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More data on resistance of HCV genotype (GT) 3 and 4 to direct-acting antivirals (DAAs) are still needed. Here we investigated the presence of resistance-associated substitutions (RASs) pre- and post-treatment and their emergence under DAAs in HCV GT3- and GT4-infected patients failing DAA regimens by next-generation sequencing (NGS). Sanger sequencing and NGS were performed on NS5B and NS5A in plasma samples prior to and post treatment of 13 patients. Positions implicated in resistance to anti-NS5A and anti-NS5B in the literature were analysed. No baseline RASs was detected in NS5B but one GT4r virus developed the mutation S282T at failure. In NS5A, pre-existing RASs or polymorphisms were detected in viruses of 6/10 patients (L28M for a GT4a, M28V for a GT4r, L30R for a GT4a, 2 GT4d and 1 GT4r, and T58P for a GT4d) by Sanger sequencing and in viruses of 7/10 patients by NGS. Additional baseline minority substitutions detected by NGS were Y93H in a GT3a, L28M in a GT4a and GT4d, and L28F in a GT4d virus. At failure, these substitutions were found at a frequency of 100%. Y93H was detected alone at baseline, whilst L28M and L28F were accompanied by polymorphisms L30R or L30R + T58P. Use of NGS in patients failing DAAs and infected by HCV GT3 and GT4 revealed the emergence of specific patterns of substitutions in NS5A and NS5B, in particular substitutions at position 28 in NS5A in GT4 virus, highlighting the need to list these substitutions in guidelines for resistance interpretation.

International audience; The aim of this study was to assess the analytical performances, sensitivity and specificity, of two rapid tests (Covid- Presto® test rapid Covid-19 IgG/IgM and NG-Test® IgM-IgG COVID-19) and one automated immunoassay (Abbott SARS-CoV-2 IgG) for detecting anti- SARS-CoV-2 antibodies. This study was performed with: (i) a positive panel constituted of 88 SARS-CoV-2 specimens collected from patients with a positive SARS-CoV-2 RT-PCR, and (ii) a negative panel of 120 serum samples, all collected before November 2019, including 64 samples with a cross-reactivity panel. Sensitivity of Covid-Presto® test for IgM and IgG was 78.4% and 92.0%, respectively. Sensitivity of NG-Test® for IgM and IgG was 96.6% and 94.9%, respectively. Sensitivity of Abbott IgG assay was 96.5% showing an excellent agreement with the two rapid tests (κ = 0.947 and κ = 0.936 for NGTest ® and Covid-Presto® test, respectively). An excellent agreement was also observed between the two rapid tests (κ = 0.937). Specificity for IgM was 100% and 86.5% for Covid-Presto® test and NG-Test®, respectively. Specificity for IgG was 92.0%, 94.9% and 96.5% for Covid-Presto®, NGTest ®, and Abbott, respectively. Most of the false positive results observed with NG-Test® resulted from samples containing malarial antibodies. In conclusion, performances of these 2 rapid tests are very good and comparable to those obtained with automated immunoassay, except for IgM specificity with the NG-Test®. Thus, isolated IgM should be cautiously interpreted due to the possible false-positive reactions with this test. Finally, before their large use, the rapid tests must be reliably evaluated with adequate and large panel including early seroconversion and possible cross-reactive samples.

BackgroundHepatitis B virus (HBV) infection is a public health problem in Togo and transmission to the child occurs mainly during childbirth. The objective of this study was to estimate the prevalence of HBV among childbearing women and infants born to HBV positive mothers in Togo.MethodsA national cross-sectional study was carried out in six cities in Togo in the six health regions in Togo. Mother-child pairs were recruited from immunization centers or pediatric wards in Lomé, Tsévié, Atakpamé, Sokodé, Kara and Dapaong in 2017. Women aged 18 and over with one child of at least 6 months old were included. A standardized questionnaire was used for data collection and HBV screening was performed using Determine® rapid tests. The prevalence of HBV, defined by a positive HBV surface antigen (HBsAg), was estimated in mothers and then in infants of mothers who were positive for HBsAg. Logistic regression model was performed to identify risk factors for HBsAg positivity in mothers.ResultsA total of 2105 mothers-pairs child were recruited. The median age of mothers and infants was 29 years, interquartile range (IQR) [25–33] and 2.1 years, IQR [1–3] respectively. About 35% of women were screened for HBV during antenatal care and 85% of infants received three doses of HBV immunization. Among mothers, the prevalence of HBV was 10.6, 95% confidence interval (95% CI) [9.4–12.0%], and 177 had detectable HBV viral load (> 10 IU/mL). Among mothers with positive HBsAg, three infants also had positive HBsAg, a prevalence of 1.3, 95% CI [0.2–3.8%]. In multivariable analysis, HIV-infection (aOR = 2.19;p = 0.018), having at least three pregnancies (aOR = 1.46;p = 0.025) and living in Tsévié (aOR = 0.31;p ConclusionIn this study, one out of 10 childbearing women were infected with HBV, but less than 2% of infant born to HBV positive mothers under 5 years’ old who received immunization under the Expanded Program on Immunization were infected. Improving antenatal screening and providing targeted interventions in babies could help eliminate HBV in Togo.

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.

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.

Background & Aims Hepatitis C virus (HCV) infection is an independent risk factor for chronic kidney disease and leads to faster liver disease progression in patients requiring hemodialysis than in those with normal renal function. Little is known about the use of a sofosbuvir-containing regimen for infected patients on hemodialysis. We aimed to describe the pharmacokinetics, safety and efficacy of sofosbuvir in 2 dosing regimens and associated antiviral agents in HCV-infected patients requiring hemodialysis. Methods Multicenter, prospective and observational study of patients receiving sofosbuvir, 400mg once daily (n=7) or 3 times a week (n=5), after hemodialysis with simeprevir, daclatasvir, ledipasvir or ribavirin was conducted. Drug plasma concentrations were determined by liquid chromatography-tandem mass spectrometry before and after a 4h hemodialysis and 1.5h after last drug intake at the end of hemodialysis. Results Plasma concentrations of sofosbuvir or its inactive metabolite sofosbuvir-007 did not accumulate with either regimen between hemodialysis sessions or throughout the treatment course. Sofosbuvir-007 extraction ratio (52%) was consistent with historical data. In one patient receiving the once daily regimen, sofosbuvir-007 half-life was slightly higher (38h) than for patients with normal renal function receiving a full dose. Hemodialysis did not remove any other associated anti-HCV agents. Clinical and biological tolerance was good for all patients. Two relapses occurred with the 3 times a week regimen and none with the once daily. Conclusions A regimen including sofosbuvir, 400mg once daily, could be proposed for HCV-infected patients requiring hemodialysis and should be associated with close clinical, biological, cardiovascular, and therapeutic drug monitoring. Lay summary Hepatitis C Virus (HCV) infection in hemodialysis patients is prevalent and aggressive. Effective anti-HCV treatment in these patients may stabilize their renal disease. However, sofosbuvir, the cornerstone of most anti-HCV–containing regimens, should not be administered to these patients until more data is available. In this pharmacokinetic study, sofosbuvir full dose (400mg once daily) administered every day with another direct antiviral agent did not accumulate in hemodialysis patients and was safe and effective.

Background and Aims: Mother-to-child (MTC) hepatitis B virus (HBV) transmission has been mainly studied in Asia. The geographical origins of women and HBV genotypes differ in Europe. The aims were to determine the rate and risk factors of MTC HBV transmission from women with high HBV DNA loads in a maternity hospital in Paris France. Methods: Retrospective study of HIV-negative HBs Ag-positive pregnant women with HBV DNA loads above 5 Log10 I.U/ml who were not given lamivudine or tenofovirDF during pregnancy between 2004 and 2011. Results: Among 11 417 pregnant women 437 (4%) showed a positive HBs Ag. Among these women 52 had HBV DNA loads above 5 Log10 I.U/ml: 41 10 and 1 born in Asia sub-Saharan Africa and Europe respectively. Among the 52 women 40 were eligible for the analysis: no antiviral therapy during pregnancy; children over 9 months old. Twenty-eight (70%) women were assessed corresponding to 41 childbirths. Eleven children (27%) had positive HBs Ag 14 (34%) had positive HBc and HBs Ab 16 (39%) had positive HBs Ab only. The risk of having positive HBs Ag according to maternal HBV DNA loads was 14% for HBV DNA loads less or equal to 8 Log10 I.U/ml 42% for HBV DNA loads over 8 Log10 I.U/ml P = 0.04 but not related to the womens origin HBV genotype. Conclusions: This study confirms that serovaccination does not fully protect newborns from MTC HBV transmission when maternal HBV DNA loads exceed 5 Log10 I.U/ml regardless of the womens origin or HBV genotype.

OBJECTIVE This study investigated the impact on virological outcome of the gag cleavage sites and the protease-coding region mutations in protease inhibitor-naive and protease inhibitor-experienced patients infected with HIV-2 receiving lopinavir (LPV) containing regimen. METHODS Baseline gag and protease-coding region were sequenced in 46 HIV-2 group A-infected patients receiving lopinavir. Virological response was defined as plasma viral load less than 100 copies/ml at month 3. Associations between virological response and frequencies of mutations in gag [matrix/capsid (CA), CA/p2, p2/nucleocapsid (NC), NC/p1, p1/p6] and gag-pol (NC/p6) cleavage site and protease-coding region, with respect to the HIV-2ROD strain, were tested using Fisher's exact test. RESULTS Virological response occurred in 14 of 17 (82%) protease inhibitor-naive and 17 of 29 (59%) protease inhibitor-experienced patients. Virological failure was associated with higher baseline viral load (median: 6765 versus 1098 copies/ml, P = 0.02). More protease-coding region mutations were observed in protease inhibitor-experienced compared with protease inhibitor-naive patients (median: 8 versus 5, P = 0.003). In protease inhibitor-naive patients, T435A (NC/p6), V447M (p1/p6), and Y14H (protease-coding region) were associated with virological failure (P = 0.011, P = 0.033, P = 0.022, respectively). T435A and V447M were associated with Y14H (P = 0.018, P = 0.039, respectively). In protease inhibitor-experienced patients, D427E (NC/p1) was associated with virological response (P = 0.014). A430V (NC/p1) and I82F (protease-coding region) were associated with virological failure (P = 0.046, P = 0.050, respectively). Mutations at position 430 were associated with a higher number of mutations in protease-coding region (median: 10 versus 7, P = 0.008). CONCLUSION We have demonstrated, for the first time, an association between gag, gag-pol cleavage site and protease-coding region mutations, with distinct profiles between protease inhibitor-naive and protease inhibitor-experienced patients. These mutations might impact the virological outcome of HIV-2-infected patients receiving LPV-containing regimen.

In this study, assessing HIV-2 tropism among 43 paired plasma/peripheral blood mononuclear cell specimens, the concordance between proviral DNA and plasma RNA genotypic tropism prediction was 74%. All the discordances were attributable to the prediction of R5 in RNA and X4/dual-mixed in DNA. HIV-2 genotypic tropism test based on proviral DNA is a suitable tool for tropism determination in HIV-2-infected patients with low or undetectable viral load.

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.

We assessed the roles of baseline gag and gag-pol cleavage site mutations (CSM) on the virological outcome of a darunavir-based regimen in highly antiretroviral-experienced patients. We showed the association, in multivariate analysis, between the A431V gag CSM and the virological response, defined as a reduction in plasma HIV-1 RNA to P = 0.028). Our results suggest that a specific gag CSM might have a role on protease inhibitor susceptibility in an inhibitor-specific manner.

Resume La protease du virus de l’immunodeficience humaine de type 1 a pour role de cliver les precurseurs polyproteiniques Gag et Gag-Pol au niveau de sites precis appeles les sites de clivage, afin de liberer les proteines de structure (p7, p17 et p24) et les enzymes de la particule virale (protease, transcriptase inverse et integrase). Un decalage de phase en −1, medie par un signal, est requis pour que les ribosomes traduisent les ARN messagers en ces precurseurs. Lors d’un echappement a un traitement comportant des inhibiteurs de protease, des mutations dans le gene de la protease sont selectionnees et induisent une diminution de la capacite replicative virale. Elles peuvent etre parfois associees a des substitutions au niveau des sites de clivage de group specific antigen (gag). Recemment, des etudes ont montre que la presence de mutations dans les sites de clivage de gag seules, en l’absence de mutations dans le gene de la protease, pouvait etre associee a l’echec virologique.

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.

In this study, we assessed phenotypic susceptibility to dolutegravir and raltegravir in a large variety of HIV-1 ‘non-B’ subtypes (n = 72) issued from integrase inhibitor-naive clinical isolates. All samples were susceptible to both dolutegravir and raltegravir with median IC50 values of 1.22 nmol/l and 1.53 nmol/l, respectively; similar to that observed for the B subtype. Thus, despite the high prevalence of polymorphic substitutions in integrase in ‘non-B’ clinical isolates, phenotypic susceptibility to dolutegravir remained unchanged.

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.

OBJECTIVES To assess the prevalence of the K65R, K103N and M184V/I resistance mutations in the reverse transcriptase (RT) region in HIV-1-infected patients failing antiretroviral-based regimens between the years 2005 and 2010. PATIENTS AND METHODS HIV-1-infected patients experiencing virological failure between 2005 and 2010 with RT genotypic resistance tests available at the time of virological failure were analysed. K65R, K103N and M184V/I mutation frequencies were determined each year. Statistical analyses were performed using Fisher's exact test. RESULTS Among 9586 patients failing their antiretroviral-based regimens from 2005 to 2010, the prevalence of K65R tended to decrease (P = 0.054), while K103N and M184V/I mutation frequencies decreased significantly over time (P < 0.001). The increased use of a tenofovir/emtricitabine/efavirenz single-tablet regimen was associated with decreased selection of these mutations. CONCLUSIONS The global prevalence of resistance-associated mutations to tenofovir, lamivudine/emtricitabine and efavirenz decreased over time between 2005 and 2010. Despite a stable rate of efavirenz and protease inhibitor use, this phenomenon can be explained by an increased use of single-tablet regimens, which simplify drug intake and maximize adherence.

Background Saliva sampling may provide an easier access to hepatitis C virus (HCV) screening test. HIV infection influence on specific salivary antibody detection has not been extensively studied. Objectives An anti-HCV antibodies (HCV-Ab) test was adapted for saliva specimens and its performances were analysed according to the patients' HIV status and related factors such as CD4 cell counts and HIV viral load. Methods Four patients groups were selected: (i) HCV and HIV negative volunteers ( n =28); (ii) HCV positive and HIV negative patients ( n =30); (iii) HCV negative and HIV positive patients ( n =30); (iv) HCV and HIV co-infected patients ( n =30). Saliva samples were collected (Salivette system, Sarstedt) and an in-house adapted HCV-Ab detection assay was performed (MONOLISA anti-HCV PLUS Version 2, Biorad). HIV viral load, CD4 cells counts and HCV viremic status were reported. Results Sensitivity and specificity of saliva anti-HCV antibody tests in the HIV negative groups were 90% and 100%, respectively, compared to 73% and 93%, respectively in the HIV infected population. Compared to the HIV negative population, HIV mono-infected patients presented higher absorbance values ( p =0.01) and HIV/HCV co-infected population presented lower HCV-Ab absorbance values ( p p =0.02), HCV replication ( p =0.16) but not with CD4 cell counts ( p =0.64). Conclusion Performances of salivary HCV antibodies testing are strongly deteriorated in the HIV positive population, especially for patients with residual HIV replication. This serious limitation should prompt careful testing of non-invasive screening tests for hepatitis C in HIV-infected patients before use in real screening conditions.

International audience; OBJECTIVES: The aims of the study were to assess in patients with advanced HIV disease receiving antiretroviral therapy (ART) intensification with enfuvirtide (i) resistance at virological failure (VF), (ii) impact of baseline tropism on immunovirological response, and (iii) HIV-1 DNA tropism evolution during ART. METHODS: The ANRS 130 APOLLO randomized trial evaluated in naive patients the immunovirological impact of standard ART without (control arm) or with enfuvirtide. Tropism was determined on RNA and DNA by V3-loop sequencing interpreted using the Geno2Pheno algorithm. RESULTS: At baseline the median CD4 cell count was 30 cells/mm(3). Among the 170 patients assessable in this virological substudy, HIV-1 RNA tropism was as follows: 60% of viruses were R5 and 40% were R5X4/X4. HIV-1 DNA tropism was as follows: 54% were R5 and 46% were R5X4/X4. At week 24, 39% and 49% of patients experienced VF in the enfuvirtide and control arms, respectively. In the enfuvirtide arm, only resistance-associated mutations to enfuvirtide were detected. In the control arm, two patients displayed drug-resistant viruses at the time of VF. No impact of baseline tropism was observed on immunovirological response, regardless of the study arm. Among the 25 patients experiencing DNA tropism switch between baseline and week 24, 16 (64%) switched from R5 to R5X4/X4. These latter were mostly successfully suppressed patients receiving enfuvirtide and exhibiting poorer immunological response. CONCLUSIONS: Baseline RNA tropism had no impact on the immunovirological response. Drug resistance mutations were only detected for the fusion inhibitor. Finally, the mechanism of replenishment of the viral cellular reservoir with X4 viruses observed needs to be further analysed.

Background Little is known in HIV-2 infection about the kinetics of disappearance of raltegravir (RAL)-resistant virus after RAL withdrawal. Methods RAL was interrupted in four highly antiretroviral- experienced HIV-2-infected patients exhibiting a virological failure when receiving RAL. Integrase gene was sequenced from plasma samples collected at the time of RAL failure and at further time points following RAL withdrawal. Results At the time of RAL withdrawal, virus exhibited different integrase resistance pathways: G140S/Q148R, E92Q/N155H, T97A/N155H and T97A/Y143C. In patient 1, the G140S/Q148R double-mutant was still detected at month (M)7 and at M11 after stopping RAL, but was no longer detected at M15. Regarding patient 2, the double- mutant E92Q/N155H was still present at M2 and M8 after stopping RAL, and was no longer detected at M12. In patient 3, RAL-resistant virus with T97A/N155H mutations were still present 1 month after stopping RAL, and were no longer detected at M14. Regarding patient 4, the mutant T97A/Y143C was still detected at M1 and M3 following RAL withdrawal. At M18 after RAL stop, integrase genotypic pattern evolved to T97A/Y143G. Conclusions Persistence of HIV-2 RAL-resistant mutants was observed in all the key genetic RAL resistance pathways. These findings have clinical implications especially in HIV-2-infected patients for whom therapeutic arsenal is limited compared to HIV-1, since the persistence of resistant mutants might compromise the possible efficacy of upcoming second-generation integrase inhibitors.

We studied seven heavily pretreated HIV-2-infected patients exhibiting a virological failure while receiving a salvage raltegravir-containing regimen. At the time of virological failure, different resistance genetic pathways were observed: T97A-Y143C, Q148K, Q148R, G140S-Q148R, E92Q-Y143R-N155H, and T97A-N155H. Thus, despite a 40% difference in integrase genes between HIV-1 and HIV-2, the genetic pathways leading to raltegravir resistance are similar.

In this study of nine clinical isolates obtained from integrase inhibitor-naive HIV-2-infected patients, the median EC₅₀ value for the new integrase inhibitor S/GSK1349572 was 0.8 nM (range 0.2-1.4), and is similar to HIV-1 reference strains. We found a seven-, 13- and 18-fold increase in EC₅₀ values to S/GSK1349572 for the HIV-2 double (T97A + Y143C; G140S + Q148R) and triple (G140T + Q148R + N155H) mutants, respectively, obtained from two raltegravir-experienced patients.

ANRS 127 was a randomized pilot trial involving naïve patients receiving two dual-boosted protease inhibitor (PI) combinations. Virological response, defined as a plasma HIV RNA level of gag,gag-pol, and thegag-polframeshift region. The wholegaggene and protease-coding region were amplified and sequenced at baseline and at week 16 for 48 patients still on the allocated regimen at week 16. No major PI resistance-associated mutations were detected either at baseline or in the 26 patients who did not achieve virological response at week 16. Baseline cleavage site substitutions in the product of thegagopen reading frame at positions 128 (p17/p24) (P= 0.04) and 449 (p1/p6gag) (P= 0.01) were significantly more frequent in those patients not achieving virological response. Conversely, baseline cleavage site mutation at position 437 (TFP/p6pol) was associated with virological response (P= 0.04). In multivariate analysis adjusted for baseline viral load, these 3 substitutions remained independently associated with virological response. We demonstrated here,in vivo, an impact of baseline polymorphicgagmutations on virological response in naïve patients receiving a combination of two protease inhibitors. However, it was not possible to link the substitutions selected under PI selective pressure with virological failure.

Pralidoxime methylsulfate (Contrathion ® ) is widely used to treat organophosphate poisoning. For the first time, we developed a specific assay for urinary pralidoxime using capillary zone electrophoresis (CZE) in the following conditions: fused-silica capillary (length: 47 cm, internal diameter: 75 μm), electrolyte solution: 25 mM sodium borate (pH 9.1), voltage: 15 kV, temperature: 25 °C, injection time: 1 or 2 s, on-line UV detection: 280 nm. Sample preparation did not require a deproteinization step (1:5 dilution in water). The method was linear between 0.125 and 2 mg mL −1 of pralidoxime (quantification limit: 0.10 mg mL −1 ). Coefficients of variation for intra- and inter-assay precision were below 10% for all three control levels (0.15–1.15 mg mL −1 ). This assay was successfully applied to urine specimens from organophosphate poisoned patients treated by Contrathion ® ( n = 10). This CZE method allows the measure of pralidoxime in urine within 15 min with excellent precision, selectivity, and sensitivity. It is simple (no pretreatment) and convenient, thus suitable for the monitoring of Contrathion ® therapy in organophosphate poisoned patients.

s of the Fifty-first Interscience Conference on Antimicrobial Agents and Chemotherapy, Chicago, IL, USA, 2011. Abstract 1738a. American Society for Microbiology, Washington, DC, USA. 9 Buckley MS, Wicks LM, Staib RL et al. Pharmacokinetic evaluation of ambrisentan. Expert Opin Drug Metab Toxicol 2011; 7: 371–80. 10 Dingemanse J, van Giersbergen PL, Patat A et al. Mutual pharmacokinetic interactions between bosentan and lopinavir/ritonavir in healthy participants. Antivir Ther 2010; 15: 157–63. J Antimicrob Chemother 2013 doi:10.1093/jac/dks524 Advance Access publication 16 January 2013 Efficacy of a strategy for discontinuing pre-emptive ganciclovir therapy after a negative cytomegalovirus antigenaemia test result in seropositive kidney transplant recipients So-Youn Park1, Young Hoon Kim2, Duck Jong Han2, Su-Kil Park3, Jung Sik Park3, Heungsup Sung4, Hyun Jung Park1, Sung-Han Kim1, Sang-Ho Choi1, Yang Soo Kim1, Jun Hee Woo1 and Sang-Oh Lee1* Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Pungnap-dong, Songpa-gu, Seoul, Republic of Korea; Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Pungnap-dong, Songpa-gu, Seoul, Republic of Korea; Department of Nephrology, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Pungnap-dong, Songpa-gu, Seoul, Republic of Korea; Department of Laboratory Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea *Corresponding author. Tel: +82-2-3010-3301; Fax: +82-2-3010-6970; Email: soleemd@amc.seoul.kr