HIV-2 inhibits HIV-1 gene expression via two independent mechanisms during cellular co-infection

IMPORTANCE

Twenty-five years after the first report that HIV-2 infection can reduce HIV-1-associated pathogenesis in dual-infected patients, the mechanisms are still not well understood. We explored these mechanisms in cell culture and showed first that these viruses can co-infect individual cells. Under specific conditions, HIV-2 inhibits HIV-1 through two distinct mechanisms, a broad-spectrum interferon response and an HIV-1-specific inhibition conferred by the HIV-2 TAR. The former could play a prominent role in dually infected individuals, whereas the latter targets HIV-1 promoter activity through competition for HIV-1 Tat binding when the same target cell is dually infected. That mechanism suppresses HIV-1 transcription by stalling RNA polymerase II complexes at the promoter through a minimal inhibitory region within the HIV-2 TAR. This work delineates the sequence of appearance and the modus operandi of each mechanism.

Immunization by exposure to live virus (SIVmne/HIV-2287) during antiretroviral drug prophylaxis may reduce risk of subsequent viral challenge

Rationale/Study design

A major challenge in the development of HIV vaccines is finding immunogens that elicit protection against a broad range of viral strains. Immunity to a narrow range of viral strains may protect infants of HIV-infected women or partners discordant for HIV. We hypothesized that immunization to the relevant viral variants could be achieved by exposure to infectious virus during prophylaxis with antiretroviral drugs. To explore this approach in an animal model, macaques were exposed to live virus (SIV_mne or HIV-2₂₈₇) during prophylaxis with parenteral tenofovir and humoral and cellular immune responses were quantified. Subsequently, experimental animals were challenged with homologous virus to evaluate protection from infection, and if infection occurred, the course of disease was compared to control animals. Experimental animals uninfected with SIV_mne were challenged with heterologous HIV-2₂₈₇ to assess resistance to retroviral infection.

Methodology/Principal findings

Juvenile female Macaca nemestrina (N = 8) were given ten weekly intravaginal exposures with either moderately (SIV_mne) or highly (HIV-2₂₈₇) pathogenic virus during tenofovir prophylaxis. Tenofovir protected all 8 experimental animals from infection, while all untreated control animals became infected. Specific non-neutralizing antibodies were elicited in blood and vaginal secretions of experimental animals, but no ELISPOT responses were detected. Six weeks following the cessation of tenofovir, intravaginal challenge with homologous virus infected 2/4 (50%) of the SIV_mne-immunized animals and 4/4 (100%) of the HIV-2₂₈₇-immunized animals. The two SIV_mne-infected and 3 (75%) HIV-2₂₈₇-infected had attenuated disease, suggesting partial protection.

Conclusions/Significance

Repeated exposure to SIV_mne or HIV-2₂₈₇, during antiretroviral prophylaxis that blocked infection, induced binding antibodies in the blood and mucosa, but not neutralizing antibodies or specific cellular immune responses. Studies to determine whether antibodies are similarly induced in breastfeeding infants and sexual partners discordant for HIV infection and receiving pre-exposure antiretroviral prophylaxis are warranted, including whether these antibodies appear to confer partial or complete protection from infection.

xCT/SLC7A11 antiporter function inhibits HIV-1 infection

Human macrophages are protected by intrinsic antiviral defenses that provide moderate protection against HIV-1 infection. Macrophages that do become infected can serve as long-lived reservoirs, to disseminate HIV-1 to CD4+ T cells. Infection of macrophages with HIV-1 and HIV-2 is inhibited by constitutive mobilization of antioxidant response master transcription regulator Nrf2. The downstream mediator of this restriction was not identified. Among the tens of genes controlled directly by Nrf2 in macrophages, we found that xCT/SLC7A11, a 12-transmembrane, cystine-glutamate antiporter promotes antiretroviral activity. We show here that depletion of xCT mRNA increases HIV-1 infection. Reconstitution of xCT knock out cells with wild-type xCT but not a transport-deficient mutant restores anti-HIV-1 activity. Pharmacological inhibitors of xCT amino acid transport also increase infection. The block is independent of known restriction factors and acts against HIV-1 and HIV-2. Like the block triggered through Nrf2, xCT function impedes infection immediately before 2-LTR circle formation.

Acceptability of on-site rapid HIV/HBV/HCV testing and HBV vaccination among three at-risk populations in distinct community-healthcare outreach centres: the ANRS-SHS 154 CUBE study

BACKGROUND

HIV, HBV and HCV infections continue to represent major health concerns, especially among key at-risk populations such as men who have sex with men (MSM), people who inject drugs (PWIDs), transgender women (TGW) and sex workers (SW). The objective of the ANRS-CUBE study was to evaluate the acceptability of a healthcare, community-based strategy offering a triple rapid HIV-HBV-HCV testing, and HBV vaccination, targeted at three priority groups (MSM, PWIDs and TGW/SWs), in three community centers, in the Paris area.

METHODS

This longitudinal multicentric non-randomized study included all adult volunteers attending one of the three specialized community centers in Paris, between July 2014 and December 2015. HIV, HBV and HCV status and acceptability of HBV vaccination were evaluated.

RESULTS

A total of 3662, MSM, 80 PWIDs and 72 TGW/SW were recruited in the three centers respectively. Acceptability of rapid tests was 98.5% in MSM and 14.9% in TGW/SWs, but could not be estimated in PWIDs since the number of users attending and the number of proposals were not recorded. User acceptability of HBV vaccination was weak, only 17.9% of the eligible MSM (neither vaccinated, nor infected) agreed to receive the first dose, 12.2% two doses, 5.9% had a complete vaccination. User acceptability of HBV vaccination was greater in PWIDs and TGW/SWs, but decreased for the last doses (66.7 and 53.3% respectively received a first dose, 24.4 and 26.7% a second dose and 6.7 and 0% a third dose). Fifty-three participants (49 MSM and 4 PWIDs) were discovered HIV positive, more than half with a recent infection. All but two HIV positive participants were linked to appropriate care in less than one month.

CONCLUSIONS

Rapid HIV-HCV-HBV screening showed a very high level of acceptability among MSM. Efforts need to be made to improve immediate acceptability for HBV vaccination, especially among MSM, and follow-up doses compliance. Our results show the important role of community centers in reaching targets, often fragile, populations, while also suggesting the need to reinforce on-site human support in terms of testing and vaccination, especially when addressing PWIDs.

Risk factors associated with infection of blood-borne virus among people who used methamphetamine

BACKGROUND

The surge of methamphetamine use has been a complicating factor compounding the steeply increasing number of drug overdose deaths in the U.S. Infection from blood-borne viruses including hepatitis B virus (HBV), hepatitis C virus (HCV) and HIV, related to methamphetamine use continue to grow. This study aims to examine the risk factors associated with HBV, HCV and HIV among people who used methamphetamine.

METHODS

People who ever used methamphetamine were identified from five National Health and Nutrition Examination Survey (NHANES) cohorts, 2007 to 2016. The outcome was either positive or negative for blood-borne viruses as identified from laboratory tests. Weighted statistics for the combined ten years of data were calculated by multiplying the weighted variable for laboratory measurements by 0.2. We examined the association of sexual activities (sexual partners, sexual identity), drug use behaviors (poly-drug use, injection drug use, frequency of drug use, age started using methamphetamine), demographics, and socio-economic status with blood-borne viruses using bivariate and multivariable logistic regression models.

RESULTS

There were 1132 participants representing approximately 11,996,319 persons who ever used methamphetamine in the U.S. Blood-borne viruses' positive rate was 13.0 per 100,000. Multivariable logistic regression analyses showed significant associations of blood-borne infections with age 40-49 years (vs. age 20-29 years, adjusted odds ratio 4.77, 95% CI 1.11-20.55), age 50-59 years (vs. age 20-29 years, 10.25, 2.40-43.82), living within poverty index 1-1.9 (vs. poverty index > = 2, 2.55; 1.19-5.49), living below the poverty threshold (vs. poverty index > = 2, 2.55; 1.11-5.86), having lower than high school education (vs. equal or higher than high school education, 3.13; 1.51-6.46), sexual identity as other than heterosexual (vs. heterosexual, 5.60; 1.72-18.28), using methamphetamine and heroin and cocaine (vs. using methamphetamine alone, 4.24; 1.06-16.92), injection drug use (vs. no injection drug use, 3.15; 1.61-6.16), and started using methamphetamine at age above 25 (vs. started using methamphetamine at age between 10 and 17, 2.09; 1.01-4.35).

CONCLUSIONS

Among people who use methamphetamine, those who use polysubstance, or who inject substances, are in urgent need for vaccination and interventions to avoid further harm from blood borne infections.

Convergent Evolution of HLA-C Downmodulation in HIV-1 and HIV-2

HLA-C-mediated antigen presentation induces the killing of human immunodeficiency virus (HIV)-infected CD4+ T cells by cytotoxic T lymphocytes (CTLs). To evade killing, many HIV-1 group M strains decrease HLA-C surface levels using their accessory protein Vpu. However, some HIV-1 group M isolates lack this activity, possibly to prevent the activation of natural killer (NK) cells. Analyzing diverse primate lentiviruses, we found that Vpu-mediated HLA-C downregulation is not limited to pandemic group M but is also found in HIV-1 groups O and P as well as several simian immunodeficiency viruses (SIVs). We show that Vpu targets HLA-C primarily at the protein level, independently of its ability to suppress NF-κB-driven gene expression, and that in some viral lineages, HLA-C downregulation may come at the cost of efficient counteraction of the restriction factor tetherin. Remarkably, HIV-2, which does not carry a vpu gene, uses its accessory protein Vif to decrease HLA-C surface expression. This Vif activity requires intact binding sites for the Cullin5/Elongin ubiquitin ligase complex but is separable from its ability to counteract APOBEC3G. Similar to HIV-1 Vpu, the degree of HIV-2 Vif-mediated HLA-C downregulation varies considerably among different virus isolates. In agreement with opposing selection pressures in vivo, we show that the reduction of HLA-C surface levels by HIV-2 Vif is accompanied by increased NK cell-mediated killing. In summary, our results highlight the complex role of HLA-C in lentiviral infections and demonstrate that HIV-1 and HIV-2 have evolved at least two independent mechanisms to decrease HLA-C levels on infected cells.IMPORTANCE Genome-wide association studies suggest that HLA-C expression is a major determinant of viral load set points and CD4+ T cell counts in HIV-infected individuals. On the one hand, efficient HLA-C expression enables the killing of infected cells by cytotoxic T lymphocytes (CTLs). On the other hand, HLA-C sends inhibitory signals to natural killer (NK) cells and enhances the infectivity of newly produced HIV particles. HIV-1 group M viruses modulate HLA-C expression using the accessory protein Vpu, possibly to balance CTL- and NK cell-mediated immune responses. Here, we show that the second human immunodeficiency virus, HIV-2, can use its accessory protein Vif to evade HLA-C-mediated restriction. Furthermore, our mutational analyses provide insights into the underlying molecular mechanisms. In summary, our results reveal how the two human AIDS viruses modulate HLA-C, a key component of the antiviral immune response.

Routine HIV Test Results in 6 US Clinical Laboratories Using the Recommended Laboratory HIV Testing Algorithm With Geenius HIV 1/2 Supplemental Assay

BACKGROUND

Geenius HIV 1/2 Supplemental Assay (Geenius; Bio-Rad Laboratories) is the only Food and Drug Administration-approved HIV-1/HIV-2 antibody differentiation test for the second step in the HIV laboratory testing algorithm. We characterized the occurrence of true HIV-1 and HIV-2 infections as well as false results in 6 US clinical laboratories using Geenius.

METHODS

We examined routine HIV testing outcome data from the time the laboratories began using the algorithm with Geenius until September 30, 2017. We calculated the positive predictive value for Geenius HIV-1 and HIV-2 reactivity separately.

RESULTS

Of 5,046,684 specimens tested, 41,791 had reactive antigen/antibody test results. Most specimens with reactive antigen/antibody results were HIV-1 antibody-positive established infections (n = 32,421), 1,865 of which also had indeterminate HIV-2 bands present. Ninety-three specimens were HIV-2 antibody positive or untypable for HIV-1/HIV-2 antibody. Acute HIV-1 infections were found in 528 specimens; 881 specimens lacked the nucleic acid test to determine the possibility of acute HIV-1 infection. False-positive antigen/antibody test results were present in 7505 specimens. Few specimens (n = 363) had false-positive antigen/antibody results with indeterminate Geenius and negative HIV-1 nucleic acid test results. The positive predictive values of Geenius reactivity were 99.4% for HIV-1 and 4.3% for HIV-2.

CONCLUSIONS

Routine testing using the laboratory testing algorithm with Geenius resulted in most specimens resolving as HIV negative or HIV-1 positive. The occurrence of indeterminate HIV-2 bands with a Geenius final assay interpretation of HIV-1 positive was more common than true HIV-2 infections. Reporting indeterminate HIV-2 results in this situation may cause confusion with interpreting HIV infection status.

HBsAg, anti-HCV and anti-HIV seroprevalence among blood donors in Southeastern Anatolia, Turkey, 2011-2015

Transmission of infections through blood and blood product transfusion is a serious healthcare problem. There are insufficient up-to-date data about seroprevalence of HBsAg, anti-HCV and anti-HIV ½ among healthy blood donors in Turkey. We aimed to investigate the seroprevalence of HBsAg, anti-HCV and anti-HIV ½ in Southeastern Anatolia, Turkey. HBsAg, anti-HCV, and anti-HIV ½ analysis results among blood donors who applied to Dicle University Faculty of Medicine, Diyarbakir District Blood Centre, between January 1, 2011 and December 31, 2015 were retrospectively evaluated. HBsAg, anti-HCV, and anti-HIV 1/2 screenings were performed using a fully automated device with the microparticle enzyme immunoassay method (MEIA). The chi-square (χ2) test was applied to variables. Among the donors, 1607 (1.73%) were HBsAg-positive, 255 (0.27%) were anti-HCV-positive and two (0.0021%) were positive for anti-HIV 1/2. HBsAg positivity rates by years were 2.50% in 2011, 1.92% in 2012, 1.74% in 2013, 1.53% in 2014 and 1.27% in 2015 (p<0.001). HBsAg-positivity was 0.78% for the donors between 18-24 years of age, 1.90% for those between 25-49 years of age and 3.92% for donors over the age of 49 (p<0.001). Anti-HCV positivity rates were as follows: 0.35% in 2011, 0.34% in 2012, 0.29% in 2013, 0.23% in 2014 and 0.16% in 2015 (p<0.001). Verified anti-HIV 1/2 positivity was observed for only two donors (0.0021%) within five years. HBsAg and anti-HCV positivity were observed to decrease significantly over the years and were significantly lower among younger donors.

eCD4-Ig Limits HIV-1 Escape More Effectively than CD4-Ig or a Broadly Neutralizing Antibody

The engineered antibody-like entry inhibitor eCD4-Ig neutralizes every human immunodeficiency virus type 1 (HIV-1), HIV-2, and simian immunodeficiency virus isolate it has been tested against. The exceptional breadth of eCD4-Ig derives from its ability to closely and simultaneously emulate the HIV-1 receptor CD4 and coreceptors, either CCR5 or CXCR4. Here we investigated whether viral escape from eCD4-Ig is more difficult than that from CD4-Ig or the CD4-binding site antibody NIH45-46. We observed that a viral swarm selected with high concentrations of eCD4-Ig was increasingly resistant to but did not fully escape from eCD4-Ig. In contrast, viruses selected under the same conditions with CD4-Ig or NIH45-46 fully escaped from those inhibitors. eCD4-Ig-resistant viruses acquired unique changes in the V2 apex, V3, V4, and CD4-binding regions of the HIV-1 envelope glycoprotein (Env). Most of the alterations did not directly affect neutralization by eCD4-Ig or neutralizing antibodies. However, alteration of Q428 to an arginine or lysine resulted in markedly greater resistance to eCD4-Ig and CD4-Ig, with correspondingly dramatic losses in infectivity and greater sensitivity to a V3 antibody and to serum from an infected individual. Compensatory mutations in the V3 loop (N301D) and in the V2 apex (K171E) partially restored viral fitness without affecting serum or eCD4-Ig sensitivity. Collectively, these data suggest that multiple mutations will be necessary to fully escape eCD4-Ig without loss of viral fitness.IMPORTANCE HIV-1 broadly neutralizing antibodies (bNAbs) and engineered antibody-like inhibitors have been compared for their breadths, potencies, and in vivo half-lives. However, a key limitation in the use of antibodies to treat an established HIV-1 infection is the rapid emergence of fully resistant viruses. Entry inhibitors of similar breadths and potencies can differ in the ease with which viral escape variants arise. Here we show that HIV-1 escape from the potent and exceptionally broad entry inhibitor eCD4-Ig is more difficult than that from CD4-Ig or the bNAb NIH45-46. Indeed, full escape was not observed under conditions under which escape from CD4-Ig or NIH45-46 was readily detected. Moreover, viruses that were partially resistant to eCD4-Ig were markedly less infective and more sensitive to antibodies in the serum of an infected person. These data suggest that eCD4-Ig will be more difficult to escape and that even partial escape will likely extract a high fitness cost.

Differences among diagnostic testing algorithms in the time from HIV diagnosis to care

BACKGROUND

The association between the type of diagnostic testing algorithm for HIV infection and the time from diagnosis to care has not been fully evaluated. Here we extend an earlier analysis of this association by controlling for patient and diagnosing facility characteristics.

STUDY DESIGN

Descriptive analysis of HIV infection diagnoses during 2016 reported to the National HIV Surveillance System through December 2017. Algorithm type: traditional = initial HIV antibody immunoassay followed by a Western blot or immunofluorescence antibody test; recommended = initial HIV antigen/antibody immunoassay followed by HIV-1/2 type-differentiating antibody test; rapid = two CLIA-waived rapid tests on the same date.

RESULTS

In multivariate analyses controlling for patient and diagnosing facility characteristics, persons whose infection was diagnosed using the rapid algorithm were more likely to be linked to care within 30 days than those whose infection was diagnosed using the other testing algorithms (p < 0.01). The median time to link to care during a 30-day follow-up was 9.0 days (95% CI 8.0-12.0) after the rapid algorithm, 17.0 days (95% CI 17.0-18.0) after the recommended algorithm, and 23.0 days (95% CI 22.0-25.0) after the traditional algorithm.

CONCLUSIONS

The time from HIV diagnosis to care varied with the type of testing algorithm. The median time to care was shortest for the rapid algorithm, longest for the traditional algorithm, and intermediate for the recommended algorithm. These results demonstrate the importance of choosing an algorithm with a short time between initial specimen collection and report of the final result to the patient.

HIV-1/2 screening in blood centers: implementing a two-step serological screening assay approach to reduce donor deferral

BACKGROUND

Screening blood donations for human immunodeficiency virus 1/2 (HIV-1/2) infection in blood centers is often done with a highly sensitive 3rd-generation immunoassay which may cause false-positive results. Donations found repeatedly reactive (RR) are discarded regardless of negative HIV-1/2 nucleic acid testing (NAT) and confirmatory assays results. These donors are notified and deferred if RR in a subsequent donation. We evaluated the introduction of a secondary 4th-generation serological assay to the overall algorithm performance.

METHODS

All donations collected between January 2016 and May 2018 (574,338) were screened using 3rd-generation immunoassay (PRISM HIV O Plus) and NAT (Procleix Ultrio/Ultrio Elite). Serology RR donations were tested with 4th-generation Architect HIV Ag/Ab Combo and Vidas HIV Duo Ultra and a confirmatory assay (Geenius HIV-1/2).

RESULTS

The two 4th-generation assays found that 86% (179/209 on Architect) and 94% (182/193 on Vidas) of the 3rd-generation immunoassay RR were negative for HIV-1/2, which were also negative by confirmatory assay. Only 14% (30/209 on Architect) and 6% (11/193 on Vidas) that were 3rd-generation HIV-1/2 RR required confirmation, of which eight donors were confirmed as HIV positive. The probability of missing an HIV-1 infected donor by this algorithm is one in a million RR cases.

CONCLUSION

The introduction of a two-step serological screening algorithm in blood centers whereby 4th-generation assay will be performed for all 3rd-generation RR blood donors will reduce the number of donations requiring confirmation, save time and money, and most importantly, reduce the number of discarded blood donations and allow re-entry processes.

Limited HIV-2 reservoirs in central-memory CD4 T-cells associated to CXCR6 co-receptor expression in attenuated HIV-2 infection

The low pathogenicity and replicative potential of HIV-2 are still poorly understood. We investigated whether HIV-2 reservoirs might follow the peculiar distribution reported in models of attenuated HIV-1/SIV infections, i.e. limited infection of central-memory CD4 T lymphocytes (TCM). Antiretroviral-naive HIV-2 infected individuals from the ANRS-CO5 (12 non-progressors, 2 progressors) were prospectively included. Peripheral blood mononuclear cells (PBMCs) were sorted into monocytes and resting CD4 T-cell subsets (naive [TN], central- [TCM], transitional- [TTM] and effector-memory [TEM]). Reactivation of HIV-2 was tested in 30-day cultures of CD8-depleted PBMCs. HIV-2 DNA was quantified by real-time PCR. Cell surface markers, co-receptors and restriction factors were analyzed by flow-cytometry and multiplex transcriptomic study.

HIV-2 DNA was undetectable in monocytes from all individuals and was quantifiable in TTM from 4 individuals (median: 2.25 log₁₀ copies/10⁶ cells [IQR: 1.99–2.94]) but in TCM from only 1 individual (1.75 log₁₀ copies/10⁶ cells). HIV-2 DNA levels in PBMCs (median: 1.94 log₁₀ copies/10⁶ PBMC [IQR = 1.53–2.13]) positively correlated with those in TTM (r = 0.66, p = 0.01) but not TCM. HIV-2 reactivation was observed in the cells from only 3 individuals. The CCR5 co-receptor was distributed similarly in cell populations from individuals and donors. TCM had a lower expression of CXCR6 transcripts (p = 0.002) than TTM confirmed by FACS analysis, and a higher expression of TRIM5 transcripts (p = 0.004). Thus the low HIV-2 reservoirs differ from HIV-1 reservoirs by the lack of monocytic infection and a limited infection of TCM associated to a lower expression of a potential alternative HIV-2 co-receptor, CXCR6 and a higher expression of a restriction factor, TRIM5. These findings shed new light on the low pathogenicity of HIV-2 infection suggesting mechanisms close to those reported in other models of attenuated HIV/SIV infection models.

HIV-2 induces a still poorly understood attenuated infection compared to HIV-1. We investigated whether this infection might follow peculiarities associated with other models of attenuated HIV-1/SIV infection, i.e. a limited infection of a key subset of memory CD4 T lymphocytes, the central-memory ones (TCM). Thus we studied the infection rates in peripheral blood cells from 14 untreated HIV-2 infected individuals from the ANRS-CO5 HIV-2 cohort, and found; 1) a lack of infection of monocytes, 2) extremely low infection in central-memory CD4+ T lymphocytes while HIV-2 predominated in the transitional-memory cells, 3) a poor replicative capacity of HIV-2 in individuals cells. We then investigated the cellular expression of a hundred-host genes potentially involved in HIV-2 control. We found in individuals’ TCM cells, compared to TTM ones, a lower expression of CXCR6, a potentially alternative co-receptor of HIV-2 but not of HIV-1, and a higher expression of TRIM5α, a restriction factor to which HIV-2 is more sensitive than HIV-1. Altogether our findings shed new light on the low pathogenicity of HIV-2 suggesting mechanisms close to those reported in other models of attenuated HIV/SIV infection models.

Investigating the addition of oral HIV self-tests among populations with high testing coverage - Do they add value? Lessons from a study in Khayelitsha, South Africa

Introduction

HIV self-testing (HIVST) offers a useful addition to HIV testing services and enables individuals to test privately. Despite recommendations to the contrary, repeat HIV testing is frequent among people already on anti-retroviral treatment (ART) and there are concerns that oral self-testing might lead to false negative results. A study was conducted in Khayelitsha, South Africa, to assess feasibility and uptake of HIVST and linkage-to-care following HIVST.

Methods

Participants were recruited at two health facilities from 1 March 2016 to 31 March 2017. People under 18 years, or with self-reported previously-diagnosed HIV infection, were excluded. Participants received an OraQuick Rapid HIV-1/2 Antibody kit, and reported their HIVST results by pre-paid text message (SMS) or by returning to the facility. Those not reporting within 7 days were contacted by phone. Electronic and paper-based clinical and laboratory records were retrospectively examined for all participants to identify known HIV outcomes, after matching for name, date of birth, and sex. These findings were compared with self-reported HIVST results where available.

Results

Of 639 participants, 401 (62.8%) self-reported a negative HIVST result, 27 (4.2%) a positive result, and 211 (33.0%) did not report. The record search identified that of the 401 participants self-reporting a negative HIVST result, 19 (4.7%) were already known to be HIV positive; of the 27 self-reporting positive, 12 (44%) were known HIV positive. Overall, records showed 57/639 (8.9%) were HIV positive of whom 39/57 (68.4%) had previously-diagnosed infection and 18/57 (31.6%) newly-diagnosed infection. Of the 428 participants who self-reported a result, 366 (85.5%) reported by SMS.

Conclusions

HIVST can improve HIV testing uptake and linkage to care. SMS is acceptable for reporting HIVST results but negative self-reports by participants may be unreliable. Use of HIVST by individuals on ART is frequent despite recommendations to the contrary and its implications need further consideration.

BioRad BioPlex® HIV Ag-Ab assay: Incidence of false positivity in a low-prevalence population and its effects on the current HIV testing algorithm

BACKGROUND

The BioPlex® HIV Ag-Ab assay, unlike other HIV 1/2 antigen/antibody immunoassays, is capable of differentiating positive HIV-1 antibodies (Groups M and O) from HIV-2 antibodies and/or HIV-1 p24 antigen in a single test.

OBJECTIVE

The Alaska State Virology Laboratory (ASVL) adopted the BioPlex® HIV Ag-Ab assay early 2017 and can report on its performance in terms of false positivity in a low-prevalence population and its effects on the current HIV testing algorithm recommended by the Centers for Disease Control and Prevention (CDC).

STUDY DESIGN

Specimens received between March 2017 and August 2018 were screened using the BioPlex® HIV Ag-Ab assay. Specimens screening positive for HIV antibodies or antigen were further confirmed using the Geenius™ HIV 1/2 Supplemental Assay and/or HIV RNA testing.

RESULTS

Of the 12,338 sera screened by the BioPlex assay for HIV, 35 specimens were positive. Only 22 of the specimens were confirmed by supplemental testing and were considered to be truly positive (PPV, 62.9%). RNA was not detected in these cases suggesting initial false positivity on the BioPlex® HIV Ag-Ab assay. True positive results had index values (IDX) of >180 whereas false positive IDX's were between 1 and 4, with the exception of one specimen.

CONCLUSIONS

We suggest that specimens demonstrating positivity with low IDX values <4 on the BioPlex® HIV Ag-Ab assay proceed directly to RNA testing, essentially bypassing supplemental antibody confirmation tests, to reduce turnaround time and cost of HIV confirmation.

Performance of Bio-Rad HIV-1/2 Confirmatory Assay in HIV-1, HIV-2 and HIV-1/2 dually reactive patients - comparison with INNO-LIA and immunocomb discriminatory assays

BACKGROUND

Being able to discriminate between HIV-1, HIV-2 and HIV-1/2 dual infection is imperative for the appropriate selection of antiretroviral therapy (ART) in regions with high HIV-2 endemicity.

OBJECTIVES

To evaluate Bio-Rad Geenius HIV-1/2 Confirmatory Assay against INNO-LIA HIV 1/2 Score and ImmunoComb HIV 1/2 BiSpot with an emphasis towards ability to discriminate between HIV-1, HIV-2 and HIV-1/2 dual infection.

MATERIAL AND METHODS

131 samples from ART naïve HIV infected patients in Guinea-Bissau were selected retrospectively and tested with Geenius, INNO-LIA and Immunocomb. HIV-1/2 RNA were measured in all samples and HIV-1/2 DNA in 59 samples.

RESULTS

The Geenius reader typed 62 samples as HIV-1 reactive, 37 samples as HIV-2 reactive and 32 samples as HIV-1/2 dually reactive. Geenius manual reading classified 10% more samples as HIV-1/2 dually reactive (n = 35). INNO-LIA typed 63 samples as HIV-1 reactive, 36 samples as HIV-2 reactive and 32 samples as HIV-1/2 dually reactive while Immunocomb classified a large proportion of samples as HIV-1/2 dually reactive (n = 45). The measurement of agreement of the Geenius reader compared with INNO-LIA and Immunocomb was 92.4% and 84.0% respectively while the measurement of agreement of Geenius manual reading compared with INNO-LIA and Immuncomb was 93.1% and 89.3% respectively.

CONCLUSIONS

Geenius has similar performance characteristics as INNO-LIA, and performs considerably better than Immunocomb, for differentiating between HIV types. This is especially true when using the Geenius reader while manual reading of the Geenius assay seemed to overestimate the numbers of HIV-1/2 dually reactive samples.

Performance evaluation of the Bio-Rad Geenius HIV 1/2 supplemental assay

BACKGROUND

In the US, the HIV diagnostic algorithm for laboratory settings recommends the use of an HIV-1/HIV-2 differentiation supplemental assay after an initial reactive antigen/antibody (Ag/Ab) assay result. Since the discontinuation of the Multispot HIV-1/HIV-2 Rapid Test (MS), the Geenius HIV-1/2 Supplemental assay (Geenius) is the only FDA-approved supplemental differentiation test.

OBJECTIVE

We compared the performance of Geenius to MS and Western Blot (WB).

STUDY DESIGN

The relative seroconversion plasma reactivity of Geenius and MS was assessed using a 50% cumulative frequency analysis from 17 HIV-1 seroconverters. In addition, previously characterized plasma specimens, 186 HIV-1 positive, 100 HIV-2 positive, and 93 Ag/Ab-positive/HIV-1 RNA-negative, were tested with Geenius v1.1 software. McNemar's test was used for paired comparison analysis. A subset of 48 specimens were retested with the upgraded Geenius v1.3 software.

RESULTS

In HIV-1 seroconverters, the relative seroconversion reactivity was 2.5 and 2 days before the first positive HIV-1 WB for Geenius and MS, respectively. In HIV-1 positive samples, Geenius performed similarly to HIV-1 WB (p=0.1687) and MS (p=0.8312). In HIV-2 positive samples, Geenius underperformed compared to HIV-2 WB (p=0.0005) and MS (p=0.0012). When using the upgraded software among the HIV-1 positive and Ag/Ab-reactive/HIV-1 RNA-negative samples, gp140 reactivity decreased without affecting characterization of HIV-2 samples.

CONCLUSIONS

With HIV-1 samples, Geenius, WB and MS performance was similar as supplemental tests. The updated Geenius software reduced false gp140 reactivity, but had no impact on identifying true HIV-2 infections. Further evaluation will assess the impact of the Geenius software update on final diagnostic interpretations.

Performance of the Alere Determine™ HIV-1/2 Ag/Ab Combo Rapid Test with algorithm-defined acute HIV-1 infection specimens

BACKGROUND

The capacity of HIV Antigen/Antibody (Ag/Ab) immunoassays (IA) to detect HIV-1 p24 antigen has resulted in improved detection of HIV-1 infections in comparison to Ab-only screening assays. Since its introduction in the US, studies have shown that the Determine HIV-1/2 Ag/Ab Combo assay (Determine Ag/Ab) detects HIV infection earlier than laboratory-based IgM/IgG-sensitive IAs, but its sensitivity for HIV-1 p24 Ag detection is reduced compared to laboratory-based Ag/Ab assays. However, further evaluation is needed to assess its capacity to detect acute HIV-1 infection.

OBJECTIVE

To assess the performance of Determine Ag/Ab in serum from acute HIV-1 infections.

STUDY DESIGN

Select serum specimens that screened reactive on a laboratory-based Ag/Ab IA or IgM/IgG Ab-only IA, with a negative or indeterminate supplemental antibody test and detectable HIV-1 RNA were retrospectively tested with Determine Ag/Ab. Results were compared with those of the primary screening immunoassay to evaluate concordance within this set of algorithm-defined acute infections.

RESULTS

Of 159 algorithm-defined acute HIV-1 specimens, Determine Ag/Ab was reactive for 105 resulting in 66.0% concordance. Of 125 that were initially detected by a laboratory-based Ag/Ab IA, 81 (64.8%) were reactive by Determine Ag/Ab. A total of 34 acute specimens were initially detected by a laboratory-based IgM/IgG Ab-only IA and 24 (70.6%) of those were reactive by Determine Ag/Ab.

CONCLUSIONS

Due to their enhanced sensitivity, laboratory-based Ag/Ab IAs continue to be preferred over the Determine Ag/Ab as the screening method used by laboratories conducting HIV diagnostic testing on serum and plasma specimens.

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.

HIV-2 infection is associated with preserved GALT homeostasis and epithelial integrity despite ongoing mucosal viral replication

The mechanisms that enable preservation of gut mucosal integrity during persistent viral replication and inherent inflammation remain unclear. Here, we investigated, for the first time, gut homeostasis in HIV-2 infection, a naturally occurring form of attenuated HIV disease. We found viral replication in both sigmoid and ileum of asymptomatic HIV-2+ patients (range: 240-851 circulating CD4+T-cells per μl) despite their undetectable viremia, accompanied by interferon-γ-producing CD8 T-cell expansion, irrespective of antiretroviral treatment. Nevertheless, there was no CD4 T-cell depletion, and Foxp3+ and IL-17- or IL-22-producing CD4 T-cell numbers were unaffected. Moreover, IL-22-producing innate lymphoid cells and IL-22-induced antimicrobial peptides and mucins were maintained. In agreement, the epithelium histology was preserved, including tight junction protein zonula occludens (ZO-1) levels. Furthermore, in vitro infection of colon epithelia with primary isolates revealed no HIV-2 impact on ZO-1 expression. Notably, sigmoid transcriptional levels of CCL20 and CCL28 were significantly increased, in direct correlation with GM-CSF, indicating a local response able to enhance CD4 T-cell recruitment. In conclusion, maintenance of mucosal integrity in HIV-2 infection was associated with T-cell recruitment responses, potentially counteracting CD4 T-cell depletion due to HIV-2 replication. These data have unique implications for the design of therapies targeting gut homeostasis in HIV-1 infection and other chronic inflammatory settings.

Analytical performances of simultaneous detection of HIV-1, HIV-2 and hepatitis C- specific antibodies and hepatitis B surface antigen (HBsAg) by multiplex immunochromatographic rapid test with serum samples: A cross-sectional study

BACKGROUND

The HIV/HCV/HBsAg Triplex consists in manually performed, visually interpreted, lateral flow, immunochromatographic rapid diagnostic test simultaneously detecting in 15min human immunodeficiency virus (HIV)-1 and HIV-2 and hepatitis C virus (HCV)- specific antibodies (Ab) (IgG and IgM) and hepatitis B virus (HBV) surface antigen (HBsAg) in serum, plasma and whole blood.

METHODS

A hospital-based cross-sectional study was conducted on a prospective panel of serum samples from adult inpatients included from routine analysis irrespectively of age and sex, including 250 sera positive for HIV-1-specific Ab, 250 for HCV-specific Ab, 250 for HBsAg and 250 sera negative for HIV- and HCV- Ab and HBsAg, and from 110 HIV-2-infected patients living in Ivory Coast, according to the results obtained by the reference chemiluminiscent microparticle immunoassay (CMIA) Abbott Architect i2000SR analyzer (Abbott Diagnostic, Chicago, IL, USA). Among HCV-seropositive sera, 187 were positive for HCV RNA (chronic infection), whereas 63 were negative (resolved infection), respectively. Serum samples were further tested blindly by HIV/HCV/HBsAg Triplex according to manufacturers' recommendations.

RESULTS

HIV/HCV/HBsAg Triplex showed very high sensitivity and specificity, as well as excellent concordance with CMIA Abbott results, as shown in the Table. Lower sensitivity was observed only in individuals who had cleared their HCV infection (presence of HCV-specific Ab in absence of HCV RNA). The mean lower limit of HBsAg detection was 2.38±0.63 IU/ml. Erythrocytes-spiked serum samples gave similar results than serum samples.

CONCLUSIONS

Advantages of HIV/HCV/HBsAg Triplex for HIV-1, HIV-2, HCV and HBV include the requirement for less overall specimen volume, fewer finger-sticks if capillary whole blood is used, cost savings through lower cost per virus tested, improved patient flow with results for multiple viruses available at the same time, overall service delivery efficiencies with less time required per infected patient; and patient benefits from fewer visits and lower cost associated with each clinic attendance. The screening of chronic HIV, HCV and HBV by multiplex HIV-1/HIV-2/HCV/HBsAg Triplex may improve the "cascade of screening" and quite possibly linkage-to-care with reduced cost.

Staging of recent HIV-1 infection using Geenius rapid confirmatory assay compared to INNO-LIA, New Lav and Blot 2.2 assays

BACKGROUND

Besides confirmation of HIV seropositivity, Western Blot (WB) assays play an important role for identification of recent infection based on incomplete antibody reactivity and lack of p31 band.

OBJECTIVES

We evaluated the capacities of the Geenius™ HIV1/2 Confirmatory Assay (Bio-Rad), a new generation rapid confirmatory assay based on immune-chromatography and automated reading, for staging of HIV-1 infection.

STUDY DESIGN

Sixteen samples collected during early HIV-1 infections (Fiebig stage III-VI) were tested using the Geenius assay, and compared to HIV Blot 2.2 WB assay (MP Diagnostics), New Lav Blot I WB assay (Bio-Rad) and INNO-LIA™ HIV I/II Score Dot Blot assay (Fujirebio). Results obtained with Geenius and INNO LIA in 47 newly diagnosed chronic HIV-1 infections were also compared.

RESULTS

The p24 band was less frequently detected in early HIV-1 infections using the Geenius (3/16) compared to the New Lav (15/16, p<0.0001), INNO-LIA (13/16, p=0.0011), and Blot 2.2 (13/16, p=0.0011). Testing samples collected during chronic infection allowed to confirm that p31 band and complete Gag, Pol, Env profiles were less frequently observed using the Geenius assay compared to the INNO LIA assay (p=0.027 for p31, and p=0.0015 for complete profile).

CONCLUSIONS

The Geenius assay is a simple and rapid test showing a high sensitivity to detect Env bands and to confirm HIV-1 seropositivity during the early phases of infection. However, this test is less suitable for distinguishing between later stages of acute and chronic infections because of a reduced sensitivity to detect the p31 and p24 bands compared to INNO LIA and New Lav assays.

The characteristics of screening and confirmatory test results for HIV in Xi'an, China

OBJECTIVES

Individuals with recent or acute HIV infection are more infectious than those with established infection. Our objective was to analyze the characteristics of detection among HIV infections in Xi'an.

METHODS

A 4th-generation kit (Architect HIV Ag/Ab Combo) and three 3rd-generationEIA kits (WanTai, XinChuang and Livzon) were used for HIV screening. Overall, 665 individuals were identified as positive and were tested by western blotting (WB). The characteristics of the screening and confirmatory tests were analyzed, including the band patterns, the early detection performance and the false-positive rates.

RESULTS

In total, 561 of the 665 patients were confirmed as having HIV-1 infection, and no HIV-2 specific band was observed. Among these 561 WB-positive cases, reactivity to greater than or equal to 9 antigens was the most commonly observed pattern (83.18%), and the absence of reactivity to p17, p31 and gp41 was detected in 6.44%, 5.9% and 2.86% of the cases, respectively. Two cases were positive by the 4th-generation assay but negative by the 3rd-generation assay for HIV screening and had seroconversion. The false-positive rate of the Architect HIV Ag/Ab Combo (22.01%) was significantly higher than those of WanTai (9.88%), XinChuang (10.87%) and Livzon (8.93%), p<0.05.

CONCLUSION

HIV infection in Xi'an is mainly caused by HIV-1, and individuals are rarely identified at the early phase. Although the false-positive rate of the 4th-generation assay was higher than that of the 3rd-generation assay, it is still recommended for use as the initial HIV screening test for high-risk individuals. In Xi'an, a 3rd-generation assay for screening could be considered.

Comparative evaluation of three FDA-approved HIV Ag/Ab combination tests using a genetically diverse HIV panel and diagnostic specimens

BACKGROUND

HIV Ag/Ab combination assays are recommended by CDC for routine screening and several HIV Ag/Ab combination tests are now FDA-approved. Maintaining high specificity and consistent sensitivity across diverse HIV strains is critical for these assays to accurately detect HIV infection and expedite delivery of patient results.

OBJECTIVES

To evaluate performance of three FDA-approved HIV tests: ARCHITECT HIV Combo (Abbott), ADVIA Centaur HIV Combo (Siemens) and BioPlex HIV Ag-Ab (Bio-Rad).

STUDY DESIGN

Sensitivity and specificity were evaluated using an extensive panel of 28 HIV infected human specimens and 17 cultured virus isolates representing multiple genotypes, 6 seroconversion panels, 4 human samples with acute infection, WHO p24 standard and 4020 clinical specimens.

RESULTS

The p24 limit of detection (LOD) for the WHO standard was 0.19IU/ml, 0.70IU/ml, and 1.77IU/ml in BioPlex, ARCHITECT, and Centaur respectively. The distribution of LODs across 15 HIV-1 isolates was substantially narrower in ARCHITECT (5-33pg/ml) than in BioPlex (11-198pg/ml) and Centaur (6-384pg/ml). All assays detected antibodies to the majority of HIV-1 and HIV-2 variants. However, reduced sensitivity was observed for Centaur in detection of antibodies to HIV-1 group M (CRF02_AG), O and N variants. BioPlex and ARCHITECT showed better seroconversion sensitivity than Centaur, detecting one bleed (3-7 days) earlier in 4 (BioPlex) and 3 (ARCHITECT) of 6 seroconversion panels. ARCHITECT demonstrated the highest specificity (99.90-100%) compared to BioPlex (99.80%) and Centaur (99.42%).

CONCLUSIONS

The overall performance of ARCHITECT and BioPlex was superior to Centaur, especially for detection of acute HIV infection.

Relevance of cutoff on a 4th generation ELISA performance in the false positive rate during HIV diagnostic in a low HIV prevalence setting

BACKGROUND

Despite the high specificity of fourth-generation enzyme immunoassays (4th-gen-EIA) for screening during HIV diagnosis, their positive predictive value is low in populations with low HIV prevalence. Thus, screening should be optimized to reduce false positive results.

OBJECTIVES

The influence of sample cutoff (S/CO) values by a 4th-gen-EIA with the false positive rate during the routine HIV diagnosis in a low HIV prevalence population was evaluated.

STUDY DESIGN

A total of 30,201 sera were tested for HIV diagnosis using Abbott Architect^® HIV-Ag/Ab-Combo 4th-gen-EIA at a hospital in Spain during 17 months. Architect S/CO values were recorded, comparing the HIV-1 positive results following Architect interpretation (S/CO≥1) with the final HIV-1 diagnosis by confirmatory tests (line immunoassay, LIA and/or nucleic acid test, NAT). ROC curve was also performed.

RESULTS

Among the 30,201 HIV performed tests, 256 (0.85%) were positive according to Architect interpretation (S/CO≥1) but only 229 (0.76%) were definitively HIV-1 positive after LIA and/or NAT. Thus, 27 (10.5%) of 256 samples with S/CO≥1 by Architect were false positive diagnose. The false positive rate decreased when the S/CO ratio increased. All 19 samples with S/CO ≤10 were false positives and all 220 with S/CO>50 true HIV-positives. The optimal S/CO cutoff value provided by ROC curves was 32.7. No false negative results were found.

CONCLUSIONS

We show that very low S/CO values during HIV-1 screening using Architect can result HIV negative after confirmation by LIA and NAT. The false positive rate is reduced when S/CO increases.

Comparison of turnaround time and total cost of HIV testing before and after implementation of the 2014 CDC/APHL Laboratory Testing Algorithm for diagnosis of HIV infection

BACKGROUND

Updated recommendations for HIV diagnostic laboratory testing published by the Centers for Disease Control and Prevention and the Association of Public Health Laboratories incorporate 4th generation HIV immunoassays, which are capable of identifying HIV infection prior to seroconversion.

OBJECTIVES

The purpose of this study was to compare turnaround time and cost between 3rd and 4th generation HIV immunoassay-based testing algorithms for initially reactive results.

STUDY DESIGN

The clinical microbiology laboratory database at Mayo Clinic, Rochester, MN was queried for 3rd generation (from November 2012 to May 2014) and 4th generation (from May 2014 to November 2015) HIV immunoassay results. All results from downstream supplemental testing were recorded. Turnaround time (defined as the time of initial sample receipt in the laboratory to the time the final supplemental test in the algorithm was resulted) and cost (based on 2016 Medicare reimbursement rates) were assessed.

RESULTS

A total of 76,454 and 78,998 initial tests were performed during the study period using the 3rd generation and 4th generation HIV immunoassays, respectively. There were 516 (0.7%) and 581 (0.7%) total initially reactive results, respectively. Of these, 304 (58.9%) and 457 (78.7%) were positive by supplemental testing. There were 10 (0.01%) cases of acute HIV infection identified with the 4th generation algorithm. The most frequent tests performed to confirm an HIV-positive case using the 3rd generation algorithm, which were reactive initial immunoassay and positive HIV-1 Western blot, took a median time of 1.1 days to complete at a cost of $45.00. In contrast, the most frequent tests performed to confirm an HIV-positive case using the 4th generation algorithm, which included a reactive initial immunoassay and positive HIV-1/-2 antibody differentiation immunoassay for HIV-1, took a median time of 0.4 days and cost $63.25. Overall median turnaround time was 2.2 and 1.5 days, and overall median cost was $63.90 and $72.50 for 3rd and 4th generation algorithms, respectively.

CONCLUSIONS

Both 3rd and 4th generation HIV immunoassays had similar total numbers of tests performed and positivity rates during the study period. A greater proportion of reactive 4th generation immunoassays were confirmed to be positive, and the 4th generation algorithm identified several cases of acute HIV infection that would have been missed by the 3rd generation algorithm. The 4th generation algorithm had a more rapid turnaround time but higher cost for confirmed positive HIV infections and overall, compared to the 3rd generation algorithm.

[Comparative study of HIV-1/2 antibody confirmatory assay: Geenius™ versus INNO-LIA™]

OBJECTIVE

The aim of the study is to compare two confirmatory tests for HIV-1/2 infection.

METHODS

A prospective study was carried out between 01/01/2015 and 12/31/2015. Serum samples with repeatedly positive results in the Antibody-Antigen-HIV-1/2 (Architect, Abbott) screening assay were included. The serum samples corresponding to new diagnosed cases were selected and were used to compare the two confirmatory assays: Geenius™ HIV-1/2 (Bio-Rad) and INNO-LIA™ HIV-1/2 score line-immunoassay (Innogene-tics®). The HIV-1 viral load (Cobas® AmpliPrepHIV, Ro-che) was performed in discordant or indeterminate cases.

RESULTS

Eight five samples were included. The results of both confirmatory assays were concordant in 80/85 samples: 53 HIV-1, 1 HIV-2, 25 negative and one indeterminate. Cohen's Kappa concordance coefficient between Geenius™ and INNO-LIA™ techniques was very high (0.878).

CONCLUSIONS

The concordance between the two assays is high. The procedure for Geenius™ is simple and fast. Geenius™ is a good alternative to include in the HIV-1/2 diagnostic algorithm.

A review of HIV point-of-care tests

Current epidemiological data show a large proportion of those with HIV in the UK remain undiagnosed. There is high level of transmission of HIV and other sexually transmitted infections among men having sex with men (MSM). There is credible evidence that there are increasing rates of HIV transmission in heterosexuals. In MSM the uptake of confidential HIV testing is increasing although 43% of those who are HIV positive may leave the clinic unaware of their infection. Rapid access to genitourinary (GU) medicine services varies but there is still a significant problem with less than 50% of those attending GU medicine clinics not being seen within 48 hours. Within our speciality, new methods are being developed to help improve access to diagnostic services. One of these developments is the increasing use of rapid point-of-care tests, which may overcome some of the barriers to HIV testing and diagnosis. We look at the availability, practical implications, benefits and potential difficulties of implementing these devices in HIV testing services.

Importance of an Early HIV Antibody Differentiation Immunoassay for Detection of Dual Infection with HIV-1 and HIV-2

Background

HIV-2 is primarily endemic in West Africa and India, however, in time of global migration, a possible HIV-2 infection or co-infection with HIV-1 should be recognized right at the time of HIV diagnosis, in order to enable optimized antiretroviral treatment. Laboratory HIV testing consists of a combined HIV1/2/O antibody + antigen screening test and subsequent confirmation and type differentiation by a serological test formatted as a multi-line or multi-spot assay. CDC has proposed a revised alternative HIV diagnostic strategy which, in case of a reactive result in a combined HIV1/2/O antibody + antigen screening test, comprises an HIV-1 nucleic acid test (NAT) for HIV confirmation instead of an antibody differentiation immunoassay (ADI). Only a negative NAT must be further investigated by an ADI, thus saving expenses for ADI in most instances. We have investigated this alternative strategy with respect to its recognition of dual HIV-1 and HIV-2 infection.

Methods and Results

Anonymized data of HIV notifications of patients newly diagnosed with HIV in Switzerland between 2007 and 2014 were analysed retrospectively. In a total of 4'679 notifications, we found 35 HIV-2 infections, 9 (25.7%) of which were dually infected with HIV-1. In 7 of the 9 dual HIV-1 and HIV-2 infections, HIV-1 RNA testing at the time of HIV diagnosis was positive with concentrations from 102 to 94'300 copies/mL plasma. HIV-1 RNA data were not available for the other two cases.

Conclusions

The alternative CDC strategy would have missed the concomitant HIV-2 infection in at least 7, but probably even more, of the 9 dually infected patients, as the detectable HIV-1 RNA would have precluded a supplemental ADI. Early ADI is mandatory for diagnosis of dual HIV-1/HIV-2 infection and guidance of appropriate therapy.

Care of Patients With HIV Infection: Diagnosis and Monitoring

Appropriate screening for HIV infection is the cornerstone of HIV-related care. There have been several recent changes in testing technology and screening recommendations. The US Preventive Services Task Force recommends universal HIV screening at least once for adolescents and adults ages 15 to 65 years, and additional screening for patients at higher risk, although evidence is insufficient to determine optimum rescreening intervals. All pregnant women should be screened for HIV infection in the first trimester, and pregnant women at high risk should be screened again in the third trimester. The Centers for Disease Control and Prevention recommends use of an algorithm using fourth-generation tests for screening; this decreases the window period between infection and detection to as few as 14 days, thereby reducing the number of false-negative results. Home HIV testing kits, which require follow-up confirmatory testing, also are available. Clinicians should be aware of HIV-specific laws in their states, including those criminalizing HIV exposure and transmission. Thorough medical and laboratory evaluations are essential at initiation of care for patients with HIV infection, along with appropriate follow-up monitoring, as recommended in various guidelines.

Successful Orthotopic Heart Transplantation and Immunosuppressive Management in 2 Human Immunodeficiency Virus-Seropositive Patients

Few orthotopic heart transplantations have been performed in patients infected with the human immunodeficiency virus since the first such case was reported in 2001. Since that time, advances in highly active antiretroviral therapy have resulted in potent and durable suppression of the causative human immunodeficiency virus-accompanied by robust immune reconstitution, reversal of previous immunodeficiency, a marked decrease in opportunistic and other infections, and near-normal long-term survival. Although human immunodeficiency virus infection is not an absolute contraindication, few centers in the United States and Canada have performed heart transplantations in this patient population; these patients have been de facto excluded from this procedure in North America. Re-evaluation of the reasons for excluding these patients from cardiac transplantation is warranted in light of such significant advances in antiretroviral therapy. This case report documents successful orthotopic heart transplantation in 2 patients infected with human immunodeficiency virus, and we describe their antiretroviral therapy and immunosuppressive management challenges. Both patients were doing well without sequelae 43 and 38 months after transplantation.

HIV Interaction With Human Host: HIV-2 As a Model of a Less Virulent Infection

HIV-1 and HIV-2 are the causal agents of AIDS. While similar in many ways, a significant amount of data suggests that HIV-2 is less virulent than HIV-1. In fact, HIV-2 infection is characterized by a longer asymptomatic stage and lower transmission rate, and the majority of HIV-2-infected patients can be classified as long-term non-progressors or elite controllers. The mechanisms underlying the ability of human host to naturally control HIV-2 infection are far from being completely understood. The identification of the differences between HIV-1 and HIV-2 interactions with human host cells could provide important insights into several aspects of retroviral pathogenesis that remain elusive, with significant implications for HIV vaccine development and therapy. In this review, we delve into some of the differences that notably distinguish HIV-2 from HIV-1, highlighting possible consequences in the pathogenesis and natural history of both infections.

Assessment of Oral Fluid HIV Test Performance in an HIV Pre-Exposure Prophylaxis Trial in Bangkok, Thailand

Background

Rapid easy-to-use HIV tests offer opportunities to increase HIV testing among populations at risk of infection. We used the OraQuick Rapid HIV-1/2 antibody test (OraQuick) in the Bangkok Tenofovir Study, an HIV pre-exposure prophylaxis trial among people who inject drugs.

Methods

The Bangkok Tenofovir Study was a randomized, double-blind, placebo-controlled trial. We tested participants’ oral fluid for HIV using OraQuick monthly and blood using a nucleic-acid amplification test (NAAT) every 3 months. We used Kaplan-Meier methods to estimate the duration from a positive HIV NAAT until the mid-point between the last non-reactive and first reactive oral fluid test and proportional hazards to examine factors associated with the time until the test was reactive.

Results

We screened 3678 people for HIV using OraQuick. Among 447 with reactive results, 436 (97.5%) were confirmed HIV-infected, 10 (2.2%) HIV-uninfected, and one (0.2%) had indeterminate results. Two participants with non-reactive OraQuick results were, in fact, HIV-infected at screening yielding 99.5% sensitivity, 99.7% specificity, a 97.8% positive predictive value, and a 99.9% negative predictive value. Participants receiving tenofovir took longer to develop a reactive OraQuick (191.8 days) than participants receiving placebo (16.8 days) (p = 0.02) and participants infected with HIV CRF01_AE developed a reactive OraQuick earlier than participants infected with other subtypes (p = 0.04).

Discussion

The oral fluid HIV test performed well at screening, suggesting it can be used when rapid results and non-invasive tools are preferred. However, participants receiving tenofovir took longer to develop a reactive oral fluid test result than those receiving placebo. Thus, among people using pre-exposure prophylaxis, a blood-based HIV test may be an appropriate choice.

Trial Registration

ClinicalTrials.gov NCT00119106.

Evaluation of the Bio-Rad Geenius HIV 1/2 Confirmation Assay as an Alternative to Western Blot in the Korean Population: A Multi-Center Study

Recently updated recommendations for diagnosis of HIV infection suggest a new diagnostic algorithm including HIV-1/HIV-2 antibody differentiation immunoassay instead of western blot (WB) as a confirmatory testing. We evaluated Bio-Rad Geenius HIV1/2 confirmation assay as a simple and reliable alternative to WB in the Korean population with low HIV prevalence. The Geenius HIV1/2 was performed in a total of 192 serum specimens (140 reactive and 52 nonreactive specimens by ARCHITECT HIV Ag/Ab Combo assay) that were prospectively collected from five institutions. HIV-1 nucleic acid amplification test (NAT) was performed in negative or indeterminate specimens by Geenius HIV1/2 or WB. Among 140 reactive specimens by HIV Ag/Ab assay, 82 (58.6%) were positive for HIV-1 Ab by Geenius HIV1/2. Among 58 negative or indeterminate specimens by Geenius HIV1/2, four specimens (6.9%) were positive by HIV-1 NAT. The sensitivity and specificity of Geenius HIV1/2 were 95.3% and 100.0%, respectively. When we considered only WB, the sensitivity and specificity of Geenius HIV1/2 were 100.0% and 99.1%, respectively. Agreement between Geenius HIV1/2 and WB was excellent (weighted Kappa = 0.89). The Geenius HIV1/2 is simple and time-saving compared with WB. It has an excellent performance and can be a reliable alternative to WB. HIV-1 NAT should be performed in negative or indeterminate specimens by Geenius HIV1/2 to detect acute HIV infection as recommended in new HIV testing algorithms.

Decreasing Proportion of Recent Infections among Newly Diagnosed HIV-1 Cases in Switzerland, 2008 to 2013 Based on Line-Immunoassay-Based Algorithms

Background

HIV surveillance requires monitoring of new HIV diagnoses and differentiation of incident and older infections. In 2008, Switzerland implemented a system for monitoring incident HIV infections based on the results of a line immunoassay (Inno-Lia) mandatorily conducted for HIV confirmation and type differentiation (HIV-1, HIV-2) of all newly diagnosed patients. Based on this system, we assessed the proportion of incident HIV infection among newly diagnosed cases in Switzerland during 2008-2013.

Methods and Results

Inno-Lia antibody reaction patterns recorded in anonymous HIV notifications to the federal health authority were classified by 10 published algorithms into incident (up to 12 months) or older infections. Utilizing these data, annual incident infection estimates were obtained in two ways, (i) based on the diagnostic performance of the algorithms and utilizing the relationship ‘incident = true incident + false incident’, (ii) based on the window-periods of the algorithms and utilizing the relationship ‘Prevalence = Incidence x Duration’. From 2008—2013, 3’851 HIV notifications were received. Adult HIV-1 infections amounted to 3’809 cases, and 3’636 of them (95.5%) contained Inno-Lia data. Incident infection totals calculated were similar for the performance- and window-based methods, amounting on average to 1’755 (95% confidence interval, 1588—1923) and 1’790 cases (95% CI, 1679—1900), respectively. More than half of these were among men who had sex with men. Both methods showed a continuous decline of annual incident infections 2008—2013, totaling -59.5% and -50.2%, respectively. The decline of incident infections continued even in 2012, when a 15% increase in HIV notifications had been observed. This increase was entirely due to older infections. Overall declines 2008—2013 were of similar extent among the major transmission groups.

Conclusions

Inno-Lia based incident HIV-1 infection surveillance proved useful and reliable. It represents a free, additional public health benefit of the use of this relatively costly test for HIV confirmation and type differentiation.

A decade of follow-up and therapeutic drug monitoring in HIV-2 immunocompromised patients at St Camille and General Lamizana Military Medical Centers, Burkina Faso, West Africa

Although, HIV-2 is generally less pathogenic than HIV-1 and its progression towards AIDS occurs less frequently. HIV-2 remains an important cause of disease in West Africa. This study aimed to evaluate HIV-1 and HIV-2 prevalence among pregnant women and to describe the demographic and clinical profile of patients with HIV-2 infection from 2003-2013 at St Camille and General Lamizana Military Medical Centers. A retrospective investigation was conducted using 12,287 medical records from patients screened for HIV. To respond to the lack of data available regarding HIV-2 treatment and also to address the approach to clinical, biological as well as therapeutic monitoring, 62 HIV-2 infected patients' medical records were studied. Seroprevalence of 10.6 and 0.14% were obtained, respectively for HIV-1 and HIV-2 among 12,287 women screened during the study period. From the sixty two (62) HIV-2 patients, the average age was 49.2 years (sex ratio was 0.65). The weight loss and diarrhea were the major clinical manifestations observed, respectively 54.8 and 25.8%. Fungi and herpes zoster (shingles) infections were reported as major opportunistic infections. Also, nearly half of the patients had more than 60 kg, less than 2% were in WHO stage IV and about 2/3 had a CD4 count bellow 250 cells mm(-3). AZT-3TC-IDV/LPV/R was the most prescribed combination. The gain in weight gain the Body Mass Index (BMI) improvement and the non-significant increase of the rate of CD4 between 1st (M1) and 24th month (M24) were observed after treatment with antiviral.

Lv4 Is a Capsid-Specific Antiviral Activity in Human Blood Cells That Restricts Viruses of the SIVMAC/SIVSM/HIV-2 Lineage Prior to Integration

HIV-2 and SIV_MAC are AIDS-causing, zoonotic lentiviruses that jumped to humans and rhesus macaques, respectively, from SIV_SM-bearing sooty mangabey monkeys. Cross-species transmission events such as these sometimes necessitate virus adaptation to species-specific, host restriction factors such as TRIM5. Here, a new human restriction activity is described that blocks viruses of the SIV_SM/SIV_MAC/HIV-2 lineage. Human T, B, and myeloid cell lines, peripheral blood mononuclear cells and dendritic cells were 4 to >100-fold less transducible by VSV G-pseudotyped SIV_MAC, HIV-2, or SIV_SM than by HIV-1. In contrast, transduction of six epithelial cell lines was equivalent to that by HIV-1. Substitution of HIV-1 CA with the SIV_MAC or HIV-2 CA was sufficient to reduce HIV-1 transduction to the level of the respective vectors. Among such CA chimeras there was a general trend such that CAs from epidemic HIV-2 Group A and B isolates were the most infectious on human T cells, CA from a 1° sooty mangabey isolate was the least infectious, and non-epidemic HIV-2 Group D, E, F, and G CAs were in the middle. The CA-specific decrease in infectivity was observed with either HIV-1, HIV-2, ecotropic MLV, or ALV Env pseudotypes, indicating that it was independent of the virus entry pathway. As₂O₃, a drug that suppresses TRIM5-mediated restriction, increased human blood cell transduction by SIV_MAC but not by HIV-1. Nonetheless, elimination of TRIM5 restriction activity did not rescue SIV_MAC transduction. Also, in contrast to TRIM5-mediated restriction, the SIV_MAC CA-specific block occurred after completion of reverse transcription and the formation of 2-LTR circles, but before establishment of the provirus. Transduction efficiency in heterokaryons generated by fusing epithelial cells with T cells resembled that in the T cells, indicative of a dominant-acting SIV_MAC restriction activity in the latter. These results suggest that the nucleus of human blood cells possesses a restriction factor specific for the CA of HIV-2/SIV_MAC/SIV_SM and that cross-species transmission of SIV_SM to human T cells necessitated adaptation of HIV-2 to this putative restriction factor.

HIV-1 and HIV-2, the two lentiviruses that cause AIDS in humans, are members of a family of such viruses that infect African primates. HIV-1 is a zoonosis that was transmitted to humans from chimpanzees. HIV-2 was transmitted to humans from sooty mangabey monkeys. In several documented cases of cross-species transmission of lentiviruses it has been shown that replication of the virus in the new host species necessitated that the virus adapt to species-specific antiviral factors in the host. Here we report that human blood cells possess an antiviral activity that exhibits specificity for viruses of the HIV-2/SIV_MAC/SIV_SM lineage, with restriction being greatest for SIV_SM and the least for epidemic HIV-2. Here we show that this dominant-acting, antiviral activity is specific for the capsid and blocks the virus after it enters the nucleus. The evidence suggests that, in order to jump from sooty mangabey monkeys to humans, the capsid of these viruses changed in order to adapt to this antiviral activity. In keeping with the practice concerning anti-lentiviral activities we propose to call this new antiviral activity Lv4.

Performance of Alere Determine HIV-1/2 Ag/Ab Combo rapid test for acute HIV infection: a case report

We describe a case of symptomatic acute HIV infection in a young man where a fourth-generation rapid screening test combining HIV-specific antibody and p24 antigen was negative. In highly suspicious cases of acute HIV infection, plasma HIV RNA assays together with conventional, non-rapid screening tests should be used.

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.

Evaluation of 9 rapid diagnostic tests for screening HIV infection, in Lomé, Togo

PURPOSE

HIV rapid diagnostic tests (RDT) could be greatly contributive for a universal access to HIV diagnosis. However, according to the WHO, these tests need to be assessed before they can be used in routine.

METHOD AND RESULTS

We assessed 9 RDT in routine clinical use between 2009 and 2013. The sensitivity and specificity observed for 7 tests were≥99% and≥98%, respectively: FIRST RESPONSE HIV1-2-O PMC Medical, India, GENIE Fast HIV 1-2 and GENIE™ III HIV(1/2) Bio-Rad, France, HIV TRI-DOT+Ag;J. Mitra, INDIA; SD BIOLINE HIV(1/2) 3.0 and SD BIOLINE HIV/SYPHILIS DUO Standard Diagnostic, Korea; and VIKIA HIV(1/2); BioMérieux, France. Two tests had performances inferior to WHO recommendations: INSTI HIV1/2 Biolytical Canada; sensitivity=97.8% and HEXAGON HIV HUMAN GmbH Germany; specificity=94.8%.

CONCLUSION

Seven of 9 RDT had excellent performances. Nevertheless, they can be used only after training staff, and taking into account national algorithm for their safe use.

Re-testing and misclassification of HIV-2 and HIV-1&2 dually reactive patients among the HIV-2 cohort of the West African Database to evaluate AIDS collaboration

INTRODUCTION

West Africa is characterized by the circulation of HIV-1 and HIV-2. The laboratory diagnosis of these two infections as well as the choice of a first-line antiretroviral therapy (ART) is challenging, considering the limited access to second-line regimens. This study aimed at confirming the classification of HIV-2 and HIV-1&2 dually reactive patients followed up in the HIV-2 cohort of the West African Database to evaluate AIDS collaboration.

METHOD

A cross-sectional survey was conducted from March to December 2012 in Burkina Faso, Côte d'Ivoire and Mali among patients classified as HIV-2 or HIV-1&2 dually reactive according to the national HIV testing algorithms. A 5-ml blood sample was collected from each patient and tested in a single reference laboratory in Côte d'Ivoire (CeDReS, Abidjan) with two immuno-enzymatic tests: ImmunoCombII® (HIV-1&2 ImmunoComb BiSpot - Alere) and an in-house ELISA test, approved by the French National AIDS and hepatitis Research Agency (ANRS).

RESULTS

A total of 547 patients were included; 57% of them were initially classified as HIV-2 and 43% as HIV-1&2 dually reactive. Half of the patients had CD4≥500 cells/mm(3) and 68.6% were on ART. Of the 312 patients initially classified as HIV-2, 267 (85.7%) were confirmed as HIV-2 with ImmunoCombII® and in-house ELISA while 16 (5.1%) and 9 (2.9%) were reclassified as HIV-1 and HIV-1&2, respectively (Kappa=0.69; p<0.001). Among the 235 patients initially classified as HIV-1&2 dually reactive, only 54 (23.0%) were confirmed as dually reactive with ImmunoCombII® and in-house ELISA, while 103 (43.8%) and 33 (14.0%) were reclassified as HIV-1 and HIV-2 mono-infected, respectively (kappa= 0.70; p<0.001). Overall, 300 samples (54.8%) were concordantly classified as HIV-2, 63 (11.5%) as HIV-1&2 dually reactive and 119 (21.8%) as HIV-1 (kappa=0.79; p<0.001). The two tests gave discordant results for 65 samples (11.9%).

CONCLUSIONS

Patients with HIV-2 mono-infection are correctly discriminated by the national algorithms used in West African countries. HIV-1&2 dually reactive patients should be systematically investigated, with a standardized algorithm using more accurate tests, before initiating ART as at least 4 out of 10 of them could initiate an effective first-line ART for HIV-1 and optimize their second-line treatment options.

Finger-stick whole blood HIV-1/-2 home-use tests are more sensitive than oral fluid-based in-home HIV tests

Background

Several countries have recently recommended the expansion of anti-human immunodeficiency virus (HIV) antibody testing, including self-testing with rapid tests using oral fluid (OF). Several tests have been proposed for at-home use, but their diagnostic accuracy has not been fully evaluated.

Objective

To evaluate the performance of 5 rapid diagnostic tests for the detection of anti-HIV-1/2 antibodies, with 4 testing OF and 1 testing whole blood.

Methods

Prospective multi-center study in France. HIV-infected adults and HIV-uninfected controls were systematically screened with 5 at-home HIV tests using either OF or finger-stick blood (FSB) specimens. Four OF tests (OraQuick Advance Rapid HIV-1/2, Chembio DPP HIV 1/2 Assay, test A, and test B) and one FSB test (Chembio Sure Check HIV1/2 Assay) were performed by trained health workers and compared with laboratory tests.

Results

In total, 179 HIV-infected patients (M/F sex ratio: 1.3) and 60 controls were included. Among the HIV-infected patients, 67.6% had an undetectable HIV viral load in their plasma due to antiretroviral therapy. Overall, the sensitivities of the OF tests were 87.2%, 88.3%, 58.9%, and 28% (for OraQuick, DPP, test A, and test B, respectively) compared with 100% for the FSB test Sure Check (p<0.0001 for all comparisons). The OraQuick and DPP OF tests' sensitivities were significantly lower than that of the FSB-based Sure Check (p<0.05). The sensitivities of the OF tests increased among the patients with a detectable HIV viral load (>50 copies/mL), reaching 94.8%, 96.5%, 90%, and 53.1% (for OraQuick, DPP, test A, and test B, respectively). The specificities of the four OF tests were 98.3%, 100%, 100%, and 87.5%, respectively, compared with 100% for the FSB test.

Conclusion

An evaluation of candidates for HIV self-testing revealed unexpected differences in performance of the rapid tests: the FSB test showed a far greater reliability than OF tests.

[Evolution of postoperative sequelae of pulmonary tuberculosis in HIV seropositive]

Cette étude rapporte les aspects cliniques et évolutifs des séquelles pulmonaires tuberculeuses (SPT) opérées chez les séropositifs (VIH+). Il s'agit d'une étude prospective transversale réalisée entre Novembre 2005 et Octobre 2012. Elle a porté sur 20 patients VIH+, ayant dans leurs antécédents, une tuberculose pulmonaire (TP) traitée et déclarée guérie, et admise dans ladite période pour une chirurgie de la SPT secondaire. Une enquête sérologique VIH a été réalisée systématiquement au cours du bilan pré-opératoire. Le diagnostic pré-opératoire de la SPT, la mortalité, les complications post- opératoires (CPOP), le séjour hospitalier, le suivi à moyen terme des STP opérées ont été évalués. Les séropositifs étaient VIH1+ (n = 12; 60%), VIH1&2+ (n = 4; 20%) et VIH2+ (n = 4; 20%). La durée moyenne d’évolution des STP était de 26,22 ± 21,3 mois. Les STP étaient les pyothorax ou pleurésies enkystées (n = 16; 80%), le poumon détruit (n = 2;10%) et les dilatations de bronches (n = 2;10%). Les VIH+ ne présentaient pas d'aspergillome pulmonaire. Le séjour hospitalier moyen était 13,1 ± 10,2 jours. Le suivi total était de 82 patients-année avec une moyenne de suivi de 4,2 ± 2,3 ans (extrêmes: 1 et 7 ans). Le taux de mortalité à court et moyen terme était nul. Aucun décès post-opératoire immédiat n'a été noté. Les CPOP immédiates étaient les bullages prolongés chez 75% des immunodéprimés. Les CPOP tardives (n = 3) étaient un syndrome restrictif pulmonaire, un pyothorax persistant et une pachypleurite résiduelle restrictive. A court terme, le taux de guérison radiologique était de 80% (n = 16).

Trend in prevalence of syphilis among voluntary blood donors in Xi'an, China from 2006 to 2010

This study was conducted to examine the prevalence of syphilis among blood donors in the Xi'an region of China. All blood donors were unremunerated volunteers recruited from 2006 to 2010. Anti-Treponema pallidum and anti-HIV serology responses were determined using ELISA kits. Among 159 902 voluntary blood donors tested, a total of 575 syphilis (0.36%) and 55 HIV (0.03%) infections were identified. While an increasing trend was shown for the prevalence of both syphilis and HIV over the 5-year period, there was no statistical correlation between the two infections. Our results indicate that syphilis and HIV infections are increasing risk factors for the spread of blood-borne infections. Further investigations and improvements in blood collection and testing procedures are needed to help ensure the safety of donated blood in China.

Link between primate lentiviral coreceptor usage and Nef function

Simian immunodeficiency virus (SIVsmm) infection of sooty mangabeys (Cercocebus atys) is characterized by stable CD4⁺ T cell counts despite high plasma levels of CCR5-tropic viruses. However, in rare instances, SIVsmm acquires CXCR4 coreceptor tropism and causes severe CD4⁺ T cell depletion, albeit without clinical signs of immunodeficiency. Here, we show that CXCR4-tropic SIVsmm strains lost their ability to downmodulate TCR-CD3 by evolving unusual Nef mutations that initially reduced (I132V) and subsequently disrupted (I123L and L146F) interaction with the CD3 ζ chain. This coevolution of Env and Nef function suggests that CD3 downmodulation is advantageous for viral replication in activated CCR5⁺ memory T cells, but not in resting naive CXCR4⁺ T cells that have not yet undergone TCR-CD3-mediated stimulation. This may explain why HIV-1, which generally lacks the CD3 downmodulation function, commonly switches to CXCR4 usage, whereas this is extremely rare for SIV strains that have retained this Nef activity.

Large-scale graphene micropattern nano-biohybrids: high-performance transducers for FET-type flexible fluidic HIV immunoassays

Large-scale FET-type graphene micropattern (GM) nano-biohybrid-based immunosensor (GMNS) is fabricated in a controlled fashion to detect human immunodeficiency virus 2 antibody. Flexible GMNS shows a highly sensitive response and excellent mechanical bendability. The flexible GMNS in fluidic systems also has a stable response. This is the first experimental demonstration of a large-scale flexible fluidic FET-type immunoassay based on GM nano-biohybrids.

Centers for Disease Control and Prevention (CDC). Detection of acute HIV infection in two evaluations of a new HIV diagnostic testing algorithm - United States, 2011-2013

The highly infectious phase of acute human immunodeficiency virus (HIV) infection, defined as the interval between the appearance of HIV RNA in plasma and the detection of HIV-1-specific antibodies, contributes disproportionately to HIV transmission. The current HIV diagnostic algorithm consists of a repeatedly reactive immunoassay (IA), followed by a supplemental test, such as the Western blot (WB) or indirect immunofluorescence assay (IFA). Because current laboratory IAs detect HIV infection earlier than supplemental tests, reactive IA results and negative supplemental test results very early in the course of HIV infection have been erroneously interpreted as negative. To address this problem, CDC has been evaluating a new HIV diagnostic algorithm. This report describes two evaluations of this algorithm. An HIV screening program at a Phoenix, Arizona emergency department (ED) identified 37 undiagnosed HIV infections during July 2011-February 2013. Of these, 12 (32.4%) were acute HIV infections. An ongoing HIV testing study in three sites identified 99 cases with reactive IA and negative supplemental test results; 55 (55.6%) had acute HIV infection. CDC and many health departments recognize that confirmatory supplemental tests can give false-negative results early in the course of HIV infection. This problem can be resolved by testing for HIV RNA after a reactive IA result and negative supplemental test result.