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Background HIV-2 resistance to integrase strand-transfer inhibitors (INSTIs) is characterized by two main pathways: (i) mutations at codons 143, 148 and155; and (ii) amino acid insertion after integrase codon 231 (231ins). Objectives To complete INSTI resistance data on HIV-2 by determining the viral replicative capacity and INSTI phenotypic susceptibility of integrase mutants obtained through site-directed mutagenesis. Methods Site-directed mutants (SDMs) were constructed and viral stocks produced. Viral replicative capacity was assessed by measuring HIV-2 viral load at days 3, 7 and 14. In vitro phenotypic susceptibility was measured using the ANRS PBMC assay. Results Viruses bearing 231ins did not present impaired replicative capacity, except the 231ins GIRGK mutant. A 231ins GK SDM was resistant to raltegravir and cabotegravir, but remained susceptible to dolutegravir and bictegravir. SDMs harbouring a 5 amino acid insertion (GYKGK or SREGK) were both resistant to all INSTIs. The SDM with T97A+N155H, with or without E92Q, was resistant to all INSTIs, except bictegravir. Conclusions These first data on the newly described resistance pathway 231ins, using site-directed mutagenesis, showed no measurable impact on viral fitness and confirmed the decreased susceptibility to a first-generation INSTI (raltegravir) and cabotegravir. Resistance to second-generation INSTIs (dolutegravir and bictegravir) occurred for mutants with a 5 amino acid 231ins.

Highly active antiretroviral (ARV) therapy has been used for many years, but the use in low- and middle-income countries of antiretroviral drugs with low genetic barrier to resistance, combined with limited availability of viral load testing, has led to higher rates of acquired drug resistance, sustaining the rate of transmitted drug resistance. Here, we describe the evolution of ARV drugs with the ongoing development of injectable long-acting forms and the requirements regarding all new ARV drugs (i.e., no transmitted drug resistance, no cross-resistance and high genetic barrier to resistance). Then, we report the evolution of both transmitted and acquired resistance regarding new ARV drugs. The WHO has set very ambitious but motivating goals for HIV testing, treatment and viral suppression, aiming to achieve rates of 95% for all three by 2025. Reaching these goals requires a wide implementation and use of close virological monitoring in LMICs.

• RT-PCR for SARS-CoV-2′s diagnostic has many false negatives and long turnaround times. • In our study 20% of RT-PCR negative patients had a rapid Sars-CoV2 IgG/IgM positive. • Rapid SARS-CoV2 IgG/IgM may be used as a complementary assay to the RT-PCR. • They can be useful in emergency patient's triage and admission. • They help avoiding to admit a patient infected with SARS-CoV-2 in a COVID-free area.

Treatment of multidrug-resistant HIV-2 is an emerging issue, because of the rapid selection of mutations at time of virological failure and the low number of antiretrovirals active on HIV-2. The aim of this study was to determine the susceptibility of HIV-2 primary isolates to ibalizumab, a long-acting monoclonal antibody that binds to CD4 that is approved for the treatment of MDR HIV-1.In-vitro phenotypic susceptibility of 16 HIV-2 primary isolates was measured using a modified version of the ANRS peripheral blood mononuclear cells (PBMC) assay. Susceptibility to ibalizumab was assessed through 50% inhibitory concentrations and maximum percentage inhibitions (MPI), and gp105 was sequenced to look for determinants of reduced susceptibility.Ibalizumab inhibited viral replication of all 16 isolates, with a median IC 50 value of 0.027 μg/ml (range = 0.001-0.506 μg/ml), and a median MPI of 93%. Although two isolates presented higher IC 50 (above 0.1 μg/ml), they did not exhibit a loss of potential N-linked glycosylation sites in V5 loop, as reported in HIV-1 strains with reduced susceptibility. However, both presented shorter V1 and V2 loops than the HIV-2 reference strain.Ibalizumab inhibits HIV-2 replication, with IC 50 and MPI in the range of those reported for HIV-1. These in vitro data support the use of ibalizumab in patients with MDR HIV-2, in combination with an optimized background regimen.

Genetic diversity of HIV-2 groups A and B has not yet been fully described, especially in a few Western Africa countries such as Ivory-Coast or Mali. We collected 444 pol, 152 vif, 129 env, and 74 LTR sequences from patients of the French ANRS CO5 HIV-2 cohort completed by 221 pol, 18 vif, 377 env, and 63 LTR unique sequences from public databases. We performed phylogenetic reconstructions and revealed two distinct lineages within HIV-2 group A, herein called A1 and A2, presenting non-negligible genetic distances and distinct geographic distributions as A1 is related to coastal Western African countries and A2 to inland Western countries. Estimated early diversification times for groups A and B in human populations were 1940 [95% higher probability densitiy: 1935–53] and 1961 [1952–70]. A1 experienced an early diversification in 1942 [1937–58] with two distinct early epidemics in Guinea-Bissau or Senegal, raising the possibility of group A emergence in those countries from an initial introduction from Ivory-Coast to Senegal, two former French colonies. Changes in effective population sizes over time revealed that A1 exponentially grew concomitantly to Guinea-Bissau independence war, but both A2 and B lineages experienced a latter growth, starting during the 80s economic crisis. This large HIV-2 genetic analysis provides the existence of two distinct subtypes within group A and new data about HIV-2 early spreading patterns and recent epidemiologic evolution for which data are scarce outside Guinea-Bissau.

Objective To describe lymphoma in HIV-2-infected patients and compare their characteristics with lymphoma in HIV-1-infected patients. Design Ancillary analysis from a single center prospective cohort of HIV-lymphoma. Methods We report on 16 patients with HIV-2-lymphoma diagnosed after 1996 and included in a prospective cohort of HIV-lymphoma. Five additional HIV-2-infected patients coinfected with HIV-1 or/and HTLV-I (6 lymphomas) are separately reported. The incidence of lymphoma in HIV-2 patients was evaluated in the French multicentric HIV-2 cohort. Results Incidence of lymphoma in the French HIV-2 cohort was estimated as 0.6/1000 patient-years. In our series, the median CD4 cell count was 166 x106/L at the time of lymphoma diagnosis and 50% of patients had undetectable plasma HIV-2-RNA. Lymphomas were non-Hodgkin lymphoma (n = 12) and classical Hodgkin lymphoma (n = 4). Similarly to HIV-1-lymphoma, clinical presentation was aggressive in most cases. All but one patient received intensive chemotherapy. Complete remission was achieved in 13 cases and one patient relapsed. The overall survival was not statistically different from that observed in patients with HIV-1-lymphoma. The six additional lymphomas observed in five HIV-2-infected patients coinfected with HIV-1 or/and HTLV-I presented with similar clinical presentation, but worse prognosis. Conclusions Despite the lower pathogenicity of HIV-2, the risk of developing lymphoma seems to be close to that observed in HIV-1 population with similar lymphoma characteristics. Compared to HIV-1, HIV-2-infected patients developed lymphoma later in their life, but at a similar CD4 cell count level.

The HIV-2 virus is not widely spread worldwide, with only one to three million infected people, mainly in West Africa. HIV-2 is responsible for an attenuated infection compared to HIV-1. Thus, HIV-2 infection is characterized by low and frequently undetectable viral loads and a slower course to AIDS. Describing the infection natural history differences between these two viruses, and then determining the mechanisms underlying the HIV-2 lower pathogenicity, is essential to identify the mechanisms underlying the immunopathogenicity of HIV infection. Studies conducted to date have identified both host-related and virus-related factors contributing to an improved immune control and the attenuated viral replication. In this review, we summarize the origins and epidemiology of HIV-2, the natural history of infection, the main virological tools for monitoring the infection course, and the main mechanisms explaining the attenuated infection of HIV-2. We also indicate the points remaining to be explored.

BackgroundIntegrase strand transfer inhibitors (INSTIs) are crucial for the treatment of human immunodeficiency virus (HIV) type 2 infection, due to limited available therapeutic options. Recently, bictegravir has been approved for HIV-1, but no data are currently available for HIV-2.MethodsWe assessed the phenotypic susceptibility of 12 HIV-2 clinical isolates, obtained from 2 antiretroviral-naive and 10 antiretroviral-experienced patients, to 5 INSTIs (bictegravir, cabotegravir, dolutegravir, elvitegravir, and raltegravir) at the virological failure of an INSTI-based regimen. The 50% inhibitory concentrations (IC50s) were determined. Phenotypic inhibitory quotients were determined using trough INSTI plasma concentrations.ResultsWild-type viruses were susceptible to the 5 INSTIs, with IC50s in the nanomolar range. Bictegravir had a lower IC50 than the other INSTIs on those HIV-2 isolates bearing major, resistance-associated mutations (codons 143, 148, and 155). We identified a new resistance profile—a 5–amino-acid insertion at codon 231 of the HIV-2 integrase (231INS)—in 6 patients at the virological failure of a raltegravir-based regimen. Those patients had adequate raltegravir concentrations, but harbored multiresistant viruses with low genotypic susceptibility scores (median = 1.5). This insertion rendered isolates highly resistant to raltegravir and elvitegravir, and moderately resistant to dolutegravir and cabotegravir. Regarding bictegravir, 2 isolates remained susceptible and 2 had a slight increase in IC50 (3- to 5-fold change).ConclusionsOur results confirm the potency of INSTI on HIV-2 clinical isolates with wild-type integrase. In addition, we identified a new resistance pathway, 231INS, selected in antiretroviral-experienced patients with multiresistant HIV-2 viruses. This highlights the need of close follow-up of those patients initiating an INSTI-based regimen.

The worldwide demand for SARS-CoV-2 RT-PCR testing resulted in a shortage of diagnostic kits. RNA extraction step constitutes a major bottleneck to perform diagnostic. The aim of this study was to assess performances of different extraction-free SARS-CoV-2 RT-PCR assays compared to a reference RT-PCR assay. The panel of evaluation consisted of 94 samples: 69 positive and 25 negative for SARS-CoV-2 by reference RT-PCR. Three extraction-free RT-PCR assays were assessed: (i) PrimeDirect® Probe RT-qPCR Mix (Takara), (ii) PrimeScript®RT-PCR (Takara), and (iii) SARS-CoV-2 SANSURE®BIOTECH Novel Coronavirus (Sansure). The overall sensitivity of PrimeDirect, PrimeScript and Sansure assays was 55.1 %, 69.6 % and 69.6 %, respectively. The sensitivity increased among samples with Ct

BackgroundMolecular assays on nasopharyngeal swabs remain the cornerstone of COVID-19 diagnostic. Despite massive worldwide efforts, the high technicalities of nasopharyngeal sampling and molecular assays, as well as scarce resources of reagents, limit our testing capabilities. Several strategies failed, to date, to fully alleviate this testing process (e.g. saliva sampling or antigen testing on nasopharyngeal samples). We assessed the performances of a new ELISA microplate assay quantifying SARS-CoV-2 nucleocapsid antigen (N-antigen) in serum or plasma.MethodsThe specificity of the assay, determined on 63 non-COVID patients, was 98.4% (95% confidence interval [CI], 85.3 to 100). Performances were determined on 227 serum samples from 165 patients with RT-PCR confirmed SARS-CoV-2 infection included in the French COVID and CoV-CONTACT cohorts.FindingsSensitivity was 132/142, 93.0% (95% CI, 84.7 to 100), within the first two weeks after symptoms onset. A subset of 73 COVID-19 patients had a serum collected within 24 hours following or preceding a positive nasopharyngeal swab. Among patients with high nasopharyngeal viral loads, Ct value below 30 and 33, only 1/50 and 4/67 tested negative for N-antigenemia, respectively. Among patients with a negative nasopharyngeal RT-PCR, 8/12 presented positive N-antigenemia. The lower respiratory tract was explored for 6/8 patients, showing positive PCR in 5 cases.InterpretationThis is the first demonstration of the N-antigen antigenemia during COVID-19. Its detection presented a robust sensitivity, especially within the first 14 days after symptoms onset and high nasopharyngeal viral loads. These findings have to be confirmed with higher representation of outpatients. This approach could provide a valuable new option for COVID-19 diagnosis, only requiring a blood draw and easily scalable in all clinical laboratories.

Background: The virus responsible of severe acute respiratory syndrome named SARS-CoV-2 and causing the new coronavirus disease (COVID-19) has gone global within three months. The current gold standard technique used to detect SARS-CoV-2 is real-time reverse transcription-polymerase chain reaction (rRT-PCR) from naso-pharyngeal swabs but it may be negative in up to 30% of COVID-19 patients. Detection of specific antibodies against SARS-CoV-2 may therefore enhance sensitivity of the current biological diagnosis, as well as monitor the extent of the epidemics in global or specific population, such as health-care worker. Many serological assays are currently available, but their clinical performances are still to be evaluated. Material and Method: A total of 2,594 serum samples collected from patients with SARS-CoV-2 infection documented by a positive rRT-PCR were enrolled in this study. They were tested for IgM/IgG/IgA against SARS-CoV-2 using 31 commercial assays. Antibody response was assessed depending on the onset of symptoms. In addition, 1,996 pre-epidemic serum samples expected to be negative were tested to assess specificity. Results: Rapid tests for qualitative detection of anti-SARS-CoV-2 antibodies (RDTs) achieved 77.4-100%, and ELISA/CLIA (ELISA) assays 58.8-100% for SARS-CoV-2-specific total antibodies (TAb) specificity. From 15 days after onset of symptoms, 13/18 RDT and 8/13 ELISA reached sensitivity > 90%. However, only 4 RDT and 3 ELISA assays fitted both sensitivity (> 90%) and specificity (> 98%) criteria according to French recommendations. Conclusions: Serology may offer valuable information during the course of COVID-19 pandemic, at the condition that commercial assays give reliable results. Contrasted performances were observed among the 31 commercial assays we evaluated, which underlines the importance of independent evaluation before clinical implementation. Funding Statement: This study was funded by the Agence Nationale de Recherche sur le SIDA et les Hepatites Virales (ANRS, AC43)". Declaration of Interests: JM Pawlotsky has served as an advisor and/or a speaker for Abbvie, Gilead, GlaxoSmithKline, Merck, Regulus and Siemens Healthcare. C Vauloup-Fellous served as un expert (rubella and CMV serology) for Abbott Diagnostics, Roche Diagnostics, Siemens Healthcare and DiaSorin. No other authors have any competing interests to declare. Ethics Approval Statement: The study was carried out in accordance with the Declaration of Helsinki. This work was a retrospective non-interventional study with no addition to standard care procedures. Reclassification of biological remnants into research material after completion of the ordered virological tests was approved by the local interventional review board of hospital. According to the French Public Health Code (CSP Article L.1121-1.1) such protocols are exempted from individual informed consent.

In-depth study of HIV often requires large stock of patients-derived viruses obtained through viral cultures. HIV cultures are currently limited by low recovery rates, especially when viral load is below 100,000 copies per mL. This is problematic for HIV-2 as most patients have spontaneously low to undetectable viremia. New approaches have been developed to enhance viral recovery rates but they are complex or costly to implement. We tested the impact of μMACSTM VitalVirus Isolation Kit (Miltenyi), a HIV virions capture method using paramagnetic microbeads directed against CD44, a human glycoprotein present in HIV envelope. This method separates viruses from interfering proteins in 45 min, using a reduced sample volume (200 μL versus 1000 μL for classic culture assays). The impact of this purification method on virus recovery rate was assessed with 23 HIV-1 and 29 HIV-2 plasma samples with a wide range of viral loads, in comparison to a classic culture assay used routinely in our laboratory. For both HIV-1 and HIV-2, the culture identification delay was decreased using viral purification (≤7days in most cases). The recovery rate of cultures was improved for HIV-2 isolates (17/29 versus 8/29; p = 0.03) but not for HIV-1 (7/23 versus 5/23; p = 0.74). Notably, HIV-2 isolates with viral loads over 10,000 copies per mL were frequently recovered in culture (68% versus 32% without purification; p = 0.03). This marked improvement on HIV-2, but not on HIV-1, cultures is puzzling. CD44-microbeads may enable a close and prolonged contact between cells and viruses, and may thus overcome HIV-2 difficulties to infect target cells.

Objectives To assess the prevalence of minority resistant variants (MRV) and X4-tropic minority variants in ART-naive HIV-2-infected patients. Patients and methods ART-naive HIV-2-infected patients with detectable plasma viral load (>100 copies/mL) included in the ANRS HIV-2 CO5 Cohort were assessed. We performed ultra-deep sequencing (UDS) of protease, RT, integrase and gp105 regions. Only mutations in the HIV-2 ANRS list >1% were considered. HIV-2 tropism was assessed by V3 loop region UDS, and each read was interpreted with determinants of CXCR4-coreceptor use. Results Among the 47 patients assessed, three displayed plasma viruses with a resistance-associated mutation (RAM) above the 20% detection threshold, all in RT, resulting in a prevalence of transmitted drug resistance for NRTI of 7.9% (95% CI 0.0%-16.5%). No RAM above the 20% detection threshold was found in protease or integrase. At the 1% detection threshold the transmitted drug resistance prevalence was 9.8% (95% CI 0.6%-19.0%), 13.2% (95% CI 3.5%-22.9%) and 4.5% (95% CI 0%-17.5%) for PI, NRTI and integrase inhibitors. The most prevalent MRV was the PI RAM I50V detected in three samples. Tropism analysis showed that 21% of patients (4 of 19) exhibited X4-tropic viruses: two in majority proportion and two in minority proportions (1.5% and 1.9%). Conclusions In this first study assessing the prevalence of MRV in HIV-2 infection among ART-naive patients, we observed a 2-3-fold higher prevalence of RAM when a 1% detection threshold of mutations was used compared with a 20% threshold. Similarly, the proportion of patients with X4-tropic viruses was twice as high when UDS was used.

Background The new Roche Cobas 6800 platform (C6800) has been recently introduced for viral load (VL) measurement. Objectives Comparing C6800 to Cobas Ampliprep/Cobas TaqMan v2.0 (CAP/CTM) for the quantification of HIV, HBV and HCV viremia, and to the Abbott RealTime assay (ABB) for HCV quantification. Study design We analysed 121 samples for HBV, and 139 for HIV-1 including 2 groupO and 137 group M viruses (36.5% subtype B, 27.0% CRF02_AG, 22.6% from other clades, and 14% subtype not available). For the 100 HCV samples compared with CAP/CTM, 42% were genotype 1 and 17% were genotype 4. For the 68 HCV samples compared with ABB, 52.9% were genotype 1 and 22.1% were genotype 4. Results C6800 results correlated well with those of CAP/CTM for all three viruses (R2: 0.97–0.99). However, C6800 can yield different viraemia results: higher for HIV (mean difference: +0.11 log10 copies/mL, p Conclusion Overall, the comparison tests between C6800 and CAP/CTM systems are satisfactory for the three viruses. Frequent discrepancies were observed between C6800 and ABB for HCV.

Zika virus is known to be transmitted by mosquitoes. The authors report the sexual transmission of Zika virus to a woman in Paris from a man who had recently traveled from Brazil.

More than 1 million individuals, mainly in West Africa, are thought to be infected with HIV-2. Acute HIV-2 infection is rarely observed, only 2 primary infections have been described to date. We report a detailed case of HIV-2 primary infection in a 69-year-old French bisexual Caucasian man, thereby providing valuable insights into HIV-2 early infection.

First-line raltegravir-containing combination antiretroviral therapy in 30 patients living with HIV-2 was well tolerated and yielded a median CD4 gain at 1 year of 87 cells/µL, and HIV-2 RNA, Background New options for first-line treatment of human immunodeficiency virus type 2 (HIV-2) infection are needed. We evaluated an integrase inhibitor (raltegravir)–containing regimen. Methods Antiretroviral therapy (ART)–naive adults with symptomatic infection by HIV-2 only, CD4 count 50 cells/μL/year over the past 3 years, or a confirmed plasma HIV-2 RNA (pVL) load ≥100 copies/mL were eligible for this noncomparative trial. The composite primary endpoint was survival at 48 weeks without any of the following: CD4 gain from baseline 6 copies by PCR in 32%. At week 48, the composite endpoint of success was reached in 40% [95% confidence interval, 22.7%–59.4%]. Failure was mainly (50%) due to CD4 gain 6 copies by PCR in 12% of participants. Median CD4 gain was 87 cells/µL (IQR, 38–213 cells/µL; n = 28). No serious adverse reactions were reported. Conclusions Raltegravir-containing ART is a safe option for first-line treatment of HIV-2 infection, yielding a comparable success rate to protease inhibitors. Clinical Trials Registration NCT 01605890.

Major differences exist between HIV-1 and HIV-2 in terms of epidemiology, pathogenicity, sensitivity to antiretrovirals. Determining the type of HIV infecting a patient is essential for management. The aim of this study was to evaluate the ability of simple/rapid tests to differentiate between HIV-1 and/or HIV-2 infections. We analyzed 116 samples from patients infected with HIV-1 (n = 61), HIV-2 (n = 47), or HIV-1+HIV-2 (n = 8) at the chronic stage of infection. Each sample was tested with SD Bioline HIV-1/2 3.0, ImmunoFlow HIV1–HIV2, ImmunoFlow HIV1–HIV2 (WB), Genie III HIV-1/HIV-2, ImmunoComb HIV1&2 BiSpot. HIV-1, or HIV-2 single infection was identified with a sensitivity ranging from 90% to 100%. The ability to detect dual infection was less sensitive (12.5–100%). SD Bioline HIV-1/2 3.0, ImmunoFlow HIV1–HIV2, and Genie III were unable to detect HIV-1 group O infection in one, one and two cases, respectively. The specificity of detection of HIV-1, HIV-2, or HIV-1+HIV-2 antibodies differed greatly (36–100%). ImmunoComb BiSpot had the highest sensitivity values (99–100% for HIV-1, 98% for HIV-2, and 75–87.5% for dual infection) and specificity values (94–100% for HIV-1, 100% for HIV-2, and 97–100% for dual infection). In conclusion, this study showed that no single rapid test had a perfect sensitivity/specificity ratio, particularly in the case of the double infections. J. Med. Virol. 87:2061–2066, 2015. © 2015 Wiley Periodicals, Inc.

HIV-2 infection is characterized by a very low replication rate in most cases and low progression. This necessitates an approach to patient monitoring that differs from that for HIV-1 infection. Here, a new highly specific and sensitive method for HIV-2 DNA quantification was developed. The new test is based on quantitative real-time PCR targeting the long terminal repeat (LTR) andgagregions and using an internal control. Analytical performance was determined in three laboratories, and clinical performance was determined on blood samples from 63 patients infected with HIV-2 group A (n= 35) or group B (n= 28). The specificity was 100%. The 95% limit of detection was three copies/PCR and the limit of quantification was six copies/PCR. The within-run coefficients of variation were between 1.03% at 3.78 log10copies/PCR and 27.02% at 0.78 log10copies/PCR. The between-run coefficient of variation was 5.10%. Both manual and automated nucleic acid extraction methods were validated. HIV-2 DNA loads were detectable in blood cells from all 63 patients. When HIV-2 DNA was quantifiable, median loads were significantly higher in antiretroviral-treated than in naive patients and were similar for groups A and B. HIV-2 DNA load was correlated with HIV-2 RNA load (r= 0.68; 95% confidence interval [CI], 0.4 to 0.8;P< 0.0001). Our data show that this new assay is highly sensitive and quantifies the two main HIV-2 groups, making it useful for the diagnosis of HIV-2 infection and for pathogenesis studies on HIV-2 reservoirs.

Background Atazanavir/ritonavir (ATV/r) is a boosted protease inhibitor recommended to minimize the risk of mother-to-child HIV-1 transmission (MTCT). We aimed to assess the pharmacokinetics, safety and efficacy of ATV/r in HIV-1-infected pregnant women and their neonates. Methods A multicentre, cross-sectional, non-interventional cohort of HIV-1-infected pregnant women receiving ATV/r (300/100 mg once daily) who delivered in three Paris hospitals from 2006 to 2013 was designed. We determined antiretroviral trough plasma concentrations using liquid chromatography–mass spectrometry at each of the three trimesters, delivery and post-partum. ATV concentrations at 24 h (C24h) were interpreted by the 150–850 ng/ml efficacy–tolerance thresholds. Safety data and newborn HIV status were recorded. A mother's virological failure was defined as two successive measurements of plasma HIV-1 RNA>50 copies/ml within the 2 months before delivery. Results 103 pregnant women were included, mostly from sub-Saharan Africa (88%). ATV C24h at each of the three trimesters and delivery remained similar to post-partum values. No dose adjustment was needed during pregnancy. The median plasma ratio of fetal/ maternal ATV level was 0.19 ( n=28). Only three patients showed two successive detectable viral loads but Conclusions In this population, an ATV/r-containing anti-retroviral regimen demonstrated good pharmacokinetics, virological efficacy and safety. No significant impact of pregnancy on ATV C24h was found. No dose adjustment was required.

To assess the virological response, genotypic resistance profiles, and antiretroviral plasma concentrations in HIV-2 antiretroviral-treated (antiretroviral therapy, ART) patients in Côte d'Ivoire.A cross-sectional survey was conducted among HIV-2 patients receiving ART. Plasma HIV-2 viral load was performed using the Agence Nationale de Recherche sur le SIDA et les hépatites virales (ANRS) assay. Protease and reverse transcriptase sequencing was performed using in-house methods and antiretroviral plasma concentrations were assessed using ultra performance liquid chromatography combined with tandem mass spectrometry.One hundred and forty-five HIV-2-treated patients were enrolled with a median CD4 cell count of 360 cells/μl (interquartile range, IQR = 215-528). Median duration of ART was 4 years (IQR = 2-7) and 74% of patients displayed viral load less than 50 copies/ml. Median plasma HIV-2 RNA among patients with viral load more than 50 copies/ml was 3016 copies/ml (IQR = 436-5156). Most patients (84%) received a lopinavir/ritonavir-based regimen. HIV-2 resistance mutations to nucleoside reverse transcriptase inhibitors and protease inhibitors were detected in 21 of 25 (84%) and 20 of 29 (69%) samples, respectively. The most prevalent nucleoside reverse transcriptase inhibitor resistance mutations were M184I/V (90%), Q151M (24%), and S215F/Y (24%). The most prevalent protease inhibitor resistance mutations were V47A (60%) and I54M (30%). Median CD4 cell counts were 434 cells/μl (292-573) and 204 cells/μl (122-281) in patients with viral load less than 50 copies/ml and those exhibiting virological failure (P 0.0001), respectively. The proportions of patients with adequate antiretroviral plasma concentrations were 81 and 93% in patients displaying virological failure and in those with viral load less than 50 copies/ml, respectively (P = 0.046), suggesting good treatment adherence.We observed adequate drug plasma concentrations and virological suppression in a high proportion of HIV-2-infected patients. However, in cases of virological failure, the limited HIV-2 therapeutic arsenal and cross-resistance dramatically reduced treatment options.

Plasma HIV-2 viral load has been reported as predictive of AIDS in HIV-2 infected patient but the lack of sensitivity of the current HIV2 viral load assay is a limitation for the monitoring of the HIV-2-infected patients. Objective To validate a new quantification assay based on a synthetic HIV-2 RNA transcript and real-time PCR with primers and probes selected in the LTR region, together with high-performance reagents and a protective RNA carrier. Study design We quantified 23 HIV-2 group A and B supernatants and 58 plasma samples with our TAQMAN-PCR assay and compared the results to those of our previously published in a real time reference PCR performed onto Light Cycler technology, the LC-PCR with a detection of 2.0 log10 copies/ml. Results The performance of TAQMAN-PCR was significantly improved, yielding a detection limit of 17 RNA copies/ml. There was a major difference (1–5 log10 copies/ml) between LC-PCR and TAQMAN-PCR values for HIV-2 group B supernatants. Twenty-six of 27 plasma samples with levels higher than 2.0 log10 copies/ml in LC-PCR were positive by TAQMAN-PCR. Ten of the 31 plasma samples below the LC-PCR detection limit were quantifiable with the TAQMAN-PCR. Conclusions The new primers and probe in the LTR region can circumvent HIV-2 diversity, making our method suitable for use in HIV-2 group B-infected patients. Use of a high-performance RT enzyme and RNA carrier protection contributed to improving the detection limit. This study confirms that plasma viral load is lower than 17 copies/ml in a large number of HIV-2-infected patients.

The Simian Immunodeficiency Virus of sooty mangabeys (SIVsmm) has been revealed to be at the origin of Human Immunodeficiency Virus type 2 (HIV-2) in humans, firstly detected from two Portuguese patients in 1986. HIV-2 is mainly restricted to West Africa where it infects up to 1 to 2 million people. HIV-2 is also present in Europe, mainly Portugal and France, India and United States of America. Two major HIV-2 groups, groups A and B, were generated by two independent transmission events involving infected sooty mangabeys from the Tai forest in Ivory Coast. Seven other HIV-2 groups have been described, but each has only been identified in one patient. To date, no subtypes have been formally described but some preliminary data suggest that HIV-2 group A may be divided in two distinct subtypes with distinct geographical origins. To date only two recombinant forms have been described: one circulating recombinant form (CRF01_AB) and one unique recombinant form. In this review, we focused mainly on molecular data available and their insights about HIV-2 origins, diversity, drug resistance and global epidemiology.

BACKGROUND: Human immunodeficiency virus type 2 (HIV-2) infection is characterized by a slower progression than HIV type 1. It is not known whether markers of inflammation such as high-sensitivity C-reactive protein (hsCRP), interleukin 6 (IL-6), and soluble CD14 (sCD14) may predict disease progression among HIV-2 patients. METHODS: We performed longitudinal retrospective analysis using 384 samples from 71 patients included in the HIV-2 French cohort ANRS CO5 and followed for a median of 8 years. Baseline was the time of the first available measurement. Disease progression was defined by the occurrence of death, Centers for Disease Control and Prevention B/C stage HIV-related event, drop in CD4

The aim of this study was to describe HIV-2 R5/X4-tropism distribution in antiretroviral-naive HIV-2-infected patients. Population sequencing of the gp105 region was performed on peripheral blood mononuclear cells issued from 151 antiretroviral-naive patients. Tropism was successfully determined in 46 of 151 samples (30%) with six of 46 (13%) X4-tropic viruses. X4-tropism was associated with lower CD4 cell count (337 vs. 551/mm; P = 0.032) but not with plasma viral load. Thus, X4-tropism prevalence in HIV-2 antiretroviral-naive patients is similar to that observed in HIV-1.

OBJECTIVE The use of CCR5 inhibitors requires a tool to predict human immunodeficiency virus type 2 (HIV-2) tropism, as established in HIV-1. The aim of our study was to identify genotypic determinants of HIV-2 tropism located in the gp105 V3 loop. METHODS HIV-2 tropism phenotypic assays were performed on 53 HIV-2 clinical isolates using GFP expressing human osteosarcoma T4 [GHOST(3)] cell lines expressing CD4 and CCR5 or CXCR4 coreceptors. The gp105 V3 loop was sequenced and analyzed. RESULTS Thirty-four HIV-2 isolates were classified as R5, 7 as X4, and 12 as X4/R5 (dual). Substitution at residue 18 was always associated with a dual/X4 tropism (P < .00001). The following determinants were associated with dual/X4 tropism: a global net charge of more than +6 (P < .00001), V19K/R mutation (P < .00001), S22A/F/Y mutation (P < .002), Q23R mutation (P < .00001), and insertions at residue 24 (P < .00001), I25L/Y (P < .0004), R28K (P < .0004), and R30K (P < .014). These mutations were not found in R5 isolates, except R28K and R30K, which were detected in 4 and 5 R5 isolates, respectively. The 4 major genotypic determinants of dual/X4 tropism were mutation at residue 18, V19 K/R mutation, insertions at residue 24, and V3 global net charge. CONCLUSIONS We established a strong association between HIV-2 phenotypic tropism and V3-loop sequences, allowing for the prediction of R5- and/or X4-tropic viruses in HIV-2 infection.

Objective Recently, we have reported the role of baseline gag cleavage site mutations on the virological outcome of a dual-boosted protease inhibitor regimen in antiretroviral-naive patients (2IP-ANRS 127 trial). The objective of this substudy was to characterize, in patients experiencing virological failure, from the 2IP-ANRS 127 trial, the viral quasispecies present at baseline and at virological failure in gag cleavage site, in gag-pol frameshift and in protease-coding region. Methods In four patients, we analysed by clonal analysis the viral population in gag cleavage site (p17/p24, p24/p2, p2/p7, p7/p1, p1/p6(gag)), in p6(gag), in gag-pol frameshift [p1/transframe protein (TFP)/p6(pol)] and in protease-coding region. Results Clonal analysis of protease-coding region failed to detect major as well as minor protease inhibitor resistance-associated mutations in all four patients. In one patient, a I15V-mutated variant increased from 13 to 100% between baseline and week 24. Clonal analysis of gag and gag-pol cleavage site showed an increase in specific viral populations in p2/p7 cleavage site between baseline and virological failure in three patients. Among them, we described in one patient, that the predominant population at virological failure harboured in p2/p7 and TFP/p6(pol)-specific genotypic profiles associated with duplication of the P(T)APP motif in p6(gag) and the I15V protease mutation on the same individual molecular clones. Conclusion We highlighted the emergence of minority viral populations in the p2/p7 cleavage site between baseline and virological failure. In addition, we showed the association of a specific protease mutation with gag and gag-pol cleavage site substitutions, suggesting their possible role in virological outcome.

Resume Introduction Le VIH-1 groupe O (VIH-O), principalement retrouve au Cameroun, presente une tres grande diversite genetique ayant des consequences sur le diagnostic et la prise en charge des patients, necessitant la mise au point d’outils specifiques. Objectif Presenter les moyens actuellement disponibles pour depister les infections a VIH-O et assurer leur traitement, ainsi que les premieres donnees de RES-O, reseau francais d’identification et de suivi de patients infectes par le VIH-O. Methodes Le diagnostic a ete confirme par serotypage de l’enveloppe, specifique de groupe. La charge virale a ete evaluee par une technique LTR-O, mise au point au laboratoire et comparee a la trousse non specifique RealTime HIV-1 (Abbott). Le sequencage des regions cibles des antiretroviraux (protease, transcriptase inverse [TI], integrase et Gp41) a ete realise par amorces specifiques. L’analyse des mutations de resistance a ete faite grâce a l’algorithme ANRS utilise pour les VIH-M. Resultats L’infection par un VIH-O a ete confirmee chez 117 patients. La charge virale montre une equivalence entre les deux techniques, avec une tendance a la sous-quantification de la technique Abbott superieure a 1 Log pour 5 % des prelevements. Parmi les souches etudiees, 70 a 100 % possedent au moins neuf mutations dans la protease, quatre dans la TI et une dans la Gp41, avec pour consequence une resistance genotypique naturelle a certaines molecules antiretrovirales. Discussion Le diagnostic et le suivi d’une infection par le VIH-O est possible. L’impact du polymorphisme naturel de ce variant sur la reponse au traitement est meconnu.

Objectives: To study the relative impact of HIV-1 infection and associated immunodepression on the severity of Plasmodium falciparum malaria in adults returning from areas of endemic malaria. Methods: We conducted a cross-sectional study, based on data from 104 HIV-infected patients from the French Hospital Database on HIV cohort (FHDH-ANRS CO4) and 161 HIV-negative patients from Bichat hospital, with a diagnosis of imported P. falciparum malaria between 2000 and 2003. The severity of falciparum malaria episode was graded with World Health Organization (WHO) criteria 2000 or on 2007 French recommendations. Result: Depending on criteria used, 40% (WHO) and 28% (2007 French recommendations) of episodes of imported P. falciparum malaria in HIV-infected patients were classified as severe, compared with 21 % (WHO) and 11 % (2007 French recommendations) of episodes among HIV-negative patients. Among HIV-infected patients, the episodes were severe in between 22 (CD4 cell counts ≥350/μl) and 51 % (CD4 cell counts

Human immunodeficiency viruses HIV-1 and HIV-2 are the results of multi-interspecies transmissions from simian virus to humans. HIV-1 viruses are very divergent and are classified in three groups: M, N and O. The group M is subdivided in nine subtypes and numerous Circulating Recombinant Forms. In 1996, protease inhibitors and HAART disposal have modified the prognostic of the HIV infection. However, one of the major problems is the emergence of antiretroviral resistance. A major advance from the last year is the access to antiretroviral in resources limited countries. On the other hand, the development of a vaccine is today hypothetic.

INTRODUCTION The lesser pathogenicity of HIV-2 relative to HIV-1 is generally attributed to its slower replication. To compare the amounts of total HIV DNA during human HIV-1 and HIV-2 infection, we developed a quantitative real-time PCR method with a unique external quantification standard based on a single plasmid harboring both the HIV-1 and the HIV-2 LTR. METHODS Viral DNA load was compared between 40 HIV-1-infected and 42 HIV-2-infected antiretroviral-naive patients. RESULTS The difference between HIV-1 and HIV-2 proviral DNA load was highly significant in patients with CD4 cell counts > 500 cells/microl [HIV-1: n = 14; median, 2.5; interquartile range (IQR), 2.1-2.7; HIV-2: n = 22, median, 1.6; IQR, 1.0-2.0] and in patients with CD4 cell counts between 300 cells/microl and 500 cells/microl (HIV-1: n = 12; median, 2.7; IQR, 2.3-2.8; HIV-2: n = 11; median, 2.0; IQR, 1.0-2.4). Too few HIV-2-infected patients had CD4 cell counts < 300 cells/microl to detect a significant difference but DNA values were again lower in HIV-2-infected patients (HIV-1: n = 14; median, 2.9; IQR, 2.2-3.2; HIV-2: n = 9; median, 2.7; IQR, 2.2-3.3). CONCLUSIONS These differences are in line with the natural histories of the two infections and show that HIV-2 infection is a valid model for studying the pathophysiology of HIV infection in general.

Summary: The high genetic diversity of HIV-1 has a major impact on the quantification of plasma HIV-1 RNA, representing an increasingly difficult challenge. A total of 898 plasma specimens positive for HIV-1 RNA by commercial assays (Amplicor v1.5; Roche Diagnostic Systems, Alameda, CA or Versant v3.0; Bayer Diagnostics, Emeryville, CA) were tested using the Agence Nationale de Recherches sur le SIDA second-generation (G2) real-time reverse transcriptase polymerase chain reaction (RT-PCR) test: 518 samples containing HIV-1 of known subtype, including 88 from 2 subtype panels and 430 harboring B (n = 266) and non-B (n = 164) group M HIV-1 subtypes from patients followed up in 2002 through 2005 at Necker Hospital (Paris, France), and 380 samples from 10 different countries (Argentina, Cambodia, Cameroon, Central African Republic, France, Ivory Coast, Madagascar, Morocco, Thailand, and Zimbabwe). HIV-1 RNA values obtained by G2 real-time PCR were highly correlated with those obtained by the Amplicor v1.5 for B and non-B subtypes (R2 = 0.892 and 0.892, respectively) and for samples from diverse countries (R2 = 0.867 and 0.893 for real-time PCR vs. Amplicor v1.5 and real-time PCR vs. Versant v3.0, respectively). Approximately 30% of specimens harboring non-B subtypes were underquantified by at least −0.51 log10 in Amplicor v1.5 versus 5% underquantified in G2 real-time PCR. Discrepant results were also obtained with subtype B samples (14% underquantified by Amplicor v1.5 vs. 7% by G2 real-time PCR). Similar percentages were observed when comparing results obtained with the G2 real-time PCR assay with those obtained using the Versant assay. Addressing HIV-1 diversity, continual monitoring of HIV-1 RNA assays, together with molecular epidemiology studies, is required to improve the accuracy of all HIV RNA assays.

Objective To compare the efficacy of assisted reproductive technology (ART) in women infected with human immunodeficiency virus type 1 (HIV-1) versus HIV-negative controls. Design Retrospective case-control study. Setting University hospital ART unit. Patient(s) Eighty-two women infected with HIV-1 and 82 women as seronegative controls. Intervention(s) Ovarian stimulation, oocytes retrieval, standard in vitro fertilization (IVF) or intracytoplasmic sperm injection, embryo transfer. Main Outcome Measure(s) Clinical pregnancies and live-birth rates. Result(s) After oocyte retrieval, all women infected with HIV-1 infected were matched 1:1 to HIV-negative controls according to the following criteria: date of ART attempt, age, parity, main cause of infertility, ART technique, and rank of attempt. Only the first IVF cycle during the study period was considered for each couple. We found no statistically significant differences between the two groups for ovarian stimulation data, fertilization rate, or average number of embryos transferred. The clinical pregnancy rate per transfer was statistically significantly lower for the cases compared with the controls (12% vs. 32%), as were the implantation rate (10% vs. 21%) and the live-birth rate (7% vs. 19%). Conclusion(s) In one of the largest studies to pair six factors that influence the results of ART, HIV infection in women was associated with poorer outcomes after ART. These results suggest that women with controlled HIV-1-infection should be counseled not to delay ART in cases of self-insemination failure or other causes of infertility. Fertility preservation by vitrification of oocytes in women whose pregnancy should be delayed may be an important future consideration.

Objective In HIV-1, hypermutation introduced by APOBEC3F/3G cytidine deaminase activity leads to defective viruses. In-vivo impact of APOBEC3F/3G editing on HIV-2 sequences remains unknown. The objective of this study was to assess the level of APOBEC3F/3G editing in HIV-2-infected antiretroviral-naive patients. Methods Direct sequencing of vif and pol regions was performed on HIV-2 proviral DNA from antiretroviral-naive patients included in the French Agence Nationale de Recherches sur le SIDA et les hepatites virales CO5 HIV-2 cohort. Hypermutated sequences were identified using Hypermut2.0 program. HIV-1 proviral sequences from Genbank were also assessed. Results Among 82 antiretroviral-naive HIV-2-infected patients assessed, 15 (28.8%) and five (16.7%) displayed Vif proviral defective sequences in HIV-2 groups A and B, respectively. A lower proportion of defective sequences was observed in protease-reverse transcriptase region. A higher median number of G-to-A mutations was observed in HIV-2 group B than in group A, both in Vif and protease-reverse transcriptase regions (P = 0.02 and P = 0.006, respectively). Compared with HIV-1 Vif sequences, a higher number of Vif defective sequences was observed in HIV-2 group A (P = 0.00001) and group B sequences (P = 0.013). Conclusion We showed for the first time a high level of APOBEC3F/3G editing in HIV-2 sequences from antiretroviral-naive patients. Our study reported a group effect with a significantly higher level of APOBEC3F/3G editing in HIV-2 group B than in group A sequences.

BACKGROUND Dolutegravir has shown in vitro activity against human immunodeficiency virus type 2 (HIV-2). We report safety and efficacy data of regimens containing dolutegravir (50 mg twice daily) in antiretroviral-experienced, HIV-2-infected patients. METHODS HIV-2-infected patients experiencing virological failure to raltegravir received dolutegravir with optimized background antiretroviral combinations within the French Named Patient Program (NPP). Plasma HIV-2 RNA (pVL) was assessed at time of dolutegravir initiation (baseline), month 3, and month 6. Antiretroviral trough plasma concentrations (C12h) were determined using liquid chromatography coupled with tandem mass spectrometry. RESULTS Thirteen HIV-2-infected-patients, with a median duration of 15 years' infection and given 16 previous antiretroviral regimens, were included in NPP. Median follow-up was 9 months (min-max, 3-15 months). Median baseline pVL and CD4 cell count were 9544 copies/mL (inter quartile range [IQR], 3096-23 120 copies/mL) and 100 cells/µL (IQR, 77-171 cells/µL), respectively. Available integrase genotypic resistance patterns were Y143C/G/H/R (n = 5), Q148R/K (n = 2), and N155H (n = 4). Optimized background antiretroviral regimens conferring a genotypic sensitivity score ≤2 in 10 patients included nucleoside reverse transcriptase inhibitors associated with darunavir/ritonavir (n = 12), saquinavir/ritonavir (n = 2), and maraviroc (n = 3). At months 3 and 6, pVL was undetectable in 6 of 13 and 4 of 12 patients, respectively, and median CD4 count was 161 (101-188) cells/µL and 167 (135-1353) cells/µL, respectively. Median dolutegravir C12h was 4086 (1756-5717 ng/mL) ng/mL in 9 patients. No serious events were notified except 1 death from progressive multifocal leukoencephalopathy at month 4. CONCLUSIONS Optimized dolutegravir-containing antiretroviral regimens supported by good plasma exposure provide a substantial initial efficacy rate for salvage therapy in heavily antiretroviral-experienced HIV-2-infected patients with virus harboring resistance to first-generation integrase inhibitors. Larger numbers of patients and longer follow-up are needed to confirm these findings.

ObjectivePrevious studies have described the presence of the L74V reverse transcriptase (RT) mutation in highly experienced individuals as a risk factor for reduced response to tenofovir and selection of the K65R mutation. This study examined whether, in the context of a first-line abacavir/lamivudine highly active anti-retroviral therapy (HAART) regimen, K65R might occur as a minority population where L74V was detected at virological failure.MethodsFour previously ART-naive individuals undergoing virological failure were selected, all receiving abacavir and lamivudine with either protease inhibitors or efavirenz and with virus displaying L74V and M184V or M184V alone following transient L74V emergence. Clonal analyses from plasma viral RNA were performed on samples taken at baseline and after virological failure. Clones were screened for the presence of K65R by real time K65R-selective PCR (K65R-sPCR). RT genes from clones displaying K65R were sequenced.ResultsAt baseline, all clones were wild type at codon 65 by K65R-sPCR, except in one patient in which one of 720 clones exhibited K65R. At failure with M184V and L74V present by bulk sequencing, this K65R was retained in one of 855 clones assessed. One additional patient (M184V alone by bulk sequencing) displayed K65R in one of 466 failure clones. Virological failure samples from the remaining two patients were wild type at codon 65 in all of 524 and 270 clones, respectively.ConclusionsMinority species harbouring K65R are uncommon and occur at very low population densities in patients experiencing virological failure on first-line abacavir/lamivudine-containing HAART.

In 61 antiretroviral-naive HIV-2-infected patients starting triple therapy at a median CD4 cell count of 136 cells/microl, the median increase was 41 cells/microl at month 12, which was no different among those on protease inhibitors or triple nucleoside analogues. Despite virological response, as the median plasma load was under the detectable threshold from month 3, CD4 cell recovery remained poor in treated HIV-2 infection. Our results raise the question of the optimal regimen to recommend in HIV-2-infected patients.

OBJECTIVE To evaluate HIV-2-specific proliferative, interferon (IFN)gamma- and interleukin (IL)-2-producing T-cell responses in HIV-2 infection and their relationship with plasma HIV-2 RNA. METHODS HIV-2-Gag-p26 and cytomegalovirus (CMV)-specific CD4 T-cell responses from 19 untreated HIV-2-infected subjects (median CD4 cell counts, 561 x 10/l) were compared by lymphoproliferation assay, IFNgamma secretion in culture supernatants by ELISA, and intracellular staining (ICS) of IFNgamma and IL-2. CD8 responses were assessed by IFNgamma-ELISpot using pools of SIVmac239-Gag peptides (87% of homology with HIV-2). RESULTS HIV-2-specific IFNgamma production was detected in 53% and 92% patients by ELISA and ICS, respectively, while HIV-2-specific IL-2 production was detected in only 33% by ICS and lymphoproliferation in 21% patients. All IL-2-producing CD4 T cells co-produced IFNgamma. Overall, frequencies of Th1 responses to HIV-2 were similar to CMV in subjects with undetectable plasma HIV-2 RNA, while significantly lower than CMV in HIV-2 RNA-positive subjects, despite similar CD4 cell counts in both groups. In addition, proliferative responses to HIV-2 were correlated to IFNgamma secretion (r > 0.68, P < 0.01), and were significantly higher in HIV-2 RNA-negative (P < 0.05) than in HIV-2 RNA-positive subjects. Frequencies of SIV-Gag-specific CD8 cells, detected in 93% of patients, were also higher in HIV-2 RNA-negative subjects, though not significantly. Overall, HIV-2-specific T-cell responses were not correlated to CD4 cell counts. CONCLUSION Proliferative, IFNgamma- and IL-2-producing T-cell responses to HIV-2 are as robust as CMV-specific responses in untreated HIV-2 subjects with undetectable plasma HIV-2 levels, independently of CD4 cell depletion and despite lower frequencies of IL-2-producing T cells compared to IFNgamma. In addition, lymphoproliferative responses to HIV-2 were associated with lack of viral replication.

In HIV-2 infection, many studies have reported a high frequency of selection of the Q151M mutation, but its impact on phenotypic susceptibility of HIV-2 isolates remains unclear. Four HIV-2 infected patients from the French ANRS HIV-2 cohort, with evidence of Q151M mutation in both plasma and available peripheral blood mononuclear cells (PBMCs) co-cultivated supernatants, were selected. In vitro phenotypic susceptibilities to different nucleoside reverse transcriptase inhibitors (NRTIs) were determined using a PBMC assay. In HIV-2 isolates, the Q151M mutation alone impacts only the phenotypic susceptibility to stavudine and abacavir. A decrease in susceptibility to all NRTIs was observed when Q151M was selected with V111I, a mutation of unknown impact on HIV-1 resistance. Clinical relevance of these phenotypic susceptibility results needs to be evaluated in HIV-2 treated patients.

The objective of the study was to determine retrospectively which substitutions in the reverse transcriptase (RT) gene are selected in vivo during nucleoside RT inhibitors (NRTI) containing regimen in HIV-2 infected subjects. Thirty-four HIV-2 patients having received NRTI-containing regimen with available specimens and amplifiable RT gene were studied. Analyses of RT gene were undertaken after a median NRTI exposure of 51 months (range: 5–128). Mutations at positions known to be involved in HIV-1 resistance were observed in 26/34 patients. Selection of Q151M mutation was observed in nine out of 34 isolates (26%) after a median NRTIs exposure of 41 months (range: 12–77). In 8/9 cases, Q151M mutation was associated with other substitutions at positions known to be involved in HIV-1 resistance: K65R (n = 6), D67N (n = 1), N69S or T (n = 2), K70R (n = 3), M184V (n = 4), S215Y (n = 1). Compared with HIV-1 infection, there is a high frequency of selection of Q151M mutation in HIV-2 infected patients receiving various combinations of NRTIs. In these highly thymidine analogue pretreated patients, the selection of thymidine analogue mutations was low suggesting that the pathway to resistance is very different between these two viruses. J. Med. Virol. 74:197–201, 2004. © 2004 Wiley-Liss, Inc.

The diversity of HIV complicates viral load measurement for patient management and treatment monitoring. Numerous studies have shown that non-B group M variants can be underestimated and that group O strains are not detected by commercial tests. More recent versions of the kits used for previous studies have improved the quantification of non-B variants but are still unable to detect or correctly quantify group O strains. In this study, the authors evaluated the new Abbott LCx HIV RNA Quantitative viral load kit with a large collection of samples from Europe and central Africa. One hundred thirty-three group M samples, including 69 from patients infected with non-B variants, and 70 group O samples were tested. The LCx system was compared with the Cobas Amplicor HIV-1 Monitor vl.5 test and with a quantitative real-time polymerase chain reaction method based on LightCycler technology. The LCx and Cobas tests had similar quantification ranges for group M samples and a high degree of linearity (r 2 = 0.9582). The LCx method quantified group O variants (31 of the 48 patients were quantifiable) and gave values within the range of those obtained with the LightCycler assay. The two assays were sensitive but showed only moderate linearity (r 2 = 0.6195), probably because of higher diversity of group O strains and the use of primers and probes in different regions. In conclusion, the authors showed that the LCx kit allowed quantification of the large group M diversity and group O variants.

Background: Plasma viral load monitoring is an integral part of the standard of care for HIV-infected patients in industrialized countries. In developing countries, viral load assay is either unaffordable or hindered by on-site maintenance and/or technical problems. Objectives: To evaluate a new and simple quantitative assay for plasma HIV reverse transcriptase (RT) activity; and to compare RT activity-based and RNA-based quantification in plasma samples from patients infected by different subtypes of HIV-1 group-M, HIV-1 group-O and HIV-2. Methods: The RT-based viral load assay involves separation of the virion-protected RT and quantification of its activity with an enzyme immunoassay. Plasma viraemia was quantified both by RT activity and by RNA copies in 322 samples from 236 HIV-1 group M-infected patients, including serial samples from 54 patients. Samples from 49 patients infected by HIV-1 group O or HIV-2 were also tested. Results: RT activity and RNA copies were detected in 70% of plasma samples; respectively 25% and 1% of samples contained detectable RNA copies or RT activity alone. Measured RT activity corresponded to 48%, 96% and 100% of samples with 1.7-4.0 log 10 , 4.1-4.8 log 10 and 4.9-6.7 log 10 RNA copies/ml, respectively. The values of the two assays correlated independently of the HIV subtype (P< 0.0001) and group/type (P < 0.03). Patient follow-up showed a similar pattern of viraemia with the two assays. Conclusion: Plasma RT activity assay is a simple, cheap and reliable alternative for HIV viral load determination. As such, it could be particularly valuable for diagnosis and treatment monitoring in developing countries.

Objectives: BMS-626529 is a member of the new drug class of HIV-1 attachment inhibitors currently in development. Mutations selected during in vitro experiments with BMS-626529 are located in the gp120 region: L116P, A204D, M426L, M434I-V506M and M475I. A differential antiviral activity of BMS-626529 was observed depending of the viral subtype. The aim of our study was to assess the prevalence of subtype-related polymorphisms previously described as being associated with in vitro resistance to BMS-626529 in patients infected with different HIV-1 ‘non-B’ subtypes. Patients and methods: The prevalence of substitutions in gp120 was assessed in 85 HIV-infected patients (not previously treated with attachment inhibitors and infected with HIV-1 ‘non-B’ subtypes) by performing direct sequencing of the gp120 region. Results: The most prevalent HIV-1 subtype was CRF02_AG (n ¼46, 54%). The M426L substitution was found in virus from 10 patients (11.8%), mainly in subtypes D and CRF02_AG. The M434I substitution was found in virus from 11 patients (12.9%), mainly in subtypes CRF02_AG and CRF06_cpx. None of the CRF02_AG viruses harboured both M426L and M434I substitutions. Conclusions: In our series, the M426L substitution in the gp120 region was detected in 46% and 7% of subtype D and CRF02_AG samples, respectively, and might affect the activity of BMS-626529 against these specific subtypes. Further studies are needed to better describe associations between HIV-1 ‘non-B’-subtype-related polymorphism profiles and the level of phenotypic resistance to attachment inhibitor BMS-626529.