Reflex Human Immunodeficiency Virus (HIV) Type 1 RNA Testing Enables Timely Differentiation of False-Positive Results From Acute HIV Infection

Accurate, timely human immunodeficiency virus (HIV) diagnosis is critical. Routine HIV screening program data were examined before and after reflex HIV type 1 RNA testing. Reflex testing facilitated confirmation of reactive HIV screening assays (as true or false positives) (odds ratio, 23.7 [95% confidence interval, 6.7-83.4]; P < .0001), improving detection of acute HIV and reducing unconfirmed discordant results.

Assessment of the performance regarding confirmatory diagnosis and initiation of antiretroviral therapy under a modified national HIV testing algorithm and pay-for-performance program in Taiwan

BACKGROUND

A pay-for-performance plan for rapid antiretroviral therapy (ART) commencement was initiated in 2018, while a modified testing algorithm offers immunochromatographic test (ICT) to replace Western blot (WB), and simultaneous testing with ICT and Nucleic Acid Amplification Test (NAAT) for HIV-positive sera was adopted in 2019 in Taiwan.

METHODS

Serum specimens collected from 1117 suspected or confirmed HIV infection cases in 2016-2019 were reassessed the performance of WB, ICT, and NAAT. We reviewed the medical records of 10,732 individuals diagnosed with HIV in 2015-2021 to determine the time from screening to confirmatory diagnosis, followed by ART commencement.

RESULTS

All 860 WB-positives were also positive by ICT and NAAT. The positive detection percentages were 37.0% by ICT and 51.4% by NAAT for 257 WB-indeterminate and -negative sera. The sensitivity for WB and ICT was 93.8% and 95.5%, respectively. In the people living with HIV (PLHIV) cohort, the median time from initial positive to confirmatory diagnosis decreased from 5 to 6 days before 2019 to 1 day in 2021. The median time from initial positive to ART initiation decreased from 37 days in 2015, 14 days in 2018, to 6 days in 2021. Compared to 2015-2017, the time to ART initiation was 91.48 days lower in 2018 (P < 0.001) and 100.66 days lower in 2019-2021 (P < 0.001) by the adjusted linear regression model.

CONCLUSION

A significant decrease in the time to ART initiation was observed after initiation of the pay-for-performance program and optimized testing algorithm in Taiwan.

Laboratory diagnosis of HIV: a contemporary overview in the Australian context

Over the past decade there have been technical advances in human immunodeficiency virus (HIV) assays and updates to testing regulations that have substantially changed the landscape of laboratory testing for HIV. In addition, there have been significant changes in the epidemiology of HIV in Australia in the context of highly effective contemporary biomedical treatment and prevention strategies. Here, we provide an update on contemporary issues for the laboratory detection and confirmation of HIV in Australia. These include (1) the impact of early treatment and biological prevention strategies on the serological and virological detection of HIV; (2) the updated national HIV laboratory case definition and its interaction with testing regulations, public health and clinical guidelines; and (3) novel strategies for the laboratory detection of HIV, including the incorporation of HIV nucleic acid amplification tests (NAATs) into testing algorithms. These developments present an opportunity to develop a nationally consistent contemporary HIV testing algorithm that would result in optimisation and standardisation of HIV testing in Australia.

Impaired Mitochondrial Function in T-Lymphocytes as a Result of Exposure to HIV and ART

Mitochondrial dysfunction is a described phenomenon for a number of chronic and infectious diseases. At the same time, the question remains open: is this condition a consequence or a cause of the progression of the disease? In this review, we consider the role of the development of mitochondrial dysfunction in the progression of HIV (human immunodeficiency viruses) infection and the onset of AIDS (acquired immunodeficiency syndrome), as well as the direct impact of HIV on mitochondria. In addition, we will touch upon such an important issue as the effect of ART (Antiretroviral Therapy) drugs on mitochondria, since ART is currently the only effective way to curb the progression of HIV in infected patients, and because the identification of potential side effects can help to more consciously approach the development of new drugs in the treatment of HIV infection.

Streamlining Laboratory Tests for HIV Detection

HIV is a retrovirus that primarily infects CD4 presenting cells of the human immune system, such as macrophages and dendritic cells. People die of AIDS because the disease remains undetected for long periods of time. HIV diagnostic testing has come a long way since it was introduced in the early 1980s. Early diagnosis is key to successful treatment of HIV. Assay selection is based on initial screening results and clinical information provided by the physician, both of which are essential for the laboratory’s ability to make accurate diagnoses. Detecting HIV with high specificity and sensitivity in the early stages of infection requires simple, accurate and economical methods. In this chapter we have described the indications & criteria’s for HIV testing, HIV diagnosis by utilizing variety of immunological and molecular methods, like ELISA, rapid diagnostics, Western blotting, indirect immunoassays, and nucleic acid-based tests. Diagnostic laboratories must use testing algorithms to ensure the accuracy of results and the optimal use of lab resources. Participation in laboratory quality assurance programs are also essential to ensure that diagnostic laboratories provide accurate, timely and clinically relevant test results. HIV testing is the first step in maintaining a healthy life and preventing HIV transmission.

Fluorescence and visual immunoassay of HIV-1 p24 antigen in clinical samples via multiple selective recognitions of CdTe QDs

Human immunodeficiency virus (HIV) infection inflicts significant economic and social burdens on many countries worldwide. Given the substantial morbidity and mortality from HIV infection, there is an urgent need for accurate and early detection of the virus. In this study, immunofluorescence and visual techniques are described that detect the HIV-1 p24 antigen, which relied on selective recognition of Ag⁺/Ag nanoparticles (Ag NPs) and Cu²⁺/Cu⁺ using cadmium telluride quantum dots (CdTe QDs). After the sandwich immunoreactions were accomplished, the alkaline phosphatase (ALP) hydrolyzed L-ascorbic acid 2-phosphate (AAP) to form ascorbic acid (AA) that further reduces Ag⁺ and Cu²⁺ to Ag NPs and Cu⁺, respectively. This method was highly sensitive and selective and could detect as low as 1 pg/mL of p24 antigen by naked eyes and had a good linearity in the concentration range 1-100 pg/mL. When using Ag⁺ and Cu²⁺ as media, the limit of detection (LOD) of the new method was 0.3 pg/mL and 0.2 pg/mL, respectively. Compared with clinical electrochemiluminescence immunoassay (ECLIA) results and clinical data, this method demonstrated good consistency for the quantification of HIV-1 p24 antigen in 34 clinical serum samples. In addition, this method could accurately distinguish HIV from other viruses and infections such as hepatitis B virus, systemic lupus erythematosus, hepatitis C virus, Epstein-Barr virus, cytomegalovirus, lipemia, and hemolysis. Therefore, our dual-mode analysis method may provide additional solutions to identify clinical HIV infection. An immunofluorescence and visualization dual-mode strategy for the detection of p24 antigen was constructed based on immune recognition reaction and a phenomenon that cadmium telluride quantum dots (CdTe QDs) can selectively recognize Ag⁺/Ag nanoparticles (Ag NPs) and Cu²⁺/Cu⁺.

Recognizing Laboratory Medicine's Collaborative Role in Identifying and Eliminating Health Disparities

BACKGROUND

A health disparity is a health outcome that presents in a lesser or greater extent between populations. Health disparities in diseases are products of complex interactions between social, economic, and to a lesser extent, biological factors and can be mediated by structural racism and discriminatory policies. The objective of this review is to understand how both laboratorians and nonlaboratorians think about the relationship between laboratory medicine and health disparities and to highlight ways in which laboratory medicine can play a role in eliminating health disparities.

CONTENT

We developed an electronic survey from which we selected the top responses reported by the 215 participants to frame a discussion around why laboratorians perceive health disparities exists, and how they can reduce health disparities.

SUMMARY

We found that both laboratorians and nonlaboratorians feel that laboratory medicine can and should play a role in reducing health disparities using many tools already in use in the clinical laboratory. The skills of laboratory workers in data generation, the establishment of reference ranges, control over the presentation of laboratory results, generation of test menus, and the development of novel diagnostics may impact health disparities. Laboratorians' responses in our survey indicated that they felt that they could reduce health disparities by using laboratory data to proactively track in cooperation with healthcare providers individuals with chronic conditions to prevent acute events, ensuring gender and ethnic diversity in new clinical trials, including appropriate curriculum in laboratory medicine training, using equations and reference intervals based on physiological differences and participating in unconscious bias training.

Evaluation of Serological Tests for SARS-CoV-2: Implications for Serology Testing in a Low-Prevalence Setting

BACKGROUND

Robust serological assays are essential for long-term control of the COVID-19 pandemic. Many recently released point-of-care (PoCT) serological assays have been distributed with little premarket validation.

METHODS

Performance characteristics for 5 PoCT lateral flow devices approved for use in Australia were compared to a commercial enzyme immunoassay (ELISA) and a recently described novel surrogate virus neutralization test (sVNT).

RESULTS

Sensitivities for PoCT ranged from 51.8% (95% confidence interval [CI], 43.1%-60.4%) to 67.9% (95% CI, 59.4%-75.6%), and specificities from 95.6% (95% CI, 89.2%-98.8%) to 100.0% (95% CI, 96.1%-100.0%). ELISA sensitivity for IgA or IgG detection was 67.9% (95% CI, 59.4%-75.6%), increasing to 93.8% (95% CI, 85.0%-98.3%) for samples >14 days post symptom onset. sVNT sensitivity was 60.9% (95% CI, 53.2%-68.4%), rising to 91.2% (95% CI, 81.8%-96.7%) for samples >14 days post symptom onset, with specificity 94.4% (95% CI, 89.2%-97.5%).

CONCLUSIONS

Performance characteristics for COVID-19 serological assays were generally lower than those reported by manufacturers. Timing of specimen collection relative to onset of illness or infection is crucial in reporting of performance characteristics for COVID-19 serological assays. The optimal algorithm for implementing serological testing for COVID-19 remains to be determined, particularly in low-prevalence settings.

Increasing the Assembly Efficacy of Peptidic β-Sheets for a Highly-Sensitive HIV Detection

Our recent publication illustrates the critical role of phenylalanine-mediated aromatic-aromatic interactions in determining the assembly of peptidic β-sheets. However, the effect of phenylalanine number on regulating the assembly efficacy of peptidic β-sheets remains poorly understood. We herein evaluate the assembly efficacy of β-sheets of a series of oligopeptides which contain 0, 1, 2, or 3 phenylalanine in their molecular backbones. In our assembly system, two phenylalanine (2F) is the minimum number for driving the assembly of β-sheets of oligopeptides. Oligopeptides with three phenylalanine (3F) show significantly increased assembly efficacy of β-sheets compared to that with 2F. These results suggest a positive correlation between the phenylalanine number and assembly efficacy of β-sheets. By improving the assembly efficacy of β-sheets, we further develop a highly sensitive HIV analytical system in which the specific binding of β-sheets with Congo Red induces enhanced fluorescence. For HIV p24 detection, the 3F-based analytical system (0.61 pg/mL) shows a significantly lower limit of detection (LOD) than the 2F-based analytical system (2.44 pg/mL), both of which are more sensitive than commercial ELISA (5 pg/mL) used in the clinic. This work not only illustrates the effect of phenylalanine number on regulating the assembly efficacy of β-sheets but also provides a guideline for the construction of a highly sensitive analytical system of disease diagnosis.

Difficulties of Identifying the Early HIV Antibody Seroconversion Period Depending on the Confirmatory Assay

BACKGROUND

Identification of HIV infection at the early stage is valuable for patient management, for prevention, and for research purposes. In practice, identification of a recent HIV infection at diagnosis proves challenging after HIV antibody seroconversion but can be suspected using Western blots (WBs) or immunoblots (IBs) as confirmatory assays.

METHODS

Five commercially available confirmatory assays were compared using 43 samples from recently infected individuals. This included 2 WBs (New LAV Blot I, Biorad, and HIV Blot 2.2, MP Biomedicals), 2 IBs (INNO-LIA HIV I/II, Fujirebio, and RecomLine HIV-1 & HIV-2, Mikrogen Diagnostik), and 1 immunochromatographic single-use assay (Geenius HIV1/2 supplemental assay, Biorad).

RESULTS

Following the manufacturer's recommendations for interpretation, the 2 WBs led to indeterminate results for 30% and 42% of the samples, suggesting recent infection, compared with 2%-7% for the 3 other assays. When interpreted based on the Fiebig classification, concordant stages were observed in 42% of samples, and only 49% were classified as early seroconversion by all 5 assays. For the remaining specimens, the distinction with chronic infection was highly variable depending on the assay (5%-100%).

CONCLUSIONS

Clinical laboratories must consider this variability, which must be kept in mind both for initial diagnosis and for multicenter studies for which inclusion criteria refer to serological profiles by confirmatory assays.

Recent advances in lab-on-a-chip technologies for viral diagnosis

The global risk of viral disease outbreaks emphasizes the need for rapid, accurate, and sensitive detection techniques to speed up diagnostics allowing early intervention. An emerging field of microfluidics also known as the lab-on-a-chip (LOC) or micro total analysis system includes a wide range of diagnostic devices. This review briefly covers both conventional and microfluidics-based techniques for rapid viral detection. We first describe conventional detection methods such as cell culturing, immunofluorescence or enzyme-linked immunosorbent assay (ELISA), or reverse transcription polymerase chain reaction (RT-PCR). These methods often have limited speed, sensitivity, or specificity and are performed with typically bulky equipment. Here, we discuss some of the LOC technologies that can overcome these demerits, highlighting the latest advances in LOC devices for viral disease diagnosis. We also discuss the fabrication of LOC systems to produce devices for performing either individual steps or virus detection in samples with the sample to answer method. The complete system consists of sample preparation, and ELISA and RT-PCR for viral-antibody and nucleic acid detection, respectively. Finally, we formulate our opinions on these areas for the future development of LOC systems for viral diagnostics.

Dendronized magnetic nanoparticles for HIV-1 capture and rapid diagnostic

Human immunodeficiency virus type 1 (HIV-1) remains a global public health problem. Detection and reduction of the rates of late diagnosis of HIV-1 infection are one of the main challenges in combating the HIV-1 epidemic. Magnetic nanoparticles (MNPs) have several characteristics that make them susceptible to capture HIV-1 of a wide range of biological samples reducing waiting times between the acquisition of HIV-1 infection and its detection by current techniques. Carbosilane dendrons decorated with peripheral carboxyl groups and alcoxysilane function at the focal point have been used to stabilize MNPs by co-precipitation method in one step. The characterization of these systems and of their carboxylate analogues was performed by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), dynamic light scattering (DLS), ζ potential and thermal gravimetric analysis (TGA). The ability of carboxyl and carboxylate MNPs to capture R5-HIV-1 and X4-HIV-1 strains was evaluated to achieve a rapid and easy diagnostic method in order to reduce or eliminate the risk of HIV-1 transmission.

Application of case study to introduce medical students to molecular biology techniques used in HIV diagnostics

Diagnostic molecular biology is a fast developing discipline of laboratory medicine widely used in numerous medical branches such as oncology, hematology, immunology, internal medicine, or infectious diseases, which will certainly have a major impact on clinical medicine in the near future. Nowadays, educational process is forced to face the quickly growing overflow of easily accessible data and properly guide the students not to be lead astray in the information chaos. Hence, in view of the foregoing, it appears obvious that modern medical education should put particular stress on selective acquiring, interpreting, and applying integrated multidisciplinary knowledge rather than on just absorbing and memorizing huge amount of scattered information. The presented case study aims at familiarizing the students with basic molecular biology techniques such as enzyme-linked immunosorbent assay, Western blot, and quantitative reverse transcription-polymerase chain reaction. Importantly, it is not limited only to discussing and learning the principles of the assays mentioned earlier, but it also shows their practical application in a particular diagnostic process and give the guidelines on how to explain and interpret exemplary results. In parallel, the way the case study is constructed allows a tutor to lead students into discussion on clinical aspects related to HIV infection what should eventually create complete picture of a HIV diagnostic process, thereby integrating basic knowledge of molecular biology laboratory techniques, HIV biology, and immunological response. © 2019 International Union of Biochemistry and Molecular Biology, 47(3):355-360, 2019.

Rapid immunodiagnostics of multiple viral infections in an acoustic microstreaming device with serum and saliva samples

There is a growing need to screen multiple infections simultaneously rather than diagnosis of one pathogen at a time in order to improve the quality of healthcare while saving initial screening time and reduce costs. This is the first demonstration of a five-step protein array assay for the multiplexed detection of HIV, HPV and HSV antibodies on an integrated microfluidic system. HIV, HPV and HSV reactive antibodies from both serum and saliva were rapidly detected by acoustic streaming-based mixing and pumping to enable an integrated, rapid and simple-to-use multiplexed assay device. We validated this device with 37 serum and saliva samples to verify reactivity of patient antibodies with HIV, HPV and HSV antigens. Our technology can be adapted with different protein microarrays to detect a variety of other infections, thus demonstrating a powerful platform to detect multiple putative protein biomarkers for rapid detection of infectious diseases. This integrated microfluidic protein array platform is the basis of a potent strategy to delay progression of primary infection, reduce the risk of co-infections and prevent onward transmission of infections by point-of-care detection of multiple pathogens in both serum and oral fluids.

p24 revisited: a landscape review of antigen detection for early HIV diagnosis

: Despite major advances in HIV testing, early detection of infection at the point of care (PoC) remains a key challenge. Although rapid antibody PoC and laboratory-based nucleic acid amplification tests dominate the diagnostics market, the viral capsid protein p24 is recognized as an alternative early virological biomarker of infection. However, the detection of ultra-low levels of p24 at the PoC has proven challenging. Here we review the landscape of p24 diagnostics to identify knowledge gaps and barriers and help shape future research agendas. Five hundred and seventy-four research articles to May 2018 that propose or evaluate diagnostic assays for p24 were identified and reviewed. We give a brief history of diagnostic development, and the utility of p24 as a biomarker in different populations such as infants, the newly infected, those on preexposure prophylaxis and self-testers. We review the performance of commercial p24 assays and consider elements such as immune complex disruption, resource-poor settings, prevalence, and assay antibodies. Emerging and ultrasensitive assays are reviewed and show a number of promising approaches but further translation has been limited. We summarize studies on the health economic benefits of using antigen testing. Finally, we speculate on the future uses of high-performance p24 assays, particularly, if available in self-test format.

Implementing emergency department-based HIV testing in a low-resource setting: The value of a structured feasibility assessment tool

Introduction

HIV is a worldwide health problem with continuing high rates of new infections in many parts of the world. This lack of progress in decreasing overall incidence rates has sparked innovative HIV testing strategies, including expansion of testing into the emergency department (ED) setting. Emergency departments have been shown to be high-yield testing venues in the United States and other developed world settings. The feasibility of expanding public health HIV services in the ED in limited-resource countries is unclear.

Methods

We performed a cross-sectional feasibility assessment of a convenience sample of four hospitals in the Eastern Cape, South Africa. We administered three adapted interview tools from a previously field-tested survey instrument at each facility (total of 10 interviews) to gather an overview of the health facility, their HIV counselling and testing services, and their laboratory services.

Results

All of the health facilities had access to basic commodities such as water and electricity. Many had severe human resource limitations and provided care to wide population catchment areas. In addition, there was little integration of HIV testing into current daily ED operations. Hospital staff identified numerous barriers to future ED testing efforts.

Conclusions

Although control of the HIV epidemic requires innovative testing strategies and treatment, specific assessments are warranted on how to incorporate routine HIV testing into an acute care facility like the ED, which typically has many competing priorities. The use of a prospective structured tool incorporating both barriers and benefits can provide valuable field-tested guidance for increased programme planning for HIV testing.

Problems encountered in conventional HIV 1/2 Algorithms: lack of necessity for immunoblot assays to confirm repeated ELISA reactive results

BACKGROUND

The use of conventional (serologically based) HIV 1/2 diagnostic algorithms has become controversial in recent years.

OBJECTIVES

Sera from patients who underwent verification tests were evaluated because repeated ELISA-reactive results demonstrated a HIV1+HIV2 positive band pattern.

METHODS

The line immunoassay (LIA) test was used for repeated HIV enzyme immunoassays (EIA)-reactive sera in patients at three centers. The Bio-Rad Geenius™ HIV 1/2 and the HIV-1 RNA tests were used. HIV-1 and RNA HIV-2 were investigated using PCR.

RESULTS

LIA was used to evaluate 3,224 out of 10,591 samples with repeated ELISA reactivity (30%). We found that 32 (1%) of the sera, along with HIV1 bands and HIV2 gp36 bands, were positive. Only 28 of the 32 verified serum samples with gp36 bands were repeated, and no gp36 band positivity was detected using the Bio-Rad Geenius™ HIV-1/2 confirmatory assay in these serum samples. The HIV-2 proviral DNAs were also negative. Therefore, we excluded the possibility of HIV1+2 co-infection. All samples from the 32 patients were positive for HIV-1 RNA.

CONCLUSION

Our findings highlight the need to exclude confirmatory tests like the LIA test from the current diagnostic HIV algorithm and replace it with rapid HIV-1 and HIV-2 confirmatory immunochromotographic tests.

New design, development, and optimization of an in-house quantitative TaqMan Real-time PCR assay for HIV-1 viral load measurement

Background Viral load measurement is commonly applicable to monitor HIV infection in patients to determine the number of HIV-RNA in serum samples of individuals. The aim of the present study was to set up a highly specific, sensitive, and reproducible home-brewed Real-time PCR assay based on TaqMan chemistry to quantify HIV-1 RNA genome. Methods In this study, three sets of primer pairs and a TaqMan probe were designed for HIV subtypes conserved sequences. An internal control was included in this assay to evaluate the presence of inhibition. Standard curve and threshold cycle values were determined using in vitro transcribed RNA from int region of HIV-1. A serial dilution of RNA standards was generated by in vitro transcription, from 10 to 10⁹ copies/ml to find the sensitivity and the limit of detection (LOD) of the assay and to evaluate its performance in a quantitative RT-PCR assay. Results The assay has a low LOD equivalent to 33.13 copies/ml of HIV-1 RNA and a linear range of detection from 10 to 10⁹ copies/ml. The coefficient of variation (CV) for Inter and Intra-assay precision of this in-house HIV Real-time RT-PCR ranged from 0.28 to 2.49% and 0.72 to 4.47%, respectively. The analytical and clinical specificity was 100%. Conclusions The results indicate that the developed method has a suitable specificity and sensitivity and is highly reproducible and cost-benefit. Therefore, it will be useful to monitor HIV infection in plasma samples of individuals.

Antibody detection by agglutination-PCR (ADAP) enables early diagnosis of HIV infection by oral fluid analysis

Oral fluid (OF) is a highly effective substrate for population-based HIV screening efforts, as it is noninfectious and significantly easier to collect than blood. However, anti-HIV antibodies are found at far lower concentrations in OF compared with blood, leading to poor sensitivity and a longer period of time from infection to detection threshold. Thus, despite its inherent advantages in sample collection, OF is not widely used for population screening. Here we report the development of an HIV OF assay based on Antibody Detection by Agglutination-PCR (ADAP) technology. This assay is 1,000-10,000 times more analytically sensitive than clinical enzyme-linked immunoassays (EIAs), displaying both 100% clinical sensitivity and 100% specificity for detecting HIV antibodies within OF samples. We show that the enhanced analytical sensitivity enables this assay to correctly identify HIV-infected individuals otherwise missed by current OF assays. We envision that the attributes of this improved HIV OF assay can increase testing rates of at-risk individuals while enabling diagnosis and treatment at an earlier time point.

A retrospective analysis of the application of the Elecsys® HIV combi PT assay in southern China

BACKGROUND

Fourth-generation HIV assays have been implemented worldwide as a screening test for many years. Understanding the performance of fourth-generation assay in low HIV prevalence region is pivotal to interpret the test result correctly. In this study, retrospective analysis was used to evaluate application of the Elecsys^® HIV combi PT assay.

METHODS

A total of 85 043 specimens from a low prevalence setting were detected between June 2013 and October 2015. We evaluated the false-positive rate (FPR), specificity, and positive predictive value (PPV).

RESULTS

The specificity between male and female were 99.85% and 99.82%, respectively. The PPV on male (50.75%) was higher than female (17.05%) significantly, while the FPR was 0.15% and 0.18%. The gap between false-positive (median: 1.83, [IQR]: 1.30, 3.38) and confirmed-positive (median: 407.5, [IQR]: 184.2, 871.7) is enormous. The highest s/co ratio for false-positive cases was 85.45, while the lowest s/co ratio for confirmed-positive cases was 59.68. Various reasons were attributed to false-positive cases.

CONCLUSION

Optimal cutoff value is needed to be set to reduce the false-positive cases and predict the final status of HIV infection reliably. Retrospective analysis will help us to understand more about diagnosis of HIV.

Comparison of 4th-Generation HIV Antigen/Antibody Combination Assay With 3rd-Generation HIV Antibody Assays for the Occurrence of False-Positive and False-Negative Results

OBJECTIVE

To assess the false-positive and false-negative rates of a 4th-generation human immunodeficiency virus (HIV) assay, the Abbott ARCHITECT, vs 2 HIV 3rd-generation assays, the Siemens Centaur and the Ortho-Clinical Diagnostics Vitros.

METHODS

We examined 123 patient specimens. In the first phase of the study, we compared 99 specimens that had a positive screening result via the 3rd-generation Vitros assay (10 positive, 82 negative, and 7 indeterminate via confirmatory immunofluorescent assay [IFA]/Western blot [WB] testing). In the second phase, we assessed 24 HIV-1 RNA-positive (positive result via the nuclear acid amplification test [NAAT] and negative/indeterminate results via the WB test) specimens harboring acute HIV infection.

RESULTS

The 4th-generation ARCHITECT assay yielded fewer false-positive results (n = 2) than the 3rd-generation Centaur (n = 9; P = .02) and Vitros (n = 82; P <.001) assays. One confirmed positive case had a false-negative result via the Centaur assay. When specimens from the 24 patients with acute HIV-1 infection were tested, the ARCHITECT assay yielded fewer false-negative results (n = 5) than the Centaur (n = 10) (P = .13) and the other 3rd-generation tests (n = 16) (P = .002).

CONCLUSIONS

This study indicates that the 4th-generation ARCHITECT HIV assay yields fewer false-positive and false-negative results than the 3rd-generation HIV assays we tested.

General practitioners' barriers and facilitators towards new provider-initiated HIV testing strategies: a qualitative study

European guidelines recommend offering an HIV test to individuals who display HIV indicator conditions (ICs). UK guidelines recommend performing a ‘routine offer of HIV testing’ in primary care where HIV prevalence exceeds 2 in 1000. Implementation of new provider-initiated HIV testing strategies in general practice is limited, while the numbers of undiagnosed and late for care HIV patients remain high. We have explored Dutch general practitioners’ barriers to and facilitators of both strategies. We combined semi-structured in-depth interviews with focus groups. Nine general practitioners – key informants of sexually transmitted infection/HIV prevention and control – were selected for the interviews. Additionally, we organised focus groups with a broad sample of general practitioners (n = 81). Framework analysis was used to analyse the data. Various barriers were found, related to (1) the content of the guidelines (testing the right group and competing priorities in general practice), (2) their organisational implementation (lack of time, unclear when to repeat the HIV test and overlong list of ICs) and (3) the patient population (creating fear among patients, stigmatising them and fear regarding financial costs). Multiple general practitioners stated that performing a sexual risk assessment of patients is important before applying either strategy. Also, they recommended implementing the IC-guided approach only in high-prevalence areas and combining HIV tests with other laboratory blood tests. General practitioners tend to cling to old patterns of risk-based testing. Promoting awareness of HIV testing and educating general practitioners about the benefits of new provider-initiated HIV testing strategies is important for the actual uptake of HIV testing.

The ABCs of STIs: An Update on Sexually Transmitted Infections

BACKGROUND

Sexually transmitted infections (STIs) are spread primarily through sexual contact and are a major cause of morbidity and mortality worldwide. Once identified, some STIs can be cured following appropriate therapy; for others, suppressive regimens and approaches to prevent ongoing transmission are important. The incidence of many common STIs is increasing in the US as well as worldwide, and hundreds of millions of people are currently infected. Laboratory testing plays a major role in the diagnosis and treatment of STIs, and clinical laboratorians should be familiar with the current guidelines and methods for testing.

CONTENT

Accurate and sensitive methods to diagnose STIs are essential to direct appropriate antimicrobial therapy and interrupt the cycle of disease transmission. This review summarizes laboratory testing for common bacterial, viral, and parasitic causes of STIs. Disease manifestations reviewed include cervicitis and urethritis, genital ulcerative disease, human immunodeficiency virus, viral hepatitis, human papilloma virus, and vaginitis. Recent advancements in the recognition and management of STIs, including updates to diagnostic algorithms, advances in testing methods, and emerging challenges with antimicrobial resistance, are summarized.

SUMMARY

Diagnostic methods and therapeutic guidelines for STIs are rapidly evolving. In combination with changing epidemiology, the development of novel therapeutics, and advancements in diagnostic methods, this has resulted in changing practices in laboratory testing and, subsequently, management of disease. Molecular methods have facilitated personalized therapy and follow-up regimens targeted for individual types or strains of some STIs.

Neopterin and Soluble CD14 Levels as Indicators of Immune Activation in Cases with Indeterminate Pattern and True Positive HIV-1 Infection

Background

We aimed to evaluate the roles of the plasma immune activation biomarkers neopterin and soluble CD14 (sCD14) in the indirect assessment of the immune activation status of patients with the indeterminate HIV-1 (IHIV-1) pattern and a true HIV-1-positive infection (PCG).

Methods

This cross-sectional and descriptive study included eighty-eight patients with the IHIV-1 pattern, 100 patients in the PCG, and 100 people in a healthy control group (HCG). Neopterin and sCD14 levels were determined by competitive and sandwich ELISA methods, respectively.

Results

Mean neopterin and sCD14 levels among those with the IHIV-1 pattern were significantly lower than among the PCG (p < 0.001 and p = 0.001, respectively), but they were similiar to those in the HCG (p = 0.57 and p = 0.66, respectively. Mean neopterin and sCD14 levels among the PCG were found to be significantly higher than among those with the IHIV-1 pattern (p < 0.001 and p = 0.001, respectively) and among those in the HCG (p = 0.001, p < 0.001, respectively). Neopterin did not have adequate predictive value for identifying those in the PCG (area under the curve [AUC] = 0.534; 95% CI, 0.463–0.605; p = 0.4256); sCD14 also had poor predictive value but high specificity (100%) for identifying those in the PCG (AUC = 0.627; 95% CI, 0.556–0.694; p = 0.0036).

Conclusions

While low levels of these two biomarkers were detected among those with the IHIV-1 pattern, they were found in high levels among those in the PCG. These two markers obviously cannot be used as a sceening test because they have low sensitivies. Taken together, we suggest that neopterin and sCD14 may be helpful because they both have high specificity (92%-100%) as indirect non-specific markers for predicting the immune activation status of individuals, whether or not they have true positive HIV-1.

Missed opportunities to offer HIV tests to high-risk groups during general practitioners' STI-related consultations: an observational study

OBJECTIVES

Prior research has shown that Dutch general practitioners (GPs) do not always offer HIV testing and the number of undiagnosed HIV patients remains high. We aimed to further investigate the frequency and reasons for (not) testing for HIV and the contribution of GPs to the diagnosis of HIV infections in the Netherlands.

DESIGN

Observational study.

SETTING

(1) Dutch primary care network of 42-45 sentinel practices where report forms during sexually transmitted infection (STI)-related consultations were routinely collected, 2008-2013. (2) Dutch observational cohort with medical data of HIV-positive patients in HIV care, 2008-2013.

OUTCOME MEASURES

The proportion of STI-related consultations in patients from high-risk groups tested for HIV, with additional information requested from GPs on HIV testing preconsultation or postconsultation for whom HIV testing was indicated, but not performed. Next, information was collected on the profile of HIV-positive patients entering specialised HIV care following diagnosis by GPs.

RESULTS

Initially, an HIV test was reported (360/907) in 40% of STI-related consultations in high-risk groups. Additionally, in 26% of consultations an HIV test had been performed in previous or follow-up consultations or at different STI-care facilities. The main reasons for not testing were perceived insignificant risk; 'too' recent risk according to GPs or the reluctance of patients. The initiative of the patient was a strong determinant for HIV testing. GPs diagnosed about one third of all newly found cases of HIV. Compared with STI clinics, HIV-positive patients diagnosed in general practice were more likely to be older, female, heterosexual male or sub-Saharan African.

CONCLUSIONS

In one-third of the STI-related consultations of persons from high-risk groups, no HIV test was performed in primary care, which is lower than previously reported. Risk-based testing has intrinsic limitations and implementation of new additional strategies in primary care is warranted.

Electrospinning induced surface activation (EISA) of highly porous PMMA microfiber mats for HIV diagnosis

Schematic of biological coupling to both dry substrate (DS) and wet substrate (WS) deposited fibers. (A) DS fibers without coupling, (B) WS fibers coupled to AbPE and GFP fluorescent proteins, (C) WS fibers assay coupled to HIV.

Designing Fluorescent Peptide Sensors with Dual Specificity for the Detection of HIV-1 Protease

HIV-1 protease is a key enzyme in the life cycle of HIV/AIDS, as it is responsible for the formation of the mature virus particle. We demonstrate here that phage-display peptides raised against this enzyme can be used as peptide sensors for the detection of HIV-1 protease in a simple, one-pot assay. The presence of the enzyme is detected through an energy transfer between two peptide sensors when simultaneously complexed with the target protein. The multivalent nature of this assay increases the specificity of the detection by requiring all molecules to be interacting in order for there to be a FRET signal. We also perform molecular dynamics simulations to explore the interaction between the protease and the peptides in order to guide the design of these peptide sensors and to understand the mechanisms which cause these simultaneous binding events. This approach aims to facilitate the development of new assays for enzymes that are not dependent on the cleavage of a substrate and do not require multiple washing steps.

HIV testing, staging, and evaluation

HIV testing and incidence are stable, but trends for certain populations are concerning. Primary prevention must be reinvigorated and target vulnerable populations. Science and policy have progressed to improve the accuracy, speed, privacy, and affordability of HIV testing. More potent and much better tolerated HIV treatments and a multidisciplinary approach to care have increased adherence and viral suppression. Changes to health care law in the United States seek to expand the affordability and access of improved HIV diagnostics and treatment. Continued challenges include improving long-term outcomes in people on lifetime regimens, reducing comorbidities associated with those regimens, and preventing further transmission.

Performance of the fourth-generation Bio-Rad GS HIV Combo Ag/Ab enzyme immunoassay for diagnosis of HIV infection in Southern Africa

BACKGROUND

Fourth-generation HIV assays detect both antigen and antibody, facilitating detection of acute/early HIV infection. The Bio-Rad GS HIV Combo Ag/Ab assay (Bio-Rad Combo) is an enzyme immunoassay that simultaneously detects HIV p24 antigen and antibodies to HIV-1 and HIV-2 in serum or plasma.

OBJECTIVE

To evaluate the performance of the Bio-Rad Combo assay for detection of HIV infection in adults from Southern Africa.

STUDY DESIGN

Samples were obtained from adults in Soweto and Vulindlela, South Africa and Dar es Salaam, Tanzania (300 HIV-positive samples; 300 HIV-negative samples; 12 samples from individuals previously classified as having acute/early HIV infection). The samples were tested with the Bio-Rad Combo assay. Additional testing was performed to characterize the 12 acute/early samples.

RESULTS

All 300 HIV-positive samples were reactive using the Bio-Rad Combo assay; false positive test results were obtained for 10 (3.3%) of the HIV-negative samples (sensitivity: 100%, 95% confidence interval [CI]: 98.8-100%); specificity: 96.7%, 95% CI: 94.0-98.4%). The assay detected 10 of the 12 infections classified as acute/early. The two infections that were not detected had viral loads<400 copies/mL; one of those samples contained antiretroviral drugs consistent with antiretroviral therapy.

CONCLUSIONS

The Bio-Rad Combo assay correctly classified the majority of study specimens. The specificity reported here may be higher than that seen in other settings, since HIV-negative samples were pre-screened using a different fourth-generation test. The assay also had high sensitivity for detection of acute/early infection. False-negative test results may be obtained in individuals who are virally suppressed.

HIV-1 infection using dried blood spots can be confirmed by Bio-Rad Geenius™ HIV 1/2 confirmatory assay

BACKGROUND

Confirmatory assays for HIV diagnosis are not well implemented in low-income countries with limited infrastructures. Geenius™ HIV 1/2 Confirmatory Assay is a single-use immunochromatographic test for the confirmation and differentiation of individual HIV-1/2 antibodies validated in venous whole blood, serum and plasma. However, dried blood specimens (DBS) are easier to collect, store and transport than plasma/serum in remote settings from limited resource countries and mobile populations.

OBJECTIVES

To evaluate the confirmatory assay Geenius™ HIV 1/2 for HIV diagnosis using DBS specimens.

STUDY DESIGN

We collected DBS from 70 Guinean women previously diagnosed as HIV-1 infected by rapid tests using whole blood samples in Equatorial Guinea and from 25 HIV-negative Guinean women and HIV-exposed infants diagnosed by molecular testing in Madrid. Geenius HIV 1/2 was performed by eluting two drops of dried blood from each patient and following the manufacturer instructions for the assay but using 40μl of the eluted blood as specimen. The results obtained were confirmed by western blot.

RESULTS

Geenius™ HIV 1/2 successfully confirmed the HIV-1 positive and negative infection in all tested DBS specimens, providing 100% specificity [95% Confidence Interval (CI): 86.2%-100%]. No HIV 1/2 coinfections were found in the study cohort. This is the first report that proves a good performance of Geenius™ HIV 1/2 for the HIV-1 infection confirmation using only two drops of dried blood.

CONCLUSIONS

Our results approve the utility of this confirmatory assay using DBS when a lack of adequate infrastructure to collect, store or transport plasma/serum is found. DBS are a practical alternative to plasma/serum for HIV serological diagnosis.

Eradicating syphilis, hepatitis C and HIV in MSM through frequent testing strategies

PURPOSE OF REVIEW

The rates of sexual transmission of HIV, syphilis and hepatitis C in MSM are rising in most countries. Recent research has raised the question of whether increasing testing and treatment of these infections could substantially reduce their transmission.

RECENT FINDINGS

Although mathematical models suggest this strategy could be potentially effective in reducing transmission, there is currently very limited evidence that community-wide incidence has been curtailed by this strategy.

SUMMARY

If increasing in testing is to substantially reduce the incidence of these infections then significant increases in testing are required together with innovative approaches to testing and healthcare delivery. Notwithstanding this, relatively simple approaches to increasing testing are currently underutilized.

HIV prevention in clinical care settings: 2014 recommendations of the International Antiviral Society-USA Panel

IMPORTANCE

Emerging data warrant the integration of biomedical and behavioral recommendations for human immunodeficiency virus (HIV) prevention in clinical care settings.

OBJECTIVE

To provide current recommendations for the prevention of HIV infection in adults and adolescents for integration in clinical care settings.

DATA SOURCES, STUDY SELECTION, AND DATA SYNTHESIS

Data published or presented as abstracts at scientific conferences (past 17 years) were systematically searched and reviewed by the International Antiviral (formerly AIDS) Society-USA HIV Prevention Recommendations Panel. Panel members supplied additional relevant publications, reviewed available data, and formed recommendations by full-panel consensus.

RESULTS

Testing for HIV is recommended at least once for all adults and adolescents, with repeated testing for those at increased risk of acquiring HIV. Clinicians should be alert to the possibility of acute HIV infection and promptly pursue diagnostic testing if suspected. At diagnosis of HIV, all individuals should be linked to care for timely initiation of antiretroviral therapy (ART). Support for adherence and retention in care, individualized risk assessment and counseling, assistance with partner notification, and periodic screening for common sexually transmitted infections (STIs) is recommended for HIV-infected individuals as part of care. In HIV-uninfected patients, those persons at high risk of HIV infection should be prioritized for delivery of interventions such as preexposure prophylaxis and individualized counseling on risk reduction. Daily emtricitabine/tenofovir disoproxil fumarate is recommended as preexposure prophylaxis for persons at high risk for HIV based on background incidence or recent diagnosis of incident STIs, use of injection drugs or shared needles, or recent use of nonoccupational postexposure prophylaxis; ongoing use of preexposure prophylaxis should be guided by regular risk assessment. For persons who inject drugs, harm reduction services should be provided (needle and syringe exchange programs, supervised injection, and available medically assisted therapies, including opioid agonists and antagonists); low-threshold detoxification and drug cessation programs should be made available. Postexposure prophylaxis is recommended for all persons who have sustained a mucosal or parenteral exposure to HIV from a known infected source and should be initiated as soon as possible.

CONCLUSIONS AND RELEVANCE

Data support the integration of biomedical and behavioral approaches for prevention of HIV infection in clinical care settings. A concerted effort to implement combination strategies for HIV prevention is needed to realize the goal of an AIDS-free generation.

Human immunodeficiency virus: what primary care clinicians need to know

Human immunodeficiency virus (HIV) has evolved from an illness that consistently led to death to a chronic disease that can be medically managed. Primary care clinicians can provide beneficial care to the individual patient and potentially decrease the transmission of HIV to others through appropriate HIV screening and recognition of clinical clues to both chronic and acute HIV. Most patients who take combination antiretroviral therapy experience immune reconstitution and resume normal lives. These patients benefit from the care of an experienced primary care clinician in addition to a clinician with HIV expertise. Primary care clinicians have expertise providing preventive care, including counseling regarding healthier lifestyle choices and managing cardiovascular risk factors, osteoporosis, hypertension, and diabetes, all of which have become increasingly important for individuals with HIV as they age. This article reviews the many important roles of primary care clinicians with regard to the HIV epidemic and care of patients with HIV.