The performance of the Alere HIV combo point-of-care test on stored serum samples; useful for detection of early HIV-1 infections?

2017 ◽  
Vol 94 (5) ◽  
pp. 331-333 ◽  
Author(s):  
Carla van Tienen ◽  
Sharona Rugebregt ◽  
Sandra Scherbeijn ◽  
Hannelore Götz ◽  
Corine Geurts van Kessel

IntroductionThe Alere HIV-1/2 Antigen/Antibody Combo point-of-care test is a commercially available 4th-generation rapid test for the diagnosis of HIV infection, including acute infection. We evaluated the sensitivity of this test in samples from patients with acute, recent or chronic HIV-1 infection.MethodsA validation of the test was performed using 89 HIV-positive serum samples collected in 2008–2016, that were stored at −20°C. Twenty-three samples were only p24-positive (acute infection); 49 samples were antibody-positive and p24-positive (recent infection); 17 samples were only antibody-positive (chronic infection). HIV infection was confirmed by standard-of-care assays and PCR. Samples came from patients attending an outpatient clinic for STDs at the Public Health Department and from patients within the Erasmus Medical Center, Rotterdam, the Netherlands.ResultsThe overall sensitivity of the test for diagnosing HIV infection based on detection of p24 antigen and/or antibodies was 92% (95% CI 86% to 98%) (82/89). In acute sera with only p24 antigen positivity, the sensitivity of the test decreased to 65% (95% CI 46% to 85%) (15/23). When both antibody and antigen testing were positive, the p24 sensitivity was only 24% (95% CI 12% to 36%) (12/49), but in these sera the final test result was positive in all sera (49/49) due to the positive antibody component.ConclusionsIn a laboratory setting, this test has an overall sensitivity of 92% to detect any stage of HIV-1 infection using sera specimens. It performs relatively well in detecting early HIV and may be beneficial as an initial screening in patients with a recent exposure to HIV. Additional testing in a laboratory setting remains mandatory as a proportion of acute HIV-1 infections are missed with this test.

2017 ◽  
Vol 4 (suppl_1) ◽  
pp. S15-S15
Author(s):  
Mary Evans ◽  
Anne Patala ◽  
Ellsworth Campbell ◽  
Emily Westheimer ◽  
Cynthia L Gay ◽  
...  

Abstract Background While HIV prevention activities are often focused on younger people, older people can also be at risk for HIV infection. We aimed to characterize HIV transmission in older adults. Methods The STOP study was a multi-site prospective study of persons with acute HIV infection (AHI) from 2011 to 2013. Older adults were defined as ≥45 years and younger persons were 13–44 years. AHI was defined by a negative rapid test but a reactive antigen/antibody or HIV RNA test. We performed bivariate analysis using Pearson’s chi-square and odds ratios to examine associations between older age and transmission characteristics. Among persons with HIV-1 polymerase (pol) sequences, transmission linkages were inferred when the genetic distance between sequences was <1.5% and did not indicate directionality of transmission. Results Among 86,836 participants (median age, 29 years; 75.0% male; 51.8% MSM), HIV infection was diagnosed in 176 (1.46%) of 12,036 older adults compared with 1,150 (1.53%) of 74,800 younger people (P = 0.56). Among HIV-infected persons, AHI was diagnosed in similar proportions of older and younger people (13.1% vs. 12.6%; P = 0.86). Among HIV-infected persons who participated in partner notification (n = 1,326), older adults were less likely to report meeting a sex partner online (11.3% vs. 26.9%; OR 0.52, 95% CI = 0.35–0.78) and were less likely to name ≥2 sex partners (31.5% vs. 46.8%; OR = 0.28, 95% CI = 0.15–0.53) compared with younger people. Among HIV-infected persons with HIV-1 pol sequences (n = 537), similar proportions of older and younger people had viruses that genetically linked with another study participant (15.9% vs. 23.5%; OR 0.62, 95% CI 0.31–1.22) (Figure). Conclusion In this study, older adults had a similar frequency of newly diagnosed HIV infection, acute infection, and genetic linkage compared with younger people, suggesting that increased HIV prevention efforts may be needed in this population. Disclosures All authors: No reported disclosures.


2017 ◽  
Vol 94 (7) ◽  
pp. 475-478 ◽  
Author(s):  
Narjis Boukli ◽  
Anders Boyd ◽  
Noémie Wendremaire ◽  
Pierre-Marie Girard ◽  
Julie Bottero ◽  
...  

ObjectivesHIV testing is an important step towards diminishing incident infections. Rapid self-tests whose use is becoming more common in France could help increase access to testing, yet could fail to diagnose HIV during acute HIV infection (AHI). The aim of the present study was to evaluate HIV-detection sensitivity of a commonly used rapid self-test (STAT-VIEW HIV1/2), compared with another point-of-care rapid test (INSTI), among patients presenting with AHI.MethodsIndividuals tested at Saint-Antoine Hospital (Paris, France) with negative or indeterminate western blot (WB) results and detectable HIV-RNA were included. Rapid tests were performed retrospectively on stored serum. Patients with and without reactive rapid tests were compared, while probability of having a reactive test was modelled across infection duration using logistic regression.ResultsOf the 40 patients with AHI, 23 (57.5%) had a reactive STAT-VIEW rapid test. Patients with non-reactive versus reactive tests had a significantly shorter median time since infection (p=0.01), time since onset of symptoms (p=0.009), higher proportion with Fiebig stage III versus IV (p=0.003), negative WB results (p=0.007), higher HIV-RNA levels (p=0.001) and lower CD4+ and CD8+ cell count (p=0.03, p<0.001, respectively). When examining sensitivity over the course of AHI duration, the probability of HIV detection was 75.5% at 5 weeks from HIV transmission. The INSTI provided similar results with respect to proportion of reactive tests (62.5%), determinants for non-reactive test and probability of HIV detection at 5 weeks of infection (85.0%).ConclusionsOver half of AHI patients had reactive serology using the STAT-VIEW rapid self-test when performed on serum samples. Considering that detection sensitivity increased substantially over infection time, individuals should not rely on a negative result to accurately exclude HIV infection within at least 5 weeks of potential HIV exposure. Notwithstanding strong recommendations against rapid test use during AHI, some utility in detecting HIV is observed 5–12 weeks after transmission.


Author(s):  
Anna Jeffery- Smith ◽  
C. Y. William Tong

In the majority of UK laboratories initial testing for HIV is now performed using a fourth generation test, which is a combination test for antibody to HIV and p24 antigen. These tests should be able to detect antibody to both HIV-1 and HIV-2. In addition, due to the heterogeneity of the virus they should be able to reliably detect antibody to the main circulating subtypes of HIV-1, i.e. group M (Major), O (Outlier), and N (non-M, non-O). The p24 antigen is an HIV capsid protein which is produced in large quantities during initial infection, prior to seroconversion. The sensitivity and specificity of fourth generation tests is typically > 99%. However, all positive results need further confirmation tests, as discussed below. Third generation laboratory assays only test for the presence of antibody to HIV. Though it includes the detection of IgM (which is not included in second generation assays), they do not detect early infection with isolated HIV antigen prior to seroconversion. Point-of-care testing for HIV is performed in the clinic or at bedside. Like laboratory based assays these tests can be either third or fourth generation. The sensitivity and specificity of point-of-care tests is considered lower than that of laboratory tests, and all positive results require confirmation with a laboratory assay. The window period is the length of time following infection with HIV until the appearance of laboratory markers of HIV infection in the blood. This period varies depending on which marker, i.e. antibody or antigen, is being tested for. The window period for fourth-generation tests is between eleven days and one month. Patients being counselled prior to this testing should be advised that a negative result does not cover risk exposures in the preceding month. These patients should be advised to have repeat testing if they have any further exposure risks in the preceding month prior to testing. For third-generation tests the window period is up to three months, correlating with the amount of time it may take for antibodies to HIV to develop.


2010 ◽  
Vol 4 (1) ◽  
pp. 176-179 ◽  
Author(s):  
Darrel Cook ◽  
Mark Gilbert ◽  
Lillo DiFrancesco ◽  
Mel Krajden

1998 ◽  
Vol 36 (8) ◽  
pp. 2235-2239 ◽  
Author(s):  
Bernard Weber ◽  
El Hadji Mbargane Fall ◽  
Annemarie Berger ◽  
Hans Wilhelm Doerr

In order to reduce the diagnostic window between the time of human immunodeficiency virus (HIV) infection and laboratory diagnosis, new screening enzyme-linked immunosorbent assays (ELISAs) which permit the simultaneous detection of HIV antigen and antibody have been developed. Two fourth-generation assays, HIV DUO (Biomérieux) and HIV Combi (Boehringer Mannheim), for the combined detection of HIV antigen and antibody, were compared with a third-generation assay (HIV-1/HIV-2 3rd Generation Plus enzyme immunoassay [EIA]; Abbott) and a p24 antigen test (HIV-1 Ag monoclonal; Abbott). A total of 17 seroconversion panels, 15 cell culture supernatants infected with different HIV type 1 (HIV-1) subtypes, and 255 potentially cross-reactive serum samples were tested. Ten seroconversions were detected an average of 8.1 days earlier with HIV DUO and 7.5 days earlier with HIV Combi than with the third-generation ELISA. Overall, in the 17 seroconversion panels tested, HIV DUO detected HIV-1 infection an average of 4.8 days and HIV Combi detected infection an average of 4.4 days earlier than HIV-1/HIV-2 3rd Generation Plus EIA. HIV antigen was detected with HIV DUO and HIV Combi in all of the 15 cell culture supernatants infected with different HIV-1 subtypes, including subtype O. With fourth-generation assays, considerably fewer false-positive results (n = 4 to 6) were obtained, in comparison with the third-generation EIA (n = 18). Fourth-generation assays permit an earlier diagnosis of HIV infection than third-generation antibody screening assays through the detection of p24 antigen, which may be present in serum samples from individuals with recent HIV infection prior to seroconversion.


2018 ◽  
Vol 14 (3) ◽  
pp. 229-240
Author(s):  
Johanna Lindell

As antibiotic resistance becomes a growing health emergency, effective strategies are needed to reduce inappropriate antibiotic use. In this article, one such strategy – communicative practices associated with the C-reactive protein point-of care test – is investigated. Building on a collection of 31 videorecorded consultations from Danish primary care, and using conversation analysis, this study finds that the rapid test can be used throughout the consultation to incrementally build the case for a nonantibiotic treatment recommendation, both when the test result is forecast and reported. The study also finds that the format of reports of elevated results differs from that of ‘normal’ results, resulting in a subtle shift of authority from doctor to test.


2018 ◽  
Vol 4 (11) ◽  
pp. eaar6280 ◽  
Author(s):  
Aditya Dileep Kurdekar ◽  
L. A. Avinash Chunduri ◽  
C. Sai Manohar ◽  
Mohan Kumar Haleyurgirisetty ◽  
Indira K. Hewlett ◽  
...  

We have engineered streptavidin-labeled fluorescent gold nanoclusters to develop a gold nanocluster immunoassay (GNCIA) for the early and sensitive detection of HIV infection. We performed computational simulations on the mechanism of interaction between the nanoclusters and the streptavidin protein via in silico studies and showed that gold nanoclusters enhance the binding to the protein, by enhancing interaction between the Au atoms and the specific active site residues, compared to other metal nanoclusters. We also evaluated the role of glutathione conjugation in binding to gold nanoclusters with streptavidin. As proof of concept, GNCIA achieved a sensitivity limit of detection of HIV-1 p24 antigen in clinical specimens of 5 pg/ml, with a detection range up to1000 pg/ml in a linear dose-dependent manner. GNCIA demonstrated a threefold higher sensitivity and specificity compared to enzyme-linked immunosorbent assay for the detection of HIV p24 antigen. The specificity of the immunoassay was 100% when tested with plasma samples negative for HIV-1 p24 antigen and positive for viruses such as hepatitis B virus, hepatitis C virus, and dengue. GNCIA could be developed into a universal labeling technology using the relevant capture and detector antibodies for the specific detection of antigens of various pathogens in the future.


PEDIATRICS ◽  
1994 ◽  
Vol 94 (2) ◽  
pp. 274-275
Author(s):  
Susan E. Pacheco ◽  
William T. Shearer

Purpose of the Study. To determine the HIV vertical transmission rate in an unselected group of infants born to HIV-infected mothers, and to examine the sensitivity, specificity, and positive and negative predictive values of physical examination and diagnostic laboratory studies (HIV culture, serum quantitative immunoglobulins and HIV-1 p24 antigen) in the diagnosis of HIV infection. Study Population. A group of 142 infants referred solely because they were born to HIV-infected mothers were selected for this study. Methods. Epidemiological and clinical data were obtained retrospectively from the Baylor Pediatric AIDS Clinical Trials Group HIV Infection Registry and medical records. The information recorded included results of physical examination and diagnostic laboratory tests (HIV culture, serum quantitative immunoglobulins, and HIV-1 p24 antigen). HIV cultures were performed according to a consensus protocol developed for the National Institute of Allergy and Infectious Diseases AIDS Clinical Trials Group. Results. Of 142 infants whose HIV infection status was known at the time of the study, 17 (20%) had confirmed infection, and 68 (80%) had seroreverted with no evidence of infection. All HIV-infected infants were at least 3 months old when abnormal physical exam findings became apparent (lymphadenopathy and hepatosplenomegaly), but similar findings were noted in an equal number of HIV-uninfected infants. All infected infants available were HIV culture positive by 6 months of age (16/16). There was no positive cultures reported in the infants who seroreverted (32/32). Elevated immunoglobulins (IgG, IgA, IgM) were present by 6 months of age in a high percentage of infected infants. Nearly one-half of the uninfected infants had elevated immunoglobulin levels during the first 6 months of life, but in 50% of the cases it was IgG alone.


Author(s):  
Retno Budiarti ◽  
Siti Qamariyah Khairunisa ◽  
Nasronudin ◽  
Kuntaman ◽  
Guritno

Cellular immune has an important role in response HIV infection, which is attack the infected cells to activate signaling molecule. Hyperbaric Oxygen (HBO) worked as complementary treatment for HIV infection. The production of ROS and RNS molecules during hyperbaric exposure can affect gene expression which contributes to cellular adaptative response. This study was conducted to explore the mechanisms of cellular adaptive response to HIV infection during hyperbaric exposure. This study was carried on in vitro using healthy volunteers’ PBMCs (Peripheral Blood Mononuclear Cells) cultures infected with HIV-1. The study was conducted as a post- test only group design. The experimental unit was PBMC from venous blood of healthy volunteers which were cultured in vitro and infected by co-culturing with HIV-1 in MT4 cell line. The experimental unit consist of treatment and control group. Each group examined the expression of transcription factor NFκB, Interferon α, reverse transcriptase inhibitors (p21), and the amount of HIV-1 p24 antigen. There were increasingly significant differences in the expression of the trancription factor of NFκB, p21, and HIV-1 p24 antigen,as well as mRNA transcription of interferon α2 between treatment and controlgroup. By decreasing p24 antigen showed that HBO exposure was able to suppress HIV-1 replication. The exposure to hyperbaric oxygen at the pressure of 2.4 ATAand 98% oxygen wasable to produce ROS and RNS molecules, which play a role in cellular adaptive responses through increasing the expression of nfĸb, p21 and mRNA of interferon α2 plays a role in inhibition mechanism of HIV-1 replication in cells.


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