulose strip at the “Control” area to assess flow of the patient sample and manufacturing of the product.
Figure 4. Schematic of the rapid screening test for HTLV-I. The test uses HTLV-I p24 antigen conjugated to gold nanoparticles and an anti-human IgG antibody immobilized to a nitrocellulose strip at the “Test” area to detect human HTLV-I p24-specific IgG antibodies via immunochromatography. An HTLV-I p24-specific antibody is also immobilized to the nitrocellulose strip at the “Control” area to assess flow of the patient sample and manufacturing of the product.
Viruses 15 00129 g004
Table
Table 1. MP Diagnostics Blot 2.4 Test and Rapid Screening Test for HTLV-I test results from serum specimens collected in Salvador, Bahia, Brazil.
Table 1. MP Diagnostics Blot 2.4 Test and Rapid Screening Test for HTLV-I test results from serum specimens collected in Salvador, Bahia, Brazil.
Infection(s)NumberMP Diagnostics Blot 2.4 TestRapid Screening Test
p19, p24, p26, p28, p32, p36, p53, GD21, and rpg46-Ip19, p24, GD21,
and rpg46-I		p19, GD21,
and rpg46I		p19, p24, p26, p28, p32, p36, p53, GD21, rpg46-I, and rpg46-IIp24
HTLV-I5553/55 (96.4%)1/55 (1.8%)1/55 (1.8%)-53/55 (96.4)
HTLV-I/HTLV-II5---5/5 (100.0%)5/5 (100.0%)
Negative58----0/58 (0.0%)
Table
Table 2. Performance statistics of Rapid Screening Test for HTLV-I.
Table 2. Performance statistics of Rapid Screening Test for HTLV-I.
StatisticValue95%
Confidence Interval
Sensitivity96.4%87.5% to 99.6%
Specificity100.0%93.8% to 100.0%
Positive Predictive Value100.0%-
Negative Predictive Value98.2%88.2% to 99.1%
Table
Table 3. Cross-reaction studies with potentially interfering infections and substances.
Table 3. Cross-reaction studies with potentially interfering infections and substances.
Potentially
Interfering Infections		ReactiveNon-Reactive
HTLV-I10/100/10
HTLV-II0/1010/10
HIV-10/1010/10
HIV-20/1010/10
Hepatitis A Virus0/1010/10
Hepatitis B Virus0/1010/10
Hepatitis C Virus0/1010/10
Herpes Simplex Virus0/1010/10
Epstein–Barr Virus0/1010/10
SARS-CoV-2 (COVID-19)0/1010/10
C. trachomatis (chlamydia)0/1010/10
N. gonorrhoeae (gonorrhea)0/1010/10
T. pallidum (syphilis)0/1010/10
T. gondii (toxoplasmosis)0/1010/10
P. falciparum (malaria)0/1010/10
Potentially
Interfering Substances		ReactiveNon-Reactive
Sodium Heparin0/1010/10
Sodium Citrate0/1010/10
EDTA0/1010/10
ACD Solution A0/1010/10
Table
Table 4. Reproducibility studies with HTLV-I serum specimens.
Table 4. Reproducibility studies with HTLV-I serum specimens.
HTLV-1
Reproducibility		ReactiveNon-Reactive
Serum Specimen 15/50/5
Serum Specimen 25/50/5
Serum Specimen 35/50/5
Serum Specimen 45/50/5
Serum Specimen 55/50/5
Serum Specimen 65/50/5
Serum Specimen 75/50/5
Serum Specimen 75/50/5
Serum Specimen 95/50/5
Serum Specimen 105/50/5
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Herrera, B.B.; Mayoral, R.; Brites, C. Development and Validation of a Rapid Screening Test for HTLV-I IgG Antibodies. Viruses 2023, 15, 129. https://doi.org/10.3390/v15010129

AMA Style

Herrera BB, Mayoral R, Brites C. Development and Validation of a Rapid Screening Test for HTLV-I IgG Antibodies. Viruses. 2023; 15(1):129. https://doi.org/10.3390/v15010129

Chicago/Turabian Style

Herrera, Bobby Brooke, Rafaela Mayoral, and Carlos Brites. 2023. "Development and Validation of a Rapid Screening Test for HTLV-I IgG Antibodies" Viruses 15, no. 1: 129. https://doi.org/10.3390/v15010129

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop